362 PUYTOI'HAGA. [PhljUnir, t<(. 



pupa, arc beautifully figured ; as an instance of the damage causi-d by 

 this beetle, Curtis mentions that so long ago as 1786 the turnip crop 

 destroyed in Devonshire alone was worth 100,OOOZ. ; the eggs are laid 

 upon the under-side of the rough leaf of the turnip from April to 

 September, and they hatch in ten or even in seven days ; the larvae, 

 which are whitish grubs with the head and most of the upper surface 

 of the prothorax black, feed between the two skins or cuticles of the 

 leaf, and arrive at maturity in six days ; they then bury in the earth, 

 and in about a fortnight change to the perfect insect ; it is obvious, 

 therefore, that there are several broods in the year, and that they increase 

 to an enormous extent; the chief injury that is caused by them is the 

 destruction of the cotyledons or seed leaves, which is done by the 

 perfect insect, and entirely destroys the crop ; if once the plants can be 

 got beyond a certain stage, the attacks of the beetles do not much affect 

 them ; the application of good manure and careful preparation of the soil is 

 therefore of advantage, and some people recommend thick sowing; as 

 the autumn-hatched beetles hibernate, and are the chief source of damage 

 in spring, all clods, weeds, &c., that might be likely to harbour them 

 should be carefully removed ; in fact, clean farming is one of the greatest 

 protections that can be adopted against insect pests ; in cases of bad 

 attack, rolling with a light roller has been found beneficial, as also has 

 the use of freshly painted boards ; these, if drawn over the turnips, 

 catch large numbers ; many dressings have also been recommended, the 

 chief perhaps being " one bushel of gas-lime, fresh from the gas-house, 

 one bushel of fresh lime from the kiln, six pounds of sulphur, and ten 

 pounds of soot, well mixed together and ground to as fine a powder as 

 po.-sible ; this should always be applied very early in the morning, when 

 the dew is on the leaf, and if the fly continues troublesome the process 

 should be repeated." (See Miss Ormerod's Manual of Injurious Insects, 

 p. 151.) 



In the Entomologists' Monthly Magazine, vol. xxiii. p. 92, the Kev. 

 Theodore Wood mentions the fact that he has found P. melcena (= cn- 

 sobrina), (which is, as a rule, by no means a common species,) very de- 

 structive to seedling cabbages, bror oli, kale, &c., in the Isle of Thanet ; 

 in fact, Cruciferse generally seem to be liable to the attacks of various 

 members of this genus, which, in spite of their minute size, are 

 amongst the most injurious of all Coleoptera. 



Our British species may be divided as follows : the distinctions, 

 however, are in many cases more or less comparative, and are hard to 

 express in words ; a comparison with authentic types will be found far 

 more satisfactory than any descriptions 



I. Upper surface nnicolorotw. 



i. Upper surface bronze ; fourth joint of antennae 



in male very large, strongly inflated .... P. NODICORNI?, KfitrsA. 

 \\. Upper suiface black, bluish, or greenish ; 



fourth joint of antenna' in inulu not, or slightly, 



inflated. 



