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The selection of oviposition sites by female moths is crucial in shaping their progeny performance and survival, and consequently in determining insect fitness. Selecting suitable plants that promote the performance of the progeny is referred to as the Preference−Performance hypothesis (or 'mother‐knows‐best'). While root infestation generally reduces the performance of leaf herbivores, little is known about its impact on female oviposition. We investigated whether maize root infestation by the Western corn rootworm (WCR) affects the oviposition preference and larval performance of the European corn borer (ECB). ECB females used leaf volatiles to select healthy plants over WCR‐infested plants. Undecane, a compound absent from the volatile bouquet of healthy plants, was the sole compound to be upregulated upon root infestation and acted as a repellent for first oviposition. ECB larvae yet performed better on plants infested below‐ground than on healthy plants, suggesting an example of 'bad motherhood'. The increased ECB performance on WCR‐infested plants was mirrored by an increased leaf consumption, and no changes in the plant primary or secondary metabolism were detected. Understanding plant‐mediated interactions between above‐ and below‐ground herbivores may help to predict oviposition decisions, and ultimately, to manage pest outbreaks in the field. Summary statement: The leaf herbivore Ostrinia nubilalis can detect and selectively lay eggs on maize plants infested by the root herbivore Diabrotica virgifera, resulting in a lower performance of its progeny. Undecane was the sole volatile to be induced in leaves of root infested plants and shaped the oviposition behaviour of O. nubilalis females. [ABSTRACT FROM AUTHOR]

The European corn borer (Ostrinia nubilalis, Hbn.), enters diapause, a strategy characterized by arrest of development and reproduction, reduction of metabolic rate and the emergence of increased resistance to challenging seasonal conditions as low sub-zero winter temperatures. The aim of this study was to investigate the potential role of inorganic elements in the ecophysiology of O. nubilalis, analysing their content in the whole body, hemolymph and fat body, both metabolically active, non-diapausing and overwintering diapausing larvae by ICP-OES spectrometer following the US EPA method 200.7:2001. O nubilalis as many phytophagous lepidopteran species maintain a very low extracellular sodium concentration and has potassium as dominant cation in hemolymph of their larvae. Changes in hemolymph and the whole body sodium content occur already at the onset of diapause (when the mean environmental temperatures are still high above 0 ºC) and remain stable during the time course of diapause when larvae of this species cope with sub-zero temperatures, it seems that sodium content regulation is rather a part of diapausing program than the direct effect of exposure to low temperatures. Compared to non-diapausing O. nubilalis larvae, potassium levels are much higher in the whole body and fat body of diapausing larvae and substantially increase approaching the end of diapause. The concentration of Ca, Mg, P and S differed in the whole body, hemolymph and fat body between non-diapausing and diapausing larvae without a unique trend during diapause, except an increase in their contents at the end of diapause. [ABSTRACT FROM AUTHOR]

Simple Summary: In the Po Valley, the control of maize from insect pests (Ostrinia nubilalis and Diabrotica virgifera virgifera) can include insecticide applications. The results of research on insecticide spray's impact on beneficial insects, which can contribute to the biological control of maize pest, are reported. Aphid predators and Trichogramma brassicae (O. nubilalis egg parasitoid) were used as indicators. Chemical insecticide application significantly increased aphid abundance when no rotation protocol was applied. In addition, an alteration in aphid predator community composition was recorded. In insecticide-sprayed fields managed according to repeated crop protocols, the predator community was dominated by hoverflies, while in maize fields where crop rotation was practiced, ladybirds and Orius spp. predominated. In addition, the insecticides had a negative effect on the natural parasitism of T. brassicae. The research suggests that Integrated Pest Management strategies should be planned based on crop rotation protocols and biological control of maize pests. The European corn borer (ECB) (Ostrinia nubilalis Hübner) and to a lesser extent the western corn rootworm (Diabrotica virgifera virgifera LeConte) are a threat to maize in the Po Valley (Northern Italy), and their control can require insecticide applications. The results of a study to evaluate the effects of insecticide sprays on the beneficial insect Trichogramma brassicae (Hymenoptera: Trichogrammatidae) and aphid predators are reported. A three-year research project was carried out in two Study Areas, in Lombardy. In area 1, crop rotation was a common practice, while in area 2 repeated maize crop was practiced. The natural trend of ECB egg masses attacked by T. brassicae was affected and parasitism rates were reduced as a result of insecticide exposure (chlorpyriphos methyl, cypermethrin, alphacypermethrine). Repeated maize crop and insecticides spraying increased the abundance of the aphid population and negatively affected the aphid predator community, which mainly included ladybirds, hoverflies, true bugs and lacewings. The predator community was dominated by hoverflies in sprayed fields managed according to repeated maize crop protocols, whereas ladybirds and Orius spp. dominated in maize fields managed according to crop rotation protocols. Crop rotation protocols help to prevent ECB outbreaks; when the risk of exceeding the economic threshold limit is high, and this may be the case when maize is cultivated for seeds or for horticultural crops such as sweet corn, inundative release of T. brassicae and/or microbial control (i.e., use of Bacillus thuringiensis preparations) can integrate natural biocontrol, and provide a valuable alternative to chemical insecticides. [ABSTRACT FROM AUTHOR]

During diapause, a state of temporarily arrested development, insects require low winter temperatures to suppress their metabolism, conserve energy stores and acquire cold hardiness. A warmer winter could, thus, reduce diapause incidence and duration in many species, prematurely deplete their energy reserves and compromise post-diapause fitness. In this study, we investigated the combined effects of thermal stress and the diapause program on the expression of selected genes involved in antioxidant defense and heat shock response in the European corn borer Ostrinia nubilalis. By using qRT-PCR, it has been shown that response to chronic heat stress is characterized by raised mRNA levels of grx and trx, two important genes of the antioxidant defense system, as well as of hsp70 and, somewhat, of hsp90, two major heat shock response proteins. On the other hand, the expression of hsc70, hsp20.4 and hsp20.1 was discontinuous in the latter part of diapause, or was strongly controlled by the diapause program and refractory to heat stress, as was the case for mtn and fer, genes encoding two metal storage proteins crucial for metal ion homeostasis. This is the first time that the effects of high winter temperatures have been assessed on cold-hardy diapausing larvae and pupae of this important corn pest. [ABSTRACT FROM AUTHOR]

Simple Summary: The European corn borer (Ostrinia nubilalis) is a major pest of corn, managed successfully in North America since 1996 with transgenic Bt-corn. However, practical field resistance and early-warning increases in frequency of resistance genes for all available insecticidal Bt proteins expressed in corn were detected recently at several locations in Canada. Given the high mobility of moths, design of containment and mitigation measures would have to be implemented at large spatial scales around a resistance hotspot to be successful. Effective strategies must account for high gene flow consistent with improved understandings of this species' complex movement ecology, including migratory behavior. The European corn borer (Ostrinia nubilalis, Hübner) has been managed successfully in North America since 1996 with transgenic Bt-corn. However, field-evolved resistance to all four available insecticidal Bt proteins has been detected in four provinces of Canada since 2018. Evidence suggests resistance may be spreading and evolving independently in scattered hotspots. Evolution and spread of resistance are functions of gene flow, and therefore dispersal, so design of effective resistance management and mitigation plans must take insect movement into account. Recent advances in characterizing European corn borer movement ecology have revealed a number of surprises, chief among them that a large percentage of adults disperse from the natal field via true migratory behavior, most before mating. This undermines a number of common key assumptions about adult behavior, patterns of movement, and gene flow, and stresses the need to reassess how ecological data are interpreted and how movement in models should be parameterized. While many questions remain concerning adult European corn borer movement ecology, the information currently available is coherent enough to construct a generalized framework useful for estimating the spatial scale required to implement possible Bt-resistance prevention, remediation, and mitigation strategies, and to assess their realistic chances of success. [ABSTRACT FROM AUTHOR]

