Ill 



SCOLIIDAE MUTILLIDES 



95 



much to be desired. From the observations of Radoszkowsky 

 it is clear that other species of Mutillides are by no means 

 confined to the nests of Bovibus but live at the expense of 

 Aculeate Hymenoptera of various groups. This naturalist asserts 

 that the basal abdominal segment of the parasite resembles in 

 form that of the species on which it preys. 



The apterous condition of the females of Mutillides and 

 Thynnides is very anomalous in the Fossors ; this sex being in 

 the other families distinguished for activity and intelligence. 

 The difference between the sexes is also highly remarkable. The 

 males differ from the females by the possession of wings and by the 

 structural characters we have mentioned, and also in a most striking 



8 



FIG. 38. Mutilla stridula. Europe. A, Male ; B, female. 



manner in both colour and form ; Burmeister, indeed, says that in 

 South America the metropolis of Mutillides there is not a single 

 species in which the males and females are alike in appearance ; this 

 difference becomes in some cases so extreme that the two sexes of 

 one species have been described as Insects of different families. 



Upwards of one thousand species are assigned to the genus 

 Mutilla, which is distributed over the larger part of the world ; 

 there is so much difference in these species as to the nervuration 

 of the wings in the males, that several genera would be formed 

 for them were it not that no corresponding distinctions can be 

 detected in the females. Three or four species of Mutilla are 

 described as being apterous in the male as well as in the 

 ft -male sex ; they are very rare, and little is known about them. 

 Only three species of Mutillides occur in Britain, and they are 

 but rarely seen, except by those who are acquainted with their 



