206 INSECTS INJURIOUS TO VEGETATION. 



are very long and tubular, their eyes are globular, but they 

 have not eyelets, their antennae are long, and usually taper 

 towards the extremity, and their legs are also long and very 

 slender, and there are only two joints to their feet. Their 

 upper are nearly twice as large as the lower wings, are much 

 longer than the body, are gradually widened towards the ex- 

 tremity, and nearly triangular; they are almost vertical when 

 at rest, and cover the body above like a very sharp-ridged roof. 



The winged plant-lice provide for a succession of their race 

 by stocking the plants with eggs in the autumn, as before 

 stated. These are hatched in due time in the spring, and the 

 young lice immediately begin to pump up sap from the tender 

 leaves and shoots, increase rapidly in size, and in a short time 

 come to maturity. In this state, it is found that the brood, 

 without a single exception, consists wholly of females, which 

 are wingless, but are in a condition immediately to continue 

 their kind. Their young, however, are not hatched from eggs, 

 but are produced alive, and each female may be the mother of 

 fifteen or twenty young lice in the course of a single day. 

 The plant-lice of this second generation are also wingless 

 females, which grow up and have their young in due time ; 

 and thus brood after brood is produced, even to the seventh 

 generation or more, without the appearance or intervention, 

 throughout the whole season, of a single male. This extraor- 

 dinary kind of propagation ends in the autumn with the birth 

 of a brood of males and females, which in due time acquire 

 wings and pair; eggs are then laid by these females, and with 

 the death of these winged individuals, which soon follows, the 

 race becomes extinct for the season. 



Plant-lice seem to love society, and often herd together in 

 dense masses, each one remaining fixed to the plant by means 

 of its long tubular beak; and they rarely change their places 

 till they have exhausted the part first attacked. The attitudes 

 and manners of these little creatures are exceedingly amusing. 

 When disturbed, like restive horses, they begin to kick and 

 sprawl in the most ludicrous manner. They may be seen, at 

 times, suspended by their beaks alone, and throwing up their 

 legs as if in a high frolic, but too much engaged in sucking to 



