248 MEANS OF DEFENCE OF INSECTS. 



rise from a secretion of this kind being noticed upon it. 

 I have observed that one species (Coccinella bipunc- 

 tata) when taken ejects from its joints a yellow fluid 

 which yields a powerful but not agreeable scent of opium. 

 Asilus crabroniformis, a dipterous 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, likewise, upon the same occasion 

 ejects from its proboscis a^rown and fetid drop a . 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 b . That of Cimbex 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, sometimes to the distance of more than a foot c . 

 The caterpillar of the great emperor moth (Saturnia 

 Pyri,} also spirts out, when, the spines that cover them 

 are touched, clear lymph from its pierced tubercles d . 

 Willughby has remarked a curious circumstance with 

 respect to a water-beetle (Acillus 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 exucjing 6 ; and 

 what may confirm his statement, I have more than once 

 observed such a fluid issue from the male of this genus. 

 The caterpillar of the puss-moth (Centra vinula), as 



a De Geer, ii. 734. b Reaumur, v. 96. c De Geer, ii. 937 

 d Rosel, iv. 1G2. De Geer, i. 273. 

 ? Rai. Hist. Ins. 94. n. 3. 



