ART. 4 NORTH AMERICAN WEEVILS BUCHANAN 5 



1. Basal margin of elytra (the deflexed portion extending downward to the 



mesonotum) perpendicular, or nearly so, from side to side — about as in 

 Tanymecus confertus. (Fig. 17.) Legs setose and also with a coating of 

 large, rounded, appressed scales. Elytral scales dense and broadly over- 

 lapping 2. 



la. Surface of elytra, in vicinity of scutellum, sloping gently forward and 

 downward to level of mesonotum, the basal margin perpendicular only at 

 the sides, about as in AfeZamomp/iMS alternatus, etc. (Fig. 18.) Legs with 

 numerous hairs, but without appressed scales, the dense surface punctation 

 plainly visible. Elytral scales rounded, less numerous, and as a rule only 

 narrowly overlapping. Pacific Coast species Group III- 



2. Form rather stout, the elytra slightly inflated behind. Elytral setae truncate 



at tip, shorter, stouter, in a nearly regular single row along each interval, 

 and, in side view, distinctly curved and inclined. Pronotal tubercles 

 moderately to strongly developed, though sometimes obscured by a surface 



crust. Eastern species Group I. 



2a. Form more slender, subparallel. Elytral setae acute at tip (bristlelike), 

 longer, more numerous and less regular, and more nearly erect. Pronotum 

 not tuberculate. Western species Group II. 



GROUP I (MESAGROICUS sens, str.) 



The four species included here are normally some shade of brown 

 in color, with more or less distinct paler markings often showing 

 around upper margin of eyes, sides of prothorax, and on humeri. 

 The elytra are sometimes obscurely and irregularly mottled with 

 darker and lighter blotches. The tarsi and claws are shorter and 

 stouter than in the western species. The plumose scales are few in 

 number and feeble in development (except in 'plumosus) . The mete- 

 pisternal suture is sometimes visible, but frequently is covered by an 

 exudation. The elytral setae may be said to form a single regular 

 row along each interval, although this regularity is only approximate, 

 the setae often becoming slightly uneven or staggered in spots. 

 This tendency toward irregularity is more pronounced in herricM 

 and plumosus than in the first two species. 



KEY TO GROUP I 



1. Scales on first and second abdominal segments large (size of elytral scales) and 



simple; punctures on these two segments moderate to large in size and well 



separated (figs. 4 and 5); dorsal setae stouter 2. 



la. Abdominal scales minute, plumose; abdominal punctures very small and 

 densely crowded; dorsal setae more slender 4. 



2. Scape, when laid across middle of eye, reaching or slightly passing its hind 



margin; size smaller, seldom as much as 4 mm.; elytral setae shorter and 



in a more nearly regular row along each interval minor, new species. 



2a. Scape extending %, or slightly more, across eye, but not reaching hind 

 margin; size 4-6 mm.; elytral setae longer 3. 



3. Eyes only moderately convex; pronotal tubercles somewhat irregular in size 



and shape, and often more or less obscured by a crust; abdominal punc- 

 tures smaller; pronotum more transverse (25 to 18 in male; 28 to 20 in 

 female — average of 6 specimens of each sex); Middle Western States. 



oblongus, new species. 



