April, 11)18] Parasites of LeaJ-IIoppers 195 



In the species studied, the act of pairing was unobserved. 

 In spite of the fact that with Gonatopus erythrodes (Perkins) and 

 Ilaplogonatopiis americanus (Perk.) males and females were 

 placed together for observation under as natural conditions as 

 possible, neither sex paid any attention to the other. The 

 females were constantly running around among and over the 

 grass-blades as if searching for their prey. On the other hand, 

 the males were as a rule inactive, resting upon the sides of the 

 cage or on the grass leaves. Perkins (1905) concerning Echthro- 

 delphax, states that "pairing of the sexes is of short duration, 

 and after copulation the male frequently never moves again, 

 and in general dies very quickly. " 



Parthenogenesis occurs probably to a considerable extent 

 in this sub-family. This has been proven in captivity, and 

 undoubtedly occurs to some extent under normal outside con- 

 ditions. The great disproportion of sexes in some species, 

 and the fact that with others males have not been found, seems 

 to bear out that statement. In commenting on Pseudo gonatopus 

 Perkins (1905) says that but one in forty adults was a male. 

 Males have not been either captured or bred from species of 

 Eugonatopus or Agonatopiis. Adults from unfertilized eggs of 

 Gonatopus contortiilus Patton were all females, and were normal 

 and active in every way. 



Polyembryony has been recorded for this group in the case 

 of Aphelopus thelicE Gahan ms. parasitic on Thelia bimaciilata. 



The method of attack and oviposition is very similar for 

 nearly all species of the Anteonince. Upon nearing the prey the 

 female comes to a standstill, throwing her antennae backward 

 and swaying from side to side before making her jump. She 

 then throws herself upon the hopper, which may escape by a 

 quick jump. The chelate claws of the forelegs are thrust out 

 at the same time, and the prey is seized in this manner. Once 

 the hopper is captured, the female grasps it with all six legs, 

 and placing her body sidewise across that of the struggling host, 

 curls the tip of the abdomen under and thrusts the sting in 

 the ventral side of the thorax in the case with Gonatopus 

 erythrodes (Perk.) and Ilaplogonatopiis americanus (Perk.) 

 as observed by the writer, and with Echthrodelphax as noted by 

 Perkins (1905). With Gonatopus contortulus Patton, however, 

 the host is large and robust and winged, so that the method of 

 attack is varied. Here the prey is stalked from behind, and 



