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Leaf-cutting ants (Formicidae; Atta spp., Acromyrmex spp.) cut off pieces of leaves and other plant tissue and feed it to their symbiotic fungi. As this foraging behavior poses an imminent threat to agriculture, leaf-cutting ants are considered as pests of huge ecologically and economically importance. Consequently, research on leaf-cutting ants focused on their foraging decisions and interactions with their cultivated symbiotic fungi, whereas their effect on the attacked plants, apart from the loss of plant tissue, remains largely unknown. In this study, we investigated the consequences of an attack by leaf-cutting ants and analyzed the plants' defense responses in comparison to chewing caterpillars and mechanical damage. We found that an attack by leaf-cutting ants induces the production of jasmonates in several host and non-host plant species (Arabidopsis thaliana, Vicia faba, Phaseolus lunatus, Tococa quadrialata). Additionally, we showed in the natural host plant lima bean (P. lunatus) that leaf-cutting ant damage immediately leads to the emission of typical herbivory-induced plant volatiles, including green leaf volatiles and terpenoids. Further data exploration revealed clear differences in the defense-related phytohormone profile in plant species of Neotropical and Eurasian origin. Taken together, we show that leaf-cutting ant infestation and their way of clipping the plants' tissues induce jasmonate and jasmonates-mediated responses and do not differ from those to mechanical injury or larval feeding. [ABSTRACT FROM AUTHOR]

Soybean (Glycine max) is the world's most cultivated legume; currently, most of its varieties are Bt. Spodoptera spp. (Lepidoptera: Noctuidae) are important pests of soybean. An artificial neural network (ANN) is an artificial intelligence tool that can be used in the study of spatiotemporal dynamics of pest populations. Thus, this work aims to determine ANN to identify population regulation factors of Spodoptera spp. and predict its density in Bt soybean. For two years, the density of Spodoptera spp. caterpillars, predators, and parasitoids, climate data, and plant age was evaluated in commercial soybean fields. The selected ANN was the one with the weather data from 25 days before the pest's density evaluation. ANN forecasting and pest densities in soybean fields presented a correlation of 0.863. It was found that higher densities of the pest occurred in dry seasons, with less wind, higher atmospheric pressure and with increasing plant age. Pest density increased with the increase in temperature until this curve reached its maximum value. ANN forecasting and pest densities in soybean fields in different years, seasons, and stages of plant development were similar. Therefore, this ANN is promising to be implemented into integrated pest management programs in soybean fields. [ABSTRACT FROM AUTHOR]

During decision-making, animals may use either innate or plastic behaviours. This has been suggested to be important for generalist phytophagous insects where females need to assess a large range of cues during host plant selection for oviposition. To facilitate the choice, generalists may thus use innate preference hierarchies among host plants combined with phenotypic plasticity based on earlier host experience, but if populations differ in whether they rely on innate or plastic factors during decision-making is not well-known. Females from an Egyptian population of the polyphagous moth Spodoptera littoralis has previously been found to shift preference between plants in their innate preference hierarchy depending on larval host plant experience. We studied the innate preference hierarchy for three host plants (cotton, cabbage and cowpea), and whether the hierarchy shifts based on larval host plant experience, in a Northern range margin population (Italy) and a core population (Kenya) of S. littoralis, to see if and how these traits vary across populations. In addition, we studied larval performance on the three host plants in all three populations. The Italian and Kenyan populations had different innate preference hierarchies, and both hierarchies differed from the hierarchy that has previously been found in the Egyptian population. Furthermore, the host plant selection of ovipositing females was affected by larval diet in the Italian and Kenyan population, but the larval host plant experience did not completely shift the preference hierarchy as in the Egyptian population. This indicates that not only host plant preference per se, but also phenotypic plasticity during host plant selection can vary between populations. We further found that the populations responded differently to larval diet for some performance traits. However, it was only the Italian population that showed indications of any link between preference and performance, as they had slower development on their least preferred host plant. Overall, preference divergence between populations seems not to be driven by local variation in larval performance. [ABSTRACT FROM AUTHOR]

In this study, a powder of the larvae, pupae and adults of the fall armyworm Spodoptera frugiperda (J.E. Smith) was obtained, and 1% of this powder was added to solid culture media potato dextrose agar (PDA) and liquid media Sabouraud dextrose broth (SDB) and minimal medium (MM), to induce the development and virulence of the M1 strain of Metarhizium anisopliae (Metchnikoff) Sorokin, which is pathogenic against the L1 larvae of S. frugiperda. The pupa powder was selected because it causes the greatest degree of radial growth of the M1 strain (73.3 mm) in PDA (p < 0.05). The enzymatic activity of M1, in the medium with pupa powder of S. frugiperda (I), was increased on day 4 for the proteases in MMI (1.1 U min-1) and on day 2 for the lipases in MMI (7034 U) and SDBI (6004 U) (p<0.05). In the pathogenicity bioassay, the M1 strain grown on PDA with the pupa powder caused 90% mortality on day 4 in the L1 larvae, while M1 grown on PDA without the powder caused 50%. With the pupa powder, the growth of the M1 strain increased, which promoted the production of enzymes, thus, increasing the pathogenicity of M. anisopliae against the L1 larvae of S. frugiperda. [ABSTRACT FROM AUTHOR]

Plant resistance mechanisms to pathogens can lead to a lowered efficacy of insect microbial biocontrol agents, but the influence of plant variety has been little-studied. Leaves and stalks from twelve maize (Zea mays L.) inbreds with different plant pathogen resistance were evaluated for their influence on the efficacy of Beauveria bassiana (Bals.-Criv.) Vuill. against European corn borers (Ostrinia nubilalis (Hübner)). For leaf assays with first instar caterpillars, mortality on day 2 ranged from an inbred-dependent high of 76.1% to a low of 10.0% for European corn borers in leaf assays. For stalk assays with third instar caterpillars, mortality on day 4 ranged from an inbred dependent high of 83.0% and 75.0% to a low of 0.0% and 8.3% for fall armyworms and European corn borers, respectively. Lesion size ratings due to Fusarium graminearum (Schwabe) applied to tissues were often significantly correlated with the mortality levels of B. bassiana-treated caterpillars that fed on leaves and stalks. This study suggests that the influence of plant varieties on the efficacy of insect microbial pathogens can vary depending on the insect species involved and the plant tissue, and this is worth considering when new plant varieties and biocontrol strains are being developed whenever practical. [ABSTRACT FROM AUTHOR]

An early instar larva of Spodoptera ornithogalli (Guenée) was collected from spearmint, Mentha spicata (Lamiales: Lamiaceae), and reared to adult in Mecklenburg County, North Carolina. A female S. ornithogalli was collected from the same locality and laid eggs. Her offspring were reared successfully on this host. This is the first record of S. ornithogalli using Lamiaceae as a hostplant outside of the laboratory, so the agricultural and regulatory implications of this record are examined. Identification of the immature stages of S. ornithogalli is difficult with the existing literature. We illustrate key larval, pupal, and adult characters of the original specimen found on M. spicata and discuss morphological characters to distinguish S. ornithogalli from related species throughout its range. [ABSTRACT FROM AUTHOR]

The invasive fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), poses a significant global threat with serious economic implications. Global concern heightened following the first major outbreak in Africa in 2016. Our research, which confirmed the presence of FAW in Indonesia in 2015 through re-examined samples from a maize field in Lampung region of Indonesia, supports the hypothesis that the invasion pattern does not follow the predicted west-to-east chronological timeline. Historical records and reidentification suggest that FAW may have been established in Indonesia, Africa, and Australia as early as nineteenth century, suggesting its potential presence in these regions much earlier than previously thought. The spread of FAW could be linked to the movement of people and plants such as maize or Para grass (Brachiaria mutica), at least at the end of the nineteenth century. This underscores the importance of rigorous identification methods for accurately tracking invasive species like FAW. Analyzing these historical records alongside the genetic structure of populations in Southeast Asia, particularly in Indonesia, is crucial for future research aimed at developing effective management strategies to mitigate the impact on the global agriculture. [ABSTRACT FROM AUTHOR]

