Predaceous coccinellids (Coleoptera: Coccinellidae) are potential predators of various phytophagous insect pests and could be used as biological control agents. They use a wide range of chemical cues to locate their prey or to oviposit. Several surface hydrocarbons and endogenous cues likely help the aggressive coccinellids to discriminate related from unrelated victims before cannibalising them. To investigate the influence of surface chemicals on the kin-discrimination ability in a coccinellid, Propylea dissecta (Mulsant), we bred wildcaught coccinellids in the laboratory and measured relationships between surface chemicals and kin-discrimination. We found that both cannibalistic larvae and adults possess the potential of kin-discrimination based on the egg surface chemical profile of the victims. Further, when egg surface chemicals were swapped, there was a bias preference towards eggs containing related-chemical profiles and were less likely to be consumed by the cannibalistic larvae and adults.

Tomato farming suffers from yield losses due to outbreaks of fungal diseases. Current management strategies heavily rely on the use of synthetic fungicides. However, dependence on synthetic fungicides imposes risk on the environment and human health. An effective and sustainable alternative to managing fungal plant diseases is the use of biological control. This study aimed to test the efficacy of B. amyloliquefaciens N2B2 and its potential in combination with a chitinase-producing microorganism as a microbial biological control agent (MBCA) against fungal pathogens of tomato, namely, Agroathelia rolfsii, Alternaria sp., Cladosporium cladosporioides, Cladosporium tenuissimum, Colletotrichum scovillei, Fusarium equiseti, Fusarium oxysporum, and Geotrichum candidum. Screening 176 microbial isolates for chitinase activity provided three isolates producing the highest amount of chitinase. However, the chitinase production was not correlated with the control of fungal growth. Dual culture plate assays showed that B. amyloliquefaciens N2B2 inhibited the hyphal growth of all the fungal pathogens in the study. The effect of co-cultivation and the type of fungus significantly affected the zone of inhibition, and their interaction plays a significant role, suggesting that the effect of co-cultivation depends on the specific fungal species involved. In vitro studies showed that B. amyloliquefaciens N2B2 was 62.7% effective against Alternaria sp. in dual plate assays and 60.9% effective in suppressing fungal growth of A. rolfsii on detached tomato fruits. This study demonstrated the efficacy of B. amyloliquefaciens and showed the importance of bioprospecting for alternative and sustainable ways to control the fungal pathogens of tomatoes.

The present study was carried out at the Bio-Control Laboratory, Entomology Section, R. C. S. M. College of Agriculture, Kolhapur, Maharashtra, India, to assess the effect of Metarhizium anisopliae (Metschn.) Sorokin strain AAI on the mortality and the larval protein concentration of fall armyworm. The investigation observed a 16.67% to 86.67% mortality in second instar fall armyworm (FAW) and 6.67% to 40.00% mortality in the third instar FAW in response to the tested conidial concentrations (1 x 104, 1 x 105, 1 x 106, 1 x 107 and 1 x 108 conidia/mL). On subjecting the larval mortality to probit analysis, a LC50 value of 1.43 × 106 conidia/mL and 5.53 × 108 conidia/mL was recorded against second and third instar FAW, respectively. A varied trend was observed with respect to the effect of entomopathogenic fungi on the protein concentration of FAW. The conidial concentration 1 × 106 conidia/mL decreased the protein content of third instar FAW to a greater extent than the other treatments, 96 and 144 h post treatment with respect to the control. 96 h post treatment, the larvae recorded a higher mean protein concentration (42.30 mg/g larval weight) than the control when treated by 1 × 107 conidia/mL of M. anisopliae. No treatment recorded a higher mean protein concentration than the control 144 h post treatment. Further, the protein concentration in FAW larvae decreased as the infection progressed.

