Show plant lice have odd life cycle kj acle Y little insects often do serious injury to different crops prepared by the united states department of 0 agriculture aphids aphid or plant lice ilce which often do serious injury to the plants they infest have bavle a curious life history which dr P W mason of the bureau of entomology describes in the 1928 yearbook of the united states department part ment of agriculture issued recently if we examine a branch of a tree or other plant which Is in infested says doctor mason alason we will see the aphids in most species grouped together in colonies usually either cither on the under side of a leaf or along a twig they may be greenish brownish black or of other color depending on the species or even covered with a mealy powder or long filaments unusual life history these insects have a very unusual life history one differing from those of almost all other fi bisects sects the egg Is laid in the fall of them the year usually on the bark of the twig with the coming of warm in the spring this egg hatches into what Is 18 known its as the stem stam mother there are no males until the next fall the stem mother gives birth to living young without the necessity of fertilization these young are till all fe AN males and when mature give birth to other living young this continues throughout the sum summer nier there being numerous generations in each generation there are usually some which are winged and others which are wingless each form being fully mature As the spring advances the number of winged lorms forms increases until in the case of many species they aliey fly away to an entirely different kind of plant plants so chosen are known as summer hosts on them new colonies are started and there may be se several generations on them before the return migration to the winter host bost on the tatter latter the true sexes which have been produced mate and the eggs are laid forms of aphids thus we see that there are several forms of aphids such us as the stem mother the wingless viviparous female the winged viviparous female the male and tile the egg laying female these may vary considerably from each other in appearance and have often leen been described as distinct species |