Nutrition is vital to health, but while the link between diet and body nutritional composition is well explored in humans and other vertebrates, this information is not well understood in insects, despite the vital roles they play in ecosystems, and their increasing use as experimental models. Here we used Nutritional Geometry to explore the rapid physiological response to ingested nutrients in the haemolymph nutritional profile of Spodoptera littoralis caterpillars. We ask whether blood nutrients are maintained homeostatically in the face of variable nutritional intake, or if regulation is more flexible for some nutrients than others (allostasis), which allows animals to adapt to stress by responding in a way that prioritises efficiency of responses in the face of trade‐offs. Caterpillars were placed on 1 of 20 diets, systematically varying in their nutrient ratios (protein: carbohydrate) and density (calorie content), and their consumption was measured. After 48 h, caterpillars were bled, and the macronutrient (protein, carbohydrates and lipids) and nutrient metabolite (amino acids and simple sugars) content of the haemolymph was measured. Proteins comprised 93% of the haemolymph macronutrient pool on average and their concentration increased with protein eaten. The amino acid (AA) pool was dominated by five AAs, and the total pool increased with total nutrient intake. However, the ratio of essential to non‐essential AAs increased as the proportion of protein consumed increased. Carbohydrates were tightly controlled, increasing only on the most extreme carbohydrate intakes. Simple sugars were dominated by glucose and trehalose, and overall, the simple sugar pool showed high levels of homeostasis. Rather than strict homeostasis of blood nutritional properties, an allostatic model seemed to be a better fit for blood nutrient regulation in this generalist herbivore. This flexibility in response to the nutritional composition of the diet may, in part, explain how this species has evolved to extreme dietary generalism and may play a role in its worldwide pest status. Given the range of fitness‐related processes affected by the haemolymph, future studies should examine the physiological impacts of blood nutrient variation on reproduction, growth and response to infection and the trade‐offs between them. [ABSTRACT FROM AUTHOR]

Plant resistance mechanisms to pathogens can lead to a lowered efficacy of insect microbial biocontrol agents, but the influence of plant variety has been little-studied. Leaves and stalks from twelve maize (Zea mays L.) inbreds with different plant pathogen resistance were evaluated for their influence on the efficacy of Beauveria bassiana (Bals.-Criv.) Vuill. against European corn borers (Ostrinia nubilalis (Hübner)). For leaf assays with first instar caterpillars, mortality on day 2 ranged from an inbred-dependent high of 76.1% to a low of 10.0% for European corn borers in leaf assays. For stalk assays with third instar caterpillars, mortality on day 4 ranged from an inbred dependent high of 83.0% and 75.0% to a low of 0.0% and 8.3% for fall armyworms and European corn borers, respectively. Lesion size ratings due to Fusarium graminearum (Schwabe) applied to tissues were often significantly correlated with the mortality levels of B. bassiana-treated caterpillars that fed on leaves and stalks. This study suggests that the influence of plant varieties on the efficacy of insect microbial pathogens can vary depending on the insect species involved and the plant tissue, and this is worth considering when new plant varieties and biocontrol strains are being developed whenever practical.

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), a threat to maize production systems, is a polyphagous pest of global significance. There is no registered bioinsecticide of botanical origin to provide green remedy against this pest of concern. The present study reports for the first time the potency of the polar and non-polar bioinsecticidal leads sourced from Lippia alba (Mill.) N.E. Br. leaves. Shade-dried leaves of L. alba were extracted and evaluated; based on preliminary bioassay, the ethyl acetate leaf extract of L. alba (LEAE) was found to be the most potent against FAW in the in vitro and in vivo studies. Ultraperformance liquid chromatography-quadrupole time-of-flight-mass spectrometric (UPLCQToF-MS) analysis of LEAE revealed the rich chemical profile of 28 compounds, dominated by flavones, namely, naringenin, trihydroxy-dimethoxy flavone, and dihydroxy-trimethoxy flavone. Among others, glycosides, such as clerodendrin, calceolarioside E, forsythoside B, geniposide, and martynoside, and glucuronides, such as luteolin-7-diglucuronide, tricin-7-O-glucuronide, and luteolin-7-Oglucuronide, were also identified. LEAE exhibited exceptionally high in vitro [LC50 = 6,900 parts per million (ppm)] and in vivo (computed as damage score on a scale of 1-9) insecticidal activity against S. frugiperda, with no phytotoxicity at a dose as high as 20 times of LC50. LEAE also exhibited significant antifeedant, ovicidal, and growth regulatory activity at the 70-16,000 ppm (w/v) concentration range. In silico assessment revealed strong binding of martynoside, calceolarioside E, and forsythoside B with acetylcholinesterase-, sodium-, and chloride-dependent gaminobutyric acid (GABA) receptor and ryanodine receptor, respectively, facilitated by hydrogen bonds (conventional and C-H bonds) stabilized by hydrophobic pi-sigma, pi-pi stacked, pi-alkyl, and alkyl interactions. The present study established L. alba as a potential bioresource and secondary metabolite enriched LEAE as bioinsecticide for further product development. [ABSTRACT FROM AUTHOR]

The article presents a study which examined the presence of Nucleopolyhedrovirus (NPV) infected Spodoptera frugiperda larvae in order to manage the invasive pest the fall armyworm, Spodoptera frugiperda in north India. Topics discussed include isolation and purification of polyhedral occlusion bodies (POBs), evaluation of the most potent virus isolate, and natural incidence of NPV in Spodoptera frugiperda larvae collected from different zones of Jammu and Kashmir, India.

In Sinaloa, Mexico, the fall armyworm Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) causes economic losses during two agricultural cycles per year. The insecticidal potential and antifeedant effect of the ethanolic extracts of Swietenia humilis (Zucc), Azadirachta indica (A. Juss), and Argemone mexicana (L.), were evaluated against the third instar larvae of S. frugiperda by applying an ethanolic extract of these plants at concentrations of 5% and 10% and comparing them to water that contained Tween 80 to 01%. The larvae began dying 48 h after application. At 120 h, 10% extracts of Azadirachta indica and Swietenia humilis resulted in 80% and 73% mortality, respectively. A 10% extract of Argemone mexicana simultaneously produced 53% mortality. A larval antifeedant effect was observed from the weight of the S. frugiperda diet at the beginning, and the weight of the unconsumed diet to 120 h after exposure showed that exposure to a 10% extract of Swietenia humilis and 5% of Azadirachta indica resulted in a residual diet weight of 0.207 g and 0.204 g, respectively, compared to the control (0.177 g). The larval mortality and antifeedant effects were attributed to the presence of metabolites of the plant's extracts. These results showed the potential insecticidal and antifeedant effects of S. humilis and A. indica (10%) on the larvae of fall armyworm. Resumen En Sinaloa, México el gusano cogollero Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) causa pérdidas económicas durante dos ciclos agricolas por año. Se evaluó el potencial insecticida y el efecto anti alimentario de extractos etanólicos de Swietenia humilis (Zucc), Azadirachta indica (A. Juss), y Argemone mexicana (L.),contra larvas de tercer instar de S. frugiperda, aplicándolos a concentraciones de 5% y 10% comparándolos con agua y Tween 80 al 01%. La mortalidad de larvas comenzó 48 h después de la aplicación, y a las 120 h, Azadirachta indica y Swietenia humilis al 10% tuvieron 80% y 73% de mortalidad. Argemone mexicana al 10% produjo 53% de mortalidad durantel mismo tiempo. El efecto anti alimentario en larvas de S. frugiperad se observó al pesar la dieta al inicio del bioensayo y pesando la dieta no consumida a las 120 h, mostrando que Swietenia humilis al 10% y Azadirachta indica al 5% tuvieron un peso residual de dieta de (0.207 g) y (0.204 g) respectivamente, comparada con el control (0.177 g). La mortalidad de larvas y el efecto anti alimetario se atribuye a la presencia de metabolitos de las plantas. Estos resultados muestran el potencial insecticida y el efecto anti alimentario de S. humilis y A. indica al 10% sobre larvas del gusano cogollero. [ABSTRACT FROM AUTHOR]

Control of fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) since its invasion of Africa still depends on pesticides. Early detection of adults is considered the key to the success of larvae control in the crop field. However, FAW control thresholds based on current monitoring techniques are not well established in Africa. We investigated the efficacy of moth capture frequencies and FAW incidence levels as decision tools for FAW management. Experiments were conducted over two maize cropping seasons during which FAW incidence, severity, and larvae count were recorded during destructive sampling after the application of a homologated insecticide. During the first season, the FAW incidence ranged from 37.5 ± 5.6% in the 25% incidence threshold treatment to 48.1 ± 8.1% in the control. During the second season, the incidence was significantly lower in the 25% incidence threshold treatment (55.8 ± 5.7%) compared with the control (75.7 ± 3.0%). Over the two seasons, no significant difference in FAW damage severity was recorded between the treatments and control. The highest number of larvae per plant (4.0 ± 0.6) was observed in the 10% incidence threshold treatment. Insecticide application did not consistently contribute to reducing FAW incidence and observed plant damage did not translate into yield loss. FAW control needs further investigation to establish a threshold above which damage translates into yield loss, thus necessitating control intervention.

