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 different 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 inflammation. 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 Proscarabeus), 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 
or 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 (Z/enophorus collaris) 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 bipune- 
tata), when taken, ejects from its joints a yellow fluid, which yields a 
powerful but not agreeable scent of opium. — Asilus crabroniformis, a dip- 
terous insect, once when I took it emitted a white milky fluid from its 
proboscis, the joints of the legs and abdomen, and the anus. ‘The common 
scorpion-fly (Raphidia ophiopsis) likewise, upon the same occasion ejects 
from its proboscis a brown and fetid drop.! Some insects have peculiar 
organs from which their 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 
Cimbew lutea, of 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 spirts out, when the spines 
that cover them are touched, clear lymph from its pierced 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 upon 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 such a fluid issue from the male of 
this genus. — The caterpillar of the puss-moth (Cerura vinula), as well as 
those of several other species, has a cleft in the neck between the head and 
the first pair of legs. From this issues, at the 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 
touched, it will syringe a fluid to a considerable distance, which, if it enters 
the eyes, gives them acute, but not lasting pain. The animal when taken 
' De Geer, ii. 734. 2 Reamur, v. 96. 5 De Geer, ii. 937. 
* Risel, iv. 162. De Geer, i. 273. , 5 Rai, Hist. Ins, 94, n, 3. 
EES 
