Directions for Collecting and Preserving Insects. Charles V. Riley
Fig. 3.—Cross section of Fig. 2.
It will be seen that the changes are not so great as would at first appear. The three more important orders, namely, the Hymenoptera, Coleoptera, and Lepidoptera, remain substantially the same in all classifications, and so with the three orders next in importance—the Hemiptera, Diptera, and Orthoptera. All that has been done with these three has been to rank as separate orders what by former authors were preferably considered as either families or suborders. The principal change is in the Neuroptera, of which no less than eight orders have been made. This is not to be wondered at, because the order, as formerly construed, was conceded to be that which represents the lowest forms and more synthetic types of insects, and as such necessarily contained forms which it is difficult to classify definitely.
In the discussion of the characteristics, habits, number of species, and importance of the several groups, I follow, with such changes as the advances in the science of entomology have made necessary, the arrangement shown in Fig. 1.
“Order HYMENOPTERA υμην, a membrane; πτερον, wing). Clear or Membrane-winged Flies: Bees, Wasps, Ants, Saw-flies, etc. Characterized by having four membranous wings with comparatively few veins, the hind part smallest. The transformations are complete: i.e., the larva bears no resemblance to the perfect insect.
Fig. 4.—Bold-faced Hornet,
Vespa maculata. (After Sanborn).
“Some of the insects of this order are highly specialized, and their mouth-parts are fitted both for biting and sucking, and in this respect they connect the mandibulate and haustellate insects. The common Honey-bee has this complex structure of the mouth, and if the editors of our agricultural papers would bear the fact in mind, we should have less of the never-ending discussion as to whether bees are capable of injuring fruit at first hand. The lower lip (labium) is modified into a long tongue, sheathed by the lower jaws (maxillæ), and they can sip, or, more properly speaking, lap up nectar; while the upper jaws (mandibulæ), though not generally used for purposes of manducation, are fitted for biting and cutting. The Hymenoptera are terrestrial, there existing only a very few degraded, swimming forms.
“This order is very naturally divided into two sections—the Aculeata and Terebrantia. The aculeate Hymenoptera, or Stingers, comprise all the families in which the abdomen in the female is armed with a sting connected with a poison reservoir, and may be considered the typical form of the order, including all the social and fossorial species.
| Fig. 5.—An Ichneumon Parasite, Pimpla annulipes, showing male and female abdomen. | Fig. 6.—A Chalcid Parasite, Chalcis flavipes. |
The insects of this section must be considered essentially beneficial to man, notwithstanding the occasional sting of a bee or wasp, the boring of a carpenter bee, or the importunities of the omnipresent ant. Not only do they furnish us with honey and wax, but they play so important a part in the destruction of insects injurious to vegetation that they may be looked upon as God-appointed guards over the vegetal kingdom—carrying the pollen from plant to plant, and insuring the fertilization of diœcious species, and the cross-fertilization of others; and being ever ready to clear them of herbivorous worms which gnaw and destroy. The whole section is well characterized by the uniformly maggot-like nature of the larva. The transformations are complete, but the chitinous larval covering is often so very thin and delicate that the budding of the members, or gradual growth of the pupa underneath, is quite plainly visible, and the skin often peels off in delicate flakes, so that the transition from larva to pupa is not so marked and sudden as in those insects which have thicker skins.
Fig. 7.—A Horn-tail, Tremex columba. a, larva, showing Thalessa larva attached to its side; b, head of larva, front view, enlarged; c, female pupa, ventral view; d, male pupa, ventral view; e, adult female—all slightly enlarged.
Fig. 8.—Saw-fly and Larva. Pristiphora grossulariæ; a, larva; b, imago, Walsh.
“The terebrantine Hymenoptera, or Piercers, are again divisible into two subsections: first, the Entomophaga, which are, likewise, with the exception of a few gall-makers, beneficial to man, and include the parasitic families, and the gall-flies; second, the Phytophaga, comprising the Horn-tails (Uroceridæ), and the Saw-flies (Tenthredinidæ),