SOLENOPSIS. '.,, / 101 



the insects inhabit. Vast numbers can be destroyed by placing 

 pieces of meat, sponges soaked in sugar and water, and bones near 

 the tracks, and when they are covered with ants, plunging them 

 into boiling water, but this only gives temporary relief, since as 

 long as there are a number of fertile females in the nests, the ants 

 thus killed will soon be replaced. 



I have several times endeavoured to keep this species in captivity, 

 introducing queens and numbers of workers into plaster nests, but 

 the ants do not appear to be able to live in close confinement, the 

 workers soon dying off in large numbers, and the whole colony 

 eventually perishing. 



SOLENOPSIS Westwood. 



[<ru\r]v, channel ; 6^ts, face (i.e. the channel on the head)]. 

 Type: Atta geminata F. (=mandibularis West.; West., 1841). 



Solenopsis is a large genus, about half the species of which are 

 proper to America, the remainder being distributed over Asia, 

 Africa, and Australia. Some seven species belong to the Palae- 

 arctic Region, of which only two occur in Europe. Dimorphism is 

 very prevalent in the workers of the exotic species, especially the 

 American, soldiers with very large heads being present ; the varia- 

 tion in the workers of the Palaearctic species, however, is not 

 nearly so marked. Many species are very hypogaeic in habits, 

 living underground as robbers in the nests of other ants. 



^ Head somewhat square, anteriorly with a distinct channel in the middle ; 

 clypeus armed with two teeth on the anterior margin, these teeth converging 

 back between the base of the antennae as carinae ; mandibles narrow, ter- 

 minal border furnished with four teeth ; maxillary palpi and labial palpi 

 two-jointed ; antennae ten-jointed, with a distinct two-jointed club, the 

 last joint of which is very long ; eyes small and flat. Thorax with suture 

 between pronotum and mesonotum obsolete ; suture between mesonotum 

 and epinotum distinct and deep ; epinotum unarmed. Petiole cylindrical 

 anteriorly, nodiform posteriorly ; post-petiole transverse, nodiform, not so 

 high as petiole ; gaster oval, with first segment longer than half the gaster ; 

 sting very large. 



$ Much larger than the ^. Antennae as in the ^, but eleven- join ted ; eyes 

 projecting, much larger than in the ^ ; ocelli present. Wings : fore-wings 

 with a closed cubital cell, and one discoidal cell, radial cell open. 



cJ Smaller than the $. Head short ; clypeus convex ; mandibles narrow, 

 armed with three teeth ; maxillary and labial palpi two- join ted ; antennae 

 twelve- jointed, scape short, the first joint of ihefuniculus swollen and globular. 

 Thorax : mesonotum without Mayrian furrows ; epinotum unarmed. Wings 

 as in the $. 



Original description [Westwood Ann. Mag. N. H. 6 86 (1841)] : 



" (<rw\T]v canalis et 8^is fascies, ob faciem canaliculatam. ) 



Characteres e pseudo-foemina desumpti. 



Caput maximum subquadratum horizontale postice emarginatum, supra 

 linea media longitudinali in duas partes divisum antice in medio bituber- 

 culatum. Oculi parvi laterales ante medium marginis locati. 



