Powder-wings» 



i8q 



They arc produced from eggs, the mature Insect 

 not sharing the power possessed by the plant-hce for 

 producing h\-ing voung. These eggs are elHptical in 

 shape, with a short footstalk by means of which they 

 are attached erectly to the under side of a leaf. The\- 

 are usually coloured pale yellow or orange ; and one 

 female lavs a large number of them. The\' hatch in 

 from ten da\-s to a fortnight- on an average, say, 

 twelve days ; and it is interesting to note that similar 

 periods bound the larval and pupal stages. The nev\l\' 

 hatched larva — one can hardly apply the term grub 

 in this case — immediately selects a suitable spot into 

 which to insert its beak, and there it remains until it 

 has acquired wings. At this period it is elliptical in 

 shape, almost flat, and so thin and colourless as to be 

 nearly transparent. For this reason it is difficult to 

 make out an\' organs ; but as growth proceeds these 

 become more evident. The presence or absence of 

 hairs and spines, differences of colour and of the 

 character of waxv fringes, distinguish the species one 

 from another. One organ is evident in all species from 

 the beginning. This is an opening on the upper side 

 of the hindmost segment of the body, and it is fitted 

 with a sort of lid for closing it or opening to allow the 

 extrusion of a tongue-like process. From this orifice 

 the Insect appears to furnish a sweet, sticky fluid like 

 that supplied by plant-lice and scale-Insects, and it has 

 the similar power of enlisting the kindly offices of ants 

 for their protection. In most respects these larval 

 powder-wings are like scale-Insects. 



In most species the pupal stage is entered upon 

 within the skin of the lar\'a ; on being withdrawn the 

 rudiments of the future legs and antenn<e ma\- be seen. 

 In some cases the larval skin breaks up and reveals the 

 pupa. 



The perfect Insects may be distinguished from the 

 two-winged male scale-Insects by the possession of 

 four wings. There is a connnon sj)ecies to be found 

 on the under side of bramble leaves near the ground, 

 whose habits the present writer has had the oppor- 

 tunity for watching more closely than in other species. 

 It is found that tlie female before laying her pale 

 yellow eggs takes care to dust a small area of the leaf 

 with the white meal, presumably hom the unck-r su.rface 

 of her wings. This is a u^^•ful chu' to anybod\- searching for the eggs, which are very 



I'lmtiis !>y] 



Ilu- 



POWDEK-WINGS. 



■ beautiful Init littK'-known, minute 

 hisicts appear at first sight to be little 

 moths, and thcv were regarded as such by 

 the great I-innanis. But their four wings 

 are covered with meal instead of scales, 

 and their early development is very different 

 from that of the butterfly and moth. The 

 specimen with one spot near the tip of the 

 wing is found on the under side of bramble 

 leaves ; that with two dark marks is found 

 on cabbage leaves. The lowest abounds 

 on celandine leaves. Magnified four times. 



