146 MANUAL OF VEGETABLE-GARDEN INSECTS 



more clusters. The average length of the egg-laying period 

 in the field is [)r()hahly between four and six weeks, but under 



cage conditions 

 the beetles have 

 continued to lay 

 eggs for ten weeks 

 or more. The 

 eggs hatch in four 

 to nine days. On 

 hatching, the 

 young larva be- 

 gins at once to 

 feed on the leaves. 

 In the first stage 

 it is about ^o i^^^^h 

 in length, dark 

 red in color with 

 the head, thoracic 

 shield and legs black and with a double row of black spots 

 along each side of the body. In the course of its development 



the larva passes through three or 



four stages according to different 

 observers. In the last stage it is 

 about f inch in length ; the head, 

 legs and posterior part of the cervi- 

 cal shield are black; the body is 

 red, lighter than in the first stage 

 and there are two rows of distinct 

 black spots on each side ; the ab- 

 domen is strongly convex and is 

 much larger than the head and 

 thorax (Fig. 83). The larviie be- 

 come full-grown in ten days to three weeks and then enter 

 the ground to a depth of several inches where they transform 



Fig. 83. — Larvae of the Colorado potato })eetle ( X |). 



Fig. S4. — Pupa of the Colo- 

 rado potato beetle ( X 4). 



