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Abstract Background As different biogeographic strains and isolates of entomopathogenic fungi vary in their genetic, enzymatic and pathogenic characteristics, this study assessed the virulence of 2 indigenous strains of Beauveria bassiana (Balsam) Vuillemin and Metarhizium anisopliae (Metschn.) Sorokin (Ascomycota, Hypocreales: Clavicipitaceae), isolated from naturally infected insect cadavers, against the 3rd instar nymphs of Myzus persicae (Sulzer) (Hemiptera: Aphididae) and 3rd instar larvae of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) using leaf-dip and larval-dip methods, respectively. Results Both fungal isolates exhibited considerable pathogenicity against M. persicae and S. frugiperda. Mortality in all bioassays was conidial concentration and exposure time dependent and increased significantly along with both factors (R 2 = 0.86–0.99 for B. bassiana and 0.82–0.94 for M. anisopliae). Moreover, M. anisopliae isolate appeared more virulent to S. frugiperda larvae than B. bassiana isolate, while the later fungal isolate was more lethal to M. persicae nymphs than the former one. At the highest conidial concentration (1.0 × 109 conidia/ml), M. anisopliae caused maximum mean mortality of S. frugiperda (88%) and M. persicae (65%) and B. bassiana exhibited maximum mean mortality of S. frugiperda (76%) and M. persicae (94%). Moreover, probit regression analyses showed LT50 values for M. persicae of 4.57 and 6.86 days at 1.0 × 109 conidia/ml for the isolates of B. bassiana and M. anisopliae, respectively, while LC50 values were 7.75 × 106 and 8.70 × 107 conidia/ml after 10th day of application, for the isolates of B. bassiana and M. anisopliae, respectively, against M. persicae. Similarly, LT50 values for S. frugiperda were 7.75 and 7.03 days for 1.0 × 109 conidia/ml concentration and LC50 values were 2.84 × 107 and 8.84 × 105 conidia/ml at 10th day data for the isolates of B. bassiana and M. anisopliae, respectively. Conclusion Overall study results demonstrated the effectiveness of B. bassiana and M. anisopliae against M. persicae and S. frugiperda, respectively. However, field evaluations of these indigenously isolated promising fungal strains against these insect pests.

Synthetic insecticides have been an inevitable part of plant protection throughout the world. Sublethal effects of these chemicals on beneficial insect species are one of the contemporary issues these days. Using the age-stage, two-sex life table model, this study evaluated the sublethal and transgenerational effects of six synthetic insecticides (imidacloprid, thiamethoxam, lambda-cyhalothrin, cypermethrin, chlorpyrifos and profenofos) commonly applied to winter vegetables, on the fitness and predation of the seven-spotted ladybeetle, Coccinella septempunctata, which is an efficient predator of aphids worldwide. According to results, all insecticides at their sublethal doses (LC30) significantly suppressed the emergence of adults, adult weight, fertility and fecundity of the parental generation compared to control treatment. The larval stage was prolonged and oviposition, fecundity and total longevity of the adult beetles were decreased in unexposed progeny whose parents were exposed to sublethal doses of all insecticides. Moreover, the biological parameters of adults, including the intrinsic rate of increase (r), finite rate of increase (λ) and net reproductive rate (R0) were significantly reduced when exposed to sublethal doses of insecticides. The predation rate of the F1 generation adults was also decreased after exposure to the sublethal doses of insecticides. However, chlorpyrifos, profenofos, lambda-cyhalothrin and cypermethrin exhibited more deleterious effects on the fitness and population parameters of beetles than imidacloprid and thiamethoxam.

Installation of traps in the agricultural field is an economically important and cheaper technique to observe arthropods diversity. Cost-effective ecological monitoring of arthropods by traps has been gaining interest in the field of environmental entomology since last few decades. This study explains the effectiveness of four different types of traps (pitfall, yellow-sticky, pan and barrier traps) to monitor the arthropod diversity in summer and winter seasons. These traps were installed in different mango orchards located in Punjab, Pakistan. diversity of captured arthropods was 1.5 times higher in summer than in winter season. However, among the traps, pitfall traps were most effective than others for trapping edaphic arthropods in both seasons. The pan traps were found most effective in the summer season, while sticky traps in the winter season. The pitfall traps exhibited highest taxa richness index values (8.00 for summer and 5.00 for winter season), while the lowest values were recorded for barrier traps (5.00 for summer and 3.00 for winter season). Moreover, the pitfall were the most effective traps for the capture or collection of Arachnida, Coleoptera, Hymenoptera, Lepidoptera, Orthoptera and other arthropods. The PVC barrier and sticky traps were found most effective for Dipteran and Hemipteran's insects, respectively, and hence, are recommended for the ecological monitoring of these arthropod groups in future studies.

Global climate warming has been exerting impacts on agricultural pests. Pests also take some strategies to adapt to climate change. Understanding such adaptation could benefit more accurate predictions and integrated management of pest. However, adaptation to climate change has not been widely investigated in agricultural pests but has been well documented in model species, Drosophila, and reviewed by Hoffmann before 2003. To provide recent progress and references for agricultural entomologists who interested in thermal biology, here we have reviewed literatures since 2003 about adaptation to temperature changes under climate change. We mainly summarized thermal adaptation of Drosophila (especially to high temperatures) from three aspects, behaviors, plastic responses and micro-evolution and discussed how Drosophila increases their heat tolerance through these three mechanisms. Finally, we summarized the measures of thermotolerance and concluded the main progress in recent decade about the behavioral thermoregulation, mortality risks driven by limited evolutionary and plastic response under climate change, geographic distribution based on basal rather than plastic thermotolerance. We propose future work focus on better understanding adaptation of organisms including agricultural pests to climate change.

Fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae), is a destructive pest of a wide array of agricultural and horticultural crops worldwide. This in vitro research assessed the combined effect of methanolic extracts of indigenous flora of Soone Valley (Khushab, Pakistan) and nine commonly used synthetic insecticides against 3rd instar larvae of S. frugiperda using the leaf-dip bioassay method. Toxicity bioassays with twelve plant extracts revealed that the extracts of Withania somnifera (L.) Dunal, Sophora mollis (Royle) Baker and Rhazya stricta Decne. were the most effective, exhibiting minimum LC50 and LT50 values. Bioassays with synthetic insecticides revealed a significantly higher mortality of S. frugiperda larvae by emamectin benzoate (45%), chlorpyrifos (40%) and chlorantraniliprole (38%). Further bioassays with 10 binary combinations of these most effective botanical and synthetic insecticides showed that seven pesticidal combinations exhibited synergistic toxicity, and three combinations comprising emamectin benzoate exhibited an additive effect on the mortality of S. frugiperda larvae. GC–MS analyses of methanolic extracts of W. somnifera, S. mollis and R. stricta revealed 1,2,4-trimethyl-benzene and 3,5-dimethyl-octane, 1-ethyl-2-methyl-benzene, and 1-monolinoleoylglycerol trimethylsilyl ether, decane, and lupeol as major bioconstituents, respectively. Our results demonstrated that combining botanicals with synthetic insecticides can synergize their toxicity against S. frugiperda larvae, suggesting their potential incorporation into future IPM programs against S. frugiperda and other lepidopterous pests.

High-temperature events are evidenced to exert significant influence on the population performance and thermal biology of insects, such as aphids. However, it is not yet clear whether the bacterial symbionts of insects mediate the thermal tolerance traits of their hosts. This study is intended to assess the putative association among the chronic and acute thermal tolerance of two cereal aphid species, Rhopalosiphum padi (L.) and Sitobion avenae (F.), and the abundance of their bacterial symbionts. The clones of aphids were collected randomly from different fields of wheat crops and were maintained under laboratory conditions. Basal and acclimated CTmax and chronic thermal tolerance indices were measured for 5-day-old apterous aphid individuals and the abundance (gene copy numbers) of aphid-specific and total (16S rRNA) bacterial symbionts were determined using real-time RT-qPCR. The results reveal that R. padi individuals were more temperature tolerant under chronic exposure to 31 °C and also exhibited about 1.0 °C higher acclimated and basal CTmax values than those of S. avenae. Moreover, a significantly higher bacterial symbionts’ gene abundance was recorded in temperature-tolerant aphid individuals than the susceptible ones for both aphid species. Although total bacterial (16S rRNA) abundance per aphid was higher in S. avenae than R. padi, the gene abundance of aphid-specific bacterial symbionts was nearly alike for both of the aphid species. Nevertheless, basal and acclimated CTmax values were positively and significantly associated with the gene abundance of total symbiont density, Buchnera aphidicola, Serratia symbiotica, Hamilton defensa, Regiella insecticola and Spiroplasma spp. for R. padi, and with the total symbiont density, total bacteria (16S rRNA) and with all aphid-specific bacterial symbionts (except Spiroplasma spp.) for S. avenae. The overall study results corroborate the potential role of the bacterial symbionts of aphids in conferring thermal tolerance to their hosts.

Abstract This study evaluated the pathogenicity of indigenous soil isolate of Bacillus thuringiensis (Bt) strains, applied without and along with 1.0% MgCl2 salt, to Helicoverpa armigera Hübner (Lepidoptera: Noctuidae). Toxicity and effect of Bt isolate on larval development (weight) were assessed using in vitro bioassays. Six concentrations of the tested Bt with salt (i.e., 1.0 × 107, 0.5 × 105, 1.0 × 105, 1.5 × 105, and 2.0 × 105 cfu/ml), five without salt (i.e., 0.5 × 105, 1.0 × 105, 1.5 × 105, and 2.0 × 105 cfu/ml), and control were bioassayed against third-instar larvae of H. armigera under a complete randomized design (CRD), with four replications. Results revealed that both larval mortality and weight changes were significantly affected by time (F 5, 19 = 35.98; P

Whiteflies, Bemisia tabaci Gennadius (Aleyrodidae: Hemiptera), are a polyphagous economically destructive pest of several solanaceous crops around the world. Many secondary metabolites are synthesized by different biotrophic and necrotrophic fungi which are capable of inducing systemic resistance in plants against various phytophagous pests. The present laboratory work demonstrated the anti-insect impact of a protein extracted and purified partially from an entomopathogenic fungus (EPF) Lecanicillium lecanii (Zimmermann) against B. tabaci. Three different concentrations (i.e., 7.43, 11.15, and 22.31 μg mL−1) of this protein were bioassayed to assess its effect on the fecundity rate of B. tabaci on cotton (Gossypium hirsutum L.) plants. Furthermore, the possible implication of this fungal protein in defense pathways of cotton plants was evaluated by determining the expression profiles of salicylic acid (SA) and jasmonic acid (JA) pathways related to major genes through reverse transcription qPCR (RT-qPCR). According to the results, all protein concentrations exerted a significant (F3, 252 = 62.51; p ≤ 0.001) and negative impact on the fecundity rate of B. tabaci females. At the highest protein concentration (22.31 μg mL−1), the minimum rate of fecundity (i.e., 2.46 eggs female−1day−1) of B. tabaci was noted on the seventh day, whereas fecundity rates for the other two protein concentrations (i.e., 11.15 and 7.43 μg mL−1) were, respectively, 3.06 and 3.90 eggs day−1 female−1. The maximum rate of fecundity (6.01 eggs female−1day−1) was recorded in untreated (control) treatments. In addition, the foliar application of L. lecanii derived protein significantly upregulated all SA linked genes (OPR3, PPO1 and COI1) and slightly triggered up the JA linked genes (LOX1, UBQ7 and AOS) in the cotton plants. These findings revealed that this L. lecanii extracted partially purified protein triggered systemic resistance against B. tabaci in the cotton plants, proposing its putative effectiveness as an innovative biological control technique against B. tabaci and other phloem-feeding hemipteran pests. Nevertheless, further investigations such as purification and molecular and functional characterization of this L. lecanii-derived partially purified protein are required.

Mealybugs (Hemiptera; Pseudococcidae) are one of the noxious sucking pests infesting ornamental and horticulture crops including citrus. It is emerging as a severe threat to citrus industry in Indo-Pak region. This study determined in-vitro toxicity of different botanical extracts viz; neem (Azadirachta indica), sour orange (Citrus aurantium), sweet orange (Citrus sinensis) and eucalyptus (Eucalyptus camaldulensis) against adult females and 2nd instar nymphs of Drosicha mangiferae, a mealybug species regularly infesting citrus crop since last decade. Water, ethanol and acetone were used as extraction solvents. Leaf-dip and twig-dip methods were used for 2nd instar mealybug nymphs and adult female individuals, respectively. Five concentrations (0, 8, 16, 32 and 64%) of botanical extracts were bioassayed with four replications for each. Mortality of insects was observed at 24, 48 and 72 h post-treatment for nymphs and at 24 and 48 h post-treatment for adults. Data was subjected to probit analysis and two-way factorial ANOVA taking time and concentration as factors. Results revealed that the most toxic botanicals with minimum LC50 values against citrus mealybug adults were acetone extracts of A. indica and E. camaldulensis followed by ethanol extracts of C. sinensis seeds and C. aurantium leaves, while the most effective botanicals against 2nd instar mealybug nymphs were aqueous, ethanol and acetone extracts of A. indica and E. camaldulensis followed by ethanol extracts of C. sinensis peels and C. aurantium seeds. As expected, 2nd instar nymphs were found more susceptible to all extracts as compared to adult female individuals, most probably due to reduced penetration of botanical extract in adult insects due to powdery cushion on body. It is concluded that botanical insecticides can play a significant role in the management of insect/mite pests as being substitutes of toxic and hazardous synthetic chemicals. Particularly, neem (A. indica) and eucalyptus (E. camaldulensis) could be effective options against mealybugs and other hemipterous pests, and should be incorporated in the future pest management programs.

Plants rely on various physiological and molecular defense mechanisms against biotic stresses such as herbivore insects. Many entomopathogenic fungi synthesize protein molecules that can trigger these plant defenses. This laboratory study characterized the bioactivity of a partially purified protein derived from Beauveria bassiana (ARSEF 2860) against whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), which is an economically important pest of agricultural and horticultural crops worldwide. Different concentrations (i.e., 0.021, 0.042 and 0.063 μM) of fungal protein were bioassayed to determine their sub-lethal effect on the survival percentage and fecundity rate of B. tabaci on tomato (Lycopersicon esculentum) plants. In addition, the putative role of this partially purified B. bassiana protein in the defense mechanisms of plant was assessed through the expression analyses of important genes related to salicylic acid (SA)—and jasmonic acid (JA)—associated pathways using RT-qPCR. Results revealed a significant suppression of the survival percentage and fecundity rate of B. tabaci by the fungal protein. Lowest survival (41%) was recorded for the highest concentration of protein (0.063 μM), whereas mean survival for the other two protein concentrations (0.042 and 0.021 μM) were 62 and 71%, respectively. Likewise, the highest and lowest mean fecundity rates were observed for the control and the highest protein concentration (i.e., 3.3 and 1.8 eggs day−1 female−1, respectively). Furthermore, the exogenous application of B. bassiana-derived protein on tomato plants strongly up-regulated the SA-related genes (PAL, PR1, BGL2 and EDS1) and slightly up-regulated the JA-related genes (AOC, AOS, OPR3 and LOX) as compared to the control plants. These findings demonstrate the putative role of this partially purified B. bassiana protein fraction in inducing systemic resistance in the tomato plants against B. tabaci, suggesting its further purification and characterization to be used as novel biological pest control tool against B. tabaci and other sap-sucking insect pests.

This study reports the characterization of protein elicitor PeBb1 derived from entomopathogenic fungus Beauveria bassiana ARSEF-2860 strain and its putative role in induced systemic resistance in Brassica rapa ssp. pekinensis against green peach aphid Myzus persicae. The sequence of purified elicitor protein was matched with the genomic sequence of a hypothetical protein BBA_10269 from B. bassiana ARSEF-2860 (GenBank Accession No. XP_008603588.1). The protein-encoding gene PeBb1 contained 534 bp cDNA encoding a polypeptide of 177 amino acids with a molecular mass of 19 kDa. The recombinant elicitor protein was expressed in Escherichia coli using pET-28a (+) expression vector and induced necrosis in the leaves of tobacco. The effects of elicitor protein on aphid M. persicae was determined by applying three different concentrations of PeBb1 (i.e., 26, 35, 53 μM) on B. rapa plants at 4-leaf stage and the treated plants were exposed to newly emerged (0−6 h old) apterous adult aphids. Bioassay results showed significant (p < 0.05) sub-lethal effects of the exogenous application of PeBb1 elicitor on M. persicae. Moreover, the RT-qPCR gene expression analyses showed a significant up-regulation of most of the key genes linked to ethylene (ET)- and jasmonic acid (JA)-associated plant defense pathways in elicitor-treated plants. These results not only recommend the putative utilization of PeBb1 elicitor protein in future biological pest control strategies against phloem-feeding insect pests such as M. persicae, but also help in better comprehension of the mechanisms through which beneficial fungi trigger the induced plant resistance.

Honeybee populations in Côte d’Ivoire have been previously identified as belonging to one subspecies, Apis mellifera scutellata, but other studies have since reported a mixed population consisting of A. m. adansonii and A. m. jemenitica. The population structure and the geographic distribution of honeybees in Côte d’Ivoire remain unclear. This study aimed to profile the population structure of honeybees and their biogeography in Côte d’Ivoire. A total of 33 honeybee colonies were sampled from 15 localities to investigate the maternal ancestry of indigenous honeybee populations using the DraI COI-COII mtDNA test. The results revealed that the honeybee population in Côte d’Ivoire is composed of African haplotypes, all belonging to the AI sublineage. Haplotypes A1 and A4 were recorded with five new sequence variants, including three types of haplotype A1 and two types of haplotype A4. The A1e variant was the most frequent in the A. m. adansonii distributional area. The distribution of the haplotype variants was correlated with the climate pattern in Côte d’Ivoire. This is the first study in Côte d’Ivoire that gives insights into the biogeography and mitotype structure of the local honeybee populations.

Elicitors are biofactors that induce resistance in plants against different insect pests. This in vitro study evaluated the impact of a novel elicitor protein PeBC1, extracted from a necrotrophic fungus Botrytis cinerea, on the development and fecundity parameters of green peach aphid (Myzus persicae) on common beans (Phaseolus vulgaris L.). Three different concentrations of PeBC1 elicitor (i.e., 33.56, 25.43, 19.33 µg mL−1) were applied at three different temperature regimes (i.e., 18, 21, and 25 °C). Elicitor treatments were applied topically on the bean plants at 3-leaf stage and newly emerged (0⁻6 h old) apterous adult aphids were exposed to these treated leaves. In addition to the biological parameters of aphids, the relative expression levels of key genes associated with jasmonic acid (JA) and salicylic acid (SA) plant defense pathways were also determined through RT-qPCR. Results of bioassays revealed that the application of PeBC1 elicitor protein exhibited pronounced and significant (p < 0.05) sub-lethal effects on green peach aphids. The fecundity was reduced and the nymphal development time was prolonged by different concentrations of PeBC1 elicitor and temperature regimes. Gene expression studies showed that the exogenous application of PeBC1 induced a significant upregulation of the expression levels of JA and SA pathway-associated genes in bean plants. As compared to control, elicitor-treated plants exhibited an induced resistance against aphids. Our findings suggest the potential use of PeBC1 elicitor protein in future bio-intensive management strategies against sap-sucking insect pests such as green peach aphids.

Green peach aphid, Myzus persicae (Hemiptera: Aphididae), is an economically important pest of crops within more than 40 plant families all over the world. This study encompasses in-vitro pathogenicity of two strains of Beauveria bassiana (BB-72 and BB-252) and one strain of Lecanicillium lecanii (V-4) against green peach aphid (M. persicae). Using a leaf-dip method, three different bioassays were conducted comprised of filtrates and conidial concentrations of BB-72, BB-252 and V-4 fungal strains and their binary combinations. Infiltrate bioassays, 2 mL fungal filtrate of each strain was used. In conidial bioassays, three different concentrations (i.e., 1 × 106, 1 × 107 and 1 × 108 conidia mL−1) of each fungal strain were used, while in binary combination bioassays, LC50 and LC33 of these fungal strains were evaluated. According to the results, maximum pathogenicity against test aphids was observed at 10th day of all treatments. Both strains of B. bassiana (BB-72 and BB-252) exhibited higher mortality of aphids (up to 95 and 91%, respectively) than L. lecanii (V-4) strain (87%) in all three types of bioassays. Moreover, binary combinations of BB-72 and BB-252 strains showed significantly higher aphid mortality (94%) than other combinations. Reduced mortality in case of fungal combinations of V-4 strain might be due to the antagonistic effect of L. lecanii strain along with both strains of B. bassiana. Nevertheless, evaluation of combined pathogenicity of the fungal strains constitutes the novelty of this in-vitro study which revealed that both strains of B. bassiana (i.e., BB-72 and BB-252) are mutually compatible and can be utilized together as new biocontrol tools against destructive insect pests such as M. persicae.

The relationship between drying and hygroscopic ability of Crateva adansonii and Populus deltoides woods to resist feeding by Odontotermes obesus was studied. Woods were dried under the sun and in the oven for a range of 5-25 days and then these were exposed to termites for 25 days in underground pits in Randomized Complete Block Design pattern with five replications. Results showed that lowest moisture gain was observed at a short time for drying with each method. Weight loss after termites’ exposure was more in less dried sap and heartwood of either plant species. The practical implication of these results is discussed.

In the tropics, termites are major players in the mineralization of organic matter leading to the production of greenhouse gases including nitrous oxide (N2O). Termites have a wide trophic diversity and their N-metabolism depends on the feeding guild. This study assessed the extent to which N2O emission levels were determined by termite feeding guild and tested the hypothesis that termite species feeding on a diet rich in N emit higher levels of N2O than those feeding on a diet low in N. An in-vitro incubation approach was used to determine the levels of N2O production in 14 termite species belonging to different feeding guilds, collected from a wide range of biomes. Fungus-growing and soil-feeding termites emit N2O. The N2O production levels varied considerably, ranging from 13.14 to 117.62 ng N2O-N d(-1) (g dry wt.)(-1) for soil-feeding species, with Cubitermes spp. having the highest production levels, and from 39.61 to 65.61 ng N2O-N d(-1) (g dry wt.)(-1) for fungus-growing species. Wood-feeding termites were net N2O consumers rather than N2O producers with a consumption ranging from 16.09 to 45.22 ng N2O-N d(-1) (g dry wt.)(-1). Incubating live termites together with their mound increased the levels of N2O production by between 6 and 13 fold for soil-feeders, with the highest increase in Capritermes capricornis, and between 14 and 34 fold for fungus-growers, with the highest increase in Macrotermes muelleri. Ammonia-oxidizing (amoA-AOB and amoA-AOA) and denitrifying (nirK, nirS, nosZ) gene markers were detected in the guts of all termite species studied. No correlation was found between the abundance of these marker genes and the levels of N2O production from different feeding guilds. Overall, these results support the hypothesis that N2O production rates were higher in termites feeding on substrates with higher N content, such as soil and fungi, compared to those feeding on N-poor wood.

ABSTRACT: The major objective of this paper was to assess the impact of the Farmer field school (FFS) training program on the knowledge level of farmers (citrus growers) regarding improved citrus production practices. Distract Sargodha was the targeted research area for this study being the leading producer of citrus in Pakistan. Quantitative data were collected through interview schedule and analyzed through Statistical Package for Social Sciences (SPSS). It was conclude that young people were more tend towards getting training under FFS program than old age farmers. Educated farmers were in majority in FFS farmers while; conversely illiterate farmers were in majority in the category of non-FFs farmers. In category of FFS farmers livestock farming was their primary income as reported by majority (31.3%) of FFS farmers and in the case of non-FFS farmer’s crop sale was their primary income source as reported by 28.4% of non-FFs farmers. In addition to that both FFS and non-FFS farmers also earn income from nonfarm sources like business, job, foreign remittances and labour. FFS training program had positive and significant impact on the knowledge level of farmers regarding citrus production and protection practices. T-test statistics showed highly significant (P