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; . economicentomolo00smit Year: 1906 THE INSECT WORLD. 169 mandibles, and a pair of brisdy processes at the anal end of the body. Two other families belonging to the Adephaga are aquatic in the larval as well as adult stage, and are as predaceous as their terrestrial relatives. The Dytiscidce and ^^g- ^39- their larvae have been termed 'water- tigers,' and the larger species attack small fish as well as insects. In form they are oval and s
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; . economicentomolo00smit Year: 1906 THE INSECT WORLD. 169 mandibles, and a pair of brisdy processes at the anal end of the body. Two other families belonging to the Adephaga are aquatic in the larval as well as adult stage, and are as predaceous as their terrestrial relatives. The Dytiscidce and ^^g- ^39- their larvae have been termed 'water- tigers,' and the larger species attack small fish as well as insects. In form they are oval and somewhat flat- tened, and they may often be seen rising to the surface of quiet pools or spring-holes, head down, releasing a bubble of air, and then, after remaining for a little time, with the anal eXtremitV \^di\.^x-X\%%%%%%%%^r, Dytisais marginaUs.âa, larva, devour- â t \ c i'lg an Agrion larva; b, pupa; c, male beetle, the elytra aDOVe tne SUriace, of the female at side ; rf, anterior tarsus of the male, with a^ain starting for the sucking disks; e, tarsus of the female: c, b, c, about , ^ ,, rr^i ⢠natural size. bottom. 1 here IS con- siderable space between the wing-covers and the abdomen in these species, and this is utilized as a reservoir for the air which the insect breathes beneath the surface. When it becomes impure the beetle rises again to the surface, releases the vitiated air, and takes in a new supply. This ends the series Adephaga, and no practically injurious forms exist in it ; all are more or less beneficial by reason of their predaceous habits. Under some circumstances a few of the species eat pollen, and after midsummer some have been found gnawing grass-seed ; one or two species have even been found eating into the kernels of corn, so there appears to be a tendency to vary to a vegetable diet under certain conditions. In fact it has been demonstrated that in many species some vegetable matter is regularly eaten ; yet, as this feeding is not of a cha
Size: 1388px × 1441px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
