112 



ZOOLOGY. 



Germany on board ship, but in almost all cases the 

 pests so introduced have been recognized and caught. 

 Twice during 1877 they were able to increase 

 (Mulheim, SchUdau), and the same thing has hap- 

 pened once at a more recent date. (Torgau); but the 

 vigorous action of the authorities quickly exterminated 

 the beetles. 



Beetle (Fig. 81), half an inch long, dusky yellow, 

 with five longitudinal black streaks on each wing- 

 cover, and black markings on the neck-shield. Larva 

 (Fig. 82), half an inch long, thick, lieshy ; legs short 



Fro. 82.— Colorado Beetles : o, eggs ; 6, e, d, younger and older larvae ; «, pupse seen 

 from the ventral side and from the dorsal side. 



and weak. Orange-yellow, with shining black head, 

 and with black spots on the body segments. The 

 younger larvae are darker, almost blood red. When 

 the young potato plants come up, the beetles which 

 have survived the winter creep out of the soil and 

 devour the margins of the young leaves. The female 

 lays her yellow eggs (700 to 1200 ?) in heaps on the 

 leaves (Fig. 82, a). After a week the larvae appear, 

 and carry on the work of the beetles. They attain 

 their full development in seventeen to twenty days, 

 become pupae in the soil, and the beetles of the second 

 generation make their appearance in the middle of 

 June. Still a third generation may appear the same 



