62 LI^^^KA^ system. 



Genus 46. Cimex. 

 lloUrum inflected : antenna longer than the thorax : zclngs four, folded 

 crosswise; the upper ones coriaceous in the anterior part : buck flat: 

 thorax marginated : /te/^ formed for running. {PL 5. Jig. 0, 7, 8.) 

 The insects of this genus, whether as larvte or in the perfect state, 

 feed for the most part on tlie juices of plants; some on the larvje of 

 other animals: they have in general a very disagreeable. smell. The 

 larvae and pupas have six feet; they are active, and walk about like the 

 perfect insect : the former has no wings, the latter has the rudiments 

 of theiii. A great number of species are found in Britain. 



Sp. 1. Cimex kctidarius. Without wings. 

 Inhabits Europe. 



This insect (the bed-bug) is unhappily but too well known, and was 

 an inhabitant of Europe [irior to the Christian a ra; at least it is men- 

 tioned by Aristophanes and other Greek writers. Southall says it was 

 hardly known in London before 1(370; but there is good authority for 

 asserting that it was common enough there before the great tire iu 

 1666. It is a nocturnal animal, very fetid; seldom, though sometimes, 

 found with wings ; easily killed when taken alive. Bugs are said to be 

 expelled in a variety of ways, viz. by charcoal and oil of turpentine, soft 

 soap, or hard pomatum. 



Genus 47. Aphis. 

 Rostrum inflected : the vagina with five articulations and a single seta : 



antenna setaceous, longer than the thorax : wings four, erect, or none : 



feet formed for walking : the abdomen generally armed with two horns. 



{Pl.5.fg.Q.) 



The insects of this genus are small and defenceless ; but very nox- 

 ious animals, and most remarkable for the singularities in their history 

 and manners. They seldom appear before autimm, when the males im- 

 pregnate their females, which soon thereafter lay eggs or rather a sort of 

 capsule in which the young Aphides lie already perfectly formed, but 

 do not break their shell till the following spring. When they appear, 

 it is very remarkable that they are almost wholly females, with hardly 

 a male to be seen during the whole spring and summer. Notw^ith- 

 standing this, all these female Aphides without any communication 

 with a male are able to propagate their species, and seem to have re- 

 ceived the genial influence not merely for themselves alone but for 

 their posterity to the ninth generation. During the whole summer they 

 are viviparous ; and if a young Aphis be taken immediately upon ex- 

 clusion from the mother, and kept apart, it will produce young ; which 

 young, if also kept apart, will likewise produce, and so on, without the 

 presence of a male. Towards autumn, however, this singular fructifi- 

 catiou begins to lose its wonderful effects ; the Aphides cease to bring 



