CORISIJE. 545 



" of a splendid golden appearance." The larvae and pupae of 

 several species of Coreus have been observed by Westwood 

 to "differ from the imago in wanting ocelli, possessing only 

 two joints in the tarsi (although there is a slight indication 

 of an articulation in the middle of the terminal joint) ; their 

 antennae also are much thicker, especially the intermediate 

 joint. The pupa of C. scapha differs also from the irnago in 

 having the margins of the abdomen notched." Several adult 

 forms of this group are known to be partially wingless. 



The Squash-bug, Coreus (Gonocerus) tristis DeGeer (Fig. 

 549) is very destructive to squash-vines, collecting in great 

 numbers around the stem near the ground, and sucking the 

 sap with its stout beak. It is a large, blackish brown insect, 

 six -tenths of an inch long, and dirty yellowish beneath. It 

 hibernates, leaving the plant in October. About 

 the last of June the sexes meet, and the females 

 "lay their eggs in little patches, fastening them 

 with a gummy substance to the under side of the 

 leaves. The eggs are round, and flattened on 

 two sides, and are soon hatched. The young 

 bugs are proportionally shorter and more rounded 

 than the perfect insects, are of a pale ash color, Flg- 549- 

 and have quite large antennae, the joints of which are some- 

 what flattened. As they grow older and' increase in size, after 

 moulting their skins a few times, they become more oval in 

 form, and the under side of their bodies gradually acquires a 

 dull ochre-yellow color." (Harris.) The young attack the 

 leaves, causing them to wither up. Successive broods are 

 said to appear through the summer. Professor Verrill has 

 found, with the assistance of Professor S. W. Johnson, of Yale 

 College, that the odor of this and other hemipterous insects 

 bears the most resemblance to that of the formate of oxide of 

 amyl, or the formate of amylic ether. It is probable that this 

 substance is its most essential and active ingredient. (Pro- 

 ceedings of the Boston Society of Natural History, xi, p. 

 160.) 



In Neides the body is remarkably thin and slender, repeat- 

 ing the form of Ploiaria, or of Spectrum among the Orthoptera. 



In Alydus the body is small, slender, the head prolonged, 

 35 



