May, IDIS] Parasites of Leaf -Hoppers 247 



TAXONOMY. 



The relationships of the AnteonincB in the Hymowptera is a 

 much -debated question, but it is now generally concluded that 

 they are a sub-family of the BelhylidcB in the super-family 

 Proctotrupoidea. The larval sac is a structure which at once 

 distinguishes all A^iteonince, and at the same time shows their 

 possible affinity with such other forms that present this peculiar 

 characteristic. Of the three other sub-families that Kieffer 

 (1914) places with them under the BethylidcE, little is known of 

 the life history of the EmboIemincB and the Sclerogibbince. How- 

 ever, with the sub-family BethylincB, the genus Harpagocryptus 

 Perkins shows its relationship in the similar larval sac found 

 on the Orthopteron Trigonidium, which resembles that of the 

 genus Aphelopus. Perkins (1912) says: "It is interesting to 

 note that the elongate larval sac of Harpagocryptus and Aphel- 

 opus, so different from those of the other Dryinidce ( Bethylidce) , 

 is correlated with the possession of simple front tarsi in the 

 females." In working out the life cycle of Rhopalosoma poeyi 

 Cresson, parasitic on the jumping tree-cricket, Orocharis 

 saltator Uhl., Hood (1913) brought out the interesting fact that 

 here there is also a larval sac very similar to that of the Anteon- 

 incE. In commenting on Mr. Hood's paper in the same meeting, 

 Mr. Rohwer said: "One is confronted with the remarkable 

 resemblance between the larva of Rhopalosoma and some of the 

 dryinids. Perhaps the Rhopalosomidce and the {Dryinidce) 

 Anteonince had a common origin, as the larvae would indicate, 

 and the adults have specialized along different lines, though 

 retaining certain characters in common." Ashmead placed this 

 genus in a new family, which he included in the super-family 

 Vespoidea; and Rohwer believes that this is the more nearly 

 correct view. However distinct the adults of Rhopalosoma may 

 be from the Anteonince, the fact that larval sac is a feature in 

 common with both, and the development of this structure on 

 two widely- separated insect groups — the Homoptera and 

 Orthoptera — indicates at once an adaptation to the jumping 

 habit of these insects. 



The development and specialization of the chelate front 

 tarsus in the female may be taken as a criterion showing the 

 evolution of the group. The chelate tarsus is an adaptation of 

 the parasite to the structure and habit of the host. Along with 



