I89.\] 251 



WAX SECRETED BY LEPIDOPTERA. 

 BY H. GUARD KNAGOS, M.D., F.L.S. 



That certain Hjjmenoptera and Homoptera secrete wax is of course 

 well known, but there does not appear to be any satisfactory record 

 of Lepidoptera performing this function ; I say satisfactory, because 

 Kirby and Spence's extract from Molina's Chili (vol. i, p. 147) seems 

 anything but clear, the diction being so ambiguous that the reader is 

 left in doubt whether the writer really meant wax or resin. The 

 passage, which will bear repetition, runs thus: — "In Coquimbo in 

 Chili, resin, either the product of an insect, or the consequence of an 

 insect's biting ofE the buds of a particular species of Origanum, is 

 collected in great quantities. The insect in question is a small, smooth, 

 red cater])illar, about half an inch long, whicb changes into a yellowish 

 moth with black stripes upon its wings {Phaloena ceraria, Molina). 

 Early in spring vast numbers of these caterpillars collect on the 

 branches of the Chila, where they form their cells of a kind of soft 

 white wax or resin, in which they undergo their transformations. This 

 wax, which is at first very white, but becomes yellow and finally 

 brown, is collected in autumn by the inhabitants, who boil it in water 

 and make it up into little cakes for the market." 



A year or so ago my friend Mr. (Uark, of Hackney, was describing 

 to me some cells of Retinia resinana which he had received from 

 Scotland, and as his account of them reminded me of the above, I 

 begged a few in order to investigate their composition. The result 

 was that they were found to contain a very appreciable amount of 

 wax, which formed the lining of the cells, as was demonstrated by 

 dissolving off the resin by immersion in cold rectified spirit, a fluid 

 which appears to have little or no effect upon the wax, so that the 

 latter was thereby exposed to view. From this it seems to me to be 

 pretty clear that the larva is furnished with the power of secreting 

 wax for the purpose of protecting itself from contact with the tenacious 

 semi-liquid resin exuding from the wound in the fir bud ; otherwise, 

 it would inevitably become involved in the sticky medium. What an 

 interesting sight it would be to watch the formation of thewe cells 

 ab initio ! 



Previously to this, however, I was aware that the imagines of 

 certain Lepidoptera contained wax, though I had then formed no idea 

 as to the part played by it in the economy of the insect's life, for it 

 had occasionally liappencil, when cleansing greasy moths by uiethylated 



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