Additive effects of a local diatomaceous earth formulation and indigenous entomopathogenic fungi on mortality and F₁ progeny suppression of Sitophilus oryzae (Linnaeus, 1763) (Coleoptera: Curculionidae) in stored wheat

Entomopathogenic Fungi from South Sumatra, in Solid-dried Formulations, Stored for Three Months and Their Insecticidal Activities

Spodoptera frugiperda is a major pest of maize that can cause substantial yield losses. This study aimed to develop dried solid formulations of entomopathogenic fungi, evaluate their stability during three months of storage, and assess their insecticidal activity against S. frugiperda larvae. Conidia of Beauveria bassiana, Metarhizium anisopliae, and Penicillium citrinum were separately formulated using compost, wheat flour, or rice flour as carriers. The formulations were stored for one, two, and three months and subsequently tested against first-instar larvae at a concentration of 1 × 1010 conidia mL-1 through topical application. All fungal formulations significantly reduced larval body weight and fecal production compared with the control (P<0.05). They also caused significantly higher larval mortality than the control (P<0.05). After one month of storage, larval mortality ranged from 59.33 to 76.67%. The B. bassiana formulation with compost as the carrier maintained relatively high insecticidal activity, causing 76.00%, 70.00%, and 59.33% mortality after one, two, and three months of storage, respectively. After three months of storage, this formulation also resulted in the lowest pupation percentage (40.67%) and adult emergence (20.00%). In addition, the fungal treatments reduced the number of eggs laid by surviving female adults. Overall, the dried solid formulation of B. bassiana with compost showed the most consistent insecticidal activity during storage and therefore has potential as a bioinsecticide candidate against S. frugiperda. Further formulation optimization is required to improve conidial stability and extend product shelf life.

Compatibility of Hirsutella citriformis Gum with Entomopathogenic Fungi and Mortality of Bactericera cockerelli (Sulc) (Hemiptera: Triozidae)

Entomopathogenic fungi (EPF) are important microbial agents for sustainable pest management. However, their effectiveness depends on compatible formulations that preserve conidial viability and biological activity. Hirsutella citriformis Speare produces an extracellular gum with potential application as a microbial formulation component. The present study evaluated its short-term compatibility with Beauveria bassiana (Balsamo) Vuillemin and Metarhizium brunneum (Petch) conidia, together with mortality associated with gum-based treatments against Bactericera cockerelli (Šulc), under greenhouse conditions. Conidia were formulated in 0.5% (w/v) gum and applied at 1 × 107 conidia mL−1. Conidial germination remained above 90% and was not affected by gum exposure. Significant treatment effects on mortality were detected for adults and nymphs, using binomial generalized linear models. B. bassiana formulation produced 75.0% and 93.56%, whereas M. brunneum produced 65.2% and 78.2% adult and nymph mortality, respectively. The gum-containing treatment, which included Tween 80, was associated with 44.9% adult and 63.0% nymph mortality. H. citriformis gum therefore showed short-term compatibility with both fungi. However, because we did not include a Tween alone control, mortality may not be specifically attributed to the gum. Further studies will evaluate the basis of this mortality and formulation performance, under storage and field conditions.

Effects of Mesosphaerum suaveolens leaves oil Emulsifiable Concentrate and Lamda-cyhalothrin on arthropods associated with Cucumis melo in Wukari, Nigeria

Complementary effects of silicon-induced plant defense and Trichogramma pretiosum biological control of fall armyworm in maize

Data suggest that combining silicon-induced resistance with T. pretiosum biological control offers an effective and durable approach to controlling fall armyworm while improving maize performance.

INSECTICIDAL ACTIVITY OF Mentha × piperita L. (LAMIACEAE) ESSENTIAL OIL ON THE DEVELOPMENT OF THE COTTON STAINER BUG DYSDERCUS PERUVIANUS HEMIPTERO (PYRRHOCORIDAE)

Cotton (Gossypium hirsutum L.) is a crop of high economic importance; however, it is severely affected by insect pests, particularly Dysdercus peruvianus (Hemiptera: Pyrrhocoridae). The reliance on synthetic insecticides highlights the need for safer and more sustainable alternatives. This study evaluated the insecticidal potential of Mentha × piperita L. essential oil against biological parameters of D. peruvianus. Fourth-instar nymphs were subjected to contact and topical treatments at different concentrations and monitored for up to 28 days to assess mortality, development, adult emergence, reproductive performance, and morphological alterations. The essential oil showed concentration-dependent toxicity in both exposure routes. In the contact treatment, pure oil and 156.2 µg/cm² caused complete mortality within 48 h, whereas 78.1 µg/cm² promoted progressive population elimination. In the topical treatment, pure oil and 451.5 mg/mL caused complete mortality within the first 24 h. Development was impaired, reducing adult emergence to less than 5%. Reproduction was also affected, with complete inhibition of oviposition at 19.5 µg/cm² and reduced egg-laying in the remaining treatments. In addition, morphological deformities were observed in surviving individuals, indicating interference with normal development. These findings demonstrate that M. × piperita essential oil is a promising botanical insecticide with potential for the integrated management of D. peruvianus, contributing to more sustainable pest control strategies while reducing environmental impacts.

Growth Inhibitory and Morphogenetic Effects of Acetone Leaf Extract of Anisomeles malabarica on the Tobacco Leaf Caterpillar Spodoptera litura (Fabricius) (Noctuidae: Lepidoptera)

Spodoptera litura is a destructive and widely distributed insect pest responsible for considerable crop damage and substantial yield reduction. The extensive use of synthetic insecticides has adversely affected natural enemies and poses significant risks to human health and environmental safety. Consequently, botanical pesticides have emerged as potential alternatives in sustainable and organic agriculture because of their environmentally compatible characteristics and increasing consumer preference for residue-free agricultural produce. Anisomeles malabarica, an aromatic perennial herb characterised by dense pubescence, is known to possess a wide range of bioactive secondary metabolites. The present investigation evaluated the insecticidal potential of acetone leaf extract of A. malabarica against S. litura. Among the tested fractions, acetone elution 3 exhibited the highest pupal malformation (55.56%) and pupal mortality (44.44%). The same treatment produced the lowest pupal weight (0.19 g), representing a reduction of 63.40%, and the shortest pupal length (1.20 cm), representing a reduction of 21.57%. Similar observations were obtained during confirmatory screening, in which acetone elution 3 produced the lowest pupal weight (0.21 g), with a reduction of 61.11%, and the shortest pupal length (1.22 cm), with a reduction of 21.79%. Phytochemical analysis of the acetone leaf extract revealed the presence of tannins (1.32 ± 0.12) and saponins (1.11 ± 0.09), whereas flavonoids, phenols, and terpenoids were not detected. The findings of the present study indicate the potential of A. malabarica leaf extract as a botanical source for the eco-friendly management of S. litura.