1913 



ENTOMOLOGICAL SOCIETY. 



15 



The Ameiucan Tent Caterpillar (Malacosoma americana). In my re- 

 port last year 1 referred to an exce])tioiial outlii'eak of this caterpillar in 191L 

 During the past season, however, the insect was present throughout the district 

 in much larger numbers and caused widespread defoliation, particularly of apple 

 and wild clicrry trees. The Jirst date this year on which the young caterpillars 

 were noticed to be emerging from the eggs was 30th April. At the end of the first 

 v,eek in May thousands of small nests were seen throughout the district, chiefly 

 on the above two trees. In the latter half of May it was a common sight to see in 

 aj^ple orchards men going around with lighted torches burning the webs contain- 



Pigs. 6 and 7. — American Tent Caterpillar (Male and Female Moth). 



ing the caterpillars. Early in June the defoliated trees were very conspicuous 

 throughout the in.fested area. On June 9, I counted 37 large nests on one medium 

 sized cherry tree. In the Gatineau Valley district in many orchards not a single 

 leaf was left on the trees. This was also the case in orchards, in general, througii- 

 out the entire Ottawa District. 



The CoiiLiNG Moth (Carpocapsa pomoneUa) was abundant in unsprayed 

 orchards. It seemed to be more numerous this year than in 1909 and 1910. Other 

 common orchard pests, as the Oyster Shell Scale {Lepidosaphes ulmi), the Fall 

 Webworm {H ij phantria textor) and the Pear Slug {Eriocampa cerasi) were also 

 present in un. usually injurious numbers. 



Insects Attacking Forest and Shade Trees. 



^.:'% 



Fig. 8. — Forest Tent Caterpillar. 



The most remarkable outbreak of an ir,jurious insect of which we have record 

 at Ottawa occurred in 1912, viz., that of the Forest Tent Caterpillar (Malacosoma 

 disstria). In the Gatineau Valley district miles of forest country were stripped 



