242 SANITARY ENTOMOLOGY 



be found in low places where the ground is continuously wet. They are 

 usually quite near the surface, and can be located by scratching in the mud 

 and grass humus with the fingers. Where there is an accumulation of old 

 dead grass matted down in water, larvae are frequently found in this 

 grass. While this species prefers quite wet conditions, it is capable of 

 withstanding considerable drought. In making a test of drought resist- 

 ance I allowed one or two breeding jars containing larva? of this species 

 to dry out completely. One larva survived these conditions and produced 

 a perfect adult. The exact length of the larval stage of this species 

 has not yet been determined. 



I have found the larvae of Tabanus pu7ictifer to be quite numerous 

 along the shore of a lake in the Sierra Nevada Mountains. There was 

 considerable debris, — weeds, grass, and bulrushes washed up on the 

 shore. It was in this mass of partially decomposed vegetation kept 

 saturated by the waves of the lake, that the larvae seemed to flourish. 



Another Tabanus larva of an unidentified species was found in the 

 same general locality in the moist earth along the sides of small rivulets 

 high up on the lower mountain slopes. 



Prof. Hine records finding the larva? of Tabanus vivax Osten Sacken 

 in Ohio in tlie mud of a stream bed under riffles. 



Likewise, King found larvae of Tabanus kingi in the Egyptian Sudan, 

 under stones in a shallow stream where the water rippled over and around 

 the stones. The larvae were usually found under rocks not covered by 

 water. These larvae possessed pseudopodia specially fitted for clinging to 

 the stones and crawling up to the surface of the water to breathe. 



The same writer found the larvae of Tabanus ditaeniatus living in mud 

 at the bottom of a more sluggish stream, and coming to the surface of 

 the water periodically to breathe. 



King also mentions rearing adults of Tabanus par from eggs obtained 

 in a cage. The larvae were kept in jars of mud, and this mud was 

 allowed to dry up several times, and for a period of 57 days no growth 

 was made, yet when normal conditions were restored, the larvae began to 

 grow and completed development. This is somewhat in line with my own 

 experience with Tabanus phaenops, already mentioned. 



In the Philippines, Mitzmain found larvae and pupae of Tabanus 

 striatus in large numbers in sand at many points on the shore of Laguna 

 de Bay. 



Neave records finding Tabanus larvae in Northern Rhodesia in July 

 and August in the sand and mud of river banks. They often occurred, 

 especially if the mud was inclined to be dry, at a depth of as much as 

 6 or 8 inches. 



According to Hine some species of Tabanus larvae live in water for a 

 time and crawl out into dry ground, consequently one often finds Tabanid 



