230 



Cccidomyia carycccola O. S. (Hickory Seed-gall.) 



This gall was taken on Carya ovata leaves in the upland forest 

 (Sta. IV, a) Aug. 20 (No. 107); and Aug. 26 (No. 170). Many 

 galls are formed on hickory and other trees by plant-lice (Cf. Per- 

 gande, '02). 



AsiUDiE 



Deromyia discolor Loew. 



This robber-fly was taken in an open area in the lowland forest 

 (Sta. IV, c) Aug. 20 (No. 117). Williston (Kingsley's Standard 

 Natural History, Vol. 2, pp. 418-419. 1884) states that most robber- 

 flies "rest upon the ground, and fly up when disturbed, with a quick 

 buzzing sound only to alight again a short distance ahead. All their 

 food, which consists wholly of other insects, is caught upon the 

 wing .... Other flies and Hymenoptera are usually their food, 

 but flying beetles, especially Cicindelidcs, are often caught, and they 

 have even been known to seize and carry off large dragonflies. Not 

 only will they feed upon other Asilidcc, but the female frequently 

 resents the caresses of her mate by eating him up, especially if he is 

 foolish enough to put himself in her power. In an instance the 

 writer observed, a female seized a pair of her own species, and thrust- 

 ing her proboscis into the thorax of the male, carried them both off 



together The larvae live chiefly under ground or in rotten 



wood, especially in places infested with grubs of beetles upon which 

 they will feed. The young larvae will bore their way completely 

 within beetle larvae and remain enclosed until they have consumed 

 them. Many, however, are found where they evidently feed upon 

 rootlets or other vegetable substances. They undergo their trans- 

 formations in the ground. The pupae have the head provided with 

 tubercles, and on the abdominal segments there are also spiny pro- 

 tuberances and transverse rows of bristles, which aid the insects to 

 reach the surface when they are ready to escape as flies." Mar- 

 latt (Proc. Ent. Soc. Wash., Vol. 2, p. 82. 1893) observed D. dis- 

 color preying upon wasps of the genus Vespa. By seizing the head 

 of the wasp it avoids being stung. 



Deromyia umbrinus Loew. 



A specimen of this large robber-fly was taken in the south ravine 

 (Sta. IV, d) by T. L. Hankinson, with the eucerid bee Mclissodes 

 pcrple.va Cresson in its grip, Aug. 22, 1910 (No. 7530). 



