In the Dyticidæ the taste-cups are nearly as described in the Carabidæ.
The Staphylinidæ are not well provided with taste-organs. Under the clypeus of Staphylinus violaceus, on each side near the middle, is a bare rounded area, in which are situated 4 or 5 papilliform taste-cups, and at the base behind them is another linear group of about 7 slenderer, somewhat curved, taste-cups. In the Elateridæ these organs are scantily developed.
In the Buprestidæ (Buprestis maculiventris alone examined) no true taste-cups were detected. On the other hand, the Lampyridæ are well supplied with them. Under the clypeus is situated a sensory field bearing 26 taste-cups, which are rather smaller than usual. Over the epipharyngeal surface are scattered a few taste-cups, but they are small and perhaps not gustatory. Under the clypeus of Lucidota punctata Lec. is a group of 12 taste-cups, and in the middle region of the epipharynx, situated in a field extending from near the base to near the front edge, are about 40 taste-cups, which, however, are not, as is usual, arranged on each side of the median line, but are scattered among the hairs of the pilose surface of the epipharynx. In the Cleridæ the taste-cups are few in number.
In the great family of Scarabæidæ, the presence of gustatory organs is variable. None occur in Lucanus dama, though in the June beetle (Lachnosterna fusca Fröhl.) they are abundantly developed. The epipharynx bears on each side outside of a spiny area a group of about 50 taste-cups, each bearing a long seta, those on the outside of the area passing into a few high, rather slender, papillæ, without a seta. On the under side of the clypeus is a median group of 10 taste-cups of singular form, the cups being large, with broad bases, which posteriorly bear three spines, of which the median one is the largest.
Taste-cups occur without any known exception in the longicorn beetles. In Leptura canadensis they are numerous; in Euryptera lateralis they are abundant along and near the middle of the anterior half of the labral region, and in Cyllene robiniæ Forst. (or pictus Drury) they are more numerous than usual, extending in an unbroken sensory field from near the front margin of the clypeal region to near the front edge of the epipharynx. The cups vary much in size, some being one-half as large as others; and those on the sides of the sensory field bear short, and a few others rather long, bristles, showing that the taste-cups are modified tactile bristles.
The Tenebrionidæ are fairly well endowed with taste-cups, their number in Eleodes obsoleta Say amounting to 30 or 40.
Those of the Meloidæ especially are unusual in size and number.
Fig. 289.—Epipharynx (ep) of Nemognatha: cl, clypeus; gh, gathering hairs; tc, triangular sensory field dotted with taste cups; A, the field enlarged.
In Nemognatha lurida Lec. (Fig. 289) the front edge of the epipharynx contains about 80 remarkably small taste-cups, arranged irregularly in a triangular sensory space, and not more than ¼ to ⅙, as large as those on the maxillæ of the same beetle. Unless the former structures are gustatory it is difficult to account for their presence here, and it will be observed that the taste-cups in Epicauta are unusually abundant. Thus in the middle and near the front of the epipharynx of the blister-beetle over 100 gustatory cups were counted. They are conical, papilliform, and truncated at the end as if open, the edge of the opening being ragged, though bearing no bristle, except in a few cases. Around the edge of the sinus, on the under side of the labrum, is a regular marginal row of large, longer, more distinctly chitinized taste-cups, whose walls are streaked up and down by chitinous thickenings. In E. callosa Lec. there are about 55 taste-cups under the labrum, besides about 10 cells, which may be gustatory structures, situated on either side of a median setose ridge which passes back under the clypeal region.