Phytophagous insects have evolved sophisticated detoxification systems to overcome the antiherbivore chemical defenses produced by many plants. However, how these biotransformation systems differ in generalist and specialist insect species and their role in determining insect host plant range remains an open question. Here, we show that UDP-glucosyltransferases (UGTs) play a key role in determining the host range of insect species within the Spodoptera genus. Comparative genomic analyses of Spodoptera species that differ in host plant breadth identified a relatively conserved number of UGT genes in generalist species but high levels of UGT gene pseudogenization in the specialist Spodoptera picta. CRISPR-Cas9 knockouts of the three main UGT gene clusters of Spodoptera frugiperda revealed that UGT33 genes play an important role in allowing this species to utilize the poaceous plants maize, wheat, and rice, while UGT40 genes facilitate utilization of cotton. Further functional analyses in vivo and in vitro identified the UGT SfUGT33F32 as the key mechanism that allows generalist S. frugiperda to detoxify the benzoxazinoid DIMBOA (2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one), a potent insecticidal phytotoxin produced by poaceous plants. However, while this detoxification capacity is conserved in several generalist Spodoptera species, Spodoptera picta, which specializes on Crinum plants, is unable to detoxify DIMBOA due to a nonfunctionalizing mutation in SpUGT33F34. Collectively, these findings provide insight into the role of insect UGTs in host plant adaptation, the mechanistic basis of evolutionary transitions between generalism and specialism and offer molecular targets for controlling a group of notorious insect pests. [ABSTRACT FROM AUTHOR]

Simple Summary: Spodoptera exempta is a global agricultural invasive pest which posing a serious threat to the planting area of major crops of maize, wheat and rice. Our study predicted the potential suitable areas for S. exempta globally based on 841 global occurrence records and eight important bioclimatic variables, and analyzed the overlap with maize, wheat and rice planting areas. The results of the study indicate that the high potential suitable areas of S. exempta are mainly distributed in developing countries (Latin America, central South America, Central Africa, and southern Asia), with the greatest impact on global maize planting areas, followed by rice and wheat. Global warming will have a smaller limitation on the distribution of S. exempta. In view of the global potential geographic distribution of S. exempta and its damage to three major crops, the above governments of various countries should pay active attention to the prevention and control of S. exempta to protect global food security. Spodoptera exempta, known as the black armyworm, has been extensively documented as an invasive agricultural pest prevalent across various crop planting regions globally. However, the potential geographical distribution and the threat it poses to host crops of remains unknown at present. Therefore, we used an optimized MaxEnt model based on 841 occurrence records and 19 bioclimatic variables to predict the potential suitable areas of S. exempta under current and future climatic conditions, and the overlap with wheat, rice, and maize planting areas was assessed. The optimized model was highly reliable in predicting potential suitable areas for this pest. The results showed that high-risk distribution areas for S. exempta were mainly in developing countries, including Latin America, central South America, central Africa, and southern Asia. Moreover, for the three major global food crops, S. exempta posed the greatest risk to maize planting areas (510.78 × 104 km2), followed by rice and wheat planting areas. Under future climate scenarios, global warming will limit the distribution of S. exempta. Overall, S. exempta had the strongest effect on global maize production areas and the least on global wheat planting areas. Our study offers a scientific basis for global prevention of S. exempta and protection of agricultural crops. [ABSTRACT FROM AUTHOR]

Fall armyworm is one of the main pests of maize, and in all regions where it is distributed, is a limiting factor for productivity. In this study, a method to monitor this pest maize crops, was proposed. The method allowed us to randomly cover representative points of a crop field from planting until high incidence of damage by fall armyworm larvae and allowed us to determine the percentage of damage in perimeter areas and the center of a crop in field. A maize crop, surrounded by a mango orchard, a cattle grazing paddock, and other maize fields was monitored. Most maize plants were damaged adjacent to mango (23.7 – 29.6%), followed by maize surrounded by maize (20 – 21.9%), and maize adjacent to a cattle grazing paddock had fewest damaged plants (13.1 – 16.4%). Results suggested that timely control of the pest is necessary to avoid total crop damage. Surrounding crops significantly affect damage caused by S. frugiperda larvae to maize plants. Crops that allow development of diverse herbaceous plants, shrubs, and other, such as mango crops, could be a suitable ecosystem for establishing niches of insects (mostly beneficial), as observed in this study. The results are essential to implement in regions where maize is grown near surrounding crops, for timely control of fall armyworm. El gusano cogollero es una de las principales plagas del maíz y, en todas las regiones donde se distribuye, es un factor limitante para la productividad. En este estudio se propuso un método para monitorear esta plaga en los cultivos de maíz. El método nos permitió cubrir aleatoriamente puntos representativos de un campo de cultivo desde la siembra hasta la alta incidencia de daño por larvas de gusano cogollero y nos permitió determinar el porcentaje de daño en las áreas perimetrales y el centro de un cultivo en el campo. Se monitoreó un cultivo de maíz que estaba rodeado por una huerta de mango, un potrero de pastoreo de ganado y por otros campos de maíz. La mayoría de las plantas de maíz resultaron dañadas junto al mango (23.7 – 29.6%), seguidas por el maíz rodeado de maíz (20 – 21.9%), y el maíz adyacente a un potrero de pastoreo tuvo la menor cantidad de plantas dañadas (13.1 – 16.4%). Los resultados sugirieron que es necesario un control oportuno de la plaga para evitar el daño total al cultivo. Los cultivos circundantes afectan significativamente el daño causado por las larvas de S. frugiperda a las plantas de maíz. Los cultivos que permiten el desarrollo de diversas plantas herbáceas, arbustos y otras, como el cultivo de mango, podrían ser un ecosistema adecuado para el establecimiento de nichos de insectos (en su mayoría benéficos), como se observa en este estudio. Es esencial implementar los resultados en regiones donde se cultiva maíz cerca de cultivos circundantes, para el control oportuno del gusano cogollero. [ABSTRACT FROM AUTHOR]

The present study evaluated the biological control of seed extracts and chemical compounds of physic nut, Jatropha curcas through insecticidal and insectistatic activity against the armyworm, Spodoptera frugiperda. Gas chromatography-mass spectrometry analysis showed that major constituents of the hexanic extract were oleic (40.3% 2 µL extract / 10 ml solvent (v/v)), linoleic (27.3%), and palmitic (15.8%) fatty acids, while the major constituents of the acetonic extract were oleic (47.6%), linoleic (32.8%), and palmitic (14.3%) acids. In an ingestion bioassay with neonate S. frugiperda, the extracts were evaluated at six concentrations (0, 100, 250,1,000, 2,500, and 5,000 ppm). The fatty acid extracts induced a positive relationship where the higher the concentration, the greater the effect on larval and pupal weight, the development of the larvae and pupae, and larval and pupal mortality. Hexanic and acetonic extracts at 5,000 ppm caused 100% larval mortality. The oleic and linoleic fatty acids were further evaluated at (0, 100, 160, 400, 600 and 1,000 ppm). Oleic acid at 600 ppm reduced the weights of the larvae and pupae, as well as increased the mortality of the pupa, while the linoleic acid at 400 ppm reduced the weight larvae and increased mortality larval and pupal. The values of lethal concentrations fifty and ninety (LC50-LC90) of oleic and linoleic acid were 125 - 624 ppm and 199 - 630 ppm, respectively. Extracts and fatty acids from the seeds of J. curcas can be explored as useful alternatives for the control of S. frugiperda. Se evaluó el control biológico de extractos de semillas y compuestos químicos de Jatropha curcas a través de su actividad insecticida e insectistática contra el gusano cogollero, Spodoptera frugiperda. El análisis de cromatografía de gasesespectrometría de masas mostró que los principales constituyentes del extracto hexánico eran ácidos grasos oleico (40.3% de extracto de 2 µl/10 ml de disolvente (v/v)), linoleico (27.3%) y palmítico (15.8%), mientras que los principales constituyentes del extracto acetónico fueron los ácidos: oleico (47.6%), linoleico (32.8%) y palmítico (14.3%). En un bioensayo de ingestión con larvas recién nacidas S. frugiperda, los extractos se evaluaron a seis concentraciones (0, 100, 250, 1,000, 2,500 y 5,000 ppm). Los extractos de ácidos grasos indujeron una relación positiva donde a mayor concentración, mayor efecto sobre el peso larval y pupal, el desarrollo de larvas y pupas, y la mortalidad larval y pupal. Los extractos hexánico y acetónico a 5,000 ppm causaron 100% de mortalidad larval. Los ácidos grasos oleico y linoleico se evaluaron adicionalmente (0, 100, 160, 400, 600 y 1,000 ppm). El ácido oleico a 600 ppm redujo el peso de las larvas y pupas, así como aumentó la mortalidad de las pupas, mientras que el ácido linoleico a 400 ppm redujo el peso de las larvas y aumentó la mortalidad de larvas y pupas. Los valores de concentraciones letales cincuenta y noventa (LC50-LC90) de ácido oleico y linoleico fueron 125 - 624 ppm y 199 - 630 ppm, respectivamente. Los extractos y ácidos grasos de las semillas de J. curcas pueden explorarse como alternativas útiles para el control de S. frugiperda. [ABSTRACT FROM AUTHOR]