Introduction: The European corn borer (ECB), Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), is a major pest insect in maize. New cultivars and climate change have allowed range expansion of the crop northwards in Europe, and a similar range expansion of associated pests has been predicted. ECB exists as two distinct pheromone strains using different blends of (E)‐11‐tetradecenyl acetate and (Z)‐11‐tetradecenyl acetate for sexual communication; in addition, the Z‐strain feeds almost exclusively on maize. In Sweden, the maize cropping area has increased tenfold during the last two decades, increasing the potential for spread of the Z‐strain, which was recorded for the first time in the country in 2010. Aim of the study/methods: In this study, we performed trapping experiments with strain‐specific lures in maize fields in southern Sweden during 2013–2022 to monitor the presence and relative abundance of the two ECB strains and evaluate the potential increase of the Z‐strain. Trapping was also performed at least 5 km away from maize fields. Molecular markers were used to verify the strain identity of trapped males and larvae that fed on maize. Results: Catch data revealed that both pheromone strains were present in the major maize cultivation areas of Sweden, as predicted by recent modelling studies. Our data indicate that the flight period of ECB in southern Sweden lasts from the middle of June to late August, with peak flight in July. Catches of both strains were low at all trapping sites and throughout the study period and decreased further during the years following the dry summer of 2018. No Z‐strain males were trapped far away from maize fields. Conclusion: Based on our results, and the low levels of ECB‐related damage observed in local maize fields, the Z‐strain is currently not imposing a threat to Swedish maize growers. [ABSTRACT FROM AUTHOR]

The European corn borer is a major pest of corn that overwinters in corn stubble and stalks. Shredding these residues disrupts the larvae's habitat or directly harms them. A corn header has been engineered with a new type of cutting tool on its horizontal choppers, featuring sharp edges and dulled flails, to shred corn stubble near the soil surface. This study investigated the effect of the dulled flails on the shredding intensity of corn stover. Field trials compared flail knives with standard knives for particle size distribution of corn stover and structural integrity of corn stalk segments. Additionally, a common two-step method, which involved a standard knives-equipped corn header followed by tractor-driven flail mowers, was tested. The flail knives reduced the mean particle size by 3.6 mm compared to the standard knives. Subsequent processing with tractor-driven flail mowers, following the corn header using standard knives, led to a reduction in mean particle size by 11.8 mm. It also further reduced the number of incompletely destroyed stalk segments. However, completely intact internodes were scarce in all methods. Given that flail knives enhance shredding intensity without a second processing step, this concept is concluded to be effective for corn stover shredding. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission, the European Food Safety Authority (EFSA) assessed the 2021 post‐market environmental monitoring (PMEM) report on the cultivation of Cry1Ab‐expressing maize event MON 810. Evidence provided in the PMEM report shows that farmers growing maize MON 810 in Spain complied partially with refuge requirements, while full compliance was achieved in Portugal. Cry1Ab susceptibility tests performed on European and Mediterranean corn borer populations collected from north‐eastern Spain in 2021 indicated no symptoms of resistance evolution to maize MON 810. However, unexpected damage to maize MON 810 plants was observed in a field trial in the province of Girona (north‐eastern Spain), which may point to the presence of resistance alleles in this region. Information retrieved through farmer questionnaires and the scientific literature reveals no unanticipated adverse effects on human and animal health or the environment arising from the cultivation of maize MON 810. Overall, EFSA concludes that the evidence reported in the 2021 PMEM report does not invalidate its previous conclusions on the safety of maize MON 810. The possible presence of Cry1Ab resistance alleles at frequencies leading to damage to maize MON 810 plants in Girona requires twofold actions: (1) increase monitoring efforts in this area; and (2) implement remedial measures to limit the suspected evolution and spread of resistance. As in previous years, EFSA identified shortcomings on resistance monitoring that need revision. In particular, full refuge compliance must be achieved in Spain. Moreover, the sensitivity of the monitoring plan must be increased, which can be achieved by replacing the current susceptibility assays by periodic F2 screens. EFSA also recommends the consent holder to revise the farmer questionnaires to account for the emergence of teosinte as a noxious agricultural weed in maize MON 810‐growing areas in Spain. [ABSTRACT FROM AUTHOR]

Trichogramma spp. have been used or have been proposed for use in biological control programmes of lepidopteran pests, including the European corn borer, Ostrinia nubilalis, the cotton bollworm, Helicoverpa armigera, and the spruce budworm, Choristoneura fumiferana. Releases are typically made by placing cards with parasitised eggs at set points in the field. However, this method can be cost-prohibitive due to its laborious nature. As a result, labour-saving mechanised release programmes have been developed, including distribution by spray equipment. However, few have investigated applying Trichogramma with a standard pesticide application (i.e. 'tank mix'). As a first step to ascertain the feasibility of such a system, we observed the effect of immersion of T. ostriniae pupae in field-relevant concentrations of eight herbicides (bentazon, clethodim, fomesafen, quizalofop, Glacial acetic acid, glyphosate, imazamox, imazethapyr), three fungicides (Copper Hydroxide, flutriafol, and penthiopyrad), one insecticide (K+ salt of fatty acid), and five adjuvants (Ammonium Sulfate, Crop Oil Concentrate, Methylated seed oil, Non-ionic surfactant, and Urea-Ammonium Nitrate) on the emergence of T. ostriniae adults. The herbicides GAA and clethodim; the fungicides copper hydroxide, flutriafol, and penthiopyrad; and the adjuvants COC, MSO, and NIS all reduced T. ostriniae emergence compared to a water control. No emergence was observed with exposure to quizalofop, GAA, or K+ salt of fatty acid treatments. Other treatments did not affect emergence compared to water. Thus, deploying Trichogramma with a standard pesticide application may be a feasible labour-saving distribution method that warrants further investigation. [ABSTRACT FROM AUTHOR]

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The attraction of nocturnal insects by light is a known phenomenon with unknown physiological mechanisms. Butterflies of the superfamily Pyraloidea mount the strongest reactions to light, though the spectral preferences of these insects have not been studied. The moth Ostrinia scapulalis, which lives on dicotyledonous plants and is a pest of hemp and hops, is the ancestral form of the Asian and European corn borers, widespread pests of corn. Studies using a wind tunnel modified to include a light source were run to test the responses of males and females to light stimuli with emission maxima of 532, 440, and 365 nm at an illumination of 2 lx created at the point at which the insects were released; the light used was able to stimulate the photoreceptors of both compound eyes (sensitivity peaks at 352, 413, 480, and 530 nm) and simple eyes, i.e., ocelli (main sensitivity peak in the ultraviolet region of the spectrum, with an additional peak in the green region (360 and 520 nm)). Ultraviolet light was found to be the most attractive stimulus. A small percentage of insects responded to green light and displayed freezing responses close to the light source. The least attractive was blue light, which also induced freezing. Thus, flight of O. scapulalis was induced by short-wavelength light. This response is more consistent with the sensitivity of ocelli than that of compound eyes. Blue or green radiation led to masking reactions. [ABSTRACT FROM AUTHOR]

