Insects on Elm and IV illow. 
1 15 
wasps feed readily off the honey-dew excreted by this species of 
aphis, and also that bees totally disregarded it. The flow of honey- 
dew produced by this species is very copious and does much damage 
to the trees and those beneath. It is not at all unusual for willows 
and osiers to be killed outright by it. 
The effect of the punctures of these plant lice is to leave distinct 
brown scars in stripes. This plant louse is also known as the 
Aphis saligna, Walker, other synonyms being Aphis salicis, Curtis, 
Aphis viminalis, Boyer de Fonscolombe, and Lachnus vimincilis, 
Passerine. The wingless viviparous female is dark yellowisli-brown 
to greyish-brown ; the antennie red at the base, black at the tips, 
and there are two dark spots on the thorax. The abdomen is much 
rounded and in the centre is a curious horn -like projection ; the 
cornicles are large and short and there are five to six rows of large 
black spots on it. The legs are deep brown, rather long and hairy. 
In length they are about 0*16 of an inch. The pupa is much like 
the larva, but rather longer and with bright brown wing cases, and 
the dorsal tubercle is very large. 
The winged female is quite a large insect, 4 to 5 mm. in length, of 
a dull brown colour with darker marks, the abdomen being spotted 
with black, one large spot placed centrally ; this spot apparently is 
the representative of the tubercle seen in the wingless female ; the 
short cornicles are almost conical. The long wings always seem to 
be carried horizontally when the insect is at rest ; the stigma is long, 
narrow and black ; the insertion and cubitus orange-yellow. The 
legs are long, the tibiae yellowish-red, the two-jointed tarsi deep 
brown. 
As this is certainly a very harmful species steps should be taken 
to destroy them by washing the willows with paraffin emulsion. 
This species is very common in some districts on willows and 
osiers. They congregate in masses often half a foot in length and an 
inch or more wide ; they are usually grouped side by side with their 
heads pointing downwards. When disturbed these sedentary insects 
become most active, yet do not leave their abode ; they throw their 
long hind legs up and wave them about in an erratic manner, with 
the probable intention of frightening off the enemy, especially hymen - 
opterous parasites. The effect of this species on the trees is very 
strange. Some osiers observed this year were killed by them, whilst 
others close to only presented a yellow-leafed appearance ; some shed 
their leaves, others recovered in a few weeks. Cameron records a case 
where this Lachnus swarmed in such numbers at Carshalton that 
trees thirty to forty feet high had been killed by their poisonous 
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