. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. THE BA ;-WORM. 23 THE BAG-WORM. {Thyridojjteryx ephemerceformis Haw.) Although this species was not particularly destructive to our shade- trees in 18SG, and in numbers greatly inferior to the Fall Web-worm and the Tussock-moth, yet in 1879 it was much more formidable, and at irregular intervals becomes a great pest where not properly dealt with, especially in more southern States. For the past two or three years it has been on the increase in special localities in Washington, and should be carefully looked after
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. THE BA ;-WORM. 23 THE BAG-WORM. {Thyridojjteryx ephemerceformis Haw.) Although this species was not particularly destructive to our shade- trees in 18SG, and in numbers greatly inferior to the Fall Web-worm and the Tussock-moth, yet in 1879 it was much more formidable, and at irregular intervals becomes a great pest where not properly dealt with, especially in more southern States. For the past two or three years it has been on the increase in special localities in Washington, and should be carefully looked after. HABITS AND NATURAL HISTORY. The Egfjs. — Davmg winter time the dependent sacs or bags of this species may be seen hanging on the twigs of almost every kind of tree. If they happen to be on coniferous trees, and they are usually more abundant on these than on deciduous trees, they are not infrequently mistaken for the cones. In reality they are the coverings spun by our worm, and they serve not only as a protection to it, but also to the eggs. Upon cutting open the larger of these bags in winter time they will be found to contain the shell of a chrysalis (technically called the puparium), which is lilled with numerous small yellow eggs (Fig. 7 e). Each of these is a little over 1 millimeter in length, obovate in form, and surrounded by a delicate, fawn-colored, silky down. In this con- dition the egg>i remain from fall throughout the winter and early Fia. 7.—Thyridopteryx ephemerceformin: a, lart-a;-6, male chrysalis; c, fc-male niolli; d, inalo iiiotli; e, follicle and puparium cut open to'show oirgs; /, full j4rown "larva with bas; g, voiintJ laivic with their coDical upright coveiings; all natural size. The Larva and its Bag.—About the middle of May in this latitude the eggs hatch into small but active larvte, which at once commence to cou-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for
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