— and for such reading we propose to supply 

 tlie materials, in part, in the "Farmers' Li- 



BRARV." 



Entomology — derived from two Greek words 

 (entama and logos) signifying a discourse on 

 insects — treats of the "organization, habits, pro- 

 perties and classification of those articulated ani- 

 mals which are distinguished by the presence of 

 anteniKB (antenna, a Latin word for yard-arm) 

 and of breathing organs, composed of ramified 

 trachea, with or witliout air sacs." Various 

 ■writers, from Linnajus to the latest entomolo- 

 gists, have suggested classifications of the insect 

 tribes. The first-named writer classed them 

 from their wings ; Fabricins from die structiLre 

 of tht mouth, and Latreillo from a view of their 

 general organization : Kirby, a more modern 

 writer, adopts the 7iumber of legs as a basis of 

 classification ; while Kollai- thus describes them : 



" Insects are animals which have a body con- 

 sisting of one or more divisions ; articulated feet ; 

 a head conspicuously distinct from the body, 

 on which are placed two moveable horns, 

 called antenntE. They breathe through air- 

 holes, which are situated on the sides of the 

 body; the greater number having wings, in 

 their perfect state, and only a proportionably 

 small number are entirely without tliem. — 

 With the exception of certain groups, all in- 

 sects have six feet, and their bodies are divided 

 into a head, thorax, and abdomen, by notches 

 or incisions ; hence the name insect is derived 

 from the Latin word inseco, to cut or notch. 

 Before they attain their perfect state, they are 

 subject to various transformations, which are 

 called metamoi-phoses." 



By the researches of these and others who 

 have devoted their time and talents to a pa- 

 tient and laborious investigation of the sub- 

 ject, great additions have been made to the 

 stores of useful knowledge. The science, 

 however, is still in its infancy — a vast field 

 remains to be explored — and it is in the power 

 of the Farmer greatly to aid the entomolo- 

 gist, by observing the mmute, but varied and 

 interesting, habits of insects. He -would thus 

 inform him.self of the period.s, the fonn, and die 

 manner of their appearance ; of the plants which 

 are their favorite food ; of the modes of their ap- 

 proach, and the parts which they select for their 

 attacks. By adding experiment to ob.sers'adon, 

 he might also obtain a knowledge of their anti- 

 pathies; and in this way render Entomology 

 more subservient to the interests of Agriculture 

 than it has hitherto been. 



It is to this latter point that it appears the 

 proper province of the Farmer to direct the 

 course of diis department of Natural Historj-. — 

 Entomologists, lured by the love of research, 

 may well content themselves with the develop- 

 ment of such facts as will satisfy the curious 

 philosopher; and, without going bejond this, 

 they have a strong claim to the grautude of the 

 practical Agriculturist, for whose benefit they 



(191-;) 



have opened the mine of Knowledge, which 

 they offer to him to explore at his pleasure. — 

 From their investigations he may learn that the 

 ravages on die turnip crop arc caused, first, by 

 the turnip flea, (the Chrysomcla nemorum of 

 LinnsEUS,) — a coleopterous* or hard-shelled in- 

 sect, scarcely an eighth of an inch in length — 

 smooth, shining, and of a brassy color — which 

 attacks the turnip, both in its perfect and larvse 

 state ; its favorite food being the young plant, 

 just as it is beginning to unfold its cotyledon, ar 

 cup-shaped leaves — stripping an entire crop 

 with a.stouishing celerity. The next enemy of 

 the turnip plant is the saw-fly, (alhalia spina- 

 ■rum,) — so called because die instrument with 

 which Nature has supphed it to deposit its eggs, 

 ■which is placed at the extremity of the abdomen 

 of the female, on the under side, resembles, in 

 its construction and properties, the saw and au- 

 ger. The eggs of this fly are deposited on the 

 young turnip plants, from ■which they emerge 

 into larvae, with a rapidity which scientific men 

 find it difficult to explain. These larvse, of a 

 deep black color, as soon as hatched, commence 

 their attacks, which they continue until dieir 

 full growth, a period of a few weeks, when 

 they drop from the plant among the rotten 

 leaves, and speedily enclose themselves in a 

 cocoon, composed of two distinct layers of silk, 

 out of which it gnaws its way \vhen the fly is 

 matured. Inexplicable instinct is .said to teach 

 all insects to weave their cocoon thinnest in the 

 part which is to cover die head, to facilitate the 

 escape of the fly when the time for its voluntary 

 imprisonment has expired. Farmers suffer 

 greatly from the depredations of this insect. Sir 

 Arthur Young states that the loss of the turnip 

 crop in England in one year, by the ravages of 

 this insect, was estimated at $.500,000. It has 

 been known to destroy a crop of 200 acres of 

 Swedish turnips, although a belief has prevailed 

 that this species of turnip is comparatively safe 

 from their attacks. The injury they inflict is 

 the cons^amption of leaves to the stem, by which 

 the plant is destroyed, or the bulb dimmished 

 by the obstruction of die vegetable functions.- 

 The tcire v:orm (ataphcBgus Vuieatus) is another 

 enemy of the turnip plant, which cuts the stem 

 from the root, so that the plant dies on the spot. 

 This insect is the larvae of chick -beetles, (elate- 

 ridiej and is so constructed as to leap a great 

 bight. The larvae of this beetle, known under 

 the name of ■wire-worm, appears sometimes, 

 says KoUar, in great numbers, and devastates 



* Coleoptn-a, (Beetles,) with six feet, and mostly 

 with four winirs, tlie anterior pair of which are homy, 

 in the form of a covei-ing for the two posterior winirs, 

 which are sometimes wantincr. They have upper 

 and lower jaw.'?, (mandibles and maxilla;,) for gnaw- 

 ing and chewing ; their under winfs are transversely 

 folded. Examples : the may-bug, horns, (ceram byci- 

 d<je,) stag-beetles, gi-ound-beetles, (carabida,) and 

 weevils. 



