128 



PAPEKS ON CEREAL AND FORAGE INSECTS. 



then, by means of the abdominal spines, works its way to the surface, 

 from which it protrudes about two-thirds of its entire length (fig. 65). 

 By swaying backward and forward the rapidly drying pupal skin is 

 soon split across the back of the head and down the dorsum of the 

 thorax. The swaying movement now serves to work the adult out 

 until the legs are freed, when with their aid it rapidly extricates 

 itself. The males usually appear first and are swarming in the fields 

 when the females emerge, so that the latter are mated when their 

 wings are hardly dry. In Pullman, Wash., the writer observed a 

 small cloud of Tipulidae (Dicranomyia venusta Bergr.) on April 27, 

 1909, hovering under the eaves of the government field insectary. 

 Other similar observations have been made on other species and C. N. 



Ainslie (1907) noted that 

 with Trichocera bimacula 

 Walk, this was a mating 

 process. 



NATURAL ENEMIES. 

 PARASITES. 



Among insect parasites 

 but one is known to attack 

 this species or, as far as 

 the writer knows, any 

 other tipulid in this coun- 

 try. It is a small tachinid 

 fly, Admontia pergandei 

 (fig. 66), described by Mr. 

 D. W. Coquillett in 1895. These parasites were first noticed in the 

 rearing cages in which the Tipula larvae were confined, on October 7, 

 when 4 specimens emerged. Within the next week 15 more specimens 

 were taken from this cage. This genus is recorded as parasitic on 

 Tipulidae in Europe, but heretofore has not been recorded as such in 

 this country. A female of this tachinid was dissected and found to 

 contain 103 elongate-elliptical white eggs measuring 0.564 mm. in 

 length and 0.146 mm. in diameter. 



OTHER INSECT FOES. 



Prof. F. M. Webster records the carabid beetles Pterostichus lucu- 

 blandus Say and P. femoralis Kirby as probably predaceous on these 

 tipulids. He also records (1888) the larvae of Harpalus sp. and 

 Platynus sp. as preying on the larvae and pupae of Tipulidae at Ander- 

 son, Ind., and the ant Aphcenog aster fulva Koger as found in the act 

 of dragging a living adult tipulid over the ground. 



The larvae of Trombidium sp. and Rhyncholophus sp. are often 

 found attached to the base of the wings and abdomen of tipulids. 



Fig. 66. — Admontia pergandei, a parasite of Tipula 

 infuscata. Enlarged. (Original.) 



