INSECTS 



being black with white patches on the dorsum, which patches seem to 

 become larger as the age of the insect increases. 



The Haslemere district some years ago was under partial cultivation 

 of the hop, and the aphis Phorodon humuli was plentiful in the local hop- 

 gardens. This aphis and the less common P. galeopsidis, which feeds on 

 the hemp-nettle, which is not like the hop a true nettle, is now known 

 to deposit its ova in late autumn on the dead stools of the hop-vines, just 

 above the surface of the soil or a few inches below it, and thus an an- 

 swer is given to the question, what becomes of the living aphis when its 

 natural food-plant has entirely disappeared ? The answer is also made 

 more easy by what now appears to be a fact, that there is a migration 

 from the hop to the sloe at certain seasons. The sloe of course is a 

 persistent tree and not perennial like the hop. P. malaheb should be 

 probably marked off as a synonym, if this fact of migration be admitted. 

 P. galeopsidis is a distinct species. The natural checks to the increase of 

 P. humuli are well known, principally through the agency of the larvae 

 of voracious Cocinellidce and Syrphidce^ familiarly known to countrymen 

 as hop-dogs. 



Horticulture. The peach and nectarine trees have each their aphis- 

 pests ; the former particularly is infested by Myzus persicte and Rbopalosi- 

 phum diantbi. The first aphis causes open bladders on the leaves, within 

 which the insects hide ; the second rolls and crinkles the leaves, and finally 

 changes their colour to dark brown. R. diantbi is one of the usual great 

 pests of the greenhouse. Myzus cerasi is the common black aphis which 

 destroys the crops of cherry orchards. It also swarms on the garden plum, 

 which tree is further injured by the attacks of Aphis pruni and A. padi. 

 The pest known as American blight is only too familiar and obvious to 

 the apple-grower, by the white cotton-like tufts which hang to the 

 branches and trunks of orchard-trees. Scbizoneura lanigera has both aerial 

 and subterranean forms, somewhat similar to those we see in the great 

 vine-pest of France, Phylloxera vastatrix. The ova have been discovered 

 both on the branches and in the crevices of apple-bark both above and 

 underground ; singularly the males are found mouthless and incapable of 

 taking any nourishment. This blighting pest may be reduced by a copious 

 spraying with weak solutions of calcium sulphide, obtained by boiling to- 

 gether a mixture of sulphur and quicklime in water. This aphis must 

 not be confounded with another species, Aphis malt, Kalt, which does not 

 injure the trees so much and is not tomentose. Myzus ribis is common on 

 both the red and the black currant bushes. It forms red or brown open 

 tubercles on the leaves. The bright-coloured Aphis cucurbiti and the 

 ubiquitous A. rapi vie with the ' red spider ' in trying the patience of 

 the grower of melons, cucumbers and gourds. 



On passing to vegetable blights we find that through them the 

 gardener is often not happy in successfully raising his crop. The leaves 

 of the common kale and cabbage are frequently made hideous by the half- 

 decaying masses of dead and dying individuals of A. brassicte. Sometimes 

 the combined weight of these insects nearly equals the weight of the leaf 



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