Parasitization of fifth instar tasar silkworm, Antheraea mylitta, by the uzi fly, Blepharipa zebina; a host-parasitoid interaction and its effect on host's nutritional parameters and parasitoid development.

The uzi fly, Blepharipa zebina, is a well-known larval endoparasitoid of the tropical tasar silkworm, Antheraea mylitta. The present study dealt with the effect of the number of maggots developing per host on host nutritional parameters, parasitoid development and reproduction. Nutritional indices for ingestion, digestion, approximate digestibility, relative consumption rate, relative growth rate, and gain in body weight declined significantly with the increase in parasitoid burden, but the efficiency of conversion of digested food recorded a significant increase. The efficiency of conversion of ingested food remained little affected. The developmental period was significantly extended in larvae parasitized with 5 and 10 maggots per larva (mpl). Cocoon shell weight decreased by 27-63.5% in parasitized groups (1, 2, and 5 mpl) while larvae parasitized with 10 mpl could not spin cocoons. The maggot development period, recovery percentage, and fecundity of the uzi fly declined significantly with the increase in number of maggots developing per host.

Geotrichum silvicola sp. nov., a novel asexual arthroconidial yeast species related to the genus Galactomyces.

Four strains of an asexual arthroconidial yeast species were isolated from Drosophila flies in two Atlantic rain forest sites in Brazil and two strains from oak tasar silkworm larvae (Antheraea proylei) in India. Analysis of the sequences of the D1/D2 large subunit rRNA gene showed that this yeast represented a novel species of the genus Geotrichum, described as Geotrichum silvicola sp. nov. The novel species was related to the ascogenous genus Galactomyces. The closest relatives of Geotrichum silvicola were Galactomyces sp. strain NRRL Y-6418 and Galactomyces geotrichum. The type culture of Geotrichum silvicola is UFMG-354-2T (=CBS 9194T=NRRL Y-27641T).

Food utilization efficiency in fifth instar larvae of Antheraea mylitta (Lepidoptera: Saturniidae) infected with Nosema sp. and its effect on reproductive potential and silk production.

Antheraea mylitta, a sericigenous insect of economical importance is often infected with an intracellular parasite of the genus Nosema. This pathogen is known to cause fatal pebrine disease and is considered as an important factor that strongly influences the development of the host. Larvae developed from the eggs laid by a female infected with Nosema sp. showed extended development period. The increment in the larval weight declined significantly in infected larvae in comparison to uninfected ones. Food consumption, digestion, relative consumption rate (RCR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and relative growth rate (RGR) values declined significantly, but at the same time a significant increase in approximate digestibility (AD) was also observed. Silk production declined in infected larvae. Silk gland weight and shell weight also significantly declined following infection over uninfected larvae. The reproductive potential in adults declined significantly (P<0.001) with decrease in ovary weight (31.6%), fecundity (54.1%), and fertility (34.9%). Egg chorionation was also affected in adults, which developed from infected larvae. The maternal infection level in one generation (10.4 x 10(6) spores/female) decreased significantly in the next generation (8.0 x 10(6) spores/female).