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Investigations were carried out during two consecutive Rabi seasons of 2014 and 2015 at the Experimental Farm of the Department of Seed Science and Technology, Dr Y S Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh, India to study the spatial distribution of Brevicoryne brassicae in cabbage. One month old cabbage seedlings were planted in the field in the month of November during both the years. Distribution pattern of any insect population is an important aspect as it represents the interaction between individuals of the species and their habitat. Spatial distribution is useful for designing efficient sampling programmes for population estimation and development of population models. Spatial distribution is also important to understand the bioecology of the pest and to determine the sampling protocol for that species. In the present study variance to mean ratio (s2/ X),mean crowding (X*), ratio of mean crowding to mean (X*/X), 'k' of negative binomial, Taylor's power equation (s2 = 0.9099X1.55 during 2014 and s2 = 2.9861X1.1949 during 2015), Iwao's patchiness regression and optimum number of samples (Nopt) required to achieve the desired precision were calculated for different densities. Cabbage aphid, B. brassicae appeared in the fourth standard week i.e last week of January( 26.2 aphids/ plant during 2014 and 0.30 aphids/ plant during 2015) and persisted upto thirteenth standard week i.e last week of April ( 18.4 aphids/ plant during 2014 and 18.2 aphids/ plant during 2015) and followed a negative binomial distribution during both years. Optimum number of samples (Nopt) required varied with mean density as well as precision level. The present study will serve as basic information to develop a sampling plan of B. Brassicae in cabbage for its monitoring and management. [ABSTRACT FROM AUTHOR]

The present experiment was conducted at a constant temperature of 25 ± 0.5 °C, 70 ± 5 per cent relative humidity and 14L: 10D photoperiod on French bean, Phaseolus vulgaris cv. contender plants in the Biocontrol Laboratory of the Department of Entomology, Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh, India. The study revealed that Encarsia formosa exhibited a Type II functional response both on the bases of parasitism and host kill with third and fourth nymphal instars of greenhouse whitefly. The functional response parameters i.e. handling time (Th), attack rate (a), effectiveness of parasitoid (a/Th) and the maximum parasitization rate (K) on total host kill by the parasitoid on third nymphal instar was 0.575 h, 0.037 h−1, 0.064 and 41.684, respectively whereas with fourth nymphal instar, handling time (Th), attack rate (a), effectiveness of parasitoid (a/Th) and the maximum parasitization rate (K) was 0.518 h, 0.044 h−1, 0.086 and 46.317, respectively. The area of discovery of the parasitoid with third nymphal instars decreased from 0.12 to 0.09 and with fourth instar it decreased from 0.14 to 0.09 with the increase in the density of the parasitoid from 2 to 8 for both the nymphal instars (third and fourth), respectively. The mutual interference coefficient with fourth instar was highest (m = 0.285) as compared to third instar nymphs (m = 0.166). It shows its effectiveness against the greenhouse whitefly. Hence, it can be utilized as one of the component of an integrated pest management programme of greenhouse whitefly, T. vaporariorum under protected cultivation. [ABSTRACT FROM AUTHOR]

The study was conducted at Pandah farm and Khaltoo farm of seed technology and production centre, Dr. Y.S. Parmar University of Horticulture and Forestry, Nauni, Solan Himachal Pradesh, India during 2012-2013 to find out the impact of habitat on insect pollinator diversity on coriander (Coriandrum sativum L.) bloom. The survey was conducted at two different habitats, in habitat 1, field was surrounded by cultivable crops while, in habitat 2, field was surrounded by natural vegetation. Insect pollinators were identified and the Shannon-Weiner diversity index was used to measure their diversity. The diversity of insects by different sampling methods (fluorescent pan traps, scan sampling and sweep net capture) showed that more insects were observed in coriander field surrounded by natural vegetation (habitat 2) as compared to field surrounded by cultivable crop (habitat 1). Thirty nine insects belonging to 31 genera under 18 families and 8 orders were observed in the experimental habitats surrounding coriander crop. Pollinator diversity indices compared for different sampling methods in both the habitats showed different trends. The pollinator diversity indices and eveness amongst the various groups was higher in habitat 1. Richness (H max) was same in both the habitats in all sampling methods indicating that the insect visitors groups were homogenous in the two habitats for individual sampling method. Different Shannon Weiner pollinator diversity indices for different sampling methods indicated that for sampling pollinator diversity all the methods have to be collectively employed as no single method is fully reliable. [ABSTRACT FROM AUTHOR]