16 



THE ENTOMOLOGIST. 



INSTRUMENT WITH WHICH MOTHS OF THE GENUS 

 ANTHER.EA CUT OUT OF THEIR HARD COCOONS. 



By F. p. Dodd. 



I AM not aware that any Australian entomologist has yet dis- 

 covered how these silk-producing motlis contrive to work their 

 way out after bursting the pupa-shell. Many believed they 

 managed it with their woolly prolegs, aided by the liquid they 

 discharge to soften the material during the cutting process. A 

 more reasonable supposition would have been that the powerful 

 wing-veins near base performed the work, for a large percentage 

 of the moths have the scales of fore wing for one-fourth or three- 

 eighths of an inch from base completely rubbed off, giving the 

 insects quite a shabby appearance, though perfect in every other 

 way. Again, the insect whilst working seems to be employing the 

 fore wings, apparently striking with one for a time, then the other. 



However, Dr. A. J. Turner informed me that he was one day 

 watching an AnthcrcBa sivqjlex cutting out, and observed that it 

 did so with a pointed instrument, like the end of a small brad- 

 awl ; but the insect having emerged, he did not see this again. 

 As he was aware that I was breeding out several species, he ex- 

 pressed a wish that I should keep a watch when an opportunity 

 arose. I was soon able to prove that there is a cutting "weapon," 

 which our collectors appear to have failed to observe ; but that 

 is not strange, for, as the moth comes into view, his work is 

 nearly completed, and there is little necessity for him to use the 

 " cutter." This is a short hard black and curved thorn, situated 

 in the thick joiuts at base of fore wings, one on each side ; in a 

 rubbed specimen the thorn is easily discernible, but in a good 

 one it is concealed amongst the dense scales. This thorn is 

 present in all my species ; it can at once be felt in any speci- 

 men. It would be interesting to know whether anyone can state 

 whence the liquid issues which the moth discharges to soften 

 the cocoon where he cuts through ; it must issue from near the 

 thorn, for, as a rule, the scales left at base of the wing and along- 

 side of the thorax are wet and matted when the moth emerges. 



The cutting operation takes a considerable time — several 

 hours ; I have known A. lorantJii to commence work at 2.30, and 

 still be cutting at 7 o'clock, the constant " clicking " being heard 

 several yards away. This species, besides having its cocoon to 

 cut through, has the "community covering" to negotiate as 

 well — an extra one-fourth or three-eighths of an inch of tough 

 but loose material. When about to change the larvae bunch 

 together at the butt of the loranthus, and set to work together to 

 spin a great outer web, which envelopes them. When this is 

 completed each insect then constructs a cocoon, which is very 

 thick and harder than those of ^4. eucalypti, ianetta, or Ji.elenece. 



