298 



Insect Pests. 



Life-History and Habits. 

 The motli appears in May; in 1906 as early as the 12th of May at 

 Wye, the year before not until the 27th. In size it varies from 7 to 

 8 mm. in wing expansion. The anterior wings are pale ochreous 

 brown, with a snowy white basal streak, and on the inner margin 

 a thin white streak much smaller than the above ; towards the apex 

 four white converging areas above and three below ; the hind wings 

 are white with dusky base, and the long fringes are grey in the 

 female, of a dull yellowish tinge in the male. The thorax is the 

 same colour as the wings, with a median and lateral white stripes. 



The abdomen is grey, and 

 the tuft pale ochreous. 

 The legs are grey, with 

 white tarsal segments 

 spotted with fuscous. 



They lay their eggs on 

 the leaf, choosing, it seems, 

 a still, fine evening just 

 before sunset. The larvae 

 then burrow into the leaf, 

 and feed upon the soft 

 mesophyll and eat it out 

 in a more or less rounded area, the upper epidermis being left 

 intact, but quite separate from the rest of the leaf and showing quite 

 white (1 have never seen the ochreous central area described by 

 Stainton). Occasionally, when the mine is near a mid rib or the 

 edge of the leaf, the leaf becomes much puckered and folded. 



In this blister the larvre may be found up to the Ijeginning of 

 July. 



When mature the larva reaches about 4"5 mm. in length. It is 

 pale yellowish-green, tlie first three segments more yellowish, and 

 the eighth with a somewhat obscure orange-yellow spot ; the last two 

 segments are yellowish. The head pale brown, with dark brown 

 markings ; when retracted the lobes show through the first segment 

 as two brown spots. Legs very pale. 



This larva, when quite young, lies in a. curved position, Ijut as it 

 reaches maturity it straightens out. It can generally be seen in the 

 mine at work by holding the leaf up to a strong light. Some dusky 

 spots are noticeable beneath in the young larva, but they soon 

 disappear. 



Pupation takes place in the blister, and by the first or second 



[Uorace Krihjht. 

 FIG. 202.— NUT-LEAF BLISTER MOTH (Lithocolletis Corilll). 



