?;38 



ANNUAL REGISTER, 1805. 



truth. Leewenhoek had long before 

 observed that these insects were 

 TJviparous. Bonnet, whose obser- 

 vations were continued with the ut- 

 most accuracy, assures us that the 

 female aphides continue to produce 

 their young throughout the whole 

 summer ; that the males appear only 

 in autumn ; and that the females are 

 at that period oviparious. The 

 ova which are thus deposited du- 

 ring the autumn do not hatch till 

 the succeeding spring. It is how- 

 ever uncertain whether the same in- 

 dividual insects which have produ- 

 ced perfect young during the sum- 

 mer become oviparous during the 

 autumn, or whether the oviparous 

 autumnal ones ever produce living 

 young ; the preceding observations 

 relating only to the species at large. 



'J'he aphides in general are very 

 prolific insects. Reaumur com- 

 putes that each aphis may produce 

 Aliout ninety young, and that, in 

 consequence, in five generations, 

 the descendants from a single insect 

 would amount to five thousand nine 

 hundred and four million, nine hun- 

 dred thoH8.Tnd. 



The aphides are very prejudicial 

 to niJiny trees and plants, by ab- 

 sorbing the juices of the tender 

 shoots and leaves, which latter they 

 cause to cockle or warp in such a 

 manner as to fo'm one or more 

 larne concavities beneath, and in 

 which the insects generally reside 

 in great multitudes. In some years 

 they arc so numerous as to cause 

 almost a total failure of hop and 

 polatoe plantations : in other years 

 the pease are equally injured, while 

 exotics raised in sioves and green- 

 houses are frequently destroyed by 

 thrir depredations. They are also 

 supposed to be the chief, if not the 

 soijcai.SB of that viscid exudation 



or moisture so often observed on. 

 the leaves of various trees, and po- 

 pularly known by the title of honey- 

 dew ; which is said to be nothing 

 more than the excrementitious sub- 

 stance evacuated by these insects, 

 from the hinder part of the body, 

 and from the two tubular processes 

 at the tip of the abdomen. 



Of the British aphides one of the 

 largest and most remarkable is the 

 apfiis salicis, which is found on the 

 difl'erent kinds of willows, and is 

 nearly a quarter of an inch in 

 length, and of a yellowish grey 

 colour, spotted with black. When 

 bruised these insects stain the fin- 

 gers of a red colour. Towards the 

 end of September, according to the 

 observations of Mr. Curtis, multi- 

 tudes of the full grown insects of 

 this species, both winged and others, 

 desert the willows on which they feed, 

 and ramble over every neighbour- 

 ing object in such numbers, that we 

 can handle nothing in their vicinity 

 without crushing some of them ; 

 while those in a younger or less ad. 

 vanced state still remain in large 

 masses upon the trees. 



-^■iphis Millefold of Dcgeer, or the 

 yarrow aphis, is so named from its 

 being principally found on that well- 

 known plant. It is a rather small 

 species, and is of a green colour, 

 spotted with black : the males are 

 generally winged, and arc smaller 

 and more slender than the females. , 



Aphis Rosce, or rose aphis, is very, 

 frequent during the summer months 

 on the young shoots and buds of 

 roses : its size is nearly similar to 

 that of the yarrow aphis, and its 

 colour a bright green : the males 

 are furnished witli large transparent 

 wings. 



Aphis T'llice, or the lime-trees 

 aphis, is one of the most beautiful of 



the 



