Seasonal Diversity of mosquito species in Dakshina Kannada district, Karnataka, India.

BACKGROUND & OBJECTIVES: Dakshina Kannada is one of the districts of Karnataka state of India with high incidences of mosquito-borne diseases, especially malaria and dengue. The larval stages of the mosquitoes are very important in determining the prevalence of adult mosquitoes and associated diseases. Hence, the occurrence of mosquito species was investigated by sampling different water bodies present in the Dakshina Kannada district from June 2014 to May 2017. METHODS: Random sampling was carried out from permanent and temporary, artificial and natural water bodies belonging to 11 types of microhabitats using dippers and suction pumps. RESULTS: A maximum of 37 mosquito species belonging to 12 genera were recorded with the dominant genera being Culex. Most species have been recorded from temporary bodies of water with the highest number of species in receptacles. Monsoon is the most productive season, both in terms of occurrence and abundance followed by post-monsoon and pre-monsoon. The abundance of mosquito larvae was significantly higher in temporary water bodies compared to the permanent. INTERPRETATION & CONCLUSION: Abundant rainfall in the study area which produces many natural and domestic temporary water bodies accounts for mosquito breeding throughout the year.

Trends of karyotypic evolution in the genus Hipposideros (Chiroptera: Mammalia).

The karyotypes of Hipposideros speroris, H. pomona, H. lankadiva, H. ceneraceus, H. ater and H. fulvus were analysed using conventional and banding technqiues. All six species exhibited the same 2n (32) and FN (60). The genus is remarkable for its apparent karyotypic stability. These species have only biarmed autosomes, one of which is a submetacentric marker chromosome with an achromatic gap. G-banded autosomes showed that most have remained conservative in the course of evolution of the species. Structural changes seemed to have occurred more frequently in the sex elements of the karyotypes rather than in the autosomes, and non-Robertsonian changes had an appreciable role to play in karyotypic evolution. This trend is probably dictated by the maximization of the biarmed condition which reflects the formation of stabilised linkage groups from the inception of the genus. It is proposed that the ancestral lineage of the genus Hipposideros was derived from a Rhinolophoid ancester whose karyotype was akin to Rhinolophus luctus.