The invasion of maize (Zea mays L.) in 2018 by fall armyworm, Spodoptera frugiperda (J.E. Smith), threatened food security of India. In the early stage of crop growth, spray is difficult to apply because of the small size of the plant, waste of insecticide, and harm to non-target organisms. Seed treatment alone and combined with foliar spray were evaluated to manage fall armyworm in the field in June and September 2019. The experiment was a randomized block design with eight treatments. The maize seed treatments viz., chlorantraniliprole 250 g a.i./100 kg seeds alone, cyantraniliprole + thiamethoxam 238 g a.i./100 kg seeds, and cyantraniliprole + thiamethoxam 317 g a.i./100 kg seeds managed fall armyworm larvae and reduced plant damage 1 week after emergence of the crop compared with the check. A sequence of two foliar sprays resulted in the highest yield, followed by seed treatment plus a foliar spray (cyantraniliprole 19.8 + thiamethoxam 19.8 FS 8 ml/kg of seeds + emamectin benzoate 5 SG 0.4 g/liter), and seed treatments (chlorantraniliprole, cyantraniliprole+thiamethoxam). Most net returns were from cyantraniliprole 19.8 + thiamethoxam 19.8 FS 317 g a.i./100 kg of seeds and foliar application of emamectin benzoate 5 SG 12.5 g a.i./ha (US $581); the nontreated check had only US $123/ha net return. La invasión al maíz (Zea mays L.) en 2018 por el gusano cogollero Spodoptera frugiperda (J.E. Smith), amenazó la seguridad alimentaria de India. La aspersión de insecticidas es difícil de realizar en la etapa inicial de crecimiento del cultivo debido al tamaño pequeño de la planta, el desperdicio de insecticida y el daño a organismos no-objetivo. Se evaluó el tratamiento de semillas por sí solo y en combinación con aspersión foliar en junio y septiembre de 2019 para controlar el gusano cogollero en el campo. El experimento fue un diseño de bloques al azar con ocho tratamientos. Los tratamientos de semilla del maíz incluyendo clorantraniliprol 250 g i.a./100 kg de semillas solas, ciantraniliprol + tiametoxam 238 g i.a./100 kg de semillas y ciantraniliprol + tiametoxam 317 g i.a./100 kg de semillas redujeron las larvas del gusano cogollero y el daño a las plantas 1 semana después de la emergencia del cultivo en comparación con el control sin tratamiento. Una secuencia de dos aspersiones foliares dio como resultado el mayor rendimiento, seguido de un tratamiento de semillas más una aspersión foliar con (ciantraniliprol 19.8 + tiametoxam19.8 FS 8 ml/Kg de semillas – benzoato de emamectina 5 SG 0.4 g/litro) y tratamientosde semilla con (clorantraniliprol, ciantraniliprol + tiametoxam). La mayor parte de los rendimientos netos se observaron con ciantraniliprol 19,8 + tiametoxam 19,8 FS 317 gi.a./100 kg de semillas y aplicación foliar de benzoato de emamectina 5 SG 12,5 gi.a./ha (US $581); con el control sin tratamiento se obtuvieron solamente US $123/ha de rendimiento neto. [ABSTRACT FROM AUTHOR]

Use of microorganisms to manage insect pests is a strategy compatible with organic production, but variability in their effectiveness limits the adoption by growers. Prior reports indicated that increased resistance to a fungal plant pathogen in dent maize inbreds was associated with reduced efficacy of the commercialized fungal biocontrol agent Beauveria bassiana in killing maize caterpillar pests, but this aspect has not been investigated with sweet corn. Several varieties of sweet corn certified for organic production, along with sweet corn inbreds that have been used in breeding commercial sweet corn hybrids, were evaluated for their influence on the efficacy of two commercial strains of Beauveria bassiana. As occurred in prior dent corn studies, significant differences were noted in mortality levels on day 2 for European corn borers (ranging from as much as 14.9 to 58.6%) and fall armyworms (ranging from as much as 12.1 to 46.0%) depending on the sweet corn hybrids and inbreds. Higher rates of leaf colonization by B. bassiana were associated with larger lesion sizes caused by the maize pathogen Fusarium graminearum for both hybrids and inbreds. However, greater efficacy of B. bassiana in killing insects was associated with smaller lesion sizes caused by F. graminearum for some organic production sweet corn hybrids. This information indicates it is possible to develop sweet corn varieties that are both resistant to fungal pathogens and compatible with use of B. bassiana and suggests this aspect can be further improved to promote more effective organic production of sweet corn. [ABSTRACT FROM AUTHOR]

BACKGROUND: Temperature plays a critical role in the development and reproductive process of insects, therefore understanding how insects respond to temperature is vital for comprehending and predicting their population dynamics, particularly when it comes to agricultural pests. Spodoptera eridania Stoll is a polyphagous pest that has recently expanded its distribution beyond its native range. In this study, we assessed the impact of temperature on the reproduction of S. eridania and used the obtained data to develop an oviposition model that could be used to predict egg‐laying behavior under field conditions. The reproductive parameters were evaluated at temperatures of 15, 20, 25, 28, and 32 °C. RESULTS: Temperature had a significant impact on the reproductive parameters examined. Overall, as temperature increased, the pre‐oviposition period, oviposition period, and longevity decreased. Total fecundity exhibited a bell‐shaped response to temperature, with peak egg‐laying observed at 20 and 25 °C. In line with the experimental data, our model predicted higher rates of oviposition between 20 and 26 °C, thus reinforcing that this temperature range may represent the optimal conditions for the reproduction of S. eridania. CONCLUSION: The findings from our study provide a significant contribution to the understanding of the ecology of an important agricultural pest. The information generated can have practical applications in developing control strategies by enabling the aligning of the timing of control measures with peaks of reproductive activity. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), a threat to maize production systems, is a polyphagous pest of global significance. There is no registered bioinsecticide of botanical origin to provide green remedy against this pest of concern. The present study reports for the first time the potency of the polar and non-polar bioinsecticidal leads sourced from Lippia alba (Mill.) N.E. Br. leaves. Shade-dried leaves of L. alba were extracted and evaluated; based on preliminary bioassay, the ethyl acetate leaf extract of L. alba (LEAE) was found to be the most potent against FAW in the in vitro and in vivo studies. Ultraperformance liquid chromatography–quadrupole time-of-flight–mass spectrometric (UPLC-QToF-MS) analysis of LEAE revealed the rich chemical profile of 28 compounds, dominated by flavones, namely, naringenin, trihydroxy-dimethoxy flavone, and dihydroxy-trimethoxy flavone. Among others, glycosides, such as clerodendrin, calceolarioside E, forsythoside B, geniposide, and martynoside, and glucuronides, such as luteolin-7-diglucuronide, tricin-7-O-glucuronide, and luteolin-7-O-glucuronide, were also identified. LEAE exhibited exceptionally high in vitro [LC50 = 6,900 parts per million (ppm)] and in vivo (computed as damage score on a scale of 1–9) insecticidal activity against S. frugiperda, with no phytotoxicity at a dose as high as 20 times of LC50. LEAE also exhibited significant antifeedant, ovicidal, and growth regulatory activity at the 70–16,000 ppm (w/v) concentration range. In silico assessment revealed strong binding of martynoside, calceolarioside E, and forsythoside B with acetylcholinesterase-, sodium-, and chloride-dependent γ-aminobutyric acid (GABA) receptor and ryanodine receptor, respectively, facilitated by hydrogen bonds (conventional and C–H bonds) stabilized by hydrophobic pi–sigma, pi–pi stacked, pi–alkyl, and alkyl interactions. The present study established L. alba as a potential bioresource and secondary metabolite enriched LEAE as bioinsecticide for further product development.

El cultivo de uva (Vitis vinifera L.) en la región Piura, es infestado por plagas como Spodoptera eridania Stoll, especie polífaga originaria de los trópicos sudamericanos. El objetivo de realizar el trabajo de investigación fue conocer aspectos básicos sobre su morfología y biología, debido a que no se encontraban registros de los mismos en este cultivo, ni en otros de la región. Se realizaron observaciones diarias para determinar la duración del periodo de incubación de huevos, del desarrollo larval, e igualmente del estado de pupa y la longevidad de los adultos. Emergidos los adultos, se aparearon para establecer el ritmo de oviposición, y capacidad reproductiva, todos estos parámetros se evaluaron durante tres generaciones. Se determinó que, bajo condiciones de laboratorio, el ciclo de desarrollo de S. eridania fue de 34,90 días para la primera generación, 31,16 y 28,60 días para la segunda y tercera, con un registro promedio de temperatura de 27,97 °C y humedad relativa del 71,86%. Los resultados muestran que puede desarrollarse en plantaciones de vid, y serán de utilidad en la planificación de las labores propias del cultivo y en el establecimiento de estrategias de manejo integrado de plagas para reducir las infestaciones cuando estas se presenten.

