96 



HVMENOPTERA 



habits. The African and East Indian genus, Apterogyna, includes 

 some extremely peculiar Hymenoptera ; the males have the wing 

 nervuration very much reduced, and the females are very ant-like 

 owing to the deep constriction l)eliind the first abdominal ring. 



Sub-Fam. 2. Thynnides. — -Males and females very different in 

 form ; the male tvinged, the front tving with three, or only 

 two, suh-marginal cells ; the female tvingless aiul vith the 

 thorax divided itifo three sub-equal parts. 



The Thynnides are by some entomologists not separated from 



theMutillides;but 

 the distinction in 

 the structure of 

 the thorax of the 

 females is very 

 striking. In the 

 Thynnides the 

 nervuration of the 

 wing appears 

 always to extend 

 to the outer 

 margin, and in the 

 Muti Hides not to 

 do so. This family 

 is represented in 

 Britain by a single very rare Insect, Methoca ichneumonides : to 

 tlie unskilled observer the female would appear to be without 

 doubt an ant. This Insect is by some considered as the type 

 of a family distinct from the Thynnides proper. Thynnides are 

 numerous in Australia. Very little is really known as to their 

 habits, though it has been stated that they are parasitic on 

 Lepidoptera, Bakewell having obtained specimens from sub- 

 terranean cocoons of that Order. Those who are interested in 

 differences between the sexes of one species should examine the 

 extraordinary examples of that phenomenon presented by the 

 Thynnides ; the dissimilarity throughout the group — wliich is 

 now of considerable extent — being so extreme that no ento- 

 mologist would from simple inspection believe the two sexes 

 to have any connection ; but the fact that they are so con- 

 nected has been demonstrated beyond doubt. In very few 



Fn;. S9.^Mcthoc(i Icltneiimonides. A, Male ; B, female. 

 Britain. 