Nanotechnology is a promising way to enhance the stability of Bacillus thuringiensis (Bt) insecticidal proteins under environmental conditions. In this work, two emulsions were prepared through the Pickering emulsion technique, stabilized by Cu2+-SQDs/S-CN nanocomposites and by GO nanosheets. In addition, a pH-sensitive polymer was incorporated into these emulsions, allowing the Bt protein, Cry1Ab, to be released in an alkaline pH environment, as it occurs in the lepidopteran pests' gut. The effectiveness of these two nanomaterials in protecting Cry1Ab from degradation, and therefore enhancing its pesticidal activity, was assessed by exposing samples of the purified unprotected protein and encapsulated protein to high-intensity UV light and 40°C temperature treatments. The UV treatment results were evaluated using SDS-PAGE analysis and pointed out that Cry1Ab could be structurally protected by the emulsions. The bioassays with first instar larvae of the lepidopteran pest Ostrinia nubilalis confirm the nanomaterial protection to UV and temperature treatments, i.e., decreasing about half the degradation rate and increasing up to 12-fold the residual activity after UV treatment. Our results indicate that encapsulation could be an effective strategy to improve the effectiveness of Cry1Ab under environmental conditions. Key points: • Pickering emulsions are effective for solubilized Cry1Ab encapsulation. • Structural and toxicity Cry1Ab properties are enhanced by pH-sensitive encapsulation. • Cu2+−SQDs/S-CN and GO nanomaterials improve the efficacy of Bt insecticides. [ABSTRACT FROM AUTHOR]

The cultivation of sweet corn is accompanied by a number of plant protection problems. It is attacked by lot of pest, cause significant damage to the cobs, deteriorate the commercial properties and cause significant economic losses. In this regard, surveys were conducted in the period 2019-2020 in the sweet corn fields in the area of the village of Planinitsa, Burgas region, Bulgaria. Standard entomological methods were used to estimate pest densities. A mixture of plant extracts from walnut (Juglans regia L.), ailanthus (Ailanthus altissima Swing.) and tobacco (Nicotiana tabacum L.) was tested against cotton bollworm caterpillars (Helicoverpa armigera Hübner). Sweet corn is attacked by a large number of omnivorous and specialized pests. Two critical periods are: Period I-phase 5th-7th leaf, in relation to weevils; and Period II-the paniclephenophase, when european corn borer (Ostrinia nubilalis Hübner) and cotton bollworm (Helicoverpa armigera Hübner) appear. In 2019, 5% of cobs were reported as damaged by corn borer and 35% - by cotton bollworm, and in 2020, 10% and 65%, respectively. The data from the obtained results show that the mixture of plant extracts exhibits good efficacy and can be included as an alternative means of controlling cotton bollworm in integrated plant protection systems. [ABSTRACT FROM AUTHOR]

Investment of resources in reproduction can be based on individual state, environmental conditions, and perceived mate quality. Changing climates impact many aspects of the environment by increasing temperature, decreasing precipitation, and altering resource availability. Access to high-quality resources is known to improve survival under elevated temperatures, but its effects on reproduction in warming environments are largely unexplored. Here, we investigate the effects of elevated temperature and sugar resources on reproductive output within and between E- and Z-pheromone strains of the European corn borer moth [Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae)]. Corn borers prefer mates from their own strain, with reproductive output being highest for within-strain pairs. In this experiment, mating pairs were provided with a 20% sugar solution while exposed to either ambient (23 °C) or elevated (28 °C) temperatures. We measured reproductive investment as the total number of egg clusters laid 3 days after pairing. We found that at ambient temperature, sugar supplementation resulted in high investment across all pairs, including with usually unpreferred mates. However, when sugar was provided at elevated temperature, more egg clusters were laid in pairs with preferred (within-strain) mates as compared to less preferred (between-strain) mates. These results differ from temperature effects in the absence of sugar and suggest that the effects of sugar on reproductive investment in less preferred mates depend on temperature. Changes in investment may be due to differences in the allocation of extra resources to thermoregulation at elevated temperatures. Our results suggest the possibility of interactive effects of temperature and resources on sexual selection. [ABSTRACT FROM AUTHOR]

Simple Summary: The European corn borer, Ostrinia nubilalis Hbn., is an annual pest of the Romanian corn crop. The research followed the development of the European corn borer in the context of the climate warming recorded in recent years in Eastern Romania. We monitored the development of the egg, larva, pupa, and moth stages using cage studies and observations in an experimental cornfield. We also analyzed the impact of climatic conditions on developmental time. Our data show that the increase in winter temperatures ensures the survival of a higher percentage of mature larvae, which leads to intense moth flight at the end of June and the beginning of July. However, the high summer temperatures caused an increasing percentage of the larvae to transform into pupae, which led to the recording of a secondary flight in August. Although the insect is known to have one generation per year, it is apparent that a multivoltine ecotype is also present. We conclude that the climate warming we are witnessing affects the species' development and that higher larval infestations could occur. Between 2020 and 2021, we conducted research in eastern Romania to monitor the bioecology of the European corn borer (Ostrinia nubilalis Hbn.), an important pest of corn. The bioecology research established the pest stage duration (egg, larva, pupa, and moth), the flight curve, and the flight peak. The bioecological study occurred in the experimental corn field and a field cage. According to our findings, the insect has one generation per year. The European corn borer hibernates as a mature larva in corn residues and continues developing in the spring, when the weather warms. It pupates from May to July over 37 days. Analyzing the data recorded during the winters of 2020 and 2021, we observed that the warming trend favored the high survival of hibernating larvae (60.7%). Due to the large number of mature larvae that had favorable conditions during the winter, there is an intense flight, starting in June and ending in September. When the first moth was caught in the light trap, the ∑(tn-10) °C (sum of degree days) was 245.6 °C. In 2020, the flight was recorded for 94 days. In 2021, the European corn borer flight lasted 104 days. The initial egg masses were detected when the total of ∑(tn-10) °C reached 351.5 °C. Moths laid the eggs for 25 days, mostly during peak flight in late June and early July. The first larvae hatched when ∑(tn-10) °C totaled 438.4 °C, and stages III–V were recorded in the harvested crop. Understanding the bioecology of the European corn borer can offer valuable insights into managing population levels and identifying optimal timing for addressing infestations in corn crops. [ABSTRACT FROM AUTHOR]

Understanding the molecular basis of repeated evolution improves our ability to predict evolution across the tree of life. Only since the last decade has high‐throughput sequencing enabled comparative genome scans to thoroughly examine the repeatability of genetic changes driving repeated phenotypic evolution. The Asian corn borer (ACB), Ostrinia furnacalis (Guenée), and the European corn borer (ECB), Ostrinia nubilalis (Hübner), are two closely related moths displaying repeatable phenological adaptation to a wide range of climates on two separate continents, largely manifesting as changes in the timing of diapause induction and termination across latitude. Candidate genes underlying diapause variation in North American ECB have been previously identified. Here, we sampled seven ACB populations across 23 degrees of latitude in China to elucidate the genetic basis of diapause variation and evolutionary mechanisms driving parallel clinal responses in the two species. Using pooled whole‐genome sequencing (Pool‐seq) data, population genomic analyses revealed hundreds of single nucleotide polymorphisms (SNP) whose allele frequencies covaried with mean diapause phenotypes along the cline. Genes involved in circadian rhythm were over‐represented among candidate genes with strong signatures of spatially varying selection. Only one of two circadian clock genes associated with diapause evolution in ECB showed evidence of reuse in ACB (period [per]), but per alleles were not shared between species nor with their outgroup, implicating independent mutational paths. Nonetheless, evidence of adaptive introgression was discovered at putative diapause loci located elsewhere in the genome, suggesting that de novo mutations and introgression might both underlie the repeated phenological evolution. [ABSTRACT FROM AUTHOR]

