THYSANOPTBEA OK THEIPS. 



233 



THTSANOPTERA. 



Thrips, or Black Fly. 



The Thrvpidm, or Black Fly, sometimes called Thunder-fly, 

 form a distinct order of insects, characterised by having 

 four thin, narrow, fringed wings and an imperfect suctorial 

 mouth. The metamorphosis is very slight. Several of them 

 are injurious to crops, and are equally obnoxious in green- 

 houses. Thripidse are minute dark insects in their adult 

 state, and feed by suction, although the mandibles are repre- 

 sented by a pair of needle-like processes. One species, Thrips 

 cerealium (fig. 118, 1 and 2), is often very harmful to com. 



Fig. 118.— Thrips. 



1, Female Th/rvps cerealivm with wings closed ; 4, with wings expanded ; 2, 3, 5, 7, 

 nat. size ; 6, larva of T. mimitissima ; 8, T. mimutismna. (Curtis.) 



The larva and pupa are similar to the adult, but are smaller 

 and differ in colour : the larva is deep yellow, with two dusky 

 spots on the thorax ; the pupa is pale yellow, with white legs, 

 antennae, and wing-cases. The eyes and ocelli are reddish. 

 The adult is deep black and winged in the female, apterous in 

 the male. The legs are paler, and the two-jointed tarsi terminate 

 in a little gland, hence they are sometimes called " Bladder-feet." 

 The Corn Thrips is about | of a line long. This pest feeds off 



