A field survey was done in teak (Tectona grandis F.) forests in South India to explore the entomopathogenic effect of Metarhizium anisopliae (Ascomycota: Sordariomycetes) against teak defoliator, Hyblaea puera (Lepidoptera: Hyblaeidae). About 300 soils and infected insect samples were collected during the survey and thirty-six fungal isolates were isolated from soil and insect samples and characterized. The fungi were cultured on PDAY with dodine and antibiotics. Generally, the EPF culture was incubated at 27 °C in darkness for 15 days. Virulence of the Entomopathogenic Fungi (EPF) ability to germinate under cold and heat temperatures was assessed in a culture impregnated with conidia. In the experiment, it was found that for the first time Metarhizium quizhouense, Metarhizium robertsii, and Metarhizium majus species caused significantly higher mortality to hosts. These isolates of M. anisopliae, M. robertsii, M. majus, and M. quizhouense were all considered to be effective virulent and environmentally adaptive. The Metarhizium isolates were recommended as effective bio-control agents through the field investigation of teak defoliator Hyblaea puera from South India forest. This study paves the way to utilize the indigenous isolates of EPF for the control of teak defoliator and to combat the pests thatare resistant to insecticide.

The farmer interest in biological control-based management practices using entomopathogenic fungi (EPF) for the control of many economically important insects has increased. In this process, selection of effective strains of EPF is an important criterion to control the target insect pests in efficient manner. In this context, this research work was formulated to find out environmentally effective strains of EPF in the soils of costal districts of Andhra Pradesh, India. Out of 135 soil samples collected, 9 yielded 9 strains of Lecanicillium lecanii. Among all 9 L. lecanii isolates, the least median lethal concentration (LC₅₀) for 3rd instar larvae of the tobacco caterpillar, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), was 1.17 × 10⁶ spores ml⁻¹ in L-8, followed by 1.27 × 10⁶ spores ml⁻¹ in L-5 in an increasing order. Likewise, the median lethal time (LT₅₀) values of different isolates of EPF against the 3rd instar of S. litura were calculated for the uniform highest concentration of 1 × 10⁸ spores ml⁻¹. Among all 9 L. lecanii isolates, the lowest median lethal time (LT₅₀) was observed as 7.70 days by L-8, followed by 7.77 days by L-5 and 8.50 days by L-7.

In the recent years, the keen interest has been increased towards biological control-based management practices using entomopathogenic fungi (EPF) for the control of many economically important insects. In this management practices, selection of right strains of EPF is an important criteria to control the target pests in effective manner. In this context, this research work was formulated to find out environmentally effective strains of EPF in the soils of costal districts of Andhra Pradesh. Out of 135 soil samples collected, 8 soil samples yielded 8 strains of Metarhizium anisopliae. Among all 8 M. anisopliae isolates, the least median lethal concentration (LC₅₀) for 2nd instar of the tobacco caterpillar, Spodoptera litura (Lepidoptera: Noctuidae) was 1.24 × 10⁵ spores ml^-1 in M-7, followed by 1.72 × 10⁵ spores ml^-1 in M-5 and 1.86 × 10⁵ spores ml^-1 in M-4 in an increasing order. Likewise, the median lethal time (LT₅₀) values of different isolates of EPF against 2^nd instar of S.litura were calculated for a uniform highest dose of 1 × 10⁸ spores ml⁻¹. Among all 8 M. anisopliae isolates, the lowest LT₅₀ was observed as 186.44 hours post infection (hpi) with M-5 and 189.34 hpi with M-7.

Split plot design experiments were conducted to assess the performance of growth regulating compounds for mitigating moisture stress and the incidence of Brown Plant Hopper (BPH) in rice. The main plot treatments (4) comprised moisture stress free control (M₁), moisture stress during panicle initiation stage alone (M₂), moisture stress during flowering stage alone (M₃), and moisture stress during both panicle initiation and flowering stages (M₄). The sub-plot treatments (5) were foliar application of growth regulating compounds including chlormequat chloride at 200 ppm (S₁), mepiquat chloride at 200 ppm (S₂), brassinolide at 0.1 ppm (S₃), pink pigmented facultative methylotrophs (PPFM) at 1% (S₄), and no spray control (S₅). The reduced plant growth attributes were registered under moisture stress at both panicle initiation and flowering stages. The spraying of 1% PPFM during the flowering or both at panicle initiation and flowering stages led to better performance than the other treatments. Also, spraying 1% PPFM brought down the population of BPH to a considerable level during both years of experiments. This suggests that spraying 1% PPFM in the post-flowering stage helps to mitigate the ill effect the moisture stress and BPH incidence.