The Pith Moth. 69 



mentioned as having been particularly troubled with it : Worcester ; 

 Herefordshire (Eoss) ; Gloucester ; Cambridgeshire (Wisbech) ; 

 Bournemouth ; Sussex (especially at Polegate) ; Surrey and Kent 

 generally. 



Life-history. 



This moth belongs to the group of small moths known as Thidnm 

 and to the genus Laverna. Its wing expanse is a little less than 

 half an inch when fully expanded ; the front wings are almost 

 entirely black, but may be mottled with black, dark brown and 

 rusty brown ; the inner margin of the fore wings is- white to beyond 

 the middle, where an irregular oblique white bar proceeds to the tip 

 of the wing, and two branches from this intersect the black apical 

 portion ; the posterior wings are grey and, like all Tineince, have 

 long fringes; the head is almost entirely white. It is subject to 

 much variation. Some specimens are almost black ; these Stainton 

 considers a distinct variety. The moth appears in June according 

 to Stainton, but all those that have been bred or observed appeared 

 in July. Some received in 1898 hatched on July 5th, others not 

 until the 21st. Difference of locality is sure to account for a 

 difference in the time of their appearance. 



The eggs are apparently laid on the leaves ; no definite observa- 

 tions have been made, however. In July I found several small 

 batches of eggs on an apple tree previously badly attacked by Pith 

 Moth, but I am not certain if they were those of the Laverna. They 

 occurred in small batches from one-fifth to one-fourth of an inch 

 long ; in form they resembled those of the Bud Moth, ^dz., flat and 

 scale-like and almost transparent. One batch was composed of 

 twenty eggs overlapping one another like fish scales. The whole 

 surface of the egg is covered with a well-defined reticulate sculptur- 

 ing, not the outer part only, as in those of the Bud Moth or Codling 

 Moth. Penthina variegana was seen near this tree, so that it may 

 be the eggs were of that insect. 



In any case the eggs, whatever they may be like, give rise to the 

 larvae the same summer, and the young larvae feed first on the leaves. 

 As winter approaches, the larvte, wliich are still quite small, bore 

 just under the bark of a twig or into the apex of a shoot and remain 

 there most of the winter. During January and February the larvse 

 tunnel right into a young shoot and work up the pith (Fig. 8, e). 

 In this tunnel the caterpillar lives until June ; its presence does 

 not stop the leaves and blossom from unfolding, although later they 

 flag, turn brown, and die right off" (Fig. 7, b). These dead shoots 



