THRIPS. 



TOW, and croffing one another at fome diftancc from their 

 bafe. The tlirips has fix feet, and the tarfus of each foot 

 has only two articulations. Gmelin enumerates the follow- 

 ing eleven 



Species. 



Paradoxa. Brown, with abbreviated wings, and antennx 

 peftinate, fiffile ai d filiform. Found in China, but Gmehu 

 doubts whether 't be of this genus. 



PiiYSAPUs. AVith glaucous elytra or (hell-wings, and 

 black, body. Foun^l frcuuontly on flowers in Europe. 



MiNUTlssiMA. With glaucous elytra and body, and 

 brown eyes. Found as the former. 



JuNiPERiNA. With fnowy elytra and brown body. 

 Found in the galls of the juniper. 



Ulmi. Black, with fnowy ciliated wings, and acumi- 

 nated anus. Fourd gregarious on the bark of the elm. 



Urtick. Yellow, with whitifli elytra. Found folitary 

 on the leaves of the nettle, vine, and hazle. 



Fasciata. With elytra banded with white and black, 

 and brown body. Found on flowers in Europe. 



FuscA. Blackifli, with glaucous elytra. Found in 

 Denmark : the female probably fafciated ? 



Obscura. Yellowifh, with palifh elytra, and eyes and 

 wings of the abdomen black. Found in Denmark. 



RuFA. Red. Found on the fpikes of wheat ; if it be 

 not the larva of i.he minutiflima. 



Variegat ^. Variegated. Found on flax. 

 The thrips is highly injurious and deftruftive to many 

 forts of fine fruited trees, but particularly fo to thofe of 

 the grape or vine kind. The bcft and moil effeftual means 

 of preventing its mifchievous effefts, in fuch cafes, is pro- 

 bably that of frtquent good walhing of tlie trees with com- 

 mon water, by the engine or otherwife. It has lately been 

 advifed that this (hould be done every evening, as, when 

 performed in the iieat of the fun, the vines are materially 

 injured.- Indeed all fuch trees fhould, it is fuppofed, be 

 well wafhed every evening, until the berries begin to colour, 

 whether infefted with infefts or not, but efpecially in the 

 former (late ; after which it is to be wholly difcon- 

 tinued. 



Where there is a negleft of walhing the trees in this or 

 fome other way, the thrips, for the moil part, makes its ap- 

 pearance. In fuch cafes, thefe infefts may without much 

 difficulty be deftroyed by the fumigation of tobacco and 

 damp hay ; the plants or trees being well wafhed after it 

 by pure water. 



The luhue-bug is another infeft which is often very 

 hurtful to peach-trees and vines in forcing-houfes ; and 

 the caufe of which is believed to be much owing to the 

 trees not being daily properly waflied in the above manner. 

 Each of thefe forts of trees ftand in need of particular 

 management in clearing them of this infeft. 



The brown-bug too occafionally makes its appearance 

 on, and is hurtful to peach-trees in fuch fituations, efpe. 

 i;ially when they arc Ihaded, or approach near the flues of 

 the houfes. Proper walhing of the trees, in thefe cafes, 

 ■with lime-water, in the winter feafon ; and fyringing them 

 with it as foon as the leaves have fallen ofT, are often very 

 cffeftual in removing fuch infefts. 



, The green-Jly is alio very dellruftive to peach-trees, efpe- 

 cially when ni the forcing (late. Thefe are the moll effec- 

 tually deftroyed by means of well walhing the trees daily in 

 a regular maimer, after the work of forcing is begun. It is 

 the common praftice of moll gardeners to difconlinue fuch 

 wa(hings as foon as the flowers begin to make their appear- 

 ance, but others ha%e lately continued them with fuppofed 

 Vox.. XXXV. 



advantage, and not found them to prevent the fruit from 

 fetting. If any flics of this fort prefent themfelvcs, they 

 may be kept under by proper watering or wafliing, as above, 

 and by carefully picking off the firll buds on which they 

 appear, which is found to prevent them from breeding, 

 and to render the ufc of tobacco-fmoke unnccefTary. Fu- 

 migations of this fubftance are, however, fometimes bene- 

 ficial in thefe cafes in removing the vermin. 



This and the blus-Jv too are often very injurious to plum- 

 trees, efpecially after they have been affefted with the honey- 

 dew. The manner of getting rid of them in fuch cafes, 

 which has lately been recommended, is that of watering 

 the trees in a plentiful manner two or three times a week, 

 if the weather be dry ; and during the continuance of the 

 above fort of dew upon the trees, preparing the water with 

 a little common fait and the fluid part of a good portion 

 of broom that has been boiled. This mixture, it is faid, 

 effeftually kills the flies, while it does no injury to the trees, 

 if care has been taken not to ufe too large a proportion of 

 fait. This praftice alfo tends to make the trees flioot 

 ftronger, and to hinder fuch infefts from breeding. 



There is another infeft which has lately been found to 

 be greatly injurious to apple and other fruit trees, but 

 which is yet only little known to gardeners. It is the 

 Tortrix ivaberana, which may be feen well defcribed in the 

 fecond volume of the " Tranfaftions of the Horticultural 

 Society of London." It is there dated to be occafionally 

 very hurtful to fuch trees, not only in the larva (late, but 

 others ; and that its attacks are by no means confined to the 

 difeafed parts of fuch trees. The infeft in its perfeft (late 

 is a fmall moth, which is very abundant in gardens and fruit 

 grounds. 



In what regards the means of removing and defl:roymg 

 fuch infefts when their attacks become injurious, the hmts 

 given below are thrown out. The firft and moft eflential 

 procefs evidently is, it is thought, to cut away the edges of 

 the cankery parts vs'here they are chiefly found, making 

 the wound fmooth, and covering it with any compofition 

 likely to prevent the moth from depofiting her ova or eggs 

 there again. One precaution is neceffary, which is to put 

 into boiling water, or to bury at a confiderable depth, the 

 cut-out pieces of decayed bark containing the larva; ; 

 which, if left near the tree, would foon crawl from their 

 holes or other places, and remount it ; thus defeating the 

 labour of the horticulturalifl, who often, from negleft- 

 ing a flight additional trouble, lofes the benefit of more 

 painful exertions. Where the larvx are found to have in- 

 finuated themfelves generally into the rough bark of old 

 trees, it would probably, it is thought, be advifable to 

 fcrape off the whole of the lifelefs bark, and fuch portions 

 of the alburnum as are injured, as fuggefted by Mr. Knight 

 on another occafion ; a procefs which, there can be no doubt, 

 it is faid, would be advantageous to the tree in other re- 

 fpefts, as pointed out by the above writer. And where 

 projefting faw-duft-like maffes fiiew that the larva has at- 

 tacked even fmooth-barked trees, the infertion of a blunt 

 pricker into the hole would probably, in mofl: cafes, fuffice 

 to deftroy it, and do lefs injury to the tree than fufFering it 

 to attain its growth. But the mode which is moft to be 

 recommended in this, as in the cafe of almofl all infefts 

 hurtful to fruit or other trees, is, it is faid, to deftroy the 

 moths themfelves by collefting them from ofi" the trees, or 

 otlier places, during tlie fummer months, which might be 

 done by children properly direfted and provided with fuit- 

 able means for the purpofe, or in other ways. The deftruc- 

 tion of every female moth, before the depofition of tt» 

 eggs, may, it is faid, be fairly calculated to prevent the 

 i(. E ewftencc 



