REPORT OF THE ENTOMOLOGIST. 19 



the body. Then, if it were possible, a denuded potato-stalk should be 

 shown, to exhibit the method in which they carry on their work of de- 

 struction ; and, lastly, the army of parasites that help to check their rav- 

 ages, with samples of chemicals and artificial contrivances in use by 

 man to accomplish the same end, would close the short but instructive 

 lesson. Each card should be labeled with the scientific nud common 

 names of the specimen, or with any information necessary to comi)lete 

 the history of the insects. 



Should he desire to know what other species are destructive to the 

 potato, in like manner he will learn the history of Lema triliniata, Bari- 

 dhis trinotatus, and other species. When an insect is a general feeder, 

 it may be shown in the case devoted to two or three only of the plants 

 it is most destructive to, though on the card-label the other plants it 

 feeds upon should be named, or, if found on vegetation generally, the 

 word "oDJuivorous" explains the fact. 



The design of arrangement has not been as fully carried out as could 

 be desired, chiefly for want of specimens, particularly those illustrating 

 the early stages of the insects. The present collection, though, is a com- 

 mencement, forming the nucleus of what may some day be the full 

 realization of a complete cabinet of economic entomology. In colleges 

 and other institutions, however — as is the case in our own cabinet — such 

 a collection should be accompanied by a working collection, arranged 

 according to families, tribes, genera, and species, in order that the stu- 

 dent may familiarize himself with classification while studying the habits 

 of insects in relation to our farm-products. 



The groups exhibited in the twenty-four cases exhibited at the Cen- 

 tennial are as follows : 



Case A. — Thirty-nine species of insects, destroying, either directly or 

 indirectly, the root, stalk, foliage, or fruit (in the field and in the granary) 

 of Indian corn or maize. 



Case B. — Insects destroying (or proving injurious to) wheat, rye, oats, 

 and other cereal crops. Twenty-two species. 



Case G. — Insects destroying or injuring cotton. Thirty-three species. 



Case D. — Insects destroying or injuring the potato, [SoJanum tubero- 

 sum.) Sixteen species. 



Case E. — Insects proving destructive to cucurbitaceous plants, as 

 squashes, melons, &c. Seven species. Insects destroying milkweed. 

 Twenty-five species. 



Case F. — Insects destroying cabbage, turnips, &c., or the plants of the 

 kitchen-garden. Twenty-eight species. 



Case G. — Insects injuring the grape-vine or its fruit. Thirty-one spe- 

 cies. 



Case H. — Insects injurious to fruit, fruit-trees, &c. Twenty-six species. 



Case I. — Insects destroying or proving injurious to the apple. Twenty- 

 nine species. 



Case J. — Insects that annoy the housewife, commonly called " house- 

 hold pests." Forty-one species. 



Case iT.— Insects aiding in the destruction of forest-trees. Thirty- 

 seven species. 



Case L. — Insects destroying the pine. Thirty-nine species. 



Case M. — Insects destroying shade-trees. Twenty species. 



Case N. — Insects injurious to man, by injuring or destroying the wood 

 of various plants. Twenty-eight species. 



Case 0. — Gall-insects on oak. Twenty-seven species. 



Case P. — Gall-insects of other plants. Forty-four species. 



Case Q. — Insects destroying the eggs or young of fishes. Fourteen 



