Fig. 247.—Braula coeca. × 18⁄1. (After Meinert.)
Fam. 41. Braulidae.—This consists only of a minute Insect that lives on bees. The antennae are somewhat like those of the sheep-tick, though they are not so completely concealed in the cavities in which they are inserted. According to Müggenburg[[449]] a ptilinum exists, and he is also of opinion that although the parts of the mouth differ very much from those of Hippoboscidae they are essentially similar. Lucas says that Braula specially affects the thorax of the bee: Müggenburg, that it is fond of the queen-bee because of the exposed membranes between the body-segments that exist in that sex. Whether this Insect is truly Pupiparous is unknown, though Boise states that a pupa is deposited in the cell of the bee by the side of the young larva of the bee, and appears as the perfect Insect in about twenty-one days. Müggenburg suggests that Braula may be oviparous, as he has never found a larva in the abdomen. Packard says that on the day the larva hatches from the egg it sheds its skin and turns to an oval puparium of a dark brown colour. The Insect is frequently though inappropriately called bee-louse; notwithstanding its name it is not quite blind, though the eyes are very imperfect.
Fam. 42. Streblidae.— Winged; possessing halteres; the head small, narrow and free. These very rare Diptera are altogether problematic. According to Kolenati the larvae live in bats' excrement and the perfect Insects on the bats.[[450]] If the former statement be correct the Insects can scarcely prove to be Pupipara. The wing-nervuration is, in the figures of the Russian author, quite different from that of Hippoboscidae. The Streblidae have been associated by some entomologists with Nycteribiidae, and by Williston with Hippoboscidae.
Fig. 248.—Nycteribia sp., from Xantharpyia straminea. Aden. A, Upper surface of female, with head in the position of repose; B, under surface of male. x 12⁄1.
Family 43. Nycteribiidae.—The species of this family are found on bats; they are apparently rare, and we have been able to examine only one species. The form is very peculiar, the Insects looking as if the upper were the under surface. They are wingless, with a narrow head, which reposes on the back of the thorax. The prothorax appears to be seated on the dorsum of the mesothorax. According to Müggenburg there is no trace of a ptilinum. A brief note on the metamorphosis[[451]] by Baron Osten Sacken indicates that the mature larva differs from that of Melophagus in the arrangement of the stigmata; they appear to be dorsal instead of terminal. There are apparently no characters of sufficient importance to justify the association of these Insects with the other divisions of Pupipara; the sole ground for this connection being the supposed nature of the life-history of the larva.
Fig. 249—Anterior part of the body of Nycteribia sp., found on Xantharpyia straminea by Colonel Yerbury at Aden. A, Upper surface of female, with head extended; B, under surface of male, with head extended; C, claws of a foot.
Sub-Order Aphaniptera or Siphonaptera (Fleas)
Fam. Pulicidae.—Wingless, with the body laterally compressed, so that the transverse diameter is small, the vertical one great. The head indistinctly separated from the body, small, with short thick antennae placed in depressions somewhat behind and above the unfaceted eyes. These are always minute, and sometimes wanting.