50 



ILLINOIS NATURAL HISTORY' SURVEY CIRCULAR 39 



known members of this order. Mosquitoes are probably the 

 most annoying single group of insects. In addition to economic 

 forms, the order Diptera includes midges, crane flies, bee flies, 



"1% 



Fig. 54. — Diptera. Hylemyia antiqua, the 

 onion maggot. Note the fly with only a single 

 pair of wings, the maggotlike larva without 

 legs, and the darker, egg-shaped pupa or qui- 

 escent stage. The larvae feed on the roots, 

 bulbs, and stems of the onion plants, and the 

 pupae are formed in the soil around the roots. 

 The adult flies emerge and lay eggs at the 

 base of the plants or in nearby cracks in the 

 soil. 



robber flies, bluebottle flies, and a great assortment of other dif- 

 ferent kinds of insects. 



Interesting are the bee flies, which mimic other insects such as 

 honey bees, bumble bees, and wasps to an extent that wins them 

 immunity from the attention of many beginning collectors. 



Siphonaptera Wingless insects that are conspicuously flat- 



Fleas tened sideways; with stout, spiny legs, and 



with numerous spines over the body ; without 

 conspicuous antennae or tails or a forked posterior appendage 

 like that of the springtails ; usually hard ; ranging in color from 

 yellowish brown to almost black. The cat and dog flea, Cteno- 

 cephalides canis (Curtis), is shown in fig. 55. All the fleas, which 



Fig. 55. — Siphonaptera. Ctenocephalides canis. cat and dog flea: a, the 

 adult; b, the egg; c, the wormlike larva; and. rf. the pupa. Actual length of 

 adult about 0.1 inch. 



