. Annual report of the State Entomologist of Montana . Fig. 8. The Fruit-tree Bark-beetle: a. adult beetle; b. same in profile; c,pupa; d, larva—all magnified about ten times. (Chittenden, Circular 29, , ^^y. of Entomology, U. S. Dept. or Agr.) 160 MONTANA EXPERIMENT STATION. diverge, however, and increase in size as the growing larva gnawsits way away from the main burrow. Most trequently the insectlives in such numbers, with its larval galleries so closely packed to-gether and so much confused with others that it is with difficultythat individual galleries can be distinguished. The
. Annual report of the State Entomologist of Montana . Fig. 8. The Fruit-tree Bark-beetle: a. adult beetle; b. same in profile; c,pupa; d, larva—all magnified about ten times. (Chittenden, Circular 29, , ^^y. of Entomology, U. S. Dept. or Agr.) 160 MONTANA EXPERIMENT STATION. diverge, however, and increase in size as the growing larva gnawsits way away from the main burrow. Most trequently the insectlives in such numbers, with its larval galleries so closely packed to-gether and so much confused with others that it is with difficultythat individual galleries can be distinguished. The larvae transform to pupae at the end of their galleries. Thenumber of generations varies in different parts of the country be-tween one or two and four. The species is a fairly common one in the eastern part of theUnited States and may appear on nursery stock shipped in for plant-ing in Fig. 9. Work of The Fruit Tree Bark-beetle in twig of apple—natural size.(Chittenden, Circular 29, Sec. Series, Div. of Entomology, U. S. Dept. of Agr.) THE PEACH TWIG-BORER, i. In Montana markets one may occasionally find peaches containingthe larvae of this insect and from its peculiar hibernating habits itis greatly facilitated in its distribution on nursery stock. The peach twig-borer is a pest of stone fruits and is very widelydistributed. From what is known of its habits it seems evidentthat should this pest gain access to the peach, plum, and cherrytrees of this state much injury might result. The presence of this insect on nursery stock is indicated by bitsof frass attached to the bark frequently in the crotches of branchesof twigs. Each of these bits of frass covers the entrance into asmall burrow within which a young larva may be found. Thelarva at this stage is of yellowish color with the head, the top of thesegment just behind it, and the posterior end of the body above,
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectinsects, bookyear1903
