140 Insect Pests. 



plants, although the Aphis fitchii produced young artificially on 

 Meadow Foxtail, and was found on other grasses. This bears out 

 what we see is said to occur in America and explains their sudden 

 departure from the apples and later return. 



PREVENTION AND TREATMENT OF APPLE APHIDES. 

 The inquiries received regarding treatment come from all parts 

 of the country. Many growers say washing with paraffin emulsion is 

 of little use. This is certainly true, as the ova of any one species I 

 find hatch very unevenly, and the result is, many lice have damaged 

 buds and blossom and curled leaves, whilst others are coming out, 

 and thus a certain number escape the wash. If we wash as soon as 

 they begin to hatch it is no good unless we are prepared to go on 

 every day for perhaps several weeks, an impossible process. Only a 

 penetrative wash will get into the lice pro- 

 tected by curled leaves. 



After many experiments I eventually 

 have come to the conclusion the most vulner- 

 able time in the life-history of these plant 

 lice is when in the sexual stage in the 

 autumn. When we find the small wingless 

 or winged sexual forms under the leaves is 

 the time to kill them. At this time a heavy 

 paraffin emulsion may be used, as the leaves 



are f little ValllG and ^ d eS n0t matter if 



(Greatly enlarged ) we ouru them. The Apple Aphid es are then 



killed before they lay their eggs, and their 



future attack is guarded against. The emulsion must not be put on 

 with much force, as the leaves may be knocked off. The tree should 

 have a good spraying, and the ground below well wetted and also 

 the trunk, the oviparous females will then be killed. 



I am confident that autumnal spraying for these pests is most 

 essential. If it is more troublesome it does good, and the usual 

 spraying when the leaves are curled is often waste of time and 

 money, especially where we have more than one kind of aphis at 

 work. For the attack of Aphis fitchii, early spraying is, of course, of 

 use, as this species feeds openly, but not for pomi and sorbi, which 

 curl up the leaves as soon as they open. When the leaves are curled 

 the best wash to use is the tobacco wash. 



All primings should be rigorously burnt before March. Many 

 eggs are thereby destroyed. 



Mr. Bear of Magham Down, Hailsham, wrote me on the 15th of 



