i'2-2{) 



l>^\MJl;^■ ],iii. — (;iijn'S(")Mi';rjU),io. 



(1. Surface shining, the punctuation never very coarse; elytra each 



with a paler median stripe. 22Kn. t^niata. 



d(l. Surface subopaque, the punctuation coarse, close anrl flceji; elytra 



without a i>aler median stripe. 

 2257 (6995) 



2201. MAHGINALIS. 

 26. 



Systena hudsonias Forst, Nov. Sp. Ins., 1771 



Elongate, subdepressed. Pic- 

 eous black, shining ; antennae with 

 joints 3, 4 and 5 dull yellow, the 

 others more or less piceous; legs 

 black. Thorax about one-third 

 wider than long, sides feebly 

 curved, front angles obliquely 

 truncate; surface finely aluta- 

 ceous, indistinctly punctate, mi- 

 nutely wrinkled. Elytra wider at 

 base than thorax; disk coarsely and 

 closely punctate, somewhat rugose. 

 Length 4-4.5 mm. (Fig. 541.) 



Throughout the State; 

 frequent in the southern, 

 scarce in the northern coun- 

 ties, ^lay 21- August 20. Oc- 

 curs on the greater ra-gweed, 



Fig. 541, X 10. (After Forbes.) 



Ambrosia trifida L. ; also on elder and other weeds. 



*2258 (6990). Systena frontalis Fabr., Syst. Eleut, I, 1801, 300. 

 Resembles hudsonius very 



closely. Usually a little 

 broader and less shining, the 

 head reddish or reddish-yel- 

 low ; antennae and legs mostly 

 pale. Thorax more distinctly 

 and elytra less coarsely punc- 

 tate. Males in both species 

 with the last ventral segment 

 notched each side, the middle 

 lobe «-ith a deeply impressed 

 triangular median line. Length 

 .j.5-4.5 mm. (Fig. .542.) 



Throughout the State; 

 less common than hudso- 

 nias. llibernates beneath 

 bark of soft maple and 

 mullein leaves. February 

 ll-September 22. Occurs 

 most frequently on smart- 

 weed {I'oliji/oinim), the 

 greater ragweed and pin-wciMJ {('hriio/iodiitin) 



Fig. 542. X 10. (After Forbes.) 



