130 KHYNCHOPHORA. [Apion. 



The sexual differences are often remarkable ; as a rule the males may 

 be distinguished from the females by their shorter and more robust 

 rostrum, which is often more strongly punctured and more evidently 

 pubescent; the sexes, however, in many species differ in special particu- 

 lars, as the colour of the rostrum, antennae and legs, and sometimes of 

 the elytra, the dilated or curved tibiae, certain modifications of the scape 

 or funiculus of the antennae, and also of the tarsi, metasternum and 

 abdomen, &c. ; these will, however, be noticed more particularly under 

 the various species. 



The larva? of the genus Apion are small fleshy white or yellowish-white grubs with 

 corneous heads, which do not differ much from the ordinary Rhyncbophorous larvae 

 and call for no special notice ; they are found in flower-heads, and in the seed-vessels 

 of plants, sometimes in the pods, leaf-stems or stalks, and they undergo all their 

 transformations in the same place in which they were originally hatched ; according to 

 M. Bedel it is very rarely that the larvae betray their presence externally by any 

 swelling of tlie vegetable tissues (as is so often the case with Mecinus and other genera) ; 

 the larva of A. minimum, however, which is the only species that feeds on tlie 

 Salicaceae, lives under the willow leaves, accordiug t<> Ferris, in galls formed by 

 Nemattis, or, accoidingto Kaltenbach, in the galls of certain Diptera; considerable 

 speculation has been caused by the fact that large numbers of certain species (such as 

 A. cracccB, A. Oyllenhali, &c.) have been found congregated upon various trees, sucli 

 as the oak and ash, having apparently deserted their ordinary food plants ; the reason 

 of this is unknown ; M. Bedel suggests that the insects are merely seeking shelter 

 against heat or cold, but it appears probable that they may be assembling simply with 

 a view to migration from one district to another. 



The majority of our species of Apion live on different leguminous 

 plants (more especially Trifolium, Vicia, Genista, Ulex, and their 

 allies) ; occasionally certain species do considerable damage to clover- 

 fields, riddling and destroying both the leaves and seed pods ; it is hard 

 to suggest any really useful remedy, but a badly infested field should be 

 thoroughly cleaned and all the refuse carefully burnt towards the end of 

 the year ; the waste portions near the hedges should also be, if possible, 

 grubbed up and cleaned, as the Apions are not very particular as to the 

 species of Leguminous plants which they attach themselves to, and will 

 find support on various wild vetches before again attacking the cultivated 

 portions; for the next season the field and those around it should if 

 possible be planted with a crop not liable to the attacks of the insects ; 

 as, however, the species are, for the most part, provided with powerful 

 wings, no precautions can really be of much avail against an invasion. 



Besides the Leguminosce, various other families of plants are attacked 

 by different species : a list is given by M. Bedel (1. c. p. 203), which is 

 here quoted as far as it relates to the British species : 



Malvaceae: centum, radiolus, rufirostre, mdlvce, 



Crassulaceae : sedi. 



Compositae: Cynarocephalae (thistle tribe), carduorum and allies, 



onopovdi. 

 Corymbifera? : stolid urn, conflnens, sorbi, F. (J&vigafam, 



