1975] 
Lawrence & Stephan — Cerylonidae 
155 
species of Lapecautomus — piercing beak with mandibular and max- 
illary stylets — • is one which occurs throughout the subfamily in both 
larvae and adults, so that a group, even at the generic level which 
is defined on the basis of this feature alone, may well be polyphyletic. 
Within the genus Lapethus (in the broad sense), there is a general 
trend towards the elongation of the labrum, and in most forms 
examined it is somewhat elongate and deeply emarginate at the apex, 
as in L. discretus (fig. 12). In Lapethus ( — Lapecautomus ) striatus , 
the labrum is even more elongate than in discretus , but it is still 
emarginate at the tip (fig. 11). In L. dybasi, however, the apex is 
pointed. A similar trend may be found in the mandibles and max- 
illae. With respect to other characters not involved in the piercing 
apparatus, the three species presently included in Lapecautomus do 
not appear to be closely related and may well be derived from two 
or more stocks of typical Lapethus. Lapecautomus mexicanus, for 
instance, is a globose, highly convex form, which is almost impunc- 
tate and glabrous, and which has the type of pro- and mesosternum 
characteristic of a Lytopeplus. In contrast, L. striatus is more elon- 
gate and flattened, with distinctly seriate elytral punctation, erect 
vestiture, and a raised lateral pronotal margin ; in all these respects 
it resembles the type of Lapethus , L. discretus. For these reasons, 
we recognize the single genus Lapethus , and we suggest that the 
evolution of compact, globose forms and forms with piercing mouth- 
parts represent two independent trends occurring in more than one 
lineage. 
The genus Lapethus , as here delimited, contains about 25 described 
species, and a number of undescribed forms have been seen, especially 
in the New World. The group is primarily tropical, and the North 
American species are restricted to humid areas along the Pacific coast 
and in the mountains of the Southeast. 
Key to the North American Lapethus 
1. Pronotal punctation very fine and sparse, the punctures usually 
separated by at least two diameters; eyes reduced consisting of 
about 10 facets; labrum slightly longer than broad at base; size 
smaller, TL less than 1.75 mm.; Great Smoky Mountains and 
vicinity. striatus (Sen Gupta and Crowson ) 
— Pronotal punctation coarser and denser, the punctures usually 
separated by less that a diameter; eyes normal, with more than 
30 facets ; labrum slightly shorter than broad at base ; size 
larger, TL more than 1.75 m.; California. discretus Casey 
