“Bugs of this class have four wings, the upper pair covering the other pair when in repose. The forward half of each upper wing is hard like the beetle’s wing sheaths, but the other half is membranous and of fine texture. This structure makes them half sheaths for protection and half wings for flying, and it is because of this peculiarity that insects of this sort are called hemiptera, or half-winged creatures. The cicada is a half-winged insect, as is also the plant-louse, although its upper wings (I am speaking of winged plant-lice, of course), instead of being one half hard and the other half of a more delicate texture, have the same fineness and transparency throughout. But the most striking characteristic of these insects, and the one that determines their mode of life, is the beak for sucking. So we will call hemiptera all insects equipped with a pointed sucker which lies against the breast when in repose, and we will not concern ourselves with the question of wings, whether half or entirely membranous.”
“Do the hemiptera form an order by themselves?” asked Jules.
“They form an order in the same way that coleoptera, lepidoptera, hymenoptera, diptera, and so on, form each an order. But hemiptera do not undergo so thorough a transformation as other insects, being born with very nearly the form they will always have. The chief change consists in the growing of wings, which the insect does not have at first, but acquires later when it has attained sufficient [[384]]size. In some species several generations succeed one another before the winged state, which is the perfect one, is reached. Plant-lice belong to this class, the earlier generations of the year having no wings, and only the last being equipped with them.
Pear-tree Flea-louse
(Cross shows natural size)
“A hemipterous insect with habits somewhat like those of the plant louse causes considerable damage to pear-trees. It is commonly called the flea-louse of the pear, and is a small reddish insect with diaphanous wings that fold at an angle like the two sides of an acute-angled roof. It is found on pear-trees, and more rarely on apple-trees, toward the end of April. The eggs are laid one by one in slight gashes made in the leafstem by the female with a little auger situated at the end of the abdomen. The larvæ that come from these eggs grow rapidly and differ from the perfect insect only in their lack of wings. By sloughing the skin these larvæ become nymphs, short and stubby and already having on each side a rudimentary wing. In its final form the insect acquires perfect wings. In all three of its successive stages the insect plunges its sucker into the tender bark, or into the leaves, and sucks the sap. The best way to destroy these creatures is to use a hard bristle brush on those parts of the bark where they are to be found in multitudes.” [[385]]