Economic entomology for the farmer Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; economicentomol00smit Year: 1906 THE IXSECT WORLD. 387 the straw during the winter will check injury to a j^reat extent. It is certain that some near allies of Isosoma and perhaps some other genera of Chalcidids are, at least in jjart, vegetarians ; but, so far as I am aware, none other has proved in any true sense of the word injurious to cultivated crops. Hence, although, especially in the central and western parts of the United States,
Economic entomology for the farmer Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; economicentomol00smit Year: 1906 THE IXSECT WORLD. 387 the straw during the winter will check injury to a j^reat extent. It is certain that some near allies of Isosoma and perhaps some other genera of Chalcidids are, at least in jjart, vegetarians ; but, so far as I am aware, none other has proved in any true sense of the word injurious to cultivated crops. Hence, although, especially in the central and western parts of the United States, l''iG. 446. Isosoma tiitici.—a, b, larva ; /, atlult female ; .c fore-wing : h, hind wing; other letters are structural details. the 'joint-worm' may do some damage, yet it is so easily con- trolled that it scarcely affects the value of the family as a whole. The smallest of all our parasitic insects belong to the family Proctotrypidce, and even the largest of them would be ordinarily considered as small insects. Among them we find the greatest number of ^^^ parasites. As compared with the Chalcidids, these insects are rarely metallic in color, usually black or brown, sometimes yellow, and much more slender in build ; the body longer in proportion to the thickness. Their habits may be said to be in general like those of the other parasites, and they are not easily distinguished from them, except by the special student; but they rarely have the geniculated antennae described for the Chalcidids. None of these Proctotrypids are injurious, so far as we know, or feed on vegetable matter, though sojne are found in galls, appar- ently parasitic upon the original gall-maker. Taken as a whole, the parasitic Hymenoptera belonging to
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