Mycotoxins in silage corn (Zea mays L.) accumulate due to ear rot infections by certain ascomycete fungi and cause health issues in livestock. Fungal infections intensify with increase in ear‐damaging insect injury and favorable environment in the US Great Lakes region. Therefore, evaluating strategies such as hybrid insect protection and fungicide decisions to manage insects, ear rots, mycotoxin, and silage quality is crucial. Field trials were conducted in randomized complete block design at 11 Michigan site‐years across 2019–2021 using three hybrid insect protection levels under two levels of prothioconazole fungicide (treated and non‐treated). Hybrids (two per level) included: conventional (non‐Bt); Bt with Cry1F and Cry1Ab (BtE), protection only against European corn borer (ECB); and Bt with Cry1F and Vip3A (BtEW), protection against both ECB and western bean cutworm (WBC). Insect injury and ear rot index were 80%–90% and 75%–90% lower, respectively, in BtEW hybrids than non‐Bt hybrids. Strong correlation between insect injury and ear rot severity was observed when insect pressure was high. Mycotoxin levels, particularly deoxynivalenol (DON), was also lowest in BtEW hybrids. Weak correlations were observed between ear injury and mycotoxin concentration. Under low disease pressure, a 50%–70% reduction was observed in fungicide treated plots for both ear rot incidence and DON concentration. However, fungicide application did not reduce ear rot infections driven by high insect injury. Treatments had negligible impact on forage quality. Overall, results indicated that incorporating insect protection in hybrid selection decisions reduced insect feeding, disease occurrence, and mycotoxins, especially under high insect pressure. Core ideas: Mycotoxins accumulate in plants due to infection by fungal pathogens and are ubiquitous in Michigan silage corn.Ear damaging insects increased mycotoxin accumulation due to wounding that intensified fungal infections.Hybrid insect protection reduced mycotoxins by preventing ear injury due to insects and reduced fungal infections.Fungicide application did not reduce ear rot infection and mycotoxin accumulation under high insect pressure. [ABSTRACT FROM AUTHOR]

This work aimed to evaluate changes in phytic phosphorus content as the response of three maize hybrids (ZP 457, ZP 5601, and ZP 606) to different pesticide treatments for European Corn Borer (ECB) attacks and, as well as the correlation between damage caused by ECB attack and Pphy content. In the experimental field, maize ears were sampled and dried at a moisture content of 14% for the determination of changes in phytic phosphorus content in the grain. The content of phytic phosphorus was determined using UV / VIS spectrophotometry. Observed results showed the highest content of phytic phosphorus for untreated control for all tested hybrids, compared to pesticide treatments. The content of Pphy in the tested maize kernel samples ranged from 2.12 to 3.40 mg g-1. A significant positive correlation between attacks of larvae and Pphy content could indicate activation of its antioxidative function as a response to damage caused by ECB attack.

The European corn borer is a major pest of corn that overwinters in corn stubble and stalks. Shredding these residues disrupts the larvae’s habitat or directly harms them. A corn header has been engineered with a new type of cutting tool on its horizontal choppers, featuring sharp edges and dulled flails, to shred corn stubble near the soil surface. This study investigated the effect of the dulled flails on the shredding intensity of corn stover. Field trials compared flail knives with standard knives for particle size distribution of corn stover and structural integrity of corn stalk segments. Additionally, a common two-step method, which involved a standard knives-equipped corn header followed by tractor-driven flail mowers, was tested. The flail knives reduced the mean particle size by 3.6 mm compared to the standard knives. Subsequent processing with tractor-driven flail mowers, following the corn header using standard knives, led to a reduction in mean particle size by 11.8 mm. It also further reduced the number of incompletely destroyed stalk segments. However, completely intact internodes were scarce in all methods. Given that flail knives enhance shredding intensity without a second processing step, this concept is concluded to be effective for corn stover shredding.

Citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), and European corn borer (ECB), Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), are two key pests of young citrus and maize plants in Iran, respectively. In this study, the effects of sub‐sterilizing doses of gamma radiation (100–250 Gy for CLM, 90–180 Gy for ECB) on the biological and reproductive parameters of F1 progeny from irradiated males were determined. The results indicated that males irradiated at doses of ≥200 and ≥150 Gy produced highly sterile F1 descents for CLM and ECB, respectively. No adverse effects of radiation doses applied to males were observed on the F1 pupal emergence for both species, nor on the adult longevity of male and female ECB moths. However, the life span of CLM F1 male and female adults decreased with increasing doses. The sex ratio of emerged adults of F1 progeny from irradiated males was skewed towards males with increasing doses; the proportion of males to all emerged adults reached 0.52 and 0.54 at doses of 250 and 150 Gy for CLM and ECB, compared to 0.44 and 0.49 in the controls, respectively. The competitiveness index of irradiated and F1 males of both species fluctuated in acceptable ranges and in general F1 males were stronger competitors than their irradiated male parents. The results of the field cage experiments showed that the larval infestation in all cages including the released irradiated CLM and ECB moths decreased compared to the control treatment – the percentage of damaged leaves and stems in the cages with ratios of 20:1 and 7:1 irradiated‐to‐normal insects (highest ratios assayed) reached half and one‐third of the control for CLM and ECB, respectively. [ABSTRACT FROM AUTHOR]

Although corn production is affected by several harmful insects, its most important pest in the southeastern region of Europe is the European corn borer (ECB), Ostrinia nubilalis Hübner, 1796 (Lepidoptera: Pyralidae). Chemical control of O. nubilalis remains the main strategy in conventional corn production. The key to successfully achieving a high efficiency of insecticides is determining the appropriate moment of application, including the exact time in the insect's life cycle when it is most vulnerable. In this study, monitoring data on the flight dynamics of ECB adults from a seven-year period (2014–2020) were exploited for the development of a predictive model of adult numbers within the growing season. ECB monitoring was performed by using light traps at 15 different locations in the Vojvodina region (Serbia) during the specified time period. First, the calendar for Vojvodina was created based on the analytics of the collected monitoring data. Additionally, the calendar was converted to the probability of ECB occurrence during the growing season, specifying the time interval between the appearance of each generation of the pest. Second, using machine learning techniques, a phenological model was designed that included daily values of relevant meteorological features, such as cumulative degree-days, relative humidity, and precipitation. The calendar had a lower prediction error when compared to the phenological model, and it was tested as a supporting management tool for the ECB in 2021, with a root-mean-square error of the number of adults of 46.67. Such an approach could significantly reduce both the consumption of insecticides and the number of chemical treatments, respectively. Above all, this approach has broad potential in IPM and organic farming, and it is fully compatible with biological control methods. [ABSTRACT FROM AUTHOR]

The first case of field-evolved resistance in European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) to transgenic corn (Zea mays L.) producing a Bacillus thuringiensis (Bt) Berliner toxin was discovered in Nova Scotia, Canada in 2018. This case involved resistance to Bt corn producing Cry1Fa toxin. As a mitigation response, Bt corn hybrids producing only Cry1Fa were replaced in that region with hybrids producing two or three Bt toxins targeting O. nubilalis. In this study, we collected O. nubilalis in several corn-growing regions of Canada during 2018 to 2020 and tested their progeny for susceptibility to four Bt toxins produced by currently available Bt corn that targets O. nubilalis : Cry1Fa, Cry1Ab, Cry1A.105, and Cry2Ab. Based on toxin concentrations killing 50% of larvae from 23 field-derived strains relative to two susceptible laboratory strains, the resistance ratio was at least 10 for Cry1Fa for 12 strains (52% of strains) consisting of 10 strains from Nova Scotia, as well as strains from near Montreal, Quebec and Roseisle, Manitoba. We found low but statistically significant resistance relative to at least one of two susceptible strains for Cry1Ab (23% of strains), Cry1A.105 (45% of strains), and Cry2Ab (14% of strains), with maximum resistance ratios of 3.9, 5.8, and 2.0, respectively. These results provide key information for addressing O. nubilalis resistance to Bt corn in Canada. [ABSTRACT FROM AUTHOR]

