INSTITUTE, PUSA, FOR 1916-17 97 



to lay their eggs. Even a watery appearance, such as is 

 produced by a window-pane or a cemented floor, has been 

 noticed to mislead these flies into laying their eggs. Leaves 

 of big trees hanging over water at a distance from 3 to 5 

 yards, logs of wood, etc., have also been utilized by these 

 flies for oviposition. Tabanus striatus and T . hilar is have 

 more or less the same habits. 



The eggs of the larger species of Tabanus found at Pusa 

 are always laid in a mass. These eggmasses are cemented 

 by gluey substances by the mother fly, apparently to pro- 

 tect them from enemies. Eggs of one species, probably 

 Tabanus speciosus, are covered up with some chalky sub- 

 stance by the mother fly. All these eggmasses are subject 

 to the attack of Chalcidid parasites. 



The flies of Tabanus nemocallosus are moderate in size 

 and their eggs are arranged in a mass, which is apparently 

 uncemented and without any definite shape. Eggs of other 

 large species are arranged more or less in a definite pattern 

 of their own. 



Tabanus nemocallosus requires a special situation to lay 

 its eggs. A plant, Phragmites kurka, which is conspicu- 

 ously taller than its neighbours and whose top portion 

 droops downwards over deep water is almost invariably 

 selected by this fly. Another plant, Lantana aculeata, hav- 

 ing the same posture as described above, was seen to be 

 utilized by these flies in June, 1917. As many as 19 flies 

 were counted engaged in oviposition and more than 200 

 eggmasses, old and fresh, were seen deposited on a single 

 plant of Phragmites kurka in June, 1917. 



Some fresh eggmasses of Tabanus nemocallosus were 

 crushed and the leaves of a plant of Phragmites kurka were 

 smeared with the juice to see if these flies are attracted to 

 such smell for oviposition but no fly seemed to take notice 

 of it. The same experiment was repeated with the leaves 

 of Lantana aculeata but met with a negative result. 



Under laboratory conditions the emerging larvae exhi- 

 bited the gregarious habit as usual. A very few of them 



