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Biological and morphological characteristics together with electrophoretic patterns were compared for five strains of Triclzogramma ecanescens W., collected from the eggs of Mamestra brassicae L., Ostrinia nuhilulis Hb. and Agrotis segetum Schiff. in northern Maldova. Significant differences were observed in the biological characteristics including the proportion of female progeny, developmental period, longevity and fecundity. The strains also differed in the ratio of antenna1 hair length to the maximum width of flagellum in males. Patterns of esterase systems indicated that the strains differed in the mobility and intensity of esterase bands. All the strains had a strong preference for the host from which they were collected in the field. Crossing of the strains indicated that one strain was reproductively isolated. The results have application in selecting the strategy for establishing initial colony in mass rearing of parasitoids and for research on Trichogramma ecology and evolution.

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Effect of temperature on the biology of <em>Aenasius arizonensis</em> (Girault) (=<em>Aenasius bambawalei</em> Hayat) (Hymenoptera: Encyrtidae), a parasitoid of solenopsis mealybug, <em>Phenacoccus solenopsis</em> Tinsley, was studied at four constant temperatures <em>viz</em>. 20±1, 25±1, 30±1 and 35±1⁰C. Mealybugs were reared on sprouted potatoes. The parasitoid completed its development at all the temperatures studied and males developed faster than the females. For males and females, respectively, total development period was 30.56, 24.16, 13.40 and 11.60 days and 34.40, 26.20, 14.88, and 12.04 days at 20±1, 25±1, 30±1 and 35±1⁰C, respectively. The daily and total fecundity (number of hosts parasitised) was 1.42, 1.82, 3.17, 2.16 and 57.13, 63.15, 65.60, 37.46 at 20±1, 25±1, 30±1 and 35±1⁰C, respectively. Female parasitoids parasitised mealy bugs on the day of emergence at all the temperatures. At respective temperatures oviposition and post-oviposition periods were 35.86, 33.60, 18.93, 15.53 days and 2.86, 2.26, 2.60 and 2.33 days, respectively. Parasitoid males were short lived as compared to females at all the temperatures. The male and female longevity, respectively, was 23.06, 17.26, 13.20, 10.33 days and 38.66, 34.53, 20.86, 17.86 days at 20±1, 25±1, 30±1 and 35±1⁰C, respectively. Sex-ratio (male: female) was in favour of female parasitoids (1: 1.1 to 1: 1.2) at all the temperatures. Net reproductive rate (36.41), intrinsic rate of increase (0.155) and finite rate of increase (1.168) were maximum at 30±1⁰C indicating this temperature to be the most favourable for the development and reproduction of the parasitoid. Males emerged out from the small sized mummies (2.28×1.20mm) whereas; large sized mummies (2.90×1.59mm) yielded mostly the female parasitoids. Males were generally smaller in size (1.26×0.58mm) as compared to female parasitoids (1.84×0.89mm). The results of the present studies could be useful in establishing a mass rearing programme for the parasitoid.

Drying and storage of herbage for 5 days prior to distillation significantly reduced the essential oil recovery as well as oil quality. The study suggested that the geranium green biomass should be distilled afresh for better oil yield and quality in the conditions of Uttaranchal.

Intercropping in cotton is of great significance, which helps to reduce the population of insect pests by attracting natural enemies to the field and helping to get stabilized yield and high profit advantage. The study was conducted with 4 intercrops, viz., sesame, Sesamum indicum L.; pigeonpea, Cajanus cajan L.; pearl millet, Pennisetum glaucum L.; and sorghum, Sorghum bicolor L. in an experimental area during 2016 and 2017 autumn season. The objective was to study the population of parasitoids influenced by the intercrops in cotton. This is a triangular relationship between the host, parasitoids, and environment. As Encarsia spp. (Hymenoptera: Aphelinidae) and Trichogramma spp. (Hymenoptera: Trichogrammatidae) are the main parasitoids of insect pests of cotton, thus the study was undertaken on these parasitoids. The results revealed that the highest parasitization of whitefly, Bemisia tabaci (Gennadius) pupae by Encarsia spp., was recorded in cotton-pigeonpea 1:1 (33.22%), which was at par with cotton-pigeonpea 2:1 (32.16%), whereas the second highest one was in cotton-sesame 1:1 (27.33%), while the lowest parasitization was recorded in the control (16.16%). On the activity of Trichogramma spp., the significant highest percent was recorded in cotton-sesame 1:1 (10.93%), while no activity was recorded in cotton-pigeonpea, cotton-sorghum, cotton-pearl millet, and control treatments.