Yellowstriped armyworm (YSAW), Spodoptera ornithogalli, is a polyphagous pest that infests various crops, including cotton, cabbage, corn, blackberry, grape, etc. We documented egg clusters, larvae and adults of YSAW in pecan orchards in Georgia. Until now, there have been no reports of YSAW infesting pecan and its suitability as a host. To investigate the survival, development, and reproduction of YSAW on pecan, we used the age-stage, two sex life table. The YSAW successfully completed its lifecycle on pecan with an 82% preadult survival rate. The preadult duration and mean fecundity were 47.84 d and 1212.55 offspring per female. The population parameters, including intrinsic rate of increase (r), finite rate of increase (λ), net reproduction rate (R0), and mean generation time (T) were 0.1184 d−1, 1.1257 d−1, 430.67 offspring/female, and 51.05 d, respectively. This study confirms that pecan, Carya illinoinensis, is a potential host plant of YSAW and perhaps more widespread damage could be observed. [ABSTRACT FROM AUTHOR]

During two successive sugar beet growing seasons; 2021/2022 and 2022 / 2023. This field study was carried out at the Experimental Farm of Sakha Agricultural Research Station for recording the various prey of Chrysoperla carnea (Stephens) (Neuroptera :Chrysopidae ( larvae predator by visual examination method, this predator feed upon their prey in the field. Moreover, investigated the toxicity of conventional, Clozemail, and biocides Xentari® insecticides on Spodoptera spp.) Noctuidae :Lepidoptera ( and C. carnea larvae. The obtained results proved that the total numbers of prey were 197 and 196 individuals in two seasons, respectively. The most common prey was Spodoptera spp. (Eggs + larvae), leafhoppers, aphids, Pegomyia mixta Vill. (Diptera: Anthomyiidae) larvae, and Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) throughout the two seasons. In addition, the general meaning of reductions to Spodoptera spp. Larvae population due to Clozemail® and Pleo® was (82.17 and 84.11%) and (83.33 and 89.9%) during the two seasons, respectively. While Xentari® caused (77.36 and 77.65%) in two seasons, respectively. On the other hand, the general mean reduction in C. carnea larvae numbers was (83.33 and 89.90%) for Clozemail®, and (92.32 and 89.95/) for Pleo® in two seasons, respectively. Regarding the biocide, Xentari® induced reductions to the same predators with (26.85 and 22.85%) in two seasons, respectively. In conclusion, the combination and integration between C. carnea predator and biocides application are very good tools in IPM of sugar beet insects. [ABSTRACT FROM AUTHOR]

Background: Spodoptera littoralis is an important agricultural pest; thus, knowledge about the effect of latex serum and latex-synthesized nanoparticles of Calotropis procera on this species can assist in its management.. Nanotechnology is currently taking root in the agriculture economy as a substitute for pest management that is targeted, safe, and effective. The repellent and antifeedant efficacy of C. procera latex serum and its nanoparticles against S. littoralis fourth instar larvae was investigated in this work. Methods: The process of synthesizing silver nanoparticles has been carried out, followed by their subsequent characterization. The objective of this study was to assess the antifeedant properties of the latex serum and its nanoparticles against the 4th instar larvae of S. littoralis through the implementation of a bioassay. Results: With rising latex serum content, the proportion of repellency and hunger rose. In comparison to insects injected with latex serum, utilizing nanoparticles of LAgNPs with this larva via injection resulted in much increased mortality. Conclusion: According to the findings of this study, insects injected with LAgNPs died at a substantially higher rate than insects injected with latex serum. LAgNPs was efficient against S. littoralis larvae and can thus be utilized to specifically control the pest. [ABSTRACT FROM AUTHOR]

Mechanisms, including autophagy and apoptosis, which serve to regulate and ensure proper organism functions under optimal conditions, play additional defensive roles under environmental pressure.The aim of this study was to test the following hypotheses: (i) elevated autophagy and apoptosis intensity levels, as defensive processes in response to contact with cadmium, are maintained for a limited number of generations and (ii) the number of generations after which levels of cell death processes reach the reference level depends on selective pressure. Cell death processes were assessed by light and transmission electron microscopy, terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL), and cytometric analyses. Model insects (Spodoptera exiqua, Hübner, 1808) were orally exposed to various concentrations of cadmium for 18 generations and compared with reference strains exposed to cadmium or not (control) for over 150 generations. Elevated programmed cell death intensity levels decreased after several generations, indicating tolerance of individuals to cadmium in the diet and verifying the first hypothesis; however, testing the second hypothesis indicated that the number of generations depended not only on pressure intensity, but also on cell death type, since levels of autophagy remained increased for a minimum of 12 generations. Graphical Abstract [ABSTRACT FROM AUTHOR]

BACKGROUND: Maize production in Africa is hindered by a myriad of biotic challenges, key among them being invasive and native lepidopteran stemborers. Recent invasion of the continent by fall armyworm, Spodoptera frugiperda, has further exacerbated the situation. Fortunately, Cotesia icipe was found to be very promising against S. frugiperda. However, the co‐occurrence and interaction between S. frugiperda and the stemborers (Busseola fusca, Sesamia calamistis, and Chilo partellus) in maize agroecosystem may jeopardize the efficiency of C. icipe as a biocontrol agent of S. frugiperda. This study investigated the performance of C. icipe on S. frugiperda, Spodoptera littoralis and the stemborers. Specifically, the preference and acceptability of C. icipe to the host insects, the physiological suitability of the hosts for its development, and the effect of these hosts on the fitness parameters of the offspring were assessed. RESULTS: Cotesia icipe accepted all the tested hosts, albeit with higher preference for Spodoptera species than for stemborers under multiple‐choice tests. Also, the highest parasitism of up to 97% was recorded on S. frugiperda compared with parasitism on the stemborers of 43% in B. fusca. Moreover, physiological suitability and fitness traits (except for per cent female offspring) varied with host species, again being optimal on Spodoptera species. CONCLUSION: Cotesia icipe demonstrated strong potential to control S. frugiperda in maize due to its high affinity for parasitization and developmental success in this host; and despite its non‐specific parasitization, the presence of other hosts may not prevent its maximum control of S. frugiperda. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Polyamines are small, organic polycations that are ubiquitous and essential to all forms of life. Currently, how polyamines are transported across membranes is not understood. Recent studies have suggested that ATP13A2 and its close homologs, collectively known as P5B-ATPases, are polyamine transporters at endo-/lysosomes. Loss-of-function mutations of ATP13A2 in humans cause hereditary early-onset Parkinson's disease. To understand the polyamine transport mechanism of ATP13A2, we determined high-resolution cryoelectron microscopy (cryo-EM) structures of human ATP13A2 in five distinct conformational intermediates, which together, represent a near-complete transport cycle of ATP13A2. The structural basis of the polyamine specificity was revealed by an endogenous polyamine molecule bound to a narrow, elongated cavity within the transmembrane domain. The structures show an atypical transport path for a water-soluble substrate, in which polyamines may exit within the cytosolic leaflet of the membrane. Our study provides important mechanistic insights into polyamine transport and a framework to understand the functions and mechanisms of P5B-ATPases.

Spodoptera frugiperda (fall armyworm) is a notorious pest that threatens maize production worldwide. Current control measures involve the use of chemical insecticides and transgenic maize expressing Bacillus thuringiensis (Bt) toxins. Although additional transgenes have confirmed insecticidal activity, limited research has been conducted in maize, at least partially due to the technical difficulty of maize transformation. Here, we describe implementation of a sugarcane mosaic virus (SCMV) vector for rapidly testing the efficacy of both endogenous maize genes and heterologous genes from other organisms for the control of S. frugiperda in maize. Four categories of proteins were tested using the SCMV vector: (i) maize defence signalling proteins: peptide elicitors (Pep1 and Pep3) and jasmonate acid conjugating enzymes (JAR1a and JAR1b); (ii) maize defensive proteins: the previously identified ribosome-inactivating protein (RIP2) and maize proteinase inhibitor (MPI), and two proteins with predicted but unconfirmed anti-insect activities, an antimicrobial peptide (AMP) and a lectin (JAC1); (iii) lectins from other plant species: Allium cepa agglutinin (ACA) and Galanthus nivalis agglutinin (GNA); and (iv) scorpion and spider toxins: peptides from Urodacus yaschenkoi (UyCT3 and UyCT5) and Hadronyche versuta (Hvt). In most cases, S. frugiperda larval growth was reduced by transient SCMV-mediated overexpression of genes encoding these proteins. Additionally, experiments with a subset of the SCMV-expressed genes showed effectiveness against two aphid species, Rhopalosiphum maidis (corn leaf aphid) and Myzus persicae (green peach aphid). Together, these results demonstrate that SCMV vectors are a rapid screening method for testing the efficacy and insecticidal activity of candidate genes in maize.

