Larval pupation site preference (PSP) of different species of Drosophila was analyzed on fruit in the laboratory. The larvae of D. melanogaster, D. ananassae, D. virilis, D. novamexicana and D. hydei pupated on the surface of glass vials; D. simulans, D. yakuba, D. mauritiana and D. malerkotliana pupated in/on fruit; and D. rajasekari pupated on cotton plugs in all experiments. D. bipectinata larvae changed their preference from fruit in the control to glass surface for all of the fruits tested. The statistical analysis of PSP (glass and fruit) found a significant result in that compared to other species, D. mauritiana and D. ananassae preferred to pupate on cotton compared to the control.

The pupation site preference and the quantity of larval salivary gland secretion proteins (glue proteins) were analysed in 15 species of Drosophila belonging to 3 species groups. The results showed that even under constant environmental conditions, the larvae of different species prefer to pupate at different sites in various proportions. Three patterns of pupation site preference could be recognized on the basis of the preponderance of larvae pupating at different sites. The classification of different species of Drosophila under study into 3 pattern groups does not correspond with their taxonomic classification. The larvae of those species that synthesize large quantities of glue protein tend to pupate in the medium, while those synthesizing half the quantity of glue proteins pupate on the sides of the container (glass wall). The quantity of glue protein is not correlated with the size of the salivary glands.

Developmental morphometry, qualitative and quantitative analysis of the accessory gland secretory proteins, fecundity and productivity in relation to protein ejected during subsequent (first to fourth‐time) matings have been studied in Drosophila ananassae Doleschall and Drosophila varians Bock. In both species, size and secretion of accessory glands increases from 1 to 8 days and the stored secretion ejected from males to the female genital tract during subsequent mating varies. The maximum number of eggs and flies are produced from the females mated with bachelor males and it is a minimum when virgin females are mated with fourth‐time mated males. Sodium dodecylsulfate–polyacrylamide gel electrophoresis analysis of accessory gland secretory protein patterns and their glycosylation differs in both the species. Correlation coefficient analysis between gland size and quantity of secretion, percentage of secretory protein transferred per mating, and eggs and flies that emerged showed a highly significant, positive relationship. Among different matings, the number of eggs laid and flies that emerged per female between subsequent (first to fourth‐time) matings of males was found to be highly significant and the difference between fecundity and productivity between the two species was highly significant.

For the first time, the glue protein pattern polymorphism in natural populations of D. n. nasuta and D. s. neonasuta has been analyzed by SDS-PAGE. The study involving 200 and 185 isofemale lines comprising 2028 and 1900 individuals of D. n. nasuta and D. s. neonasuta, respectively, revealed the occurrence of eight variant glue protein phenotypes in D. n. nasuta and seven in D. s. neonasuta. The number and frequency of variant phenotypes in different populations of both species were found to vary. Analysis of glue protein patterns in the F1 progeny of crosses involving parents with variant glue protein phenotypes revealed that the polymorphic fractions are produced by co-dominant genes located on the X chromosome. More than 87% of the naturally inseminated adult females were found to produce polymorphic progeny. The heterozygous female larvae were found to exceed the homozygotes in the isofemale line progeny of most of the populations.

The population assemblage of Drosophilidae in the four districts of North Western Ghats was analysed. A total of 13,604 individuals comprising 17 species collected from 8 localities during the period of 2021-22 across various seasons. The study highlights the dominance of three species (Drosophila bipectinata Duda, D. malerkotliana Parshad & Paika and D. eugracilis Bock & Wheeler) belonging to ananassae and eugracilis subgroups.Overall collection data revealed the highest species richness and diversity for Dharwad and UK interior forests, whereas the maximum abundance and the highest evenness were observed in UK coastal and Belagavi forests respectively. The species rank-abundance curve revealed Dharwad forest had higher species richness and comparatively stable species assemblage. Drosophila eugracilis was the dominant species in localities of Dharwad and Belagavi forests, whereas D. bipectinata was the dominant species in both coastal and interior localities of UK forests. Rare faction curves plotted across the different seasons for all the forest localities revealed population assemblage and species richness of all forests across different seasons. Morisita index of similarities showed similarities for populations across localities and seasons. Nonparametric independent sample Kruskal-Wallis test was done to test distribution of abundance of individual species across spatial and temporal groups. The study reveals variation of population assemblage across the forests of Dharwad, Belagavi, and Uttara Kannada (coastal and interior) and dominance of D. bipectinata, D. malerkotliana and D. eugracilis.