152 



PLUM. 



also black; antennae green at their bases, tips brown. Legs 

 •with thighs and tips to the shanks brown. The frontal 

 tubercles less developed in this than in the wingless female. 

 Expanse of wings rather more than a quarter of an inch. 



.< 



Aphis hcmuli. — Winged and wingless viviparous females, magnified.* 



The wingless viviparous female is small, oval, pale green, 

 with one to three green stripes along the back. Body some- 

 time shining, and sufficiently transparent to allow the tracheae 

 to appear like silver threads. Frontal tubercles dentate. 

 First joint of the antennae gibbous and porrected. 



The ivinged male is smaller than the winged female. Colour 

 pale green excepting some parts of the thorax which are olive. 

 Antennae and wings long. Head and thorax much developed, 

 and frontal tubercles prominent. 



The above notes are abridged from Buckton's ' British 

 Aphides,' vol. i., elsewhere frequently referred to. 



Tlie ivingless oviparous female, which only appears in autumn, 

 is noted by Prof. Eiley in his English observations f as being 

 white at first, and becoming yellowish orange and olivaceous 

 with maturity, the head and the members darkening. 



The larva (or louse, as it is commonly called in its earliest 

 stage) is very pale ; later on, in the pupa state, the head and 

 fore part of the body are broad and squarish and the colour 

 green. 



For many years the migration of "Hop Aphis" from Plum 

 to Hop in the spring or early summer and return of the 

 descendants of these migrants back again from Hop to Plum 

 in the autumn has been considered to be established as the 

 case, both on the authority of many Hop growers and also by 

 observations of scientific observers qualified to distinguish one 

 kind of aphis from another. 



• The above figures are acknowledged, with thanks, as reduced copies of 

 figures 1 and 4, plate xxx., vol. i., of ' Monograph of British Aphides,' by G. B. 

 Buckton, F.E.S. 



t See ' Gardeners' Chronicle ' (London) for October 22nd, 1887. 



