AGRICULTURAL EXPERIMENT STATION. 177 



•was awarded a premium of fifty dollars and a gold medal bj- the 

 Masssaehusetts Agricultural Society. Tuis insect has spread over 

 the greater portion of the Unite 1 States and Canada and feeds 

 upon the foliage of the pear, quince, plum, and cherry doing more 

 -or less injury. Though called the pear slug it seems to prefer the 

 foliage of the cherry. 



FHi 27. FItt. 28. 



DESCKII'TION. 



Perfect insect — A four- winged fly of a glossy black color. The 

 ■wings are transparant with brownish veins and the fore wings crossed 

 by dusky markings ; legs dull 5'ellow with black thighs, excepting the 

 bind pair which is yellow in the middle and black at the extremeties. 

 The female is about one-fifth inch long and the male smaller. The 

 perfect insect is shown in Fig. 27, enlarged. 



The eggs are small and deposited singly within semi-circular in- 

 •cisions made in the skin of the leaf upon the upper or under side. 



The larva or slug when grown is about half an inch long, slim3^ 

 'blackish or olive brown; head end smaller; head small, reddish, 

 and nearlj' concealed under the first segment of the body. The 

 joung larva is white, but soon becomes olive colored and slimy. 

 The last time it molts it elongates, loses it slimj' appearance and 

 becomes clear yellow or reddish ^-ellow, and soon crawls or falls t« 

 the ground, buries itself from one to four inches and changes to the 

 •chrysalis stage. It does not spin a cocoon but forms an oval cavity 

 in the earth and cements it together with slime, thus forming a 

 <;hamber within which it transforms. The larva is shown natural size 

 and enlarged in Fig. 28, 



LIFE HISTORY. 



The flies appear the last of May or early in -June and deposit 

 their eggs as described above. The eggs hatch in about two weeks. 

 ■The slugs change their skin four or five times and come to maturity 

 in about a month, crawl to the ground, change to chrysalis state, 



12 



