74 



By comparing his insect in this way with the characters of the or- 

 ders as heretofore given he can soon ascertain to which it belongs It 

 is,true this is but one step toward arriving at the desired end, but it 

 greatly limits the field of search, and is often sufficient when aided by 

 a knowledge of its history from personal observation to direct him at 

 once to the species he is in search of. 



PREPARATORY STATES. 



, As \kn°wledgeof the preparatory states oj insects (those states or 

 stages of life which precede the perfect form) is of the utmost import- 

 ance in investigating the habits of and devising remedies against in- 

 jurious species, I present here some general considerations on this 

 subject. 



With few exceptions (such as blow-flies and a few other snecies) 

 insects are produced from eggs deposited bv the perfect female, the 

 larva? and pupae being incapable of reproduction; hence the idea 

 sometimes advanced by unscientific observers, that caterpillars or 

 grubs deposit eggs from which similar worms are produced is wholly 

 a mistake. That a larva may and often does bear within it one or 

 more eggs is true, but these have beendeposited there bv some perfect 

 insect which is parasitic upon that larva; and these 'eggs if undis- 

 turbed will produce small grubs or worms which may be taken by the 

 uninformed for the young of the larva in which thev are found, when 

 in tact, they are internal parasites which will prey upon and ulti- 

 mately destroy their host. 



The eggs of insects vary materially in form according to the spe- 

 cies depositing them Usually they are globular or nearly so, some 

 are conical others cylindrical, others shaped like flax seed, etc. some 

 are covered by little ribs or minute raised lines, and others have little 

 appendages at one end. They are deposited in various situations 

 according to the habits of the different species; many species fasten 

 them by a gummy substance to the surface of the' leaves, as the 

 squash-bug and the Colorado potato-beetle; some place them in the 

 Hower, that th e< young larvae may penetrate the fruit, as the codling 

 moth ; others pierce the pods or pulpy fruit, and deposit them there 

 in order that the young may find nourishment ready at hand, as the 

 pea-bug, (or pea-curculio) plum-curculio, etc.; others pierce the 

 stems of plants and twigs of trees with an apparatus nature has fur- 

 nished them for tins purpose, as the seventeen-year-locusts, tree-hop- 

 pers, &c; others as a large number of moths; select the grass as a 

 place to deposit them ; the female grasshopper bores into the ground 

 and deposits her eggs there in a sack, while the female cockroach car- 

 nes her sack of eggs with her ; the lace-winged fly mounts her eggs 

 on the end of a short thread of gum which is attached to a leaf amid 

 the plant-lice on which she expects the young larva? to feed Ich- 

 neumon flies are provided with long ovipositors with which thev 

 pierce the bodies of the. caterpillars and other larva? and deposit 

 their eggs within; many minute chalcis-flies pierce and deposit 

 in^SSfw he *X? 0{ ?fo**iVM6t*i the mosquito sends her eggs 

 inalitt. e boat on the surface of the water; the bot-fly deposits thim 

 on the leg of the horse that thev may he carried into the stomach, 

 their nocturna hatching place ; in fact there is no place where an\- 

 mal or vegetable life exists which is not used for a harbor for the eggs 



