Background Mycosis on the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), infecting maize was observed in research farm of Regional Agricultural Research Station, Anakapalli from October 2019 to February 2020. Main body High relative humidity (94.87%), low temperature (24.11 °C), and high rainfall (376.1 mm) received during the month of September 2019 predisposed the larval instars for fungal infection and subsequent high relative humidity and low temperatures sustained the infection till February 2020. An entomopathogenic fungus (EPF) was isolated from the infected larval instars as per standard protocol on Sabouraud’s maltose yeast extract agar and characterized based on morphological and molecular analysis. The fungus was identified as Metarhizium (Nomuraea) rileyi based on ITS sequence homology and the strain was designated as AKP-Nr-1. The pathogenicity of M. rileyi AKP-Nr-1 on S. frugiperda was visualized, using a light and electron microscopy at the host-pathogen interface. Microscopic studies revealed that all the body parts of larval instars were completely overgrown by white mycelial threads of M. rileyi, except the head capsule, thoracic shield, setae, and crotchets. The cadavers of larval instars of S. frugiperda turned green on sporulation and mummified with progress in infection. In vitro pathogenicity tests revealed the potential of AKP-Nr-1 strain of M. rileyi in management of S. frugiperda. Short conclusion The results indicated the potential of M. rileyi AKP-Nr-1 as biocontrol agent for management of the fall armyworm. This AKP-Nr-1 strain of M. rileyi needs further evaluation under field conditions to evaluate its efficacy against S. frugiperda and its effects on other hosts.

In India, the egg parasitoid Trichogramma chilonis Ishii is generally mass produced on the eggs of rice moth, Corcyra cephalonica Stainton, however, in the present study, the cost of production of T. chilonis was studied on Samia cynthia ricini, eri silkworm, and was compared with rice moth. Rearing of T. chilonis on eri silkworm eggs showed higher benefit cost-ratio of 1.89 with a net profit of Rs. 4620, whereas T. chilonis when reared on the eggs of C. cephalonica recorded a benefit cost ratio of 1.28, with a net profit of Rs. 2379. The results revealed that in one hectare area, one trichocard made from eri silkworm eggs release that containing 3500 eggs. Each parasitized egg yields 9-10 adults, thus total adults account to about 35000-40000 adults ha -1 , while in case of trichocard made from rice moth eggs, the number of cards to be released in one hectare area are 2-3, since one trichocard made from rice moth eggs consit of 16000-17000 eggs. Hence, eri silkworm can be used as an alternate host to rice moth for rearing of T. chilonis as it is a resource efficient and cost reducing technology. Further, this production technology would be suitable for promoting localized production of eri silkworm at village level especially for tribal farmers, and unemployed youth.

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High rainfall with increase in humidity (68% to 75%) along with a decrease in temperature ( 3 to 5°C less than usual ) during June, July, and August months favor the emergence of white grub beetles, its egg laying which in turn resulted in severe sugarcane clump damage by white grubs in July, August and September months. Seasonal incidence of white grub in sugarcane growing areas in Andhra Pradesh state showed that damage of sugarcane clumps caused by white grubs infestation was significantly high in march ratoon compared to February ratoon crop; January plant crop and low in January seedling plant crop. Grub damage recorded high in 4 months age sugarcane ratoon crop and low in 6 months and 7 months age sugarcane plant crop. Field efficacy of entomopathogenic nematode and entomopathogenic fungus in the management of white grub, Holotrichia consanguinea in sugarcane was investigated and promoted biocontrol in white grub endemic areas during 2017-18 to 2019-20. Entomopathogenic nematode (Heterorhabditis indica NBAII-H38), entomopathogenic fungi (Metarhizium anisopliae (NBAIR Ma4 )along with a chemical Chlorantraniliprole were evaluated through soil application. The results indicated that Heterorhabditis indica NBAII-H38 (12 kg a.i./ha) soil application two times at monthly interval resulted in higher reduction of white grub damage. Metarhizium anisopliae NBAIR Ma4 (2.5 kg a.i./ha) treated plots caused higher percentage reduction of white grub than chlorantraniliprole treatment. Entomopathogenic nematode, Heterorhabditis indica and entomopathogenic fungus, Metarhizium anisopliae were found effective than the insecticidal application in the management of sugarcane white grub. Cost benefit of biocontrol agents, Metarhizium anisopliae and H. indica was proved superior to insecticidal application. Graphical Abstract