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The cassava mealybug, Phenacoccus manihoti Matile-Ferrero is one of the most serious pests of cassava worldwide, which got recently introduced into India (traced in Kerala) as a potential invasive pest. Studies were carried out to record the incidence of mealybug, P. manihoti and its natural enemies on different varieties of cassava in Namakkal dt. of Tamil Nadu during June 2020. The observations were taken in the field in situ as well in the collected mealybug infested twigs in the laboratory. Results revealed that all the three surveyed cassava varieties viz. , Mulluvadi, Thailand white and Shree Atulya were found severely infested with cassava mealybug. A huge number of coccinellid beetles were collected from the P. manihoti colonies, which were identified as Hyperaspis maindroni Sicard, 1929 (Coccinellidae:Coccinellinae:Hyperaspidini). Molecular characterization of both grub and adult beetle of H. maindroni was carried out to confirm its identity.

Studies on the biology and feeding potential of Eocanthecona furcellata (Wolff) on Spodoptera frugiperda (Smith) were carried out at NBAIR, Bengaluru. Experimental results revealed that the total developmental period from egg to adult for male and female were 27.92±2.87 and 39.62±3.28 d, respectively. The life cycle of male and female passed through first, second, third, fourth and fifth nymphal instars (male: 2.42±0.51 d, 3.25±0.45 d, 3.25±0.45 d, 4.00±0.60 d, 4.42±0.51 d) and (female: 2.54±0.52 d, 3.46±0.52 d, 4.00±0.71 d, 4.38±0.65 d, 5.08±0.49 d), respectively. Total nymphal period is about 17.83±1.34 d for male and 19.46±1.20 days for female, respectively. Adult longevity of male is lower (10.25±2.96 d) compared to that of female (20.15±3.39 d). The premating period and mating period of adult E. furcellata was 2.33±0.50 days and 6.44±2.24 hrs, respectively. The pre-oviposition period, oviposition period of adult female was 2.89±0.60 and 11.22±1.72 days, respectively. The average number of eggs laid by the female was 209.29±28.11 in a single mated system. Egg incubation period was about 5.42±0.51 days. The predation rates of second, third, fourth, fifth instar nymphs, adult female and male on 2 nd , 4 th , 6 th instar prey of E. furcellata were (16 ±0.95, 27 ±4.06, 55±4.67, 68 ±5.41, 126 ± 4.76, 97 ± 2.85), (7±1.34, 24±2.77, 40±3.39 45±0.71, 88±1.37, 51±1.60) and (4±0.82, 9±1.64, 21±2.81, 38±1.03, 69±1.32, 36±2.73), respectively.

The present experiment was aimed at safety evaluation of different insecticides to Cryptolaemus montrouzieri Mulsant, a major predator of mealybugs. In order to understand the impact of chemical insecticides on this predator, different bioassays were carried out. The results of the study showed that the Percent mortality of C. montrouzieri at 24 HAT was highest in profenophos 50% EC (49.33%) followed by thiamethoxam (36.00%) and dinotefuran (30.67%). However, azadirachtin, buprofezin and pymetrozine were found comparatively safer insecticide to C. montrouzieri . Therefore, both of these insecticides, need to be evaluated further under different agro-climatic zones to confirm their suitability, for mealybug management in cotton ecosystem without adversely affecting the performance of C. montrouzieri .

High percentage of Homalotylus turkmenicus Myartseva (Hymenoptera: Encyrtidae) parasitizing Hyperaspis maindroni Sicard (Coleoptera: Coccinellidae) predating on the colonies of the Cassava Mealybug (CMB) Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) is observed in southern India. In the present study, cautionary note on the presence of H. turkmenicus in the food web of insects associated with the CMB and brief diagnosis of the parasitoid is presented for quick identification. The parasitism of Hy. maindroni grubs by H. turkmenicus ranged from 65.67 to 80.95 per cent. However, no primary parasitoid of the cassava mealybug was observed so far.

The search for new Bacillus thuringiensis ( Bt ) strains is a continuous process and researchers are now focusing on finding toxin proteins that are toxic to pests of insect orders that are not reported. In the present study soil and insect cadaver samples were collected from North East India comprising the states of Assam, Tripura and Mehhalaya and native Bt were isolated using standard protocols. At total of 30 Bt isolates were purified and characterized. Various types of crystal morphology were encountered that included bipyramidal, cuboidal, square, rhomboid, spherical and irregular. PCR analysis showed that diverse cry genes were expressed. The cry genes identified were Lepidoptera, Coleoptera and Diptera specific. Detected genes included cry1Ac , cry2A , cry4A , cry10A , cry16A , cry17A , cry19A , cry30Aa , cry44Aa , cry11A , cry4B , cry12A , cry8A and cry7A . Many of them were positive for Vip3A protein. The coleopteran specific Bt were evaluated against Sitophilus oryzae and Callosobruchus chinensis and NBAIR-AgBt6 was found to be toxic. The isolates are being further evaluated for use as biopesticides.

Eocanthecona furcellata (Wolff) is a potential native predator of lepidopteran larvae that can be easily reared under laboratory conditions and released in augmentative biocontrol for management of pests in various crops. For successful mass production of any predator cannibalism under crowded rearing conditions is the major limiting factor. In the present study, attempts were made to know the ideal population considered for group rearing with minimal or no cannibalism. It was recorded that the predator population of 5 to 25 on Corcyra cephalonica (S.) and Galleria mellonella L. and 5 to 30 on Samia cynthia ricini Boisd. and Spodoptera litura F. was feasible for group rearing with higher percent survival rate when reared in different group arenas. The survival percent was higher on hosts, C. cephalonica, G. mellonella, S. litura and recorded lower on S. cynthia ricini under group rearing condition.Â