216 RHYNCHOPHORA., [ Curculionine. 
il. Anterior tibia with a regular ridge running along the 
entire central line of their posterior margin; club of 
antennze smooth at base ; thorax ae long ; apex of elytra 
with a membranous border . . epee. fal OAL ANDERTNIAS 
SITONINA. 
This tribe has usually been regarded as belonging to the Otiorrhyn- 
chine, and has been classed with the Brachyderina or Phyllobiina: it 
must, however, be regarded as belonging to the sub-family Curculionine, 
although it is in some respects transitionary ; it contains only one genus, 
Sitones, which differs from all the other tribes by the structure of the 
mandibles, which are thickly punctured and pubescent on their surface, 
sharp and without a tooth on their internal edge and curved into a 
sharp hook at apex; the rostrum is short and broad ; certain of the 
species are exceedingly destructive to various leguminous crops. 
SITONES, Schonherr, 
This genus, according to the Munich catalogue, contains about eighty 
species, of which the majority occur in Europe, but a considerable 
number are found in North Africa, Northern Asia, North America, 
Mexico, &c.: according to Bedel, however, several of the North 
American species are re-described European species, which have been 
perhaps imported, and he reckons the number of known species at about 
sixty; fifty-two species, however, are recorded as European in the 
catalogue of Heyden Reitter and Weise ; nineteen have been regarded as 
British, but two of these, S. longicollis, Fahr., and S. einerascens, Fahr., 
are only varieties of S. flavescens, Marsh, and S. cambricus, Steph., 
respectively ; they are small, elongate, insects, clothed with more or 
less variegated grey, brown, whitish or sometimes slightly metallic 
scales, and in many instances so closely resemble one another that it is 
very hard to distinguish them by descriptions ; good characters, however, 
are afforded by the relative prominence of the eyes, the shape of the 
thorax and elytra aud the presence or absence of erect hairs and setz on 
the elytra; the colour is sometimes constant but sometimes varies con- 
siderably in the same species; the males are usually smaller and 
narrower than the females and present certain differences in the apical 
segment of the abdomen. 
The species are gregarious and many of them are exceedingly abun- 
dant in different localities; they live on various Papilionacee, and 
occasionally do considerable damage to clover, peas, beans, &c.; there 
are apparently two broods in each year, but very little is known of 
their true life history ; the most destructive is S. lineatus, which may 
sometimes be found on peas by countless thousands ; a description of 
iis ravages is given by Curtis (Farm Insects, p. 346, Plate L.); S. 
erinitus is occasionally injurious, but is much rarer; the beetles are 
said by Curtis and others to feed only by day, when the sun is bright, 
