

THE PEACH AND PLUM SLUG. 



97 



the cold weather of April, and represent the result of abnormal 

 conditions. 



Unlike its congener, the pear slug, the larva does not eat its 

 exuvium. 



The escape from the exuvium is made through an opening at the 

 head end, the larva simply crawling out of its old skin and leaving it 

 as a narrow line of slime on the surface of the leaf. 



Immediately after molting the larvse very freqeuntly wander away 

 from the leaf on which they have been feeding to another, sometimes 

 2 or 3 feet distant. 



During the first four instars the larva is of a peculiar sluglike 

 appearance, swollen in front and covered with the slimy secretion 

 which hides the segmentation of its body. The head is pale brown 

 and the eye spots darker. The body is translucent and the course 

 of the alimentary canal can be traced by the green food within. On 

 molting for the fourth time, however, it loses its slimy coating and 

 appears as an opaque, yellowish, caterpillar-like larva (fig. 24, d), in 

 which the segmentation can be distinctly seen. It is from five- 

 sixteenths to three-eighths of an inch in length. 



During the last molt the larva deposits several pellets of excrement 

 within the exuvium. 



Tables II to V show the data obtained on the duration of the 

 different larval stages, and Table VI gives the data for the total 

 feeding period. 



Table II. — First larval period of the peach and plum slug, Tallulah, La., 1910. 



Lot No. 



Date of | Date of 

 hatching, first molt. 



110 Aug. 14 



111 Aug. 16 



112 ...do 



123 1 Sept. 21 



Apr. 9 

 Apr. 13 

 Aug. 25 

 Sept. 20 



112 

 116. 

 1123 

 1131 



Total and average. 



Aug. 15 

 Aug. 17 

 Aug. 18 

 Sept. 24 

 Apr. 11 

 Apr. 15 

 Aug. 27 

 Sept. 24 



Number 

 of indi- 

 viduals. 



6 

 3 

 3 

 2 

 10 

 5 

 4 

 1 



34 



First 

 larval 

 period. 



Days. 



1.0 

 1.0 

 2.0 

 3.0 

 2.0 

 2.0 

 2.0 

 4.0 



1.9 



Table III. — Second larval period of the peach and plum slug, Tallulah, La., 1910. 



Lot No. 



Date of 

 first 

 molt. 



Date of 

 second 

 molt. 



Number 

 of indi- 

 viduals. 



Second 

 larval 

 period. 



123 



Sept. 24 

 Aug. 27 

 Sept. 20 

 Sept. 21 

 Sept. 24 



Sept. 26 

 Aug. 29 

 Sept. 23 



...do 



Sept. 26 



2 

 5 

 7 

 20 

 1 



Days. 

 2.0 



1123 



2.0 



1129 



3.0 



1131 



2.0 

 2.0 







Total and average 



35 



2.2 











