4:90 



ARTHROPODA. 



FiG.525.— Cicada sepJeiirfecioi* seventeen year locust. (From Riley.) a, pupa; b, pupa 

 case from which the imago, c, has escaped; d, twig bored for oviposition. 



Fig. 526. —Cicada orni. (From Schmarda.) 



or Jassid^, contain some injurious forms, Ei-ythronura vitis damaging 

 the grape, while the true hoppers, Membracid^ (fig. 527), are scarcely less 

 injurious. None of these, however, are such serious 

 pests as the plant lice and scale insects. In the 

 CocciD^, or scale insects, the wingless female dies 

 after laying the eggs and covers them with her dead 

 scale-like body. Here belong the cochineal insects, 

 Coccus cacti* the dried bodies of which furnish the 

 pigment carmine, and the lac insects, Coccus Jacca, 

 as well as a host of injurious forms, like the orange 

 scale, Aspidotiis aiiraiitii,''- and the worse San Jose 

 scale, A. peniiciosKs,* which has recently been spread 

 throughout the country. The Aphid.e, or plant lice, 

 ari! sdft-skinncd and with tlicir honey-containing 

 c-Kcrcment form a subslralum for the growth of 

 injurious fungi. They reproduce largely by parthe- 

 nogenesis, a reason for their rapid multiplication ; 

 but their spread is not rapid, since the usually vivip- 



Fio. f,27.~Cfre!i'i huhn- 

 liis* liuftalo loaf liop- 

 I)cr. (After Marlatt.) 



