SMICRONYX WEEVILS—ANDERSON 195 
are all reported by Kuschel (1949, 1952) to breed in species of Cuscuta. 
Nothing else is known about the biologies of these species. 
Oxtp Wortp species: The biologies of the species of Smicronyx of 
Europe and North Africa are better known than the biologies of the 
rest of the Old World species. At present, six species in those regions 
are known to breed in various species of Cuscuta, according to the 
works of Hustache (1930), Blair (1935), Solari (1952), and Pericart 
(1957). Some of the Cuscuta-breeding species (1.e., S. gungermanniae 
Reich and S. menozzw Solari) cause the formation of stem galls. 8. 
jungermanniae pupates in the soil, according to Bargagli (1883). 
Smicronyz (S.) reichi Gyllenhal has been reported reared from ‘larvae 
emerging from the seedheads of EHrythraea centaurium” by Blair 
(1935). Voss (1953) described a species (S. swertiae Voss) which was 
reared from galls on Swertia perrenis in Germany. Smicronyx (Cha- 
lybodontus) cyaneus Gyllenhal has been recorded by Bargagli (1883), 
Hustache (1930), and Martelli (1933) as breeding in the stems of 
various species of Phelipaea and Orobanche (Orobanchaceae) in the 
Mediterranean region; the larvae pupate in the soil. Marshall (1942) 
reports that S. gossypii Marshall adults are known to feed on cotton 
(Gossypium sp.) in the Anglo-Egyptian Sudan, but the species is 
not reported to actually breed in cotton. A single species from 
the Bihar region of India has been reported “reared from larvae liv- 
ing in galls on the stems of Cuscuta reflexa’’? by Marshall (1923). 
Khan and Murthy (1955) reported that Smicronyr albovariegatus 
Faust, an Indian species, had been found breeding in the seed capsules 
and stems of Striga species (Scrophulariaceae). When attacking the 
stems of the Striga plants, the weevils formed galls. The larvae 
were found to leave the plants and enter the soil before pupating. 
NATURAL CLASSIFICATION OF NORTH AMERICAN SUBGENERA WITH 
SUGGESTIONS CONCERNING THEIR EVOLUTION 
The ideas presented here concerning the possible steps or phases 
(see 1, 11, mt below) in the evolution of the larger natural groups of 
Smicronyx found in North America are dependent upon present evi- 
dence. The results of future investigations, particularly of the bi- 
ology of the groups, may or may not favor these ideas. The reader 
may have a clearer understanding of the groups referred to in this dis- 
cussion after reading the descriptions and discussions of the subgenera 
and species groups, and after examining diagram 1 on page 199. 
1. Susgenus Smicronyz: This subgenus probably originated some- 
time before the Pleistocene Epoch of the Cenozoic Era (see the dis- 
cussion below). The species of this subgenus (except S. profusus 
Casey and S. spretus Dietz) show little sexual dimorphism in their 
rostra, and neither the genitalia nor the second funicular segment are 
