218 



Insect Pests. 



found them forming, before any of the aphis had hatched from the- 

 eggs. Whether they are fungoid in origin I do not know, but in 

 any case they are not caused, as thought, by the plant lice, which 

 merely shelter beneath them. Neither of these aphides is said 

 to form much "honeydew," hence the diseased appearance of the 

 leaf is often not noticed as being of insect origin during the early 

 stages of the attack, unless an examination has been made of the 

 under surface. Later on "honeydew" becomes abundant, being 



especially formed by the leaf- 

 curling species ; on black cur- 

 rants the "honeydew" often 

 gives a shiny and sticky appear- 

 ance to the whole bush. 



The insects spread chiefly 

 by means of winged genera- 

 tions, which appear every now 

 and then, flying from bush to 

 bush, and there setting up fresh 

 areas of disease. These winged 

 generations may occur as early 

 as the middle of May, but 

 usually not until June. All 

 varieties seem to be attacked. 



LlFE-HlSTORY AND HABITS. 



Although the appearance 

 and habits of the two currant 

 aphides are different, yet their 

 life- histories are very similar. 

 L. The wingless viviparous female, 

 mottled with darker green ; 



FIG. 167. AN APHIS SHOWING TWO YOUNG WITHIN. 



(Greatly enlarged.) 



(I.) Rhopcdosiplium ribis 

 or " mother-queen," is shiny green, 

 legs, honey-tubes, and antenna3 pale green; eyes, red. In form it 

 is oval and convex, and slightly larger than the following species 

 (II.) ; the body being j 1 ^ inch long. The wingless females are found 

 on the under surface of the leaves and sheltered under the red, 

 orange, and yellow blisters. They appear first of all in April, and 

 occur continuously until July and even August. Every now and 

 then the lice to which they give rise turn into so-called pupre, 

 which are characterised by rudiments of wings appearing as wing 

 buds. 



The pupa is green, and does not, apart from the wing cases, 



