THE AMEEICAN ENTOMOLOGIST. 



83 



his description with our specimens, it not only 

 disagrees generically, as ah-cady explained, but 

 neither tlie size nor the markings will corres- 

 pond at all. 



We consider it, therefore, to be sufficiently 

 (■ertain that the Apple-root Plant-louse docs not 

 belong to the genus (Peniphi(/us), to which all 

 subsequent authors, in deference to Dr. Fitch's 

 authority, have hitherto referred it, but to the 

 very distinct genus {Erlosoma) to which the 

 notorious Wooly Plant-louse of Europe belongs 

 (Eriosoma lanigera, Hausm.) And here arises 

 a very interesting question : Is our American 

 Apple-root Plant-louse identical with the Euro- 

 pean Wooly Plant-louse? "\Ve think that it is 

 not, for the three following reasons: 1st, The 

 descriptions of the latter do not agree very well 

 with our insect. 2d, The European species can 

 not stand a hot climate, but is confined to Bel- 

 gium, the north of France, Germany and Eng- 

 land ; whereas our species thrives and flourishes 

 best in a hot southeru latitude. 3d, The Euro- 

 pean species exclusively infests the trunk and 

 branches of the apple-tree, and it is recorded 

 that Sir Joseph Banks "long ago extirpated it 

 from his own apple-trees by the simple method 

 of taking off all the rugged and dead old bark, 

 and then scrubbing the trunk and branches 

 with a hard brush" (Kirby and Spence, letter 

 G) ; whereas our American Root-louse normally 

 inhabits the roots, and is only occasionally and 

 in small numbers found upon the trunk and 

 branches, so that scrubbing and scraping the 

 bark would have little or no effect towards ex- 

 tirpating it. 



It has been said by ses'eral authors that the 

 true "W'ooly Plant-louse of Europe exists iu the 

 Eastern States. We incline to believe that this is 

 a mistake, and that iu every such case the few 

 individuals of our American Root-louse, that are 

 often found upon the trunk and branches and 

 suckers, have beeu mistaken for the transatlan- 

 tic species. Mr. iBnel, upon whose statements 

 Dr. Harris chiefly relied to prove the existence 

 of the Wooly Plant-louse in New England, ex- 

 pressly says that " numbers of the insects har- 

 bored on the roots." (Harris, Inj. Ins., p. 244.) 

 Dr. Fitch describes the "Wooly Plant-louse as 

 " situated near the root, particularly around the 

 base of twigs and suckers growing from the 

 trunk, and where any wound in the bark is 

 healing;" which are the precise localities pre- 

 ferred by our Root-louse whenever it lives above 

 ground. (Fitch, JV'. Y. Eep., II, § 17.) And 

 tinalli' Prof. Haldeman, in an article upon this 

 insect, asserts that it not only attacks " suckers 

 aiul small branches," but also "descends to the 



roots." {Farm Journal, 1851, Vol. I, p. 130.) 

 As to the winged specimens, which Mr. A. E. 

 Verrill discovered upon apple-twigs in Connec- 

 ticut iu the month of October, they might pos- 

 sibly have belonged to the exotic species. (Pract. 

 Entom., I, p. 21.) But as that species is de- 

 scribed as swarming in Europe in such prodigi- 

 ous numbers as to cover whole trees like a coat 

 of cotton, it seems incredible that, if it had been 

 really introduced into such a suitable climate as 

 that of New England, it should not have become 

 a great pest there. Instead of this, however, 

 all authors describe it as occurring above ground 

 in comparatively quite small numbers, wherever 

 it was supposed to exist iu the Eastern States. 

 Fi'om the enormous rate at wliich all Plant- 

 lice multiply, it is plain that, if there were no 

 check upon the increase of the Apple-root Plant- 

 louse, it would in a few years' time sweep away 

 whole orchards, especially in southern latitudes. 

 Luckily for the fruit-growers and fruit-lovers, 

 there exist one at all events, and probably two 

 such checks. The first is a very minute para- 

 sitic fly, which Prof. Haldeman figured and de- 

 scribed in 1851 as infesting in the larva state his / 

 supposed Wooly Plant-louse.* The second is a 



[Fig. -2,] 



footless maggot (Fig. 72 a) , about 4 an inch long, . 

 which preys upon the Root-lice under ground, / 

 and changes in the autumn into the pupa state 

 (Fig. 72 6), from which in the following spring 

 there emerges the perfect Fly (Fig. 72 c), which / 

 we may call the Root-louse Sy rphus-fly .f We have • 



* This flv bclouss to the Chalcis family in the Order Hijmc- I 

 voptera, and was named EfVlpWus mali by Prof. Haldeman. / 



The liffure and di'scrilition will be found in the Farm Joitrnal 

 for 18.ll, pp. 13I1-1 



t Thi.s i> til.- ~:imi- i;i-.'c,' irlVriT'l lo ill n^ A :-,t:ii.i} Report 

 ofthclSMiinr l,,ln,,r n <;-.'). :v.,.\ Mm-iv .„|,|i, .-..I I,, proy on 

 theKoot-li.T :(:p1 Im 1m1..ii- t.i 111.' .s.;,7,;,,/.v i;uiiil> , ihnu-h the 

 perfect llv Hill. -h ii,- ~Ml.,,■,|ll,.nll^ Wnil irniii ii w:i- not then 

 known. 'Wc ^u;;juiu ik^uiipliuu.-, of llii= iii::t:cl iu :iU its 

 stage.s. 



The Root-locse SyRpnus-Fi.Y (Pipiza radicum, n. .sp.) $ 

 Shining broNvn black. Head clothed with short, rather 

 .si.ii IM-, White hairs, especi.illv the low.-r part of the anterior 

 ..'•■'■;•■ :i:r! til" Mith-p -■;.:! -fill P.-,vT)v- "ntrnnrr Vrv.lh dark 

 i-'ii' ■!- 'Mil ■ r.,i.i,,r 1 1. III! 1],,. ;..i.,i- i.r..:... -tinned 



