PHORODON HUMULI VAR. MALAHEB. 
169 
Rather larger than P. Imimdi ; abdomen also 
broader. Figure long oval. Head and thorax taken 
together equal only to one fifth of the length of the 
body. Colour yellowish-green, with three darker 
green stripes on the back. Head narrow. Frontal 
tubercles porrected, but less so than in P. humidi. 
First antennal joint gibbous. Byes red. Legs and 
antennae green. 
Winged viviparous female. 
Inches. Millimetres. 
Expanse of wings 0*280 7' 10. 
Size of body 0*075x0*025 1*89x0*62, 
Length of antennae 0*070 1*77. 
,, cornicles 0*015 0*38. 
Bright green, shining. Head, lobes of the thorax, 
antennae and legs, with the exception of the upper 
parts of the femora, black. Abdomen with several 
interrupted dark transverse bands, and three large spots 
on the Carina. Two black spots under the insertions 
of the wings. First antennal joint gibbous. 
Common in May and June in the sloe, and also in 
the garden plum, under the leaves of which it forms 
considerable companies, though not so large perhaps 
as those of Aphis pruni. 
The ravages done by Phorodon humuli in some 
seasons to the hop gardens of England are very great. 
The writer of the article Aphis” in the ^ Penny 
Cyclopedia’ stated, that as long ago as the year 1802 
the excise duty paid on hops of the previous year 
fell from £100,000 to £14,000, and that the deterio- 
ration in value was entirely ascribed to the ravages of 
the fly.” Another writer in 1833 stated that the 
duty paid for hops when the fly was absent amounted 
to half a million of money. 
The agriculturist with anxiety therefore regards the 
movements of this pest, and long has called for some 
efficient method for checking its wonderful multipli- 
