^6 INSECTS OF ECONOMIC IMPORTANCE 



The pear slug*^^ (Caliroa ccrasi) 

 Order — Hymenoptera 



Eggs laid in June in the leaf, hatch in 2 weeks 

 and the slugs become full-grown in 4 or 5 weeks, 

 when they shed their green skin for a yellow one 

 and go into ground to pupate; the flies emerge in 

 about 2 weeks ; two broods of the slugs, first in June 

 and second in August ; hibernate as contracted slugs 

 in their cocoons in soil. 



Control — Spray with arsenate of lead, 2>4 

 pounds to 50 gallons of w^ater, when slugs are first 

 seen. 



The SAN JOSE scale ^' (Aspidiofus pcniiciosus) 

 Order — Hemiptera 



One of our worst pests on fruit trees ; first estab- 

 lished in this country at San Jose, Calif. ; widely 

 distributed over the United States, and infests 

 apple, peach, pear, plum, currant, etc.; first de- 

 scribed by Professor Comstock in 1880; first discov- 

 ered in the eastern United States in 1893; its orig- 

 inal home is in China. The insects pass the winter 

 in an immature form — three-fourths grown — on 

 the branches of infested trees under small, circu- 

 lar, almost black scales; young are born in the 

 spring, in June, for first generation ; often but two 

 generations a season in New York State. 



Control — Spray with lime-sulphur, i gallon to 8 

 of water, fall and spring; spray old rough-barked 

 trees with one application of 25% oil emulsion; 

 summer strengths of lime-sulphur are effective 

 when young are hatching. 



36 Marlatt— U. S. Bu. Ent.. Circ. 26. 



37 Quaintance— U. S. Bu. Ent., Circ. 124. 

 Britton— Conn. Expt. Stat., Bull. 165. 