The diamondback moth, Plutella xylostella (L.), is a serious pest of cruciferous crops worldwide and cause serious damage, resulting in up to 90 % yield loss. Heavy dependence on synthetic insecticides has led to widespread resistance and raised environmental concerns, demanding an urgent need for safer, eco-friendly pest control options. In this study, we examined the electrophysiological, behavioural responses of P. xylostella to ten Essential Oils (EOs): Pelargonium hortorum, Ocimum basilicum, Acorus calamus, Trachyspermum ammi, Piper betle, Cymbopogon nardus, Rosmarinus officinalis, Zingiber officinale, Mentha piperita, and Eucalyptus citriodora. Electro Antennogram (EAG) analysis showed that all EOs tested elicited antennal response in adult females; however, R. officinalis, A. calamus, Z. officinale and C. nardus caused significantly higher responses than the other oils tested, and this antennal response aids in host and mate selection. In the behavioural assay using the Y-tube olfactometer revealed that A. calamus, P. betel, Z. officinale, R. officinalis and P. hortorum produced highly significant repellency (P ≤ 0.01). Oviposition assays further revealed that A. calamus, P. hortorum, and Z. officinale at 5% reduced egg laying by 91.78%, 86.9%, and 73.86%, respectively and it was 2.4 to 3.0 times more effective than neem Azadirachta indica. Overall, the results demonstrate robust olfactory and behavioural impacts of several essential oils, particularly A. calamus, Z. officinale and P. hortorum, supporting their potential as botanical repellents or oviposition deterrents for integrated pest management targeting P. xylostella.

The apple ermine moth Yponomeuta malinellus (Zeller, 1838) is a major pest in apple orchards, causing severe defoliation and significant yield losses in the Republic of Armenia. While chemical insecticides are effective, their environmental and health risks necessitate the development of safer alternatives. This study evaluates the efficacy of locally produced microbiological insecticides based on Bacillus thuringiensis (Bt) strains (Bt JT-21, Bt AS-50, Bt SS-112) isolated from naturally deceased insect larvae during 2021-2024. The results demonstrated high biological effectiveness, with mortality rates reaching 90.2-98.2% in field trials and 100% in controlled settings. Statistical analysis confirmed the reliability of the findings, showing no significant differences between the tested culture liquids and the commercial Bt insecticide standard (BTB). Additionally, soil fertility indicators, including ammonifier populations and extracellular catalase activity, exhibited dynamic seasonal variations but were not negatively affected by Bt treatments. These findings highlight the potential of locally developed Bt-based insecticides as environmentally friendly alternatives for controlling defoliating pests in Armenian apple orchards.

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is recognised as a serious insect pest in Egypt due to its extensive host plant species and rapid adaptation to climatic conditions. The green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), is known as a promising multi-trophic predator that is extensively utilised in the biological control of numerous pests. This study may represent the first research in Egypt to evaluate the impact of S. frugiperda eggs on certain biological parameters of C. carnea across larval and adult stages over two generations, second generation (G2) and fourth generation (G4), compared to a control group in which larvae were fed with Sitotroga cerealella eggs. Additionally, it evaluates the consumption rates of C. carnea larval stage on eggs, the newly hatched, and the second instar larvae of S. frugiperda. The findings revealed no significant difference in duration of first and second larval instars in two generations, but there were significant differences in 3rd and whole larval instars. Moreover, the average number of eggs laid by each female in the G2 and G4 generations was 371±14.70 and 390.8±3.40, respectively, compared to the control (398.9±6.18). In contrast, the findings indicated that the larval instar of C. carnea did not consume the 2nd larval instar of S. frugiperda, and the 1st instar larvae of C. carnea refrained from feeding on the newly hatched S. frugiperda. The 1st, 2nd, and 3rd larval instars of C. carnea consumed 35.32±1.06, 87.88±1.31, and 201.80±2.55 eggs of S. frugiperda, respectively. However, the 2nd and 3rd instar larvae consumed 68.20±1.49 and 157.44±2.52 newly hatched S. frugiperda. Moreover, higher survival rates (97.6% and 93.6%) were noted for larvae feeding on eggs and newly hatched S. frugiperda, respectively. These findings suggested C. carnea as a potential agent of biological control for a wide range of insects, particularly S. frugiperda, the recently introduced invasive pest.

Entomopathogenic fungi are the most versatile fungi, which cause infection in various insects. In the current study, Beauveria bassiana at the concentrations of 102, 103, 104, 105, 106, 107 and 108 conidia/ml, sub-lethal doses of azadirachtin (0.92 and 1.11 ppm) and chlorantraniliprole (0.61ppm) were assessed against the 1st, 2nd, 3rd and 4th larval instars of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in laboratory conditions. Beauveria bassiana at a concentration of 106 conidia/ml applied against 1st and 2nd larval instars of T. absoluta resulted in a maximum mortality of 86.67% and 83.33%, respectively. The maximum mortality of the 3rd and 4th larval instars of T. absoluta, i.e., 86.67% and 80.00%, respectively, was observed with 108 conidia/ml of B. bassiana. Furthermore, it was also observed that B. bassiana mixed with chlorantraniliprole (0.61 ppm) and azadirachtin (0.92 and 1.11 ppm) suppressed the growth of B. bassiana, but the lethal effect against T. absoluta remained almost similar.

