. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. DESCRIPTION AND SEASONAL HISTORY. 23 When the larva is fully grown, it ceases to feed and seeks out some place in the crown of the plant among the litter and trash or on the ground among similar material, where it spins a cocoon (fig. 6). COCOONING AND PUPATING. The cocoon is composed of fine white threads and the construction by the apparently blind larva was in part observed by Mr. Ainslie, who describes its movements as follows: A larva was seen moving about in its snow-white, almost transparent, gauzy, unfini
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. DESCRIPTION AND SEASONAL HISTORY. 23 When the larva is fully grown, it ceases to feed and seeks out some place in the crown of the plant among the litter and trash or on the ground among similar material, where it spins a cocoon (fig. 6). COCOONING AND PUPATING. The cocoon is composed of fine white threads and the construction by the apparently blind larva was in part observed by Mr. Ainslie, who describes its movements as follows: A larva was seen moving about in its snow-white, almost transparent, gauzy, unfinished cocoon. It proved to be spinning a closer mesh from within. Instead of spinning the silk from a gland that opened into its mouth, as was supposed, the fluid from which the silk is made is taken into the mouth apparently from a gland in the caudal segment. The larva applied its mouth to an opening or gland close to the anus, appeared to move its jaws slightly, and then, with a quick movement of the body, was* straightened out as much as possible in its confined space, and instantly the head was applied to the inner network of the cocoon. A slender glistening thread was seen leaving the mouth, being attached glutinously to each thread that it crossed. The larva worked rapidly and nervously, nearly always car- rying its new thread in a rather straight line. From 30 to 50 seconds were required to discharge a single mouthful supplying thread for one-third or one-half a revolution fig. g.—The alfalfa weevil: cocoon. inside the COCOOn. Much enIarSed- (Author's illus- When all the supply was exhausted, the head groped aimlessly about for a few seconds, then was applied to the caudal gland as before. The body would then straighten with a quick movement and almost instantly the thread would be again flowing as before. The new thread was guided skillfully across the meshes, rarely if ever following the line of a thread already laid. A very slight jar would cause a sudden halt for p
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