

TASTE-ORGANS OF BEETLES 



285 



is another linear group of about 7 slenderer, somewhat curved, taste-cups. In 

 the Elateridse these organs are scantily developed. 



In the Buprestidae (Buprestis maculiventris alone examined) no true taste- 

 cups were detected. On the other hand, the Lampyridae are well supplied with 

 them. Under the clypeus is situated a sensory field bearing 20 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 Lee. 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 Cleridae the taste-cups are few in 

 number. 



In the great family of Scarabaeidae, the presence of gustatory organs is vari- 

 able. None occur in Lucanus dama, though in the June beetle (Lachnosterna 

 fitsca Frohl.) 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, 

 papillae, 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 abun- 

 dant along and near the middle of the anterior half of the labral region, and in 

 Cyllene robinice 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 sen- 

 sory field bear short, and a few others rather long, bristles, showing that the 

 taste-cups are modified tactile bristles. 



The Tenebrionidae are fairly well endowed with taste-cups, their number in 

 Eleodes obsoleta Say amounting to 30 or 40. 



Those of the Meloidpe especially are unusual in size and number. 



In Nemognatha lurida Lee. (Fig. 289) the front edge of the epipharynx 

 contains about 80 remarkably small taste-cnps, arranged irregularly in a tri- 

 angular sensory space, and not 

 more than \ to \ as large as those 

 on the maxillae 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 1QO gustatory 

 cups were counted. They are 

 conical, papilliform, and trun- 

 cated 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 Lee. there are about 55 taste-cups under 



FIG. 289. Epipharynx (ep) of Nemoenatha : cl, 

 clypeus ; gh, gathering hairs ; to, triangufar sensory 

 field dotted with taste-cups ; A, the Held enlarged. 



