For Orthorrhapha Brachycera he adopts the following arrangement: 1. Super-family Eremochaeta, for Stratiomyidae, Tabanidae, Acanthomeridae and Leptidae; 2. Tromoptera, for Nemestrinidae, Acroceridae, Bombyliidae, Therevidae, and Scenopinidae; 3. Energopoda, for Asilidae, Dolichopidae, Empidae and Lonchopteridae, Phoridae being included with doubt; 4. Mydaidae remains isolated.
This classification is based on the relations of the eyes and bristles of the upper surface, and on the powers of locomotion, aërial or terrestrial. At present it is not sufficiently precise to be of use to any but the very advanced student.
Blood-sucking Diptera.—The habit of blood-sucking from Vertebrates is, among Insects, of course confined to those with suctorial mouth, and is exhibited by various Diptera. It is, however, indulged in by but a small number of species, and these do not belong to any special division of the Order. It is remarkable that as a rule the habit is confined to the female sex, and that a large proportion of the species have aquatic larvae. This subject has many points of interest, but does not appear to have yet received the attention it merits. We give below a brief summary of the facts as to blood-sucking Diptera.
Series I. Nemocera.—In this section the habit occurs in no less than five families, viz.:
Blepharoceridae. Curupira; in the female only; larva aquatic.
Culicidae. Culex, Mosquitoes; in the female only; other genera, with one or two exceptions, do not suck blood; larvae aquatic.
Chironomidae. Ceratopogon, Midge; in the female only; exceptional even in the genus, though the habit is said to exist in one or two less known, allied genera; larval habits not certain; often aquatic; in C. bipunctatus the larva lives under moist bark.
Psychodidae. Phlebotomus: in the female only (?); quite exceptional in the family; larva aquatic or in liquid filth.
Simuliidae. Simulium, sand-flies; general in the family (?), which, however, is a very small one; larva aquatic, food probably mixed vegetable and animal microscopic organisms.
Series II. Brachycera. Tabanidae. Gad-flies: apparently general in the females of this family; the habits of the exotic forms but little known; in the larval state, scarcely at all known; some are aquatic.