206 



THE STUDY OF INSECTS 



politan insed injurious to the tomato, potato, egg-plant and tobacco. 

 ( )n the latter plant the larva is known as the tobacco splitworm. 



'I'lic adult is a small moth with the front wings mottled with black 

 and ochre and expanding a little over one-half an inch. The larva is 

 white often with a pinkish cast on the back and about § of an inch long. 

 There are several generations a year. 



The solidago gall-moth, (j'uorimoschema gallcesolidaginis . — There are 

 two kinds of conspicuous galls which are enlargements of the stems of 

 goldenrod; one of these is a ball-like enlargement of the stem and is 

 caused by the larva of a fly, Eurosta solidaginis , described in the next 



chapter; the other is spindle-shaped and is 

 caused by the moth named above. The eggs 

 are laid on the old plants in the fall and hatch 

 in spring. The young larva crawls to a new 

 shoot and boring down into it causes the 

 growth of the gall (Fig. 355). 



Sc /?, 



a ° Cu 2 



Fig. 355- — Gall of the solidago 

 gall-moth. (After Riley.) FlG. 356. — Wings of Peclinophora gossypiella. (After Busck.) 



The pink bollworm, Pectinophora gossypiella. — This species is re- 

 garded as one of the most destructive cotton insects known and ranks 

 among the half-dozen most important insect pests of the world. It 

 often reduces the yield of lint fifty per cent, or more and materially 

 lessens the amount of oil obtained from the seeds. 



The adult is a small dark-brown moth, with a wing-expanse of from -§ 

 to I of an inch. Figure 356 represents the shape and the venation of the 

 wings. The larva eats the seeds and tunnels and soils the lint, causing 

 the arrest of growth and the rotting or premature and imperfect opening 

 of the boll (Busck). 



The burdock moth, Metzneria lappella. — The stout white legless 

 caterpillar of this moth is common in the burs of burdock into which it 

 mines and eats out the seeds. It winters in the burs and transforms to 

 the moth in June and July. The moth is of a dull olive brown with 

 paler yellowish shades and streaks on the front wings. It expands from 

 I to f of an inch. 



