New Yoek Agricultural Experiment Station. 463 



Fit 



29. — Adult Female of Cacus acanthi: 

 antenna of male. 



1912, three adults emerged in the box containing eggs of nigricornis 

 and on the following day one more appeared. (Fig. 29.) The adult 



is 2.3 mm. in length. 

 The body is entirely black 

 except the legs which are 

 dark brown. The abdo- 

 men is 6-jointed, slender, 

 flattened, and club- 

 shaped. The front wings 

 have the submarginal 

 vein meeting the costa 

 just beyond the middle; 

 the stigmal vein is curved, 

 oblique, and terminates 

 in a knob. Both sexes 

 have 12-jointed antennae; 

 in the male they are 

 filiform (Fig. 29, a); in 

 the female the first joint 

 or scape is very large; the 

 second, third and fourth slender, the fifth and sixth transverse, 

 and the remaining six segments form a compact club. 



A dipterous parasite. — On August 29, 1912, a puparium of some 

 dipterous insect was found in a bottle with a sickly, yellowish- 

 looking specimen of quadripunctatus in the fifth nymphal instar, 

 which was still alive. By dissecting a number of specimens of tree 

 crickets we found one which contained a larva of the same parasite. 

 This larva was large and ovoid in shape, and of a pale yellowish 

 color. It occupied the abdominal cavity above the alimentary 

 canal and below the fat body. The cricket was alive when cut 

 open, but it was of an abnormal yellowish color and the abdomen 

 was distended. The parasitic larva pupated but we were unable to 

 rear adults from the two puparia. 



Mermis sp. In our rearings of tree crickets we have occasionally 

 noticed examples of parasitism with hairworms. Individuals that 

 were parasitized became quite sluggish in their movements during 

 the last stages of life and were more or less discolored. The tip of 

 the abdomen was generally blackish and there were also indications 

 of a dark-colored discharge from the anus. Nymphs of the fourth 



