INSTITUTE, PUSA, FOR 1916-17 101 



lows of trees. It was found that, to secure viability, these 

 eggs require to be kept under moist conditions for some 

 time previous to desiccation, to mature their contents; this 

 condition fulfilled, they can resist desiccation for over six 

 months, and it is evident that at Pusa Stegomyia scutellaris 

 hibernates in the egg stage and so remains until the hol- 

 lows in trees are filled with rain-water towards the middle 

 of the year. 



At Pusa only Stegomyia scutellaris and Aedes thomsoni 

 have been found capable of resisting a long period of desic- 

 cation. In the following species, which also breed mainly 

 in hollows in trees under natural conditions, the capacity 

 to withstand desiccation is much less, viz., Stegomyia w- 

 album, Ochlerotatus gubernatoris, Armigeres obturbans, 

 and Cyathomyia brevipalpis. 



A rmigeres magnus was observed for the first time this 

 year at Pusa and its life-history was worked out. It is 

 rather a rare mosquito for this locality and appears in the 

 early portion of the rainy season, breeding in bamboo 

 stumps, and on very rare occasions in the hollows of trees 

 as well. Its bite is rather severe. It is larvivorous in the 

 larval stage and is the third known larvivorous species 

 available in this locality, the other two being Culex concolor 

 and A rmigeres obturbans. Though it is not so highly lar- 

 vivorous as Culex concolor, it is almost equal in this respect 

 to Armigeres obturbans. It lays its eggs in small clusters 

 loosely stuck to each other. They are bigger than Stego- 

 myia eggs. The full-grown larvse have comparatively large 

 gills and their wriggling motion resembles very much that 

 of Armigeres obturbans. 



Some observations have been made on the bionomics of 

 Cyathomyia brevipalpis, a sylvan species, which does not 

 suck human blood and which has the habit of congregating 

 in very large numbers in undisturbed, dark, dry places such 

 as hollows in trees. Its eggs are laid in clusters and it 

 breeds in hollows of trees as well as in stumps of cut bam- 

 boos. Its larval siphon is comparatively very large. 



