430 



ARTHROrODA 



like the oranr;c scale, Aspidoliis aiiranlii,''' and the worse San Jose scale, .1. 

 J-iriiirioiiisr' receiuly spreail throui;h tliis country. The AruiD.E, or planl lice, 

 are sofi-skinned ami with their honey-containing excrement form a substratum 

 for the growth of injurious fungi. They reproduce largely by parthenogenesis, 

 but their s]ire:id is not rajiid, since the usually \iviparous females are wingless. 

 At limes w inged females appear and spreail the ]iests. ^\■inged males appear 

 in the autumn; the fertilized eggs endure the winter. Xone is more injurious 

 than P// \'//.i.viVij vailalrix'-' of the grape, which with us does slight damage, but 

 in Europe has destroyed whole vineyards. Sub Order III. .VPTKR.V. \\'ing- 

 less bugs with direct development, commonly known as lice; three species attack 

 man, one living in the hair (PcJicuIus capitis*), the others {P vrsliiiiciilonnii* 

 and rhlliinits i)igui)ia!is*) upon the body. Other species on other mammals. 



Order IX. Diptera. 



Like the Rhynchota, the Diptera, or flies, are sucking insects, luit 

 the haustellum is dilTcrent, consisting of a tulje, formed of laliium and 

 lal.irum, containing stylets wdiich include, besides niandil.)les aitd maxilkv 

 (often rudimentary), tlte hvpopliarynx (hg. 44(1), Only tJte anterior 

 wings (hence Diptera) are de\'eloped, the hinder wdngs being replaced by 

 the haUcrcs or balancers, small drumstick-like struc- 

 tures richl}' sitpiplied with nerves and functioning as 

 organs of equilibration (lig. 4S0). The thorax is, 

 as in tlie Hymenoptera, sharply marked oft" from head 

 and abdomen, its somites frequeiitly fused. The de- 

 velopment is holometabolous, two kinds of larva" and 

 pupie occurring. The larva' are always apodal, but 

 have either a distinct liead with biitiitg mouth parts 

 or they are headless and ha^■e a rudimeirtary sucking 

 apparatus (hg. 4S4). The pupx are correspond- 

 ingly either free with powers of motion, or are pupa- 

 coarctatx (p. 41O). Development thus affords charac- 

 ters of systematic importance, artd these are supple- 

 mented by differences in length of legs, antenna-, haustellum, and in 

 body form. In number of species the Diptera stand next to the 

 Coleoptera; in number of individuals they far exceed them. 



Sub Order I. XF.MOCRR.V. Elongate with long, many-jointed antennre. 

 long proboscis, long legs. The larv;\i live in damp places or in water, where, 

 lacking legs, they swim by movements of the body, capturing their prey with their 

 strong mouth parts. The pupa- also can swim well. The aquatic larva- have 

 two respiratory tubes at the end of the abdomen; in the pupa; thev are on the 

 back. Best known are the innocuous crane Ihes (Tirui.iD.E) and the mosquitos 

 (CuLlciD.ic) with their numerous species affecting man, among them, .S/ci^'o/Hv/a,* 

 which carry yellow fever, and Anopheles* which distribute malaria. The Ci-ri- 

 DOMYiD.f. include the injurious Hessian fly, Ccciiloiiivia destrurlor* and the pa-do- 

 genetic .l/"m,s7fl/- (fig. 456). Sub Order II. TAIMYSTOIMA. Resemble the 

 ]Muscari;e in the short stout bodies, short anlennte and legs. They resemble 



^^ 



T'lG. 4S4. — Larva 

 of . I ulIiODivid caiiicu- 

 i ar i s [ahcv Lfuckaix) . 



