354 



UTILITARIAN ZOOLOGY 



Injurious Beetles (Coleopterd). Many notorious malefactors 

 belong to this order. Among the most injurious are " wire- 

 worms ", which do great damage to the underground parts of 

 cereals, grasses, and root-crops, and are no other than the larvae 

 of the little Click- Beetles (Elaterida). The still smaller Turnip 

 Flea-Beetles (Haltica nemorum, fig. 1252, and H. unditlata), 

 popularly known as Turnip-" Flies", are very injurious to turnips 

 and related plants, for the adults attack the leaves from the 

 outside, while their larvae burrow within them. Some of the 

 " Chafers " are very injurious to trees, crops, and pastures. The 

 Common Cockchafer (Melolontha vulgaris), when adult, ravages 



the foliage of trees, while its 

 grubs live underground, and 

 attack the roots of grasses, 

 various crop - plants, and 

 many trees. A form which 

 created a " scare " in this 

 country some years ago is 

 the Colorado Beetle (Chry- 

 somela decemlineatd], a par- 

 ticularly prolific insect which, 

 both in the larval state and 

 when adult, devours potato 

 leaves. 



The larvae of Beetles 

 belonging to one family {BruckicUe} burrow in seeds, and some 

 of them infest plants of economic value, e.g. Pea- Beetles (Biuchus 

 pisi) and Bean- Beetle (B. fab&). 



The little long-snouted Weevils (Cvrculionida), of which some- 

 thing like 20,000 species have already been described, include a 

 large number of pests, of which both adults and larvae feed on 

 vegetable matter. The Pea- Weevil (Sitones lineatus], for example, 

 devours the leaves of pea, bean, clover, &c., while its larvae prey 

 upon their roots. The Apple-blossom Weevil (Anthonomus po- 

 morum) is very destructive in orchards to both apple and pear. 

 The female insect deposits her eggs in the young flower-buds, 

 one in each, and may carry on this injurious operation for two 

 or three weeks. The Corn- Weevil (Calandria granaria, fig. 1253) 

 bores holes in young grains of corn, and each of the some 1 50 eggs 

 of a single female are deposited within separate grains. Some of 



Fig. 1252. Stages of Turnip Flea-Beetle (Haltica nemorum]. 

 i, Adult (enlarged), showing wing-covers and wings spread 

 out; 2, 3, natural size of same; 4, 5, eggs (5 enlarged); 6, 7, bur- 

 rows of larvae (7 enlarged); 8, 9, larva (natural size and en- 

 larged); 10, n, pupa (natural size and enlarged). 



