The emerging elicitor protein Hrip1 was evaluated for sublethal effects and biocontrol potential in the common bean Phaseolus vulgaris. In Megoura japonica Matsumura, purified elicitor protein Hrip1 was investigated for impacts on endurance, life expectancy, juvenile expansion, fully grown procreative performance, and pathogen–pest interface. The multi-acting entomopathogenic effects of the active compounds of Alternaria tenuissima active on Hrip1 in common bean (Phaseolus vulgaris L.) plants were also investigated. Megoura japonica population expansion was reduced by Hrip1 treatments (second and third generations). In a host selection test, control plants colonized quicker than Hrip1-treated P. vulgaris plants. Hrip1 influenced the longevity, development, and fertility of insects. Hrip1-elicitor protein concentrations aided M. japonica nymph development. Similarly, seedlings treated with Hrip1 generated fewer offspring than seedlings not treated with Hrip1. Hrip1 altered plant height and leaf surface structure, reducing M. japonica reproduction and colonization. Hrip1-treated P. vulgaris seedlings exhibited somewhat increased amounts of jasmonic acid, salicylic acid, and ethylene (ET). The integrated management of insect pests and biocontrol with Hrip1 in the agroecosystem appears to be suitable against M. japonica based on these findings.

The green peach aphid (Myzus persicae Sulzer), a major and harmful chili aphid usually managed using chemical pesticides, is responsible for massive annual agricultural losses. The efficacy of two protein elicitors, PeaT1 and PeBC1, to stimulate a defensive response against M. persicae in chili was studied in this study. When compared to positive (water) and negative (buffer, 50 mM Tris-HCl, pH 8.0) controls, the rates of population growth (intrinsic rate of increase) of M. persicae (second and third generations) were lower with PeaT1- and PeBC1-treated chilli seedlings. M. persicae demonstrated a preference for colonizing control (12.18 ± 0.06) plants over PeaT1- (7.60 ± 0.11) and PeBC1 (6.82 ± 0.09) treated chilli seedlings in a host selection assay. Moreover, PeaT1- and PeBC1-treated chilli seedlings, the nymphal development period of the M. persicae was extended. Similarly, fecundity was lowered in the PeaT1- and PeBC1-treated chilli seedlings, with fewer offspring produced compared to the positive (water) and negative controls (50 mM Tris-HCl, pH 8.0). The trichomes and wax production on the PeaT1 and PeBC1-treated chilli leaves created a disadvantageous surface environment for M. persicae. Compared to control (30.17 ± 0.16 mm⁻²), PeaT1 (56.23 ± 0.42 mm⁻²) and PeBC1 (52.14 ± 0.34 mm⁻²) had more trichomes. The levels of jasmonic acid (JA), salicylic acid (SA), and ethylene (ET) were significantly higher in the PeaT1- and PeBC1-treated chili seedlings, indicating considerable accumulation. PeaT1 and PeBC1 significantly affected the height of the chili plant and the surface structure of the leaves, reducing M. persicae reproduction and preventing colonization, according to the data. The activation of pathways was also part of the defensive response (JA, SA, and ET). This present research findings established an evidence of biocontrol for the utilization of PeaT1 and PeBC1 in the defence of chili plants against M. persicae.

The emerging elicitor protein PeBA1, extracted from Bacillus amyloliquefaciens NC6, was tested against the cabbage aphid (Brevicoryne brassicae) for its biocontrol potential. Its effects on the survival, lifespan, immature development, adult reproductive performance, and pest–pathogen interaction were assessed using electrical penetration graphs (EPGs) against B. brassicae. Furthermore, the direct effects of PeBA1 with temperature and climate change in Brassica rapa ssp. Pekinensis plants were investigated by the characterization of active compounds in B. amyloliquefaciens with multi-acting entomopathogenic effects. Compared with controls, PeBA1 treatments decreased (second- and third-generation) B. brassicae population growth rates. In a host selection test, control plants were colonized faster by B. brassicae than PeBA1-treated B. rapa plants. The B. brassicae nymphal development was extended by PeBA1 concentrations. Likewise, fecundity was reduced in PeBA1-treated seedlings compared with control, with fewer offspring produced. The trichomes and wax production on PeBA1-treated leaves resulted in a hostile environment for B. brassicae. PeBA1 altered the surface structure of the leaves, reducing B. brassicae reproduction and preventing colonization. Systemic defensive processes also included the activation of pathways (JA, SA, and ET). Based on these findings against B. brassicae, integrated pest management and bio control with PeBA1 in the agroecosystem appears to be suitable.

The dangerous insect pest known as rice leaf folder Cnaphalocrocis exigua (Butler), which reduces rice output globally, twists and feeds on the young rice plant’s leaves. Protein elicitors are hypothesized to be biological components that promote rice in becoming herbivore resistant. The evolving elicitor protein PeBL2, obtained from Brevibacillus laterosporus A60, was tested for biocontrol against C. exigua. Four distinct PeBL2 doses (74.23, 45.53, 22.26, and 11.13 μg mL⁻¹) were assigned to evaluate the impact of PeBL2 on immature growth, survivability, and lifespan. Adult reproductive efficiency and the interaction between the pest and the disease were assessed against C. exigua. Further, the assessment of active compounds in PeBL2 with multi-acting entomopathogenic effects investigated the direct correlations of PeBL2 with temperature and climatic change in plants of rice (Oryza sativa L.). When compared to controls, PeBL2 treatments reduced the growing population of second- and third-generation C. exigua. Cnaphalocrocis exigua colonized control plants faster than PeBL2-treated O. sativa plants in a host selection test. PeBL2 doses delayed the development of the larval stage of C. exigua. PeBL2-treated seedlings generated less offspring than control seedlings, identical to fecundity. Trichomes and wax formation on PeBL2-treated leaves generated an adverse environment for C. exigua. PeBL2 altered the surface topography of the leaves, preventing colonization and reducing C. exigua reproduction. PeBL2-treated O. sativa seedlings exhibited somewhat increased amounts of jasmonic acid (JA), salicylic acid (SA), and ethylene (ET). Systemic defensive processes also included the activation of pathways (JA, SA, and ET). Following these results versus C. exigua, the use of PeBL2 in an agroecosystem with integrated pest management and biocontrol appears to be reasonable. These findings shed new light on a cutting-edge biocontrol technique based on B. laterosporus A60.