Plants being sessile organisms and lacking both circulating phagocytic cells and somatic adaptive immune response, have thrived on various defense mechanisms to fend off insect pests and invasion of pathogens. CYP450s are the versatile enzymes, which thwart plants against insect pests by ubiquitous biosynthesis of phytohormones, antioxidants, and secondary metabolites, utilizing them as feeding deterrents and direct toxins. Therefore, a comprehensive analysis of biotic stress-responsive CYPs from Glycine max was performed to ascertain their function against S. litura-infestation. Phylogenetic analysis and evolutionary studies on conserved domains and motifs disclosed the evolutionary correspondence of these GmCYPs with already characterized members of the CYP450 superfamily and close relatedness to Medicago truncatula. These GmCYPs were mapped on 13 chromosomes; they possess 1-8 exons; they have evolved due to duplication and are localized in endoplasmic reticulumn. Further, identification of methyljasmonate, salicylic acid, defense responsive and flavonoid biosynthesis regulating cis-acting elements, their interaction with biotic stress regulating proteins and their differential expression in diverse types of tissues, and during herbivory, depicted their responsiveness to biotic stress. Three-dimensional homology modelling of GmCYPs, docking with heme cofactor required for their catalytic activity and enzyme-substrate interactions were performed to understand the functional mechanism of their action. Moreover, to gain insight into their involvement in plant defense, gene expression analysis was evaluated, which revealed differential expression of 11 GmCYPs upon S. litura-infestation, 12 GmCYPs on wounding while foliar spray of ethylene, methyl-jasmonate and salicylic acid differentially regulated 11 GmCYPs, 6 GmCYPs, and 10 GmCYPs respectively. Our study comprehensively analysed the underlying mechanism of GmCYPs function during S. litura-infestation, which can be further utilized for functional characterization to develop new strategies for enhancing soybean resistance to insect pests. [ABSTRACT FROM AUTHOR]

Spodoptera spp. (Lepidoptera: Noctuidae) are economically important insect pests of cereal and vegetable crops in Tropical and Subtropical regions, but little is known of their distribution and diversity in countries of the Caribbean, in particular, Jamaica. In this study, larvae collected from hosts in three major vegetable producing regions of Jamaica were characterized based on morphological characters and mitochondrial cytochrome c oxidase I (COI) sequence data. Three species were identified, i.e., S. exigua, S. latifascia and S. frugiperda. All three species were prevalent on bunching onions (Allium fistulosum). S. exigua was also found on bell pepper (Capsicum annum) and S. frugiperda on corn (Zea mays). Species clades at 99% confidence were obtained in phylogenetic analyses with Jamaican COI sequences and those from different geographical locations. Separate clustering occurred with native S. latifascia and non-native S. exigua populations of the Americas. S. frugiperda corn and rice strains were closely related to native populations of the Americas and populations which invaded Africa and Asia, including those with recorded insecticide resistance. Low intraspecific genetic distances of ≤ 0.6% were obtained with the three species and apart from two exceptions, interspecific distances ranged from zero to 1.4%. Based on this sampling, the Jamaican populations are consistent with those previously reported in the Americas and elsewhere. The results provide new information about the genetic diversity of Spodoptera species affecting vegetable crops in Jamaica and establish a baseline for further studies. [ABSTRACT FROM AUTHOR]

The article focuses on the potential cost-effective use of Trichogramma parasitoids in managing Spodoptera pests, particularly the fall armyworm, which poses a significant threat to global food security. Topics include the protective scale variation on Spodoptera egg masses, the non-renewable nature of these scales, and the performance of Trichogramma species based on different egg scale thicknesses, challenging previous conclusions about their effectiveness as parasitoids.

Egg batches of Spodoptera moths are protected by scales deposited by females around and/or over eggs as a physical defense. These scales may affect the parasitism of some parasitoids, rendering biocontrol of Spodoptera eggs ineffective. In this study, we investigated the daily oviposition pattern of moths and the dynamics of egg mass scales of three Spodoptera species and examined the fitnesses of three potential egg parasitoid species to different egg mass scale thicknesses. The observations revealed that the three Spodoptera species share similar scale dynamics. From initial oviposition, S. exigua egg batches maintained a relatively high level of scale thickness (> 134.7 μm) for 2 days and S. frugiperda and S. litura for 3 days (> 105.9 μm, > 161.2 μm, respectively). During this period, the scales effectively hindered parasitism by Trichogramma species (parasitized 0.4%–14.9% eggs). Thereafter, the thickness of the scales decreased daily. The scales of the three Spodoptera species were all relatively thin (< 20.0 μm) after oviposition for 8 days, and subsequently, Trichogramma parasitized eggs more actively (parasitized up to 33.4%–36.5% eggs). Relatively, Trichogramma dendrolimi on S. frugiperda eggs, and Trichogramma chilonis on S. exigua eggs had higher parasitism. Meanwhile, Telenomus remus maintained a very stable and better performance than Trichogramma on Spodoptera species eggs with different scale thicknesses (parasitized 100% egg masses and 46.2%–60.0% eggs), which demonstrated its excellent potential as a Spodoptera species biocontrol agent. The findings elucidate the effect of egg mass scale thickness on effective parasitism by these egg parasitoid species and provide baseline information for the mixed use of Te. remus and Trichogramma against Spodoptera species. [ABSTRACT FROM AUTHOR]

Simple Summary: Previous studies have reported that infestations by species of the genus Spodoptera (Lepidoptera: Noctuidae) have increased in Cry1Ac Bt soybean fields in Brazil, indicating that chemical insecticides will be needed to reduce crop damage. For that reason, we evaluated the dose effects of the insecticides flubendiamide and thiodicarb against Spodoptera species surviving on soybean expressing Cry1A.105, Cry2Ab2 and Cry1Ac Bt proteins; soybean expressing just Cry1Ac; and non-Bt soybean. Our results indicated that L1 and L2 larvae of S. cosmioides, S. eridania and S. albula surviving on Cry1A.105/Cry2Ab2/Cry1Ac and Cry1Ac soybean leaves sprayed with 50% or 100% of the field label dose of flubendiamide (70 mL/ha) or thiodicarb (400 g/ha) presented >86% mortality. Among the Spodoptera larvae surviving insecticide treatment, only some of the S. frugiperda larvae surviving on Cry1Ac and non-Bt soybean sprayed with 50% of the field label dose of flubendiamide or thiodicarb produced fertile adults. However, the surviving insects had a longer larval stage duration and the females laid fewer eggs, indicating substantial sublethal effects on the biological traits of this species. An increase in Spodoptera species was reported in Bt soybean fields expressing Cry1Ac insecticidal proteins in Brazil, requiring additional management with chemical insecticides. Here, we evaluated the dose effects of flubendiamide and thiodicarb on Spodoptera cosmioides (Walker, 1858), Spodoptera eridania (Stoll, 1782), Spodoptera albula (Walker, 1857) and Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) that survived on MON 87751 × MON 87708 × MON 87701 × MON 89788, expressing Cry1A.105, Cry2Ab2 and Cry1Ac; MON 87701 × MON 89788 soybean, expressing Cry1Ac; and non-Bt soybean. On unsprayed Cry1A.105/Cry2Ab2/Cry1Ac soybean, only S. frugiperda showed ~60% mortality after 10 d, whereas S. cosmioides, S. eridania and S. albula showed >81% mortality. The surviving larvae of all species on this Bt soybean showed >80% mortality when exposed to the field label dose of flubendiamide (70 mL/ha) or thiodicarb (400 g/ha) or at 50% of these doses. In contrast, all four species had <25% and <19% mortality on Cry1Ac and non-Bt soybean, respectively. The surviving S. cosmioides, S. eridania and S. albula on these soybean types presented >83% mortality after exposure to both dose levels of flubendiamide and thiodicarb. Some S. frugiperda larvae surviving on Cry1Ac and non-Bt soybean sprayed with a 50% dose of either insecticide developed into adults. However, the L1 larvae developing on Cry1Ac soybean leaves sprayed with flubendiamide and the L2 larvae on this soybean sprayed with thiodicarb had a prolonged immature stage, and the females displayed lower fecundity, which are likely to impact S. frugiperda population growth on soybean. [ABSTRACT FROM AUTHOR]

