INSECTS INJURIOUS TO THE APPLE AND PEAR 573 



stages. With the third stage the small wing pads become visible 

 and in the fourth stage they extend halfway down the abdomen. 



Life History. The adults hibernate over winter under any 

 shelter available, such as the trash on affected fields, under 

 leaves, boards, stones, etc., and emerge in early spring. The 

 eggs are laid in Missouri in April. But little is known of the 

 places of oviposition, except that Taylor * has shown that some- 

 times apples are severely dimpled by the egg punctures. It is 

 evident, therefore, that the eggs are inserted in the stems or 

 leaves of the food-plants. The pale yellow egg is about one- 

 thirtieth inch long, oval, elongate, and flared at the outer end, so 

 as to be somewhat bottle-shaped. The first generation becomes 

 full grown in about a month, after which all stages may be found 

 feeding together until September or October. In southern 

 Missouri Professor Stedman states that there are three generations 

 while in northern Missouri only two, but the exact number has 

 not been carefully determined. 



Control. This is is an exceedingly difficult insect to control, 

 owing to the large number of food-plants and the fact that the 

 adult takes wing and flies off quickly upon the least disturbance. 

 As it sucks its food, arsenical insecticides are of course useless, 

 and some contact insecticide must be used with which the insect 

 may be hit. The nymphs may be sprayed at any time, but to 

 hit the adult bugs they must be sprayed in early morning, while 

 still sluggish. Spraying will be profitable where the nymphs 

 are abundant, but it is doubtful whether it will be found a satis- 

 factory means of combating the adults. Ten per cent kerosene 

 emulsion and tobacco extracts have been used successfully. 

 Where they are abundant the adults may be collected in consider- 

 able numbers by sweeping the foliage in early morning with a 

 strong insect net and then dropping them into kerosene. Clean 

 culture, including the destruction of all weeds, and such vegeta- 

 tion or trash as may furnish hibernating quarters, is important, 

 as it is observed that injury is always worse where weeds have 

 been allowed to multiply and the ground has been covered with 

 weeds and trash. 



* See E. P. Taylor, Journal of Economic Entomology, Vol. I, p. 370. 



