82 First Report on Economic Zoology. 
emitted through, this. Buckler quotes a letter from the Hon. T. de 
Grey as follows : — “ I first observed the larva by pulling up, on the 
14th May, a sickly -looking plant of Equisetum arvense. It appeared 
to be feeding on the root and stem below the surface of the ground,. 
c 
Fig. 9. — the potato stem-borer (Hydrcecia micacca ). 
a, Imago ; b and d, larva ; c, pupa ; e, hole in potato haulm caused by larva. 
(Natural size). 
but when placed in a bottle with a supply of the food plant, it 
immediately entered a stem, and fed upon the inner substance, 
hollowing it completely out, and ejecting the frass at the lower end.” 
This describes the way it has been observed working in potato haulm. 
They work with great rapidity, eight inches being tunnelled in an 