The Spodoptera complex of the family Noctuidae, represented here by S. frugiperda (J.E. Smith), S. eridania (Stoll), S. albula (Walker), and S. cosmioides (Walker), is an important group of crop pests in Brazil. Spodoptera frugiperda and S. eridania are invasive in Africa, and the former also in Asia and Oceania. The egg parasitoids Telenomus remus Nixon (Hymenoptera: Scelionidae) and Trichogramma spp. (Hymenoptera: Trichogrammatidae) are potential control agents for field use against these noctuids. We evaluated the parasitism efficiency, development, and flight capacity of an isofemale line and a regular line of T. remus , and 2 genetically variable populations of Trichogramma pretiosum Riley and Trichogramma atopovirilia Oatman and Platner (Hymenoptera: Trichogrammatidae) in these 4 members of the Spodoptera complex. All parasitoids were able to develop in the 4 hosts. The parasitoids showed good flight capacity, except for the regular line of T. remus. The Trichogramma species, despite having high viability and female:male sex ratios, showed poorer parasitism performances than T. remus. The regular T. remus line also showed good parasitism capacity and high viability but had a predominance of males. In general, the isofemale line of T. remus showed good rates of parasitism and flight capacity as well as a high viability and sex ratio, proving to be a potential candidate for an augmentative biological-control program for Spodoptera spp Guenée (Lepidoptera: Noctuidae). [ABSTRACT FROM AUTHOR]

Corn is an important food ingredient because it is the second source of carbohydrates after rice. However, there are obstacles to the attack of the armyworm pest Spodoptera frugiferda (J.E.Smith) which is found in corn plantations in Gowa and Takalar Regencies, South Sulawesi. An alternative control solution that can be applied is the use of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. In this study, formulation tests and bioassays of alginate pellet carriers will be carried out against S. frugiperda on a laboratory scale. The study was conducted from December 2021 to February 2022. Sampling of test larvae of S. frugiperda in corn plantations in Takalar Regency, propagation of the entomopathogenic fungus B. bassiana, alginate pellet production, and its application was carried out at the Pest Laboratory, Faculty of Agriculture, Hasanuddin University. The results showed that the alginate pellet formulation of B. bassiana could kill S. frugiperda larvae with different percentage levels of mortality. The treatment of 50 alginate pellets had a very significant effect with the most influential mortality among other treatments, which was equal to 80%, and had the lowest percentage rate of pupal and imago development. The addition of bran, wheat flour, tapioca flour, and corn flour formulations had an effect on the spore density of the B. bassiana alginate pellets. The P3 treatment (wheat flour) had a high spore density of 2.35 x 108 spores per ml with high mortality of S. frugiperda larvae on days 6-9 days after treatment. [ABSTRACT FROM AUTHOR]

mTORC1 is a central hub that integrates environmental cues, such as cellular stresses and nutrient availability to modulate metabolism and cellular responses. Recently, SLC38A9, a lysosomal amino acid transporter, emerged as a sensor for luminal arginine and as an activator of mTORC1. The amino acid-mediated activation of mTORC1 is regulated by the N-terminal domain of SLC38A9. Here, we determined the crystal structure of zebrafish SLC38A9 (drSLC38A9) and found the N-terminal fragment inserted deep within the transporter, bound in the substrate-binding pocket where normally arginine would bind. This represents a significant conformational change of the N-terminal domain (N-plug) when compared with our recent arginine-bound structure of drSLC38A9. We propose a ball-and-chain model for mTORC1 activation, where N-plug insertion and Rag GTPase binding with SLC38A9 is regulated by luminal arginine levels. This work provides important insights into nutrient sensing by SLC38A9 to activate the mTORC1 pathways in response to dietary amino acids.

The bacterium Clostridium perfringens causes severe, sometimes lethal gastrointestinal disorders in humans, including enteritis and enterotoxemia. Type F strains produce an enterotoxin (CpE) that causes the third most common foodborne illness in the United States. CpE induces gut breakdown by disrupting barriers at cell-cell contacts called tight junctions (TJs), which are formed and maintained by claudins. Targeted binding of CpE to specific claudins, encoded by its C-terminal domain (cCpE), loosens TJ barriers to trigger molecular leaks between cells. Cytotoxicity results from claudin-bound CpE complexes forming pores in cell membranes. In mammalian tissues, ∼24 claudins govern TJ barriers-but the basis for CpE's selective targeting of claudins in the gut was undetermined. We report the structure of human claudin-4 in complex with cCpE, which reveals that enterotoxin targets a motif conserved in receptive claudins and how the motif imparts high-affinity CpE binding to these but not other subtypes. The structural basis of CpE targeting is supported by binding affinities, kinetics, and half-lives of claudin-enterotoxin complexes and by the cytotoxic effects of CpE on claudin-expressing cells. By correlating the binding residence times of claudin-CpE complexes we determined to claudin expression patterns in the gut, we uncover that the primary CpE receptors differ in mice and humans due to sequence changes in the target motif. These findings provide the molecular and structural element CpE employs for subtype-specific targeting of claudins during pathogenicity of C. perfringens in the gut and a framework for new strategies to treat CpE-based illnesses in domesticated mammals and humans.

Pannexin 1 (Panx1) is a membrane channel implicated in numerous physiological and pathophysiological processes via its ability to support release of ATP and other cellular metabolites for local intercellular signaling. However, to date, there has been no direct demonstration of large molecule permeation via the Panx1 channel itself, and thus the permselectivity of Panx1 for different molecules remains unknown. To address this, we expressed, purified, and reconstituted Panx1 into proteoliposomes and demonstrated that channel activation by caspase cleavage yields a dye-permeable pore that favors flux of anionic, large-molecule permeants (up to ~1 kDa). Large cationic molecules can also permeate the channel, albeit at a much lower rate. We further show that Panx1 channels provide a molecular pathway for flux of ATP and other anionic (glutamate) and cationic signaling metabolites (spermidine). These results verify large molecule permeation directly through caspase-activated Panx1 channels that can support their many physiological roles.

Ascoviruses are large dsDNA viruses characterized by the extraordinary changes they induce in cellular pathogenesis and architecture whereby after nuclear lysis and extensive hypertrophy, each cell is cleaved into numerous vesicles for virion reproduction. However, the level of viral replication and transcription in vesicles compared to other host tissues remains uncertain. Therefore, we applied RNA-Sequencing to compare the temporal transcriptome of Spodoptera frugiperda ascovirus (SfAV) and Trichoplusia ni ascovirus (TnAV) at 7, 14, and 21 days post-infection (dpi). We found most transcription occurred in viral vesicles, not in initial tissues infected, a remarkably novel reproduction mechanism compared to all other viruses and most other intracellular pathogens. Specifically, the highest level of viral gene expression occurred in hemolymph, for TnAV at 7 dpi, and SfAV at 14 dpi. Moreover, we found that host immune genes were partially down-regulated in hemolymph, where most viral replication occurred in highly dense accumulations of vesicles.

Herbivory is fundamental to the regulation of both global food webs and the extent of agricultural crop losses. Induced plant responses to herbivores promote resistance and often involve the perception of specific herbivore-associated molecular patterns (HAMPs); however, precisely defined receptors and elicitors associated with herbivore recognition remain elusive. Here, we show that a receptor confers signaling and defense outputs in response to a defined HAMP common in caterpillar oral secretions (OS). Staple food crops, including cowpea (Vigna unguiculata) and common bean (Phaseolus vulgaris), specifically respond to OS via recognition of proteolytic fragments of chloroplastic ATP synthase, termed inceptins. Using forward-genetic mapping of inceptin-induced plant responses, we identified a corresponding leucine-rich repeat receptor, termed INR, specific to select legume species and sufficient to confer inceptin-induced responses and enhanced defense against armyworms (Spodoptera exigua) in tobacco. Our results support the role of plant immune receptors in the perception of chewing herbivores and defense.

