(32) 



body, this pupa works its way out of its prison, and once 

 out soon gives forth the perfect fly. The galls made by 

 these flea-lice are usually quite hard and woody, and gen- 

 erally one-celled." 



THE COXCOMB ELM GALL. Pemphigus ulmicola. FITCH. 

 (HEMIPTERA. APHID^E.) 



The leaves of the young Elms were very much infested 

 with the galls of this insect, during the past season, in the 

 valley of Springdale Cemetery. 



ITS NATURAL HISTORY. 



The egg deposited in the fall, hatches in early spring, 

 and the young larva stations itself upon the leaf, causing 



that part to bulge 

 out into a comb- 

 like appearance, 

 finally closing en- 

 tirely, making a 

 kind of prison. This 

 is. the wingless 

 mother-louse. The 

 gall increases as the 

 inhabitants af the 

 gall increase in 

 number and size. One louse will give birth to hundreds 

 of very minute and wingless young larvae, and by the end 

 of June or beginning of July the gall becomes full of lice 

 fully grown and winged. The leaf is then forced open 

 under the gall and they make their escape into the open 

 air. Parasites are often found inhabiting the same gall 

 with them, and man}' are thus destroyed. These resemble 

 the authors of the gall so closely that it often requires con- 

 siderable knowledge of Entomology to distinguish one 

 from the other. 



THE COXCOMB ELM OALL. 



