R. Maruthadurai ¹, R. D. Gautam ¹, P. Mahesh ¹

Affiliations
1 Biological Control Laboratory, Division of Entomology, Indian Agricultural Research Institute, New Delhi 110 012, IN

Abstract

Bioassay with hexane extracts of male and female whole body wash of host insects viz., Earias vittella and Spodoptera litura with Trichogramma brasiliensis revealed their kairomonal activities. Whole body extracts of male and female moths were analysed separately by gas chromatography for determining their hydrocarbon profile, which showed the presence of straight chain saturated hydrocarbons ranging from C₈ to C₃₅. The concentration of these hydrocarbons ranged from 0.02 µg/g to 2579 µg/g of insect extract. Both the host insects showed variation in number and concentration of these chemicals, which were responsible for influencing the parasitoid activity, parasitism and emergence. The foraging activity of the parasitoid as indicated by parasitoid activity index (PAI) was highest (12.00) in S. litura male body extract at concentration C₄ (1000 ppm) followed by (10.83) in E. vittella female body extract at C₅ (10,000 ppm) by T. brasiliensis. Maximum percentage parasitism of (45.55) and emergence (12.50) was observed at concentration C₄ in S. litura male body extract followed by E. vittella female body extract. Highest overall response was recorded in egg cards treated with whole body wash of male and female of S. litura and E. vittella, respectively, which may be attributed to the presence of more number of favourable saturated hydrocarbons viz.; heneicosane, tricosane, pentacosane, hexacosane, octacosane, and nonacosane, as revealed by GC. These favourable hydrocarbons at appropriate concentration of body extract of E. vittella female and S. litura male could be used for enhancing parasitization by T. brasiliensis.

Keywords

Semiochemical, Kairomone, Earias vittella, Spodoptera Litura, Trichogramma brasiliensis.

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Sudhida Gautam ¹, R. Maruthadurai ¹, R. D. Gautam ¹

Affiliations
1 Biological Control Laboratory, Division of Entomology, Indian Agricultural Research Institute, New Delhi-110012, IN

Abstract

A semi-synthetic diet named as the power packed green lacewing feed (PPGF), comprising whey protein, soybean granules, proteinex powder and glucon mixed in equal quantity by weight, was developed for Mallada desjardinsi (Navas) for increasing its reproductive potential. The cost of 1000g PPGF was worked out to be Rs. 621.00 (approx. US $14). It had a shelf life of four months at 5-10°C. The females of M. desjardinsi survived for 49 days when fed on the diet stored for eight weeks, on par with the control (58 days). Thereafter, survival declined to the lowest (16.8 days) when fed with the diet stored for 15 weeks. The predator laid maximum eggs (811.2/female) on the diet stored for four weeks, on par with that on diet stored up to eight weeks (774 eggs/female) and the control (888 eggs/female). The fecundity declined to the lowest (220.6 eggs) on PPGF stored for 15 weeks. Per cent hatchability was on par for up to eight weeks and declined significantly, with 33% on the diet stored for 15 weeks. In PPGF+honey (20%) feed combination, another peak of egg laying was recorded in females after 4^th week, whereas egg laying ceased in females that were fed with only 20% honey after the 4^th week. The females survived for up to 9 weeks maintaining productive age of more than eight weeks. PPGF+honey (20%) offered to the adults of M. astur also enhanced the fecundity (668.0) as against the control (292.14). Besides, other biological attributes were not affected due to the feeding on PPGF. These studies suggest a great potential for commercialization of PPGF in order to promote cheaper production and field utilization of green lacewings.

Keywords

PPGF, Multiplication, Mallada desjardinsi, M. astur, Shelf Life.

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R. Maruthadurai ¹, R. D. Gautam ¹

Affiliations
1 Biological Control Laboratory, Division of Entomology, Indian Agricultural Research Institute, New Delhi 110 012, IN

Abstract

The green lacewing, Mallada astur (Banks) was reared on frozen grubs of red flour beetle, Tribolium castaneum Herbst. The incubation period, larval period and pupal period were 3.0-3.3 days, 8.70-9.30 days and 9.10-10.40 days, respectively and total life cycle was completed in 20.8-22.7 days and continuous rearing for 5 generations did not alter any biological parameter significantly. The total immature mortality was 21 per cent and larval survival 76.66 per cent, when fed on a-week-old frozen prey. On prey stored at -4 to -6°C for a period of four weeks, survival was 46.5 per cent and it declined to 38.8 per cent after 42 days as against 85.5 per cent in control. A slight increase in developmental period was noticed with increase in cold storage of the prey beyond four weeks. These studies suggest that frozen grubs of T. castaneum are suitable for the multiplication of M. astur. The production of red flour beetle is cheaper than producing equivalent quantity of rice meal moth eggs, which are presently used for large scale production of the green lacewings.

Keywords

Mallada astur, Multiplication, Tribolium castaneum.

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