New Y o»k AGRICULTURAL EXPERIMENT STATION. 457 
1842 between 500 and 600 acres of turnips were destroyed in two 
localities in England by this aphid. Prof. Davis* describes it as 
a “Oelery Aphis,” and reports it as occurring on celery in Michi- 
gan. ‘It is known to occur on a large number of different garden 
plants and weeds; also to injure most kinds of greenhouse plants 
if not kept in check. Buckton gives over 60 food plants for it. 
The winged females were very numerous in this locality 
(Jamaica, N Y.) during the month of October. They Were 
especially noticed because of flying into houses and greenhouses. 
Lettuce transplanted from cold frames and beds were smoked to 
give it a start ahead of the plant lice which were already upon it. 
This louse is easily distinguished from the cabbage louse, from 
the fact that its body is not covered with a pulverulent secretion 
and it is of alivid greencolor. The antennexare nearly as long as 
the body, and black. The cornicles or nectaries reach to the end 
of the body and are also black. 
Like the cabbage louse it has no fixed habits of producing 
winged females and migrating. Probably it survives the winter 
principally on greenhouse plants, for Kaltenbacht says, “ On pot 
plants the mother (viviparous female) produces living young 
throughout the whole year.” (“Aus Topfpflanzen bringen die 
Mutter das ganze Jahr hindurch lebende Jungen.’’) 
The finding of a few egg-laying females on cabbage late in 
November here on Long Island would indicate though that eggs 
are sometimes deposited. 
‘Remedies. Probably no better remedies can be suggested than 
those already well known to florists, namely, tobacco dust and 
tobacco fumes. In the field it should be treated the same as the 
cabbage louse, especially when occurring on celery. 
Enemies. This aphid apparently is not infested with parasites 
to such an extent as the cabbage aphis, in fact, no parasitized 
_ specimens of this aphid were found on cabbage the past season. 
However, they are affected bya fungous disease (Hmpusa aphidis). 
The latter part of November nearly two-thirds of all the colonies 
on cabbage were merely yellowish brown masses stuck to the 
leaves by the threads of the fungus. This disease was also ob- 
served on the same aphid on lettuce in greenhouses. 
* Bull, No, 102, Agr’l Exp. Sta., Mich., 1893, p. 20. 
+ Monographie der Familien der Pflanzen!zeuse p. 42, 1872. 
