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Spodoptera frugiperda (J E Smith) (fall armyworm) (Lepidoptera: Noctuidae), is a key pest of maize that has recently entered in India causing damage and yield loss. A biocontrol-based integrated pest management (IPM) strategy was designed and evaluated in farmer’s field during rabi and kharif season (2018–2019). IPM strategy comprising installation of controlled release FAW pheromone traps, four releases of Trichogramma pretiosum Riley, two sprays of neem oil, one spray of each Bacillus thuringiensis (NBAIR-BT25) and Metarizium anisopliae (NBAIR Ma-35) resulted in 76 and 71.64% egg mass; 80 and 74.44% larval population reduction at 60 days after treatment during rabi and kharif season, respectively. Cob yield per acre in biocontrol-based IPM field was higher than the farmer’s practice (6–7 sprays of emamectin benzoate 5% SG) during both the seasons, and it resulted in 38.3 and 42.29% gain in yield per acre during rabi and kharif, respectively. Therefore, this module forms a base to manage the fall armyworm in an eco-friendly and farmer friendly manner. Future research with other alternatives has also been discussed.

A field trial was conducted in a farmer’s field by integrating biocontrol agents, a multiple insecticide tolerant strain (MITs), Trichogramma chilonis and formulation of Bacillus thuringiensis (NBAIR BtG4) with reduced insecticidal spray as a biocontrol-based IPM compared to insecticidal application as a farmer’s practice, for the management of the diamondback moth (DBM), Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae) infesting cabbage. Six T. chilonis releases of 100,000 parasitized eggs ha− 1 were applied. Along with parasitoid release, a liquid formulation of B. thuringiensis (2%) was applied after third and fifth releases of T. chilonis. The number of P. xylostella larvae were significantly reduced in the field treated with biocontrol-based IPM as compared to farmer’s practice after 30 and 45 days after treatment. After the 45 days, the holes on cabbage leaves were 2.2/plant in the field treated with biocontrol, opposed to 8.0 holes per plant were recorded in the farmer’s practice filed. Only 7% of cabbage head damage was recorded in the field treated with biocontrol, whereas, in farmer’s practice field, those were 32.2%. The cost-benefit analysis showed that integrating these biological control agents along with a reduced number of insecticidal sprays could reduce DBM population and percent head damage with an eventual increase in the yield.

The eggs of the factitious host insect, Corcyra cephalonica (Stainton), are used for production of several natural enemies in many countries across the world. Trichogramma spp. are used widely for the biological control of lepidopterous pests on various crops in more than 30 countries covering a total area of 3.2 million ha of agricultural and forest land. A novel and simple technique for storage of eggs of C. cephalonica by vacuum packing at 500 Hg−1 and stored at 8 ± 1 °C in refrigerator was developed to enhance egg viability for production of Trichogramma species, and assessed and compared with the traditional method. The percent parasitism of vacuum packed eggs was 100.0–75.0% after storing for 7–42 days and declined to 10.0% after 70 days storage compared to 100.0, 50.0, 40.0 and 5.0% parasitism after 7, 14, 21 and 28 days, respectively, in the traditional method. The percent emergence from parasitized eggs was identical in both vacuum and non-vacuum packed eggs indicating suitability of vacuum packing eggs. The percent females ranged 50.0–59.0% in vacuum-packed eggs and 48.4–55.8% in non-vacuum packed eggs. Vacuum packing enhanced storability of C. cephalonica eggs by 3- to 4-fold as compared to the traditional method of storage.

The host egg preference studies revealed that Trichogramma chilonis, which was collected from 8 crops, preferred the eggs of Corcyra cephalonica most (84.8% parasitism), followed by Chilo partellus (55.1%) and Helicoverpa armigera (47.9% parasitism) and Samia ricini eggs were least preferred, T. achaeae was recorded from eggs collected from 3 crops only. The parasitoids obtained from rice, sugarcane, cabbage and dolichos were more robust rather than other 4 crops. The parasitoids collected from sugarcane showed strong recognition to the crop when released back on sugarcane, while parasitoids from other crops did not show any pattern of host-plant recognition. Sugarcane appeared to be the most preferred crop for T. chilonis releases with parasitism of 30.5%, followed by paddy (18.9%), cotton (18.3%) and tomato was the least preferred host plant.