Transgenic corn, Zea mays (L.), expressing insecticidal toxins such as Cry1Fa, from Bacillus thuringiensis (Bt corn) targeting Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) resulted in over 20 years of management success. The first case of practical field-evolved resistance by O. nubilalis to a Bt corn toxin, Cry1Fa, was discovered in Nova Scotia, Canada, in 2018. Laboratory-derived Cry1Fa-resistance by O. nubilalis was linked to a genome region encoding the ATP Binding Cassette subfamily C2 (ABCC2) gene; however, the involvement of ABCC2 and specific mutations in the gene leading to resistance remain unknown. Using a classical candidate gene approach, we report on O. nubilalis ABCC2 gene mutations linked to laboratory-derived and field-evolved Cry1Fa-resistance. Using these mutations, a DNA-based genotyping assay was developed to test for the presence of the Cry1Fa-resistance alleles in O. nubilalis strains collected in Canada. Screening data provide strong evidence that field-evolved Cry1Fa-resistance in O. nubilalis maps to the ABCC2 gene and demonstrates the utility of this assay for detecting the Cry1Fa resistance allele in O. nubilalis. This study is the first to describe mutations linked to Bt resistance in O. nubilalis and provides a DNA-based detection method that can be used for monitoring. [ABSTRACT FROM AUTHOR]

Pest management is one of the biggest challenges in the plant protection of sweet corn cultivation. The most destructive insect pests of sweet corn in Hungary are European corn borer (Ostrinia nubilalis Hbn.) and the corn earworm (Helicoverpa armigera Hbn.). Damage caused mainly by larvae. Chewed corn cobs are unmarketable, and a significant yield loss can also occur. Chemical insecticides control is the most widespread, but the demand for the use of the biological method is increasing. The aim of the present work is to compare the effectiveness of the conventional chemical method and the biological control by egg-parasitic wasps, Trichogramma pintoi, T. evascens (Trichoplus capsules) under operating conditions. The research was carried out in the growing season of 2019 and 2020 in the area of Csárdaszállás-Gyomaendrőd settlements (SE Hungary). We monitored the imagos of both species using pheromone and food traps. The number of damaged corn cobs was counted on the day of harvest in the sample areas. The cob damage ratio data were analyzed using the SPSS Generalized Linear Model using a One-way, Random Block Design ANOVA method. The number of H. armigera caught peaked at the end of July in both years, while O. nubialis only started to appear in the traps at that time. Chemical control was carried out twice in 2019, which was overall more effective than the Trichoplus treatment. The proportion of damaged corn cobs was 7.2% and 9.5%, which is a significant but not a large difference. Due to very rainy weather in 2020, only one insecticide treatment was performed in conventional cultivation. This did not provide adequate protection, the proportion of damaged corn cobs exceeded 20%. Biological control, which takes into account trap signalling, was more successful this year than chemical control, but even in addition, significant damage of nearly 15% occurred. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the efficiency of a new type of corn header equipped with flail knives that shreds corn stubble close to the ground. A field trial was carried out to quantify the influence of the shredding tool design (flail knives, standard knives, horizontal choppers disengaged), harvesting speed (1.5, 3.0, 4.5, 6.0 km/h) and cutting height (approx. 20 cm variation, 4 levels) on the power consumption of the corn header, engine load and fuel consumption of the combine harvester. The regression analyses revealed that modifications of the shredding tool assembly have significant effects on the parameters of the functional relationships. The power consumption of the flail knives configuration was 15 kW/row unit at 6 km/h at the lowest cutting height setting, making it compatible with most current combine harvester models. The additional power demand and fuel consumption that arise when switching to the new shredding tool design (flail knives) show a wide range, depending on the initial situation. Compared to the standard knives at 6 km/h, the additional power consumption was 3.6–5.5 kW/row unit and the additional fuel consumption was 2.6–3.9 L/ha. Compared to the configuration with disengaged horizontal choppers, it was 5.3–6.6 kW/row unit and 3.9–5.1 L/ha, respectively. At 90% engine load the additional power requirement was 1.6–3.1 kW/row unit and the additional fuel consumption was 2.9–5.6 L/ha compared to the standard knives configuration and 2.6–3.6 kW/row unit and 5.6–7.2 L/ha respectively, compared to the configuration with disengaged horizontal choppers. [ABSTRACT FROM AUTHOR]

The pink stem borer (PSB), Sesamia cretica (Lepidoptera: Noctuidae) purple-lined borer (PLB), Chilo agamemnon (Lepidoptera: Crambidae) and European corn borer Ostrinia nubilalis, (Lepidoptera: Crambidae) are considered the most devastating insect pests of maize production in the Mediterranean region. The frequent use of chemical insecticides has resulted in the evolution of resistance to various insect pests as well as the pernicious impact on natural enemies and environmental hazardousness. Therefore, developing resistant and high-yielding hybrids is the best economic and environmental approach to cope with these destructive insects. Accordingly, the objective of the study was to estimate the combining ability of maize inbred lines (ILs), identify promising hybrids, determine gene action controlling agronomic traits and resistance to PSB and PLB, and investigate inter-relationships among evaluated traits. A half-diallel mating design was employed to cross seven diverse maize inbreds to generate 21 F1 hybrids. The developed F1 hybrids, alongside high-yielding commercial check hybrid (SC-132), were assessed in field trials for two years under natural infestation. Substantial variations were obtained among the evaluated hybrids for all recorded characteristics. The non-additive gene action was major for grain yield and its contributing traits, while the additive gene action was more important in controlling the inheritance of PSB and PLB resistance. The inbred line IL1 was identified to be a good combiner for earliness and developing short-stature genotypes. Additionally, IL6 and IL7 were recognized as excellent combiners to enhance resistance to PSB, PLB and grain yield. The hybrid combinations IL1×IL6, IL3×IL6, and IL3×IL7 were determined to be excellent specific combiners for resistance to PSB, PLB and grain yield. Strong positive associations were identified among grain yield, its related traits, and resistance to PSB and PLB. This implies their importance as useful traits for indirect selection for improving grain yield. Otherwise, the resistance against PSB and PLB was negatively associated with the silking date, indicating that earliness would be favorable for escaping from the borer's attack. It could be concluded that the inheritance of PSB and PLB resistance can be governed by the additive gene effects, and the IL1×IL6, IL3×IL6, and IL3×IL7 hybrid combinations can be recommended as excellent combiners for resistance to PSB and PLB and good yield. [ABSTRACT FROM AUTHOR]

The backbone of modern technologies is the creation of tolerant genotypes at the ECB with special emphasis on the interaction between the degree of plant damage and metabolic processes as potential responses to stress. During the vegetation period of 2016 and 2018, the variability and response of four maize genotypes to the effectiveness of insecticides and bioinsecticides and the interdependence with the dynamics of the ECB population were examined. Out of a total of 11,023 attacked plants in both years of the survey, in 2016 the largest number of plants (4,841) with a broken stalk above the ear and at the height of the ear and belonged to categories C3 to C8. In 2018, there was no damage to the tassel and ear, while 3,672 plants were dominated by leaf damage and perforation in the H2 type. In addition to the fact that more infested plants were observed in the genotypes, ZP 434 and ZP 666 the categories of damage type C5, C6 and C7 were more pronounced. The foliar treatment of plants with chlorantraniliprole in two-year research proved to be the most effective with the least number of attacked plants with a high degree of damage. In contrast, bioinsecticide treatment of plants, in addition to a large number of infested plants, was dominated by high categories of damage that deviated from all other treatments as well as from control. Within the definition of the degree of tolerance of maize genotypes, the influence of treatment on changes in secondary metabolites (phytins) in seeds was observed. It was noticed that there is a trend of positive correlation between the amount of phytin in the seed (mg g-1) with the attack of moths of the first generation and the number of dissected larvae, as well as a trend of negative correlation with the percentage of attacks of the second generation. Correlation coefficients are expressed: in the genotype ZP-600, while in the genotype ZP-666 correlation is the lowest, ie. irrelevnt. The obtained results may be of great importance in future work aimed at the selection of maize genotypes tolerant and resistant to corn borer attack, connected to the role of phytin, as an antioxidant and phosphorus deposited in corn grain. [ABSTRACT FROM AUTHOR]

The infestation and damage caused by the European corn borer (ECB), as one of the most important pests of corn, are influenced by various factors. Research on the impact of different soil tillage systems and corn fertilization on attack and damage of ECB was conducted in year 2021 in Križevci (NW Croatia). The influence of conventional tillage (ST), deep loosening (CTD shallow loosening (CTS), fertilization as recommended (FR), FR with addition of biophysiological activator Geo2 (FRG) and fertilization reduced by 50% (F50%) and F50% with addition (F50%G)) of biophysiological activator were determined. The results of the research showed that the tillage system, corn fertilization and their interactions have a significant influence on most of the measured parameters of intensity of infestation from the ECB (percentage of stem, ear shank and ear infestation, number and length of holes in stalk, number of caterpillars per plant), but not for all. Variants ST, FRG and FR and their interactions resulted in the highest infestation intensity in most parameters, but the tillage system had no significant effect on the percentage of ear shank infestation, and fertilization did not affect the percentage of stalk infestation and the number of caterpillars per plant. The highest ear mass per plant was found in soil treatment CTS and ST, in fertilization FRG and FR and in the interactions of CTS and FR and ST and FRG.

There are over 2,240 butterfly species of Lepidoptera belonging to 17 families recorded in Poland. Of those, 63 phytophagous species have been noted in vegetable agrocenoses at a level of pest status. They constitute 18% of all harmful entomofauna found on vegetable crops. The species described in this paper are common on all vegetable crops growing in Poland, and all parts of plants. The most abundant pests found on aerial parts of crops include the silver Y moth (Autographa gamma), which causes damage to 20 species of vegetables, and species belonging to the genera Mamestra, Lacanobia and Anarta, which feed on more than 10 vegetable species. Of the polyphagous leaf roller moths (Tortricidae), the most numerous are the species belonging to the genus Cnephasia. Periodically, they pose a significant threat, among others for beetroot, pea, cucumber, and lettuce. The diamondback moth (Plutella xylostella) and the cabbage butterfly (Pieris rapae) are dominant butterfly pests on brassica vegetables. A component of harmful entomofauna on onion crops is leek moth (Acrolepiopsis assectella), a species permanently dominant on onion vegetables in Poland since 1930s. The species of the family Depressariidae cause the greatest damage on the generative organs of seed crops, mainly of dill, carrot and parsley. Underground parts of vegetable crops are damaged by cut-worms (Noctuidae), which belong to the group of soil-borne pests. Among more than 60 species belonging to this family, nine cause the greatest damage to vegetable crops. The turnip moth (Agrotis segetum), as a dominant species in recent years, accounted for about 80% of cutworms damaging vegetable crops, and prefers onion, leek, carrot, parsley, celery and corn. Although the European corn borer (Ostrinia nubilalis) is considered a polyphagous species, it forms the most abundant populations on maize out of all other crops. [ABSTRACT FROM AUTHOR]

Host plant-derived semiochemicals are becoming the most promising attractants to lure corn borers to traps in the field. Following success with the European corn borer (Ostrinia nubilalis), a two-component blend bisexual lure (phenylacetaldehyde and 2-(4-methoxyphenyl)ethanol) of the host plant odor was tested in wind tunnel and field trapping experiments on the Asian corn borer (Ostrinia furnacalis) (ACB). To be able to compare the lure's performance with synthetic pheromone, a new route for the sex pheromone components (Z)-12-tetradecenyl acetate and (E)-12-tetradecenyl acetate was also developed, and the biological activity of the products was confirmed. The bisexual lure attracted both males and females of ACB in laboratory wind tunnel, and also in the field. Field trapping results indicated that traps with the bisexual lure attracted somewhat more ACB (both sexes) than pheromone baited traps, but this indication needs further confirmation. Traps baited with the bisexual lure may offer a new tool for monitoring ACB for practical purposes. [ABSTRACT FROM AUTHOR]

We aimed to monitor the species diversity and the dynamics of the number of soybean pests using light traps with an original design to develop protection systems against the main phytophages. Traps lured 44 species of insects from eight orders and 27 families. The capture of 15 species of economically important phytophages was recorded—representatives of various orders and families: order Lepidoptera—Noctuidae, Crambidae, Erebidae, and Geometridae; order Hemiptera—Flatidae; order Coleoptera—Elateridae, etc. Insect identification was carried out via morphological methods. Over the study period (93 days), 4955.41 insect specimens were caught on average per one trap. Most of the attracted insects belong to harmful entomofauna: namely the cotton bollworm (Helicoverpa armigera, Hübner)—58.9%, the beet webworm (Loxostege sticticalis, L.)—12.74%, the nutmeg moth (Anarta trifolii, Hufnagel)—6.5%, the European corn borer (Ostrinia nubilalis, Hübner)—2.68%, and some other species—19.2%. In addition to economically significant phytophages, we registered some indifferent and beneficial species. The summer dynamics of the cotton bollworm and the nutmeg moth were obtained for the entire research period. Then, we calculated the values of the indices of biodiversity and the dominance of insect species. An analysis of the index values allows us to conclude a balanced entomocomplex at the research site. [ABSTRACT FROM AUTHOR]

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‘Sinhwangok2’ is a single cross maize F1 hybrid (Zea mays L.) that was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA, in 2018. This yellow high-yielding intermediate maize hybrid was obtained by crossing between two inbred lines― KS214 and KS215. After advanced yield trials over two years in Suwon, a regional yield trial for ‘Sinhwangok2’ was conducted to evaluate its growth and yield at three different locations, from 2016 to 2018. ‘Sinhwangok2’ requires 72 days for silking and its plant height is 243 cm, similar to that of ‘Jangdaok’; its ear height ratio is 49%, like that of ‘Jangdaok’, and the hybrid shows resistance to lodging. The number of ears per 100 plants was found to be 100 and the ear length of ‘Sinhwangok2’ is 19.5 cm, which is shorter than that of ‘Jangdaok’. The weight of 100 seeds of ‘Sinhwangok2’ is 30.8 g, similar to that of ‘Jangdaok’. This hybrid shows moderate resistance to southern leaf blight (Bipolaris maydis). It has moderate resistance to European Corn Borer (Ostrinia nubilalis). The grain yield (i.e., 9.41 ton/ha) of ‘Sinhwangok2’ was found to be 13%, which is higher than that of ‘Jangdaok’. Seed production of ‘Sinhwangok2’ was 2.36 ton/ha and was considered acceptable due to a good synchronization of flowering period during crossing between the seed parent, KS214, and the pollen parent, i.e., KS215, in Yeongwol and F1 seed yield. ‘Sinhwangok2’ can thus be a suitable cultivar for all plain areas in Korea and can possibly be cultivated via double cropping with winter forage crop because of their early maturity. [ABSTRACT FROM AUTHOR]

