305 



turbed the larva retreats swiftly to the more densely woven part of its 

 cover. 



Length of fnll grown larva from 7 to 8 mm , diameter 1.5 ram , nearly 

 equal throughout, form depressed, sutures deep, especially laterally ; 

 surface smooth; color dingy translucent white, with a broad, smooth 

 pale purple dorsal band extending from the secoud to the tenth segment. 

 Head small, about one-half the diameter of the first thoracic segment, 

 opaque, yellowish white. Piliferous spots miuute, impressed, hairs 

 microscopic. Legs and prolegs yellowish white, almost transparent. 



In preparing for its transformations, the larva thickens its tent of 

 white silk, which is externally somewhat disguised by a skillful inter- 

 mingling of powdery particles of the cuticle of the leaf. It lines the 

 under side also with a mat of silk and then proceeds to cut out a broad 

 oval section around the densest part of the web, about one-half inch in 

 length. This is joined at the edges and forms an Aspidisca -like case, 

 which is dragged to some distance from the injured portion of the leaf 

 and firinlv attached to the under surface by a broad band of silk from 

 one-eighth to one-fifth of an inch long appearing like a handle to the 

 slightly curled case (Fig. 63b). Within this case the larva changes to a 

 somewhat flattened, pale brown pupa, in which state it hibernates. 



The imagines usually appear in April, often at long intervals. Of 

 the three specimens bred, one emerged on the 14th of March, one on 

 the 14th of April, and the third on the 24th of the same month. I also 

 captured a single damaged specimen some years ago during the month 

 of May. It is not in this locality at least an abundant species. 



EXPERIMENTS WITH THE PLUM CURCULIO. 



By F. M. Webster. 



These experiments were originally intended as a continuation of those 

 made during 1888 and published in the annual report of the Department 

 for that year, pp. 78, 79. On account of a lack of material, especially 

 of the domestic varieties of plums, the result of previous experiments 

 did not reflect as conclusively upon contested points as desired ; and as 

 it would hardly be proper, at the present time, to summarize results 

 based on one set of experiments made during one season, aud another 

 the next, under more or less varying conditions, the series this year 

 are also intended to repeat and elaborate some of those made on the 

 wild varieties last season. 



The source whence the material was secured is given in the rec- 

 ords of each experiment, aud I will only add that the larger portion 

 of the first was taken by myself, beneath the trees from which it had 

 fallen, the point being to change the conditions under which it was 

 found only so far as necessary to a change from one locality to another. 

 21715— No. 10 — -2 