Trichogrammatids are being mass reared and released in different ecosystems for control of lepidopterous pests for the past seven decades in India. Indiscriminate use of pesticides often results in decline in the natural enemy population besides development of tolerance in the pests and their resurgence and secondary pest outbreaks. With intensification of agriculture, pesticide consumption has increased drastically from 1950–1951 to 1990–1991 and later decreased from 1991–1992 to 2000–2001 mainly due to integrated approach, environmental concerns, and introduction of newer molecules. Among the major groups of pesticides in India – insecticides are consumed more, followed by herbicides and fungicides. Cotton receives more quantity of the pesticides (52–55 %) followed by paddy (17–18 %) and horticultural crops (13–14 %) as in 2001–2002. In the IPM program, chemical pesticides are integrated with biocontrol methods like release of egg parasitoids and biopesticides. Among 36 species of trichogrammatids described from India, only a few are being commercially mass reared and released. About ten such species have been tested for sensitivity to different pesticide groups. Those already tested include 4 in organochlorine group, 13 in organophosphates group, 12 in synthetic pyrethroid group, 32 in biopesticide group, and 21 in combination compounds for safety to biocontrol agents including trichogrammatids. Out of ten species screened for toxicity to various chemicals, T. chilonis has been more intensively screened against various pesticides by several researchers followed by T. japonicum and T. (= brasiliense) pretiosum. One of the main reasons for T. chilonis being the most widely screened against various pesticides and by various workers is due to its most dominant position in various ecosystems in India and its integration in IPM modules. In the future, studies should be oriented towards the safety of newly introduced pesticides, including combination compounds and biopesticides. Efforts should also be made to better understand the mechanism of populations building up tolerance, besides persistence by using different modern toxicological tools.

The South American tomato moth Tuta absoluta (Meyrick) is a devastating pest of tomato. In the present study Tuta-adapted strains of Trichogramma were evaluated. Amongst the three species, Trichogramma achaeae Nagaraja and Nagarkatti, Trichogramma pretiosum Riley and Trichogrammatoidea bactrae Nagaraja could parasitise T. absoluta eggs and the parasitism rates were 5.0%, 51.1% and 68.2% respectively. Adults emerged from the parasitized T. absoluta eggs (4.8%, 97.5% and 90.0% adult emergence respectively). The F1 generation adults of T. pretiosum could parasitise 29% of Corcyra cephalonica Stainton eggs, while the other two species were not successful in parasitizing. In addition, four 'hymenopteran' parasitoids, viz. T. achaeae , Neochrysocharis formosa (Westwood), Habrobracon sp. and Goniozus sp. were also observed to be associated with T. absoluta in the fields during the surveys undertaken in southern India.

A preliminary attempt was made for biological control of coconut leaf eating caterpillar, Opisina arenosella Walker, by releasing two Trichogramma species viz. T. chilonis Ishii and T. embryophagum Hartig @ 1,000 to 4,000 parasitised eggs per palm in Bangalore, India. The mean percent reduction in larval population by 75.6, 60.0, 33.3 and 50.0% in T. chilonis and 88.8%, 175.0, 66.7 and 75.0% in T. embryophagum was recorded in treated palms during 1st, 2nd, 3rd and 4th generation of the pest compared to untreated control. There was non- significant difference between various release rates irrespective of the species, indicating that lower release rate of 1,000 parasitised eggs/palm as adequate. On sentinel egg cards, parasitism was low 2.0 - 5.0%, 0.0 - 2.0% and 0.0% in T. chilonis, and T. embryophagum released palms and untreated control palms, respectively. The field trial gave an indication that Trichogramma could be a potential parasitoid against O. arenosella and it is suggested that the parasitoids could be released and tested on a large scale in endemic areas to authenticate efficacy.