60 



THIRD ANNUAL REPORT OF 



THE COCKLEBUR SPHENOPHORUS- 

 Schoenherr. 



■Sp h e n op I, o r u s %> ulchellus, 



In closing this chapter on snout-beetles I intro- 

 duce this species (Fig. 23, a shaded back view; 

 b outline side-view,) not that it is injurious, but 

 because it belongs to the same genus, and is 

 closely allied to the preceding insect; and be- 

 cause its larval habits, which are now given for 

 the first time, may lead us more readily to discover 

 those of its more injurious ally. 



The color of this beetle above, is of a deep 

 brick-red inclining to blood-red, often with a tinge of orange, and it is 

 marked with black as in the figure* the whole underside being also 

 black. The larva bores the stalks of the common cocklebur (Xan- 

 thium strum.arium,) and differs from most other snout-beetle larva in 

 having a dark mahogony-brown head, and in the anal joint being 

 slantingly truncated and furnished with fuscous elevations which give 

 rise to short stiff bristles. It transforms in the fall of the year within 

 the stem and issues as a beetle about the end of September.* 



Of our other N. A. snout-beetles may be mentioned as especially 

 injurious the Grape Curculio (Cmliodes incequalis, Say), Grape-cane 

 Curculio (Baridius sesostris, Lee.) Potato-stalk weevil (Baridius 

 trinotatus, Say), the different nut-weevils (genus Balaninus), the 

 Grain-weevil (SitopMlus granarius, Linn.), the White-pine weevil 

 \Pissodes stroll, Peck), and the Cranberry-weevil (Anthonomus 

 sicturalis,Lec.) The first three have already been treated of in my 

 first Report, the nut-weevils will form the subject of a future article, 

 and the others have either been fully treated of in standard works or 

 are not particularly injurious in Missouri. 



-This insect seems to differ from 13-punctatus, Say, in absolutely nothing but in having a 

 large black patch at the tip of the elytra instead. of two spots. I have bred four specimens from 

 cocklebur, and they are all tolerably constant in the characters accorded to pulchellus. But 1 am 

 strongly of opinion that we have to deal here with but one species, and that with a sufficiently 

 large series, the dividing line could not be drawn. At all events 13-punctatus is very variable in 

 the size of its spots, and the greatest variation occurs in these two at the tip of the elytra, while 

 Say describes and figures a variety of his \3-punctatus which is singularly intermediate between 

 the two species. In three specimens of 13-punetatus in my cabinet, the two posterior spots are 

 so large that they almost meet, while in some specimens they are not larger than the other elytra! 

 spots. 



