MEANS OF DEFENCE OF INSECTS. 421 



a frog, and is probably the means of securing the nest from the attack of 

 many enemies. — Dr. Arnold observed a species of bug {Scutellera) 

 abundant upon some polygamous plants which he could not determine, and 

 in all their diflerent states. They were attended closely by^ hosts of ants, 

 and when disturbed emitted a very strong smell. One of these insects 

 ejected a minute drop of fluid into one of his eyes, which occasioned for 

 some hours considerable pain and inflannnation. In the evening, however, 

 they appeared to subside ; but on the following morning the inflammation 

 was renewed, became worse than ever, and lasted for three days. 



Other insects, when under alarm, discharge a fluid from the joints and 

 segments of their body. You have often seen what has been called the 

 unctuous or oil beetle (Meloe Proscarabccus), and I dare say, when you 

 took it, have observed orange-coloured or deep-yellow drops appear at its 

 joints. As these insects feed upon acrid plants, the species of crow-foot 

 (;r Ranunculus, it is probable that this fluid partakes of the nature of their 

 food, and is very acrimonious — and thus may put to flight its insect 

 assailants or the" birds, from neither of which it could otherwise escape, 

 being a very slow and sluggish, and at the same time very conspicuous 

 animal. Another beetle {E/enophoriis coUaris) has likewise this faculty. 

 — The lady-bird, we know, has been recommended as a cure for the tooth- 

 ache. This idea may have taken its rise from a secretion of this kind 

 being noticed upon it. I have observed that one species (Coccinella hiptinc- 

 tata), when taken, ejects from its joints a yellow fluid, which yields a 

 powerful but not agreeable scent of opium. — Asilus crabronifvrmis, a dip- 

 terous insect, once when 1 took it emitted a white milky fluid from its 

 proboscis, the joints of the legs and abdomen, and the anus. The common 

 scorjMon-fly {Rapkidia ojjhiojjsiii) likewise, upon the same occasion ejects 

 from its proboscis a brown and fetid drop.' Some insects have peculiar 

 organs from which tlieir fluids issue, or are ejaculated. Thus the larvae of 

 saw-flies, when taken into the hand, cover themselves with drops, exuding 

 from all parts of their body, of an unpleasant penetrating scent.^ That of 

 Citiibcx liitea,o( the same tribe, from a small hole just above each spiracle, 

 syringes a similar fluid in horizontal jets of the diameter of a thread, some- 

 times to the distance of more than a foot.^ — The caterpillar of the great 

 emperor moth (Saturnia Pavonia major) also s|)irts out, when the spines 

 that cover them are touched, clear lyriiph from its |)ierced tubercles.* — 

 Willoughby has remarked a curious circumstance with respect to a water 

 beetle (Acilius sulcatus) which ought not to be overlooked. A transverse 

 line of a pale colour is observable ui)on the elytra of the male ; where this 

 line terminates certain oblong pores are visible, from which he affirms he 

 has often seen a milky fluid exuding*; and what may confirm his state- 

 ment, I have more than once observed sucii a fluid issue from tlie male of 

 tiiis genus. — The caterpillar of the puss-moth {Cerura vinida), as well as 

 tliose of several other species, has a cleft in the neck between the head and 

 the first pair of legs. From this issues, at tiie will of the animal, a singular 

 syringe, laterally bifid; the branches of which are terminated by a nipple 

 perforated like the rose of a watering-pot. By means of this organ, when 

 toucheil, it will syringe a fluid to a considerable distance, wi'ich, if it enters 

 the eyes, gives them acute, but not lasting pain. The animal when taken 



1 De Geer, ii. 734. * Rcamur, v. 96. ' De Geer, ii. 937. 



4 Rosel, iv. 162. De Geer, i. 273. * Eai, Hist. Ins. 94. n. 3. 



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