New York Ageicultueal Experiment Station. 407 



In 1911 some caterpillars continued to feed on apple leaves until 

 June 30. Pupation commenced June 26 and continued until July 6. 

 Adults first appeared on July 10, and some continued to emerge 

 until July 17. One moth lived until August 15. 



During 1912 a colony of caterpillars, apparently in the second 

 larval instar, was collected on June 12 and these on June 24 were in 

 the fourth instar. On July 1 the caterpillars began to pupate and 

 the last cocoon was spun July 17. Moths made their appearance 

 on July 10 and some continued to emerge until July 15. One moth 

 which was confined in a breeding cage lived until August 17. 



FUTURE IMPORTANCE OF THE INSECTS. 



The occurrence of the Yponomeuta caterpillars in New York 

 during recent years raises the question as to the role these insects 

 are destined to play as fruit pests in the United States. This cannot 

 be answered satisfactorily as so little data is available upon the 

 actual behavior of these lepidopterons in this country. Our knowl- 

 edge regarding them in New York is limited solely to a small terri- 

 tory about nursery plantings in certain nursery centers, and if they 

 exist in other states they have apparently not attracted attention. 

 With the ability of these insects to survive the conditions incidental 

 to the importation of nursery stock from abroad and to escape the 

 ordinary nursery inspection, the wonder is that they have not before 

 this succeeded in establishing themselves along the avenues of trade 

 in America. For it is to be noted that in New York a close super- 

 vision over shipments and plantings of imported nursery stock has 

 only been maintained since 1909 and the condition of foreign pur- 

 chases with respect to the ermine moths and other dangerous species 

 as a result of more rigid inspection is well known. If earlier impor- 

 tations were as commonly infested with these pests as they have 

 been during the past four years it would seem not improbable that 

 somewhere these moths have made their escape from nurseries to 

 adjoining plantings where perhaps they have secured a foothold. 

 In states where there has been no such inspection the danger that 

 such has taken place is obviously much greater. 



Since the discovery of the ermine moths in this State the Division 

 of Nursery Inspection has taken special precautions with imported 

 stock and whenever infested plants have been detected they have 

 been destroyed. In addition the surroundings of nurseries have 

 also been inspected and there has so far been no evidence that these 

 lepidopterons have gained a footing in New York. Nevertheless 

 pests of foreign origin have entailed such great losses upon our 

 farmers that it would be unwise for the nursery-inspection service 

 in all of the states not to recognize the danger threatened by these 

 moths and seek by precautionary and other measures to prevent 

 them from becoming permanently established in this country. 