13-Lipoxygenases (LOXs) initiate the synthesis of jasmonic acid (JA), the best-understood oxylipin hormone in herbivory defense. However, the roles of 9-LOX-derived oxylipins in insect resistance remain unclear. Here, we report a novel anti-herbivory mechanism mediated by a tonoplast-localized 9-LOX, ZmLOX5, and its linolenic acid-derived product, 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid (9,10-KODA). Transposon-insertional disruption of ZmLOX5 resulted in the loss of resistance to insect herbivory. lox5 knockout mutants displayed greatly reduced wound-induced accumulation of multiple oxylipins and defense metabolites, including benzoxazinoids, abscisic acid (ABA), and JA-isoleucine (JA-Ile). However, exogenous JA-Ile failed to rescue insect defense in lox5 mutants, while applications of 1 μM 9,10-KODA or the JA precursor, 12-oxo-phytodienoic acid (12-OPDA), restored wild-type resistance levels. Metabolite profiling revealed that exogenous 9,10-KODA primed the plants for increased production of ABA and 12-OPDA, but not JA-Ile. While none of the 9-oxylipins were able to rescue JA-Ile induction, the lox5 mutant accumulated lower wound-induced levels of Ca2+, suggesting this as a potential explanation for lower wound-induced JA. Seedlings pretreated with 9,10-KODA exhibited rapid or more robust wound-induced defense gene expression. In addition, an artificial diet supplemented with 9,10-KODA arrested fall armyworm larvae growth. Finally, analysis of single and double lox5 and lox10 mutants showed that ZmLOX5 also contributed to insect defense by modulating ZmLOX10 -mediated green leaf volatile signaling. Collectively, our study uncovered a previously unknown anti-herbivore defense and hormone-like signaling activity for a major 9-oxylipin α-ketol. Insect herbivory of maize induces the expression of a gene encoding a tonoplast-localized 9-lipoxygenase, ZmLOX5, which produces an α-ketol, 9,10-KODA. This 9-oxylipin serves a potent signaling role in herbivory defense downstream of jasmonic acid by regulating the synthesis of 12-OPDA, abscisic acid, and ZmLOX10-mediated green leaf volatile. The study thus uncovers a previously unknown anti-herbivore defense and hormone-like signaling activity for a major 9-oxylipin α-ketol. [ABSTRACT FROM AUTHOR]

Diet composition is vital in shaping gut microbial assemblage in many insects. Minimal knowledge is available about the influence of transgenerational diet transition on gut microbial community structure and function in polyphagous pests. This study investigated transgenerational diet-induced changes in Spodoptera littoralis larval gut bacteriome using 16S ribosomal sequencing. Our data revealed that 88% of bacterial populations in the S. littoralis larval gut comprise Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. The first diet transition experiment from an artificial diet (F0) to a plant diet (F1), cabbage and cotton, caused an alteration of bacterial communities in the S. littoralis larval gut. The second transgenerational diet switch, where F1 larvae feed on the same plant in the F2 generation, displayed a significant variation suggesting further restructuring of the microbial communities in the Spodoptera larval gut. F1 larvae were also challenged with the plant diet transition at the F2 generation (cabbage to cotton or cotton to cabbage). After feeding on dierent plant diets, the microbial assemblage of F2 larvae pointed to considerable dierences from other F2 larvae that continued on the same diet. Our results showed that S. littoralis larval gut bacteriome responds rapidly and inexplicably to dierent diet changes. Further experiments must be conducted to determine the developmental and ecological consequences of such changes. Nevertheless, this study improves our perception of the impact of transgenerational diet switches on the resident gut bacteriome in S. littoralis larvae and could facilitate future research to understand the importance of symbiosis in lepidopteran generalists better. [ABSTRACT FROM AUTHOR]

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a polyphagous pest native to the tropical and subtropical Americas, but it has recently invaded the Eastern Hemisphere and spread rapidly. This migratory moth, which can fly long distances, now poses a global threat as a transboundary pest. To establish an efficient management program against this pest, monitoring of its occurrence is essential. Lures impregnated with four synthetic pheromone components of S. frugiperda – (Z)‐9‐tetradecenyl acetate (Z9‐14:Ac), (Z)‐11‐hexadecenyl acetate, (Z)‐7‐dodecenyl acetate, and (Z)‐9‐dodecenyl acetate – are commercially available, and traps baited with them are used for monitoring. However, in Japan, these pheromone traps frequently capture many non‐target moths, particularly Mythimna loreyi (Duponchel) (Lepidoptera: Noctuidae). We therefore reexamined the sex pheromone of S. frugiperda in an attempt to improve the monitoring lures and discovered trace amounts of (Z,E)‐9,12‐tetradecadienyl acetate (Z9E12‐14:Ac) in female extracts at ca. 0.2% of the primary component (Z9‐14:Ac). We verified its activity in males by field trap bioassays as well as antennal electrophysiology and demonstrated that this fifth component enhances the attractiveness of synthetic pheromones composed of the other four components to S. frugiperda and reduces the bycatch of M. loreyi. As Z9E12‐14:Ac is found in pheromones of most Spodoptera species, it may have been a pheromone component in the common ancestor and played a key role in divergence of pheromone systems in the genus Spodoptera. [ABSTRACT FROM AUTHOR]

Simple Summary: The invasion of Spodoptera eridania and the damage it has caused to crop systems in recent years has raised concerns about its potential risks. In this study, we aimed to map the invasion risk of S. eridania worldwide based on an optimized MaxEnt model. The results indicated the suitable habitat concentrated in southern North America, South America, western Europe, central Africa, southern Asia, and eastern Oceania. Under climate change, suitable habitats for S. eridania will expand and shift to higher latitudes in the future. Countries without S. eridania invasion but that are at invasive risk, such as the European Union, Southeast Asian countries, and Australia should take appropriate quarantine measures to prevent the entry of this pest. The southern armyworm (Spodoptera eridania), a polyphagous crop pest native to tropical America, has been found in Africa (2016) and India (2019), causing defoliation and damage to the reproductive structures of cassava, soybean, and tomato. The damage caused by this pest to crop systems has raised concerns regarding its potential risks. Therefore, we predicted the potential geographical distribution of S. eridania under climate change conditions using 19 bioclimatic variables based on an optimized MaxEnt model. The results showed that annual precipitation (bio12), mean temperature of the warmest quarter (bio10), and precipitation of the driest month (bio14) were important bioclimatic variables influencing the potential distribution. The prediction showed that the suitable habitat area was approximately 3426.43 × 104 km2, mainly concentrated in southern North America, South America, western Europe, central Africa, southern Asia, and eastern Oceania. In response to global climate change, suitable habitats for S. eridania will expand and shift to higher latitudes in the future, especially under the SSP5-8.5 scenario. Because of the current devastating effects on crop production, countries without S. eridania invasion, such as the European Union, Southeast Asian countries, and Australia, need to strengthen phytosanitary measures at border ports to prevent the introduction of this pest. [ABSTRACT FROM AUTHOR]

The fall armyworm, Spodoptera frugiperdais a highly destructive pest of cereals and is native to the tropical and subtropical regions of North, Central and South America. The insect is polyphagous with a host range of 353 plant species in 76 families and was reported to cause 8.3 to 20.6 million tones losses in maize yield/year which represents 21 - 53% of the total production. A total of 48 parasitoids (6 species of egg parasitoids, 4 species of egglarval parasitoids, 34 species of larval parasitoids, 3 species of larval-pupal parasitoids and one pupal parasitoid) of Spodoptera frugiperda have been recorded in African countries since its invasion in 2016. In addition, 18 predator species have been found to be associated with this insect in maize and rice fields. In Asian countries, a total of 24 parasitoids (6 egg parasitoids, 2 egg-larval parasitoids and 16 larval parasitoids) have been recorded as well as 11 predator species. The most common egg parasitoid is Telenomus remus which is recorded in 8 countries of Africa as well as three countries of Asia (out of the 4 countries mentioned in Asia). The most common egg-larval parasitoid in Africa is Chelonus bifoveolatus as it is recorded in 8 countries whereas Ch. formosanus and Ch. nr blackburni are recorded in India (Asia). The most common larval parasitoids in Africa are Coccygidium luteum (7 countries), Cotesia icipe (6 countries) and Charops sp. (6 countries), whereas the most common one in India (Asia) is Campoletis chlorideae. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the effect of the hexane fraction of the crude extract of the fruits and seeds of Ricinus communis (HFFSRC) on eggs of Spodoptera cosmioides and Spodoptera frugiperda and on caterpillars of Spodoptera eridania, S. frugiperda, and S. cosmioides, under laboratory conditions through topical application and ingestion, as well as to identify the compounds in the hexane fraction through high-performance chromatography (HPLC-ESI-Q-TOF-MS/MS). To do so, three bioassays were conducted: (1) the effect of HFFSRC at 2% (20,000 mg·mL−1) on eggs of S. cosmioides and S. frugiperda, (2) the lethal effect of HFFSRC at 2% applied topically, and (3) the lethal effect of HFFSRC at 2% applied to soybean-leaf discs on first-, second-, third-, and fourth-instar caterpillars of the three insect species. It was found that 2% HFFSRC had an ovicidal effect on S. frugiperda and S. cosmioides, completely reducing larvae hatching and the insecticidal effect for the four instars of the three insect species when applied topically and on food. Five compounds were identified in the HFFSRC: three flavonoids, one ricinoleic acid, and one cinnamic acid. HFFSRC at 2% had an acute ovicidal and insecticidal effect on caterpillars of the studied species, configuring itself as a potential insecticide. [ABSTRACT FROM AUTHOR]