BIOLOGICAL INVESTIGATION OF SPHENOPHORUS 
CALLOSUS OLIV. 
BY Z. P. METCALF 
HISTORY, SYNONYMY, AND CLASSIFICATION 
The corn bill bug ( Sphenophorus callosus Olivier) belongs to the 
family Curculionidop, the sub-family Calandrincv of the sub-order 
Rhynchophora. This family includes various species of bill bugs 
proper, many of wbicli are of economic importance in the United States, 
preying upon corn, grasses, etc., and the rice and granary weevils wbicli 
feed upon various kind's of stored products and grains. 
Blatckley and Leng (1916) describe tlie sub-family Calandrincv as 
follows: “A ratlier small group of usually large, robust species, having 
the antennae elbowed, inserted near the base of beak, their grooves very 
short, not receiving the scape; funicle 6-jointed, club not annulated, 
shining; labrum wanting; mouth cavity elongate, peduncle of men- 
tum narrow, elongate, concealing the oral organs; mandibles com¬ 
pressed, with three apical teeth; beak variable in length and sculp¬ 
ture; thorax truncate in front and beneath, without ocular lobes; 
elytra without epipleurae and with a strong fold on inner face; abdo¬ 
men with five ventral segments, the first and second longer, the third 
and fourth short, their sutures straight and deeply impressed, fifth 
equal to third and fourth fitting into the groove of the underside of 
elytra; last spiracle covered by the ventral segments; pygidium large, 
nearly perpendicular, exposed in both sexes; last dorsal of male quad¬ 
rate and more or less retracted or concealed; coxse all more or less 
separated, the hind ones transverse, oval; femora usually strongly 
clavate, not toothed; tibiae short, not serrate, clawed at the outer angle; 
tarsi rarely brush-like beneath, third joint rarely bilobed; claws diver¬ 
gent, simple. 
“The larvae of the larger species bore into the stems of plants, espe¬ 
cially grass and corn, while those of the smaller ones infest seeds and 
grain.” 
The genus Sphenophorus Sclioenherr is world-wide in distribution, 
containing species that are of economic importance in several countries. 
It was described in 1837 by Sclioenherr as follows: 
Genus S90. Sphenophorus nobis. 
Rhynchophorus Herbst. Schh. (1) Say—Calendra Clairville, Illiger, 
Germar; (2) Calandra Fabr. Olivier, Latreille, Germar, Dejean, Illiger, 
Oken, Sturm; (3) Curculio Linne et plures. 
Character generis —Antennae mediocres validiuscuHae articulis duobus 
basalibus funiculi oblongis turbinato-obconicis, reliquis brevibus, sub- rotunda- 
tis omnibus distanibus clava breviter ovata, compressa, cuneiformis. 
Rostrum elongatum, sub tenue, basi crassius, modice arcuatum, Thorax 
oblongus, antic angustior valde coarctatus, basi aut bi-sinuatus, aut rotunda- 
tus. 
Elytra oblonga, sub ovata, apice in pleurisque singulatim rotundata, supra 
saepissime planiuscula. 
Pedes mediocres, validi, longitudine sub aequales. 
