102 INSECTS. 



converse appears in the Diptera. As also in the Diptera 

 the missing hind-wings are represented by a pair of 

 hammer-like balancers which grow in their place ; so in 

 Stylops, in front of the wings, and situated where the 

 fore- wings would have been, is a pair of curious appen- 

 dages, supposed to be aborted wing-cases or elytra. These 

 vary in form in different species, and, standing out from 

 the shoulders, add to the singular appearance of the 

 insect The thorax is disproportionately large, the abdo- 

 men small, slender and weak ; the antenna? are in various 

 species more or less complicated, being forked or branched; 

 the mouth is very imperfect, if even at all adapted to the 

 reception of food ; and the feet are without claws. 



The females never acquire wings, and never leave the 

 body of the bee or wasp in which they and the larva?, 

 whether male or female, are parasitic, swarming sometimes 

 (according to Mr. F. Smith) to the number of 200 or 

 300. It appears, however, that their presence is not, as 

 in the case of other insect parasites, actually fatal, living 

 bees and wasps being frequently observed with the exu- 

 viae of the perfected Stylops remaining in their bodies, 

 but it is supposed that they destroy the internal organs 

 and render the insects abortive. 



The parasite is buried up to its head in the body of 

 Fio . 41 the bee, which is usually much 



swollen, and this head being 

 flattened in shape has some- 

 thing of the appearance of an 

 acarus attached to the bee 

 between the segments of the 



abdomen. 

 Stylopized Andrena. -rr-n -j -, -t -i 



the eggs are laid, is a mystery which remains to be solved. 