SUMMARY: In maize (Zea mays ssp. mays), agriculturally damaging herbivores include lepidopteran insects, such as the European corn borer (Ostrinia nubilalis), and distantly related arthropods, like the two‐spotted spider mite (Tetranychus urticae). A small number of maize lines, including B96 and B75, are highly resistant to both herbivores, and B96 is also resistant to thrips. Using T. urticae as a representative pest that causes significant leaf tissue damage, we examined the gene expression responses of these lines to herbivory in comparison with each other and with the susceptible line B73. Upon herbivory, the most resistant line, B96, showed the strongest gene expression response, with a dramatic upregulation of genes associated with jasmonic acid biosynthesis and signaling, as well as the biosynthesis of specialized herbivore deterrent compounds, such as death acids and benzoxazinoids. Extending this work with allele‐specific expression analyses in F1 hybrids, we inferred that the concerted upregulation of many defense genes, including the majority of benzoxazinoid biosynthetic genes in B96, as compared with B73, for the herbivore treatment, resulted from an assemblage of trans control and multiple cis effects acting with similar directionality on gene expression. Further, at the level of individual and potentially rate limiting genes in several major defense pathways, cis and trans effects acted in a reinforcing manner to result in exceptionally high expression in B96. Our study provides a comprehensive resource of cis elements for maize lines important in breeding efforts for herbivore resistance, and reveals potential genetic underpinnings of the origins of multi‐herbivore resistance in plant populations. Significance Statement: Upon herbivory by a generalist spider mite, transcriptome reprogramming varied among maize lines, with differences in the expression of genes involved in jasmonic acid synthesis and signaling and specialized compound production. As assessed using allelic expression, cis + trans reinforcing regulation led to the very high expression of key defense genes in the most herbivore‐resistant line. [ABSTRACT FROM AUTHOR]

Following a request from the European Commission; the European Food Safety Authority (EFSA) assessed the 2020 post-market environmental monitoring (PMEM) report on the cultivation of Cry1Ab-expressing maize event MON 810. Like previous years, there was full compliance with refuge requirement in Portugal and partial compliance with refuge requirements by Spanish farmers growing MON 810 varieties. European and Mediterranean corn borer populations collected from north-eastern Spain during the 2020 maize growing season and tested for Cry1Ab susceptibility show no symptoms of resistance to maize MON 810. The assessment of farmer questionnaires and relevant scientific publications does not indicate any unanticipated adverse effects on human and animal health or the environment arising from the cultivation of maize MON 810. Overall, EFSA concludes that the evidence reported in the 2020 PMEM report does not invalidate previous EFSA evaluations on the safety of maize MON 810. However, as in previous years, EFSA identifies shortcomings on resistance monitoring that need revision in future reports. In particular, the monitoring plan, as implemented in 2020, is not sufficiently sensitive to detect the recommended 3% resistance allele frequency. Consequently, EFSA strongly recommends the consent holder to achieve full compliance with refuge obligations in areas where adoption of maize MON 810 is high and increase the sensitivity of the monitoring plan by performing periodic F2-screens on corn borer populations from north-eastern Spain. EFSA recommends revising the farmer questionnaires when new characteristics of the receiving environment emerge which are relevant for the environmental risk assessment of MON 810 such as the emergence of teosinte. EFSA encourages the Competent authorities of concerned EU Member States, the consent holder and environmental networks to engage in a dialogue to develop a framework on how to best identify and report unexpected adverse effects from the cultivation of Bt maize varieties. [ABSTRACT FROM AUTHOR]

The fungal ear rot of maize cultivated in temperate areas is mainly due to the Fusarium species. The use of insecticides against European Corn Borer (ECB) reduces the severity of fungal ear rot as well as the fumonisin (FB) and moniliformin (MON) levels in maize kernels at harvest, which in turn results in a lowering of their effect on deoxynivalenol (DON) control. However, the direct fungicidal control of ear rot has rarely been implemented for maize, and the first studies reported conflicting results on the reduction of mycotoxins. In the present experiment, field trials were carried out in North Italy over three growing seasons to study the effect of fungicide application timings on maize to control mycotoxins, considering the interaction of the application with the insecticide treatment, according to a full factorial split plot design. The mycotoxin content was determined through LC−MS/MS analysis. The field trials showed a significant reduction in ECB severity (75%), fungal ear rot severity (68%), Fusarium Liseola section infection (46%), FBs (75%) and MON (79%) as a result of the insecticide application for all the years, while the DON content increased by 60%. On the other hand, a fungicide application alone or applied in plots protected by an insecticide was never effective for the fungal symptoms, infection or mycotoxin content. The results confirm that a correct insecticide application to control ECB damage is the most effective agrochemical solution for the control of fungal ear rot, FBs and MON. [ABSTRACT FROM AUTHOR]

Background: Genome-Wide Association Studies (GWAS) are used to identify genes and alleles that contribute to quantitative traits in large and genetically diverse populations. However, traits with complex genetic architectures create an enormous computational load for discovery of candidate genes with acceptable statistical certainty. We developed a streamlined computational pipeline for GWAS (COMPILE) to accelerate identification and annotation of candidate maize genes associated with a quantitative trait, and then matches maize genes to their closest rice and Arabidopsis homologs by sequence similarity. Results: COMPILE executed GWAS using a Mixed Linear Model that incorporated, without compression, recent advancements in population structure control, then linked significant Quantitative Trait Loci (QTL) to candidate genes and RNA regulatory elements contained in any genome. COMPILE was validated using published data to identify QTL associated with the traits of α-tocopherol biosynthesis and flowering time, and identified published candidate genes as well as additional genes and non-coding RNAs. We then applied COMPILE to 274 genotypes of the maize Goodman Association Panel to identify candidate loci contributing to resistance of maize stems to penetration by larvae of the European Corn Borer (Ostrinia nubilalis). Candidate genes included those that encode a gene of unknown function, WRKY and MYB-like transcriptional factors, receptor-kinase signaling, riboflavin synthesis, nucleotide-sugar interconversion, and prolyl hydroxylation. Expression of the gene of unknown function has been associated with pathogen stress in maize and in rice homologs closest in sequence identity. Conclusions: The relative speed of data analysis using COMPILE allowed comparison of population size and compression. Limitations in population size and diversity are major constraints for a trait and are not overcome by increasing marker density. COMPILE is customizable and is readily adaptable for application to species with robust genomic and proteome databases. [ABSTRACT FROM AUTHOR]

The peculiarities of the development and dynamics of the population density of European corn borer (ECB) on corn crops under irrigation were studied in 2019-2021 in conditions of Steppe of Ukraine. Field investigations were conducted according to generally accepted methods. The size of the experimental plots in the field experiments was 50 m2 (10.4 x 4.8 m), the replication was 4 times. Allocation of plots was randomized. The beginning of the first adults flight was observed in the 1st decade - in the middle of June at average. Mass laying of eggs and the flight of more than 50% of the butterfly population occurred in the 3rd decade of June, which coincided with the phase of pollen shedding of corn plants. Mass flight of the butterfly (flight of more than 75% of the population) was observed at the end of the 3rd decade of June - the beginning of the 1st decade of July. The revival of caterpillars began in the third decade of June and continued until the end of July. The average population density of European corn borer caterpillars in 2019-2021 were 1.6 and 1.8 specimens per stem on corn crops. The European corn borer is a dangerous pest of corn in the Steppe zone of Ukraine, where it's caterpillars damage 34.5-37.8% stems and ears of this crop. Application of Coragen 20 KS, Calypso 480 SC and Actara 25 WG at higher from recommended rates against the ECB contributed to the reduction of plants damage in 8-15 times, compared to untreated crops. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the efficiency of a new type of corn header equipped with flail knives that shreds corn stubble close to the ground. A field trial was carried out to quantify the influence of the shredding tool design (flail knives, standard knives, horizontal choppers disengaged), harvesting speed (1.5, 3.0, 4.5, 6.0 km/h) and cutting height (approx. 20 cm variation, 4 levels) on the power consumption of the corn header, engine load and fuel consumption of the combine harvester. The regression analyses revealed that modifications of the shredding tool assembly have significant effects on the parameters of the functional relationships. The power consumption of the flail knives configuration was 15 kW/row unit at 6 km/h at the lowest cutting height setting, making it compatible with most current combine harvester models. The additional power demand and fuel consumption that arise when switching to the new shredding tool design (flail knives) show a wide range, depending on the initial situation. Compared to the standard knives at 6 km/h, the additional power consumption was 3.6–5.5 kW/row unit and the additional fuel consumption was 2.6–3.9 L/ha. Compared to the configuration with disengaged horizontal choppers, it was 5.3–6.6 kW/row unit and 3.9–5.1 L/ha, respectively. At 90% engine load the additional power requirement was 1.6–3.1 kW/row unit and the additional fuel consumption was 2.9–5.6 L/ha compared to the standard knives configuration and 2.6–3.6 kW/row unit and 5.6–7.2 L/ha respectively, compared to the configuration with disengaged horizontal choppers.

Background: Hundreds of studies on environmental effects of genetically modified (GM) crops became available over the past 25 years. For maize producing insecticidal proteins from Bacillus thuringiensis (Bt), potential adverse effects on non-target organisms are a major area of concern and addressed in risk assessments. Reviews and meta-analyses have helped various stakeholders to address uncertainties regarding environmental impacts of the technology. Many field studies from Europe and other parts of the world have been published in the last decade, and those data are often not covered by previous meta-analyses. Therefore, we conducted a systematic review to answer the question: "Does the growing of Bt maize change abundance or ecological function of non-target animals compared to the growing of non-GM maize?" Methods: Literature published until August 2019 was searched systematically in 12 bibliographic databases, 17 specialized webpages, and reference sections of 78 review articles. Defined eligibility criteria were applied to screen titles, abstracts, and full texts of the retrieved references. A custom-made database was developed with quantitative data on invertebrate abundance, activity density, or predation/parasitism rates. Eligible data that did not fit the quantitative database were captured in detailed tables and summarized narratively. For the first time, a critical appraisal scheme for field studies on non-targets in GM crops was developed to estimate the risk of bias (internal validity) and the suitability to answer the review question (external validity) of all primary data. Meta-analyses on different taxonomic levels, functional groups, and types of Bt maize were conducted. Untreated Bt maize was either compared with untreated non-Bt maize, or with insecticide-treated non-Bt maize. The influence of contributions by private sector product developers on reported effects was investigated. Review findings: The database on non-target effects of Bt maize field trials contains more than 7200 records from 233 experiments and 120 articles. Meta-analyses on different taxonomic levels revealed only few and often non-robust significant effect sizes when both Bt maize and non-Bt maize were untreated. Bt maize harboured fewer parasitoids (Braconidae, Tachinidae) of the European corn borer, the main target pest of Lepidoptera-active Bt maize, compared with non-Bt maize. Similarly, sap beetles (Nitidulidae), that are associated with Lepidoptera damage, were recorded less in Bt maize. In some analyses, a negative effect of Bt maize was observed for rove beetles (Staphylinidae) and hoverflies (Syrphidae) and a positive effect for ladybeetles (Coccinellidae), flower bugs (Anthocoridae), and lacewings (Neuroptera). However, those effects were not consistent for different analyses and often related to individual articles. When untreated Bt maize was compared with pyrethroid-treated non-Bt maize, more effect sizes were significant. In particular, populations of predators were reduced after pyrethroid treatment, while few data were available for other insecticides. Funnel plots showed no evidence for publication bias and the analyses of private sector contribution revealed no evidence for influence of vested interests. Conclusions about potential effects of Bt maize on vertebrates or on animals inhabiting off-crop habitats were not possible, because only few such studies fitting the format of direct Bt/non-Bt comparisons on plot or field level were identified. Conclusions: The current work largely confirmed previously published results. The effects of Bt maize on the community of non-target invertebrates inhabiting maize fields were small and mostly neutral, especially when compared with the effects of broad-spectrum pyrethroid insecticide treatments. [ABSTRACT FROM AUTHOR]

He entertained his colleagues with a new joke every day, and eventually compiled them into "The Entomologist [sic] Joke Book" published in 1937 by the Exterminator's Log, predecessor to Pest Control. It is a I terrible i joke book - the jokes are awful ... But the book has an interesting history. In my classification system, I'd put the many jokes in the I Entomologists' Jokebook i based on ethnic or regional dialects in the category of "jokes that are no longer funny, if they ever were.". [Extracted from the article]

Within the broad topic of plant-insect interactions, insect pest management and insect plant pollination are among the most relevant research areas because of the economic impact that they can have on crop yield [[1], [3], [5]]. This Special Issue presents a collection of papers dealing with basic and applied topics in plant-insect interactions, but showing the relative importance that pest management and pollination have in this field. The central part of the study of plant-insect interactions comes from our quest for knowledge on why and how these interactions occur. Moreover, the effect of bacteria on plant repair mechanisms after insect herbivory and plant-insect interactions in general also deserves being subject to further research. [Extracted from the article]

Theory predicts that when different barriers to gene flow become coincident, their joint effects enhance reproductive isolation and genomic divergence beyond their individual effects, but empirical tests of this "coupling" hypothesis are rare. Here, we analyze patterns of gene exchange among populations of European corn borer moths that vary in the number of acting barriers, allowing for comparisons of genomic variation when barrier traits or loci are in coincident or independent states. We find that divergence is mainly restricted to barrier loci when populations differ by a single barrier, whereas the coincidence of temporal and behavioral barriers is associated with divergence of two chromosomes harboring barrier loci. Furthermore, differentiation at temporal barrier loci increases in the presence of behavioral divergence and differentiation at behavioral barrier loci increases in the presence of temporal divergence. Our results demonstrate how the joint action of coincident barrier effects leads to levels of genomic differentiation that far exceed those of single barriers acting alone, consistent with theory arguing that coupling allows indirect selection to combine with direct selection and thereby lead to a stronger overall barrier to gene flow. Thus, the state of barriers—independent or coupled—strongly influences the accumulation of genomic differentiation. [ABSTRACT FROM AUTHOR]

Most arthropod guts harbor diverse microbiota for symbiotic digestion. The European corn borer (ECB), Ostrinia nubilalis (Hübner), is a devastating pest that feeds the lignocellulose-rich tissues of maize plants. However, the potential role of ECB gut microbes in degrading maize cellulose remains largely unexplored. Here, we investigated the gut microbiota of ECB fed with different diets and their potential function in maize lignocellulose degradation. The diversity and composition of gut bacterial communities varied dramatically between the ECB larva fed with artificial diets (ECB-D) and maize plants (ECB-M). Draft genomes of the microbial consortia from ECB-D and ECB-M showed that the principal degraders of cellulose mainly belonged to Firmicutes or Proteobacteria and they were primarily found in the midgut. The cellulolytic microbial consortia contained genes encoding various carbohydrate-active enzymes (CAZyme). Furthermore, scanning electron microscopy revealed significant breakdown of lignocellulose in maize treated by the two microbial consortia for 9 days in vitro. Metabolomic analyses show that maize particles treated by two microbial consortia generate distinctive metabolomic profiles, with enrichment for different monosaccharides (i.e., Glucose, Rhamnofuranose, Isomaltose, and Cellobiose) and amino acids (i.e., Threonine, Histidine, and Lysine). The results indicated that the diet of the host impacted the composition and function of its gut microbiota and ECB exploited specific gut microbes to digest maize lignocellulose with distinctive products. Our study provides valuable microbiota resources for lignocellulose bioconversion. [ABSTRACT FROM AUTHOR]