308 OBSERVATIONS ON INSECTS. 



PTINUS PECTINICORNIS. Those maggots that make worm- 

 holes in tables, chairs, bed-posts, &c. and destroy wooden fur- 

 niture, especially where there is any sap, are the larvae of the 

 ptinus pectinicornis. This insect, it is probable, deposits its 

 eggs on the surface, and the worms eat their way in. 



In their holes, they turn into their pupce state, and so come 

 forth winged in July : eating their way through the valances 

 or curtains of a bed, or any other furniture that happens to 

 obstruct their passage. 



They seem to be most inclined to breed in beech ; hence 

 beech will not make lasting utensils or furniture. If their 

 eggs are deposited on the surface, frequent rubbing will 

 preserve wooden furniture. * 



BLATTA ORIENTALIS, (COCKROACH.) A neighbour com- 

 plained to me that her house was overrun with a kind of 

 black beetle, or, as she expressed herself, with a kind of black- 

 bob, which swarmed in her kitchen when they got up in the 

 morning before daybreak. 



Soon after this account, I observed an unusual insect in 

 one of my dark chimney closets, and find since, that in the 

 night, they swarm also in my kitchen. On examination, I 

 soon ascertained the species to be the blatta orientalis of 

 Linnaeus, and the blatta molendinaria of MoufFet. The male is 

 winged ; the female is not, but shews somewhat like the 

 rudiments of wings, as if in the pupa state. 



These insects belonged originally to the warmer parts of 

 America, and were conveyed from thence by shipping to the 



My gardener, in digging some ground, found, about six inches under 

 the surface, two of these insects alive, and perfectly formed, so early as 

 the twenty-fourth of March. When he brought them to me, they 

 appeared to be as perfect and as much alive as in the midst of summer, 

 crawling about as briskly as ever ; yet I saw no more of this insect till 

 the twenty-second of May, when it began to make its appearance. How 

 comes it, that though it was perfectly formed so early as the twenty- 

 fourth of March, it did not shew itself above ground till nearly two 

 months afterwards? MARKWICK. 



* Naturalists have observed, that the male broods of insects invariably 

 appear earlier than the female broods. Professor Rennie notices, that 

 upon the leaf of a poplar tree, of three eggs of the puss moth, (cerura 

 rinuftz,) which he found, two were hatched about a fortnight before 

 the other. The first were males, and the last a female ; thus dis- 

 tinctly proving, that eggs from which females are produced are longer 

 of hatching. As they were found on the same leaf, they were of course 

 presumed to be laid by the same parent ; at the same time, the difference 

 in the time of hatching could not depend upon any atmospherical cause. 

 ED. 



