A CITY'S TREE WORK 



491 



larvae feed in groups usually on the 

 leaf or leaves adjacent to the one on 

 which the eggs are laid (1). At the 

 end of this period it begins to curl 

 these leaves up, spinning a fine web 

 about them which forms their winter 

 nest (2). In this nest it then molts, or 

 changes its skin, and grows to a larger 

 caterpillar (3). From this time on 

 until the leaves begin to turn and drop 

 off it emerges during the day, 

 feeds on nearby leaves, and re- 

 turns at night to the nest which 

 has been firmly attached to the 

 twig or branch. When the cold 

 weather comes they pass into a 

 dormant state and remain so 

 until the first warm days of 

 spring when they wake up, 

 come out of the nests and seek 

 food. As there are a great 

 many days in early spring 

 warm enough to bring them 

 out, before the leaves are out, 

 the young larvae burrow into 

 the buds for food, thus destroy- 

 ing many of them before they 

 open. As soon as the buds 

 have really started to open our 

 young pupae have molted again 

 and pass into their third stage 

 of growth. From this time on 

 until early June they continue 

 to feed and grow, usually keep- 

 ing the tree from leaving out. 

 During the last stage of growth 

 they become logy and do not 

 feed much but crawl about 

 looking for a place upon which 

 to form their cocoon. This 

 occurs about the middle or last 

 of June and is known as pupating. 

 From this time until early in July they 

 remain in the pupae or cocoon stage (4 

 and 5). You will see from this that 

 from early in June very little feeding is 

 done and the trees therefore have a 

 chance to leaf out again. During the 

 first week in July the cocoons open and 

 the adult moth (6 and 7), a small white 

 fellow with a tuft of brown hair at the 

 extremity of its abdomen, emerges, and 

 after a few hours, flies away. These 

 white moths live from three to five days. 

 At the end of the first day or two they 



mate, after which the female lays its 

 eggs (1) and very soon dies. These 

 little moths fly only by night and are 

 attracted by the lights of a town or 

 city. This accounts for the large num- 

 bers seen just after the Fourth of July 

 covering the electric light poles. After 

 the moth dies the eggs remain on the 

 leaves for a period of ten days or two 

 weeks, when they hatch out and the 



CONTROL OF ELM LEAF BEETLE ON STREET TREES. POWER SPRAYER 

 IN OPERATION AT FITCHBURG. MASS. 



young larvae begin their work again. 



"There has been much comment on 

 the flight of the moths during July and 

 many people believe this is the time to 

 kill them. A number of methods have 

 been devised and tried for doing this. 

 Bonfires are built and thousands of 

 moths destroyed. Men are employed to 

 go around every morning sweeping the 

 moths from the electric light poles and 

 burning them. Some have turned a 

 hose on the poles, washing them off and 

 probably drowning many of them. A 

 huge suction fan was constructed and 



