86 Mr, CuRTis's Obfe'rvatlom on Aphides. 



of a box of a commodious forifri that fliall hqld about a dozen 

 plants of various fizes, to beufed as A fort of hofpital, in which in- 

 fefled plants may be fmoked feparately, and the infetSts mor^ cf- 

 feftually deftroyed, becaufe it may be rendered more perfe6lly 

 fmoke-tight. ,! . . • 



To prevent the calamities which would infallibly refult from the 

 accumulated multiplication of the more prolific animals, it has been 

 ordained by the Author of Nature, that fuch ftiould be diminifhed 

 by fcrving as food for others. On this principle, we find that moft 

 animals in this predicament ha.ve one or more natural enemies.. 

 The helplels Aphis, the fcourgc of the vegetable kingdom, has Co 

 contend with many. The principal are tlic Coccinellay the Ichneumon 

 Aphidum, and the Mu/ca aphidivora. Such as are unacquainted with 

 the hifloiy of infects will learn with fome furprife that the Cocci- 

 tiella*^ a common infeft well known even to children by the name 

 of the Lady-bird, is one of the' greateft deftroyers of the Aphides, 

 which indeed are its only food, its fole fupport, as well in its perfe(5t 

 as in its larva or grub ftate. During the feverity of winter this 

 infeft fccures itlblf under the bark of trees, or elfewhcref. When 

 the warmth of fpring has expanded the foliage of plants, the fe- 

 male depofits its eggs on them in great numbers, from whence 

 in a fliort time proceeds the larva, a fmall grub of a dark 

 lead colour fpotted with orange: thefe may be obferved in the 

 Uimnier Icaibn runnirig pretty brilkly over all kinds of plarlts ; and 

 if narrowly watched, they will be found to devour the y^phides 

 wheiever ihcy find them. The fame may be obferved of the Ladv- 

 bird in its perfecl (late. As thcfc infects in both their ftates arc 



• All the different fjiccics of Cocclnella feetl on Aphiilis; the bipunclata, by far the moft 

 common, does the molt execution. 



t Many are found in houfes ; for, early in May 1799, I counted on the window of my 

 common fitting-room, eipofcd to tlie fun, nineteen of the Coccinella biputiBata. 



very 



