22 REPORT ON INJURIOