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.

Among all the crops, the total loss due to the pests varied for each crop likely for wheat 50%, cotton 80%, maize 31%, rice 37%, potatoes 40%, and soybean 26%. Environmental stewardship and food security are the most important factors that involved in agriculture. In many cases by the misuse of insecticide led to population resurgence, pesticide residues, and pest resistance. The microorganisms like virus, fungus, protozoan or bacterium are the active ingredient in this type of pesticides. Safety of food alludes to the conditions and practices that save the quality of food to anticipate tainting and food borne sicknesses. Natural enemies and botanicals play a vital role to control pests with different mechanisms. Microbial, for example, microscopic organisms, growths, and infections are the major biopesticides being concentrated generally to create contrasting options to chemicals. The number and development rate of biopesticides demonstrate an expanding promoting pattern in recent decades. Biopesticides are host particular and biodegradable bringing about slightest persistency of leftover poisonous quality. Biopesticides make key commitments to IPM and can enormously lessen ordinary pesticides. Nowadays, the globe is working on protein-based biopesticide, and it is very effective method to control the insect pest.

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.

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.

Sucking insect pest complex, comprising of aphids Aphis gossypii Glover, jassids Amrasca devastans Distant, whiteflies Bemisia tabaci Gennadius, thrips Thrips tabaci Lindeman, red cotton bugs Dysdercus koenigii Walk and dusky cotton bugs Oxycarenus hyalinipennis Costa, has been a challenge on transgenic (Bt) cotton crop all over the world. This study assessed the field efficacy of six commercial insecticides viz.; Blaster 72.5%WP (imidacloprid + acephate), Bugatti 50%SC (imidacloprid + bifenthrin), Confidor 20%SL (imidacloprid), Jozer 202SL (imidacloprid + acetamiprid), Pouch 35%SC (pyriproxyfen + etofenprox) and Senator 41.6%EC (imidacloprid + pyriproxyfen) against sucking insect pest complex and also determined their side-effect on natural enemies of these insect pests such as ants, parasitoid wasps, green lacewings and coccinellid beetles. Experimental design was split-plot randomized complete block with three replications for each treatment. Transgenic (Bt) cotton variety (FH-118) was sown. Insecticide formulations were applied according to their field recommended dose rates upon attainment of ETLs of most of the sucking insect pests. Data regarding insect populations were recorded 3 and 7 day post treatment. Results revealed that Confidor proved to be most effective systemic insecticide against all insect pests, followed by Pouch, Senator, Blaster, Bugatti and Jozer. However, Confidor, Jozer, Bugatti, Blaster and Senator showed a top-down effect on beneficial insects causing 50–90% reduction in their populations, while Pouch showed minimum effect (< 50% reduction) on the population of beneficial insects and proved to be relatively safe. All insecticide formulations tested exhibited ≥ 50% reduction in the population of green lacewings. Similarly, whitefly parasitism recorded in the Confidor and Jozer plots was very close to that of control plots for both post-treatment observations. Based on these findings, Confidor and Jozer are recommended to be considered for their integration in sucking pests’ management strategies on transgenic crops such as Bt cotton.