ELEMENTARY ENTOMOLOGY 



A better appreciation of these general facts concerning insects' 

 growth will be secured by a more intimate study of the life of one 

 or two of each of the types of metamorphosis. 



The life of a squash-bug (Anasa tristis). Incomplete metamor- 

 phosis. About the time that squash, cucumbers, and melon vines 

 begin to " run," there is found here and there a wilted leaf, which 

 examination shows to be due to the common grayish- or brownish- 

 black squash-bug which has just emerged from hibernation. If 

 search be made in the early morning, the bugs will usually be 



found secreted under 

 clods of earth, or what- 

 ever rubbish may be 

 near the vines, from 

 which they emerge to 

 feed during the day, 

 flying about with a 

 characteristic buzz. 



Egg. For the next 

 month or six weeks the 

 females deposit their 

 eggs, mostly on the un- 

 dersides of the leaves. 

 The eggs are oval, 

 about one sixteenth 

 inch long, attached on 



FIG. 62. The squash-bug, adult and nymphs of first, 

 third, and fifth stages. (About twice natural size) 



(Photograph by Quaintance) 



one side, and laid in 

 irregular-shaped clus- 

 ters arranged in rows as shown in Fig. 63, from three or four to 

 forty eggs being found in a cluster. Newly laid eggs are a pale 

 yellow-brown, which grows darker a day or two before hatching, 

 so that the approximate development may be determined by the 

 color, which is the case with many insects' eggs. 



Nymph. In about eleven days, the exact time varying from six 

 to fifteen days according to the temperature, a small, disk-shaped 

 piece of the shell is forced open toward one end of the egg and 

 the little nymph emerges. The newborn buglet is brilliantly col- 

 ored and is quite conspicuous against the green leaves, the antennae 

 and legs being a bright crimson, the head and anterior thorax a 



