50 BRITISH APHIDES. 



crevices of the bark of the chermes oak, Quercus 

 coed/era. 



After several moults the insect assumes a flattish, 

 flasked-shaped body, and becomes distended with 

 pseudo-eggs, which are deposited, without any regular 

 order, in small patches under the leaves. Wherever 

 these insects congregate, a yellow or orange-coloured 

 spot forms on the leaf, which penetrates through the 

 substance and causes the upper surface also to appear 

 brightly speckled. 



The young hatched from these eggs are much more 

 slender in shape, and become darker and redder at 

 each skin-shedding, which occurs four times. 



In about a fortnight they become pupge, and the 

 first winged females appear late in May or in early 

 •June. 



At this stage all the winged insects are stated to 

 migrate to the hairy oak, Quercus pubescens, and there 

 they drop their pseud-ova. The resulting apterous 

 females apparently do not give rise to winged forms 

 until August. " Alors ces insects ailes, qui cette fois-ci 

 ne sont plus porteurs d'eeufs, mais bien pupiferes 

 retournent au chime kermes et deposent sur les feuilles 

 lews pupes sexuees de dimensions differentes."* The 

 largest of these are the true oviparous sexed females, 

 the smaller are the males. After coupling, the result 

 is a single fecundated egg much larger than any of the 

 pseud-ova previously developed. 



This ovum is the commencement of the new cycle, 

 and discloses the queen-mother in the spring following. 



According to Lichtenstein coupling in Phylloxera 

 ijiirrr/fs is effected soon after birth of the sexes. The 

 male is very ardent and visits many females. As they 

 are born from the second winged individuals, which 

 occur in September or later, doubtless the egg is 

 lodged in some crevice in the oak-bark and remains 

 there till the early spring. 



* Vide M. Liclitenstein's notes at the end of this section of my 

 Monograph, p. U3. 



