THE FARMERS' REGISTER. 



•329 



upon or about them. They evpn protect them 

 from their enemies, and rim about them in the hot 

 sunshine to drive away the little ichneumon flies 

 that are for ever hovering near to deposite their 

 eggs in the bodies of the lice. 



Fiant-lice differ very much in form, color, cloth- 

 ing, and in the lengih of the honey-tubes. Some 

 have these tubes quite long, as the rose-louse, 

 Aphi^ rosce, which is green, and has a little coni- 

 cal projection or stylet, as it is called, at the ex- 

 tremity ol' the body, between the two honey- 

 lubes. The cabbage-louse, Aphis brassicm, has 

 also long honey-tubes, but its body is covered 

 with a whitish mealy substance. This species is 

 very abundant on the under side of cabhatre 

 leaves in the month of August. The largest spe- 

 cies known lo me is Ibund in clusters beneath the 

 limbs of the pi^ nut hickory ( Carya porcina,) in 

 all stages of growth, from the 1st to the middle of 

 July, [t is the Aphis carycc of my Catalogue, 

 lis body, in the winiied state, measures one quar- 

 ter of an -nch lo the end of the abdomen, and 

 above four-tenths of an inch to the tips of the up- 

 per wings, which expand rather more than seven- 

 tenihs of an inch. It has no lerminiil stylet, and 

 the lioney-iubes are very short. Its body is co- 

 vered with a bluish-white substance, like the 

 bloom of a plum, with four rows of little trans- 

 verse black spots on the back ; the top of the tho- 

 rax, and the veins of the wings are black, as are 

 also the shanks, the feet, and ihe antenna;, which 

 are clothed wiih black hairs ; the thighs are red- 

 dish-brown. This species sucks the sap from the 

 limbs and not from the leaves of the hickory. 

 There is another large species, livin£r in the same 

 way on the under side of ihe branches of various 

 kinds of willows, and clustered together in great 

 numbers. About the first of October they are 

 found in the winged state. The body is one-tenth 

 of an inch in length, and the winsrs expand about 

 four-tenths. The stylet is wanting; the body is 

 black and without spots ; the wings are transpa- 

 rent, but their veins, the short honey tubercles. 

 the third joint of the antennae, and the legs are 

 tawny yellow. This species cannot be idei tical 

 with the willow-louse. Aphis salicis of Linnteus, 

 which has a spotted body ; and therefore I propose 

 to call it Aphis salicli, the plant-louse of willow 

 groves. When crushed, it communicates a stain 

 of a reddish or deep orange color. 



Some plant-hce live in the ground and derive 

 their nourishment from the roots of plants. We 

 annually lose many of our herbaceous plants, if 

 cultivated in a lieht soil, from the. exhausting at- 

 tacks of these subterranean lice. Upon pulling 

 up Chma asters, which seemed to be perishing 

 from no visible cause, I have (bund hundreds of 

 little lice, of a white coFor, closely clustpred to- 

 gether on the roots. 1 could never discover any 

 of them that were winged, and therelbre conclude 

 from this circumstance, as well'as from their pecu- 

 liar situation, that they never acquire wings. 

 Whether these are of the same species as the 

 Aphis radicum of Europe, 1 cannot ascertain, as 

 no sufficient description of the latter has ever come 

 to my notice. These little lice are attended by 

 ants, which generally make their nests near the 

 roots of the plants, so as to have their milch kine, 

 as the plant-lice have been called, within their 

 own habitations : and in consequence of the com- 

 bined operations of the lice and the ants, the 

 Vol. X.-42 



plants wither and prematurely perish. When 

 these subterranean lice are disturbed, the attendant 

 ants are thrown into the greatest confusion and 

 alarm ; they carefully take up the lice which have 

 fallen Irom the roots, and convey them in their 

 jaws into Ihe deep recesses of their nests ; and 

 liere the lice still contrive to live upon the frag- 

 ments of the roots left in the soil. It is stated in 

 Kirby and Spence's Introduction to Entomoloiryj 

 that the ants bestow the same care and attention 

 upon Ihe root-lice as upon their own offspring — 

 ihnt they defend them fr m the attacks of other 

 insects, and carry them about in their mouths to 

 chanije their pasture; and that they pay panicu- 

 lar attention to the egos of the lice, frequently 

 moisteninir them with their tongues, and in fine 

 weather bringins them to the surface of ihe nest, 

 to give them the advantage of the sun. On Ihe 

 other hand, the sweet fluid supplied in abundance 

 bv these lice forms the chief nutriment both of 

 the ants and their 'y^ung, which is sufficient to 

 account for their solicitude and care (or their va- 

 luable herds. 



The peach tree suffers very much from the at- 

 tacks of plant-lice, which live under the leaves, 

 causing them by their punctures to become thick- 

 ened, to curl or li)rm hollows beneath, and corre- 

 sponding crispy and reddish swellings above, and 

 finally to perish and drop off prematuieiy. Whe- 

 iher our insect is the same as the European 

 aphis of the peach tree (Aphis PersictB of Su\' 

 zer,) I cannot determine, lor the want of a pro- 

 per description of the latter. The depredations 

 of these lice is one of the causes, if not the only 

 cause, of the peculiar malady affiecting the peach 

 tree in the early part ol summer, and called the 

 blight. 



The injinies occasioned by plant-lice are much 

 greater than would at first be expected from the 

 small size and extreme weakness ol the insects; 

 but these make up by ilieir numbers what they 

 want in strength imlividually, and thus become 

 liTmidable enemies lo vegetation. By 'heir punc- 

 tures, and Ihe quantiiy of sap which they draw 

 li-om the leave?, the fiinctions of these important 

 organs are deringed or interrupted, the food of 

 ihe plant, which is there elaborated lo nourish the 

 siem and mature the fruit, is withdrawn, before it 

 can reach its proper desiination, or is contaminated 

 and lefi in a state unfitted to supply the wants of 

 vegetation. 



Plants are differently afTccted by these insects. 

 Souie wither and cease to grow, their leaves and 

 stems put on a sickly appearance, and soon die 

 from exhausnon. Others, though not killed, are 

 greatly impeded in iheir growth, and their lender 

 parts, which are attacked, become stunted, curled, 

 or warpect 



The punctures of thes'^ lice seem to poison 

 some plants, and ailect oihers in a most singular 

 manner, producing warts or swellings, which are 

 sometimes solid and sometimes hollow, and con- 

 tain in their interior a swarm of lice, the descend- 

 ants of a single individual, whose punctures were 

 the original cause of the' tumor. I have seen 

 reddish tumors of this kind, as big as a pigeon's 

 ^SS^, growing upon leaves, to wkich they were 

 attached by a slender neck, and retaining thou- 

 sands of sniall lice in their interior. Naturalists 

 call these tumors galls, because they seem to be 

 formed in the same way as the oak galls which 