Field experiments were conducted to assess the effectiveness of various biopesticides and plant-derived products in controlling infestation of aphid, Lipaphis erysimi Kalt. in mustard crop through two rounds of spraying. Treatments included Metarhizium anisopliae, Beauveria bassiana, Lecanicillium lecanii, Azadirachtin, NSKE (5.0%), neem oil (1.0%), karanj oil (1.0%), karanj seed extract (5.0%), and a standard check involving alternate spray of dimethoate (0.03%)/malathion (0.05%). Results indicated that among biorationals, azadirachtin, NSKE and neem oil were most effective. Though biorationals were relatively less efficacious than standard check, considering their safety to environment and residue free food production, these can be included in IPM of mustard. Similarly, these treatments exhibited the highest yield increase and net profit, with dimethoate/malathion having the highest benefit-cost ratio (15.09) compared to other treatments.

Crop activation relies completely on the rhizosphere’s bacteria. In this instance, we looked into the effectiveness of Pseudomonas spp. present in the root zone of tomato against various plant diseases like Rhizoctonia solani, Sclerotium rolfsii, and Fusarium oxysporum RACE, which range from 12.33mm to 21.66mm in the Zone of Inhibition (ZOI). Interestingly, all five Pseudomonas spp. significantly produced antimicrobial and plant growth-promoting traits involved in plant development, including siderophore, hydrogen cyanide, IAA, and phosphate solubilization. Furthermore, the biocontrol mechanism of parasitism was found to be considerably influenced by the secretion of hydrolytic enzymes by Pseudomonas spp., including chitinase, cellulase, protease, and amylase. The particular strain designated as VSMKU4040 was selected for further study out of five strains of Pseudomonas spp. because of its outstanding antagonism and other unique biological control mechanism properties. The cell-free culture supernatant of Pseudomonas spp. effectively suppressed almost all of the fungal plant diseases indicated above, compared to the control. Pinch of R. solani and S. rolfsii mycelia from the ZOI during interaction with a Pseudomonas spp. VSMKU4040 was processed for examination under a scanning electron microscope. In comparison to the control, we discover that R. solani mycelium broke, disintegrated, and deformed. In contrast, during Pseudomonas spp. VSMKU4040 interaction with S. rolfsii, there was no initiation of sclerotia development along with Pseudomonas spp. VSMKU4040 distribution, whereas in the control, we could observe the formation and intimation of sclerotia bodies in S. rolfsii, in comparison to the control. When the 16s rRNA encoding gene was compared to a 1kb marker, 1500 bp was found in Pseudomonas spp. VSMKU4040. The pure ethyl acetate extract yielded three distinct metabolites, each with a different Rf value (0.91, 0.85, and 0.8) that were found in Thin-Layer Chromatography (TLC). By using the good diffusion method, the second molecule (0.85) out of the three showed significant potential activity against fungal plant pathogens at 30μg/ml when compared to a commercial fungicide companion.

The study explored the biological parameters of the aphid-feeding ladybird beetle, Coccinella septempunctata L., focusing on its development, body measurements, cannibalistic behaviour, and predation efficiency against corn leaf aphid (Rhopalosiphum maidis F.) at two temperatures: 25±1°C and 18±1°C. The duration of life stages, including egg, larval, pre-pupal, pupal, and pre-imaginal phases, was shorter at 25±1°C, with egg period 3.30±0.10 days and the entire pre-imaginal stage lasting 17.84±0.23 days. These stages required slightly more time to complete at 18±1°C. The sex ratio at both temperatures favoured females, recorded as 1.2:1 (F:M) at 25±1°C and 1.5:1 (F:M) at 18±1°C. Females underwent pre-oviposition, oviposition, and post-oviposition periods, while males experienced a sexual maturity phase, with temperature affecting their lifespan and reproductive performance. On average, females laid 372 eggs at 25±1°C and 339 eggs at 18±1°C. The study found that cannibalistic behaviour increased with larval age and food scarcity. Both larvae and adults exhibited significant predatory activity against R. maidis. The feeding capacity per larval stage rose progressively from the first to the fourth instar, with fourth instar larvae consuming an average of 168.04±31.27 aphids per stage. Among adults, females consumed 112.20±14.80 aphids per day, while males consumed 84.20±9.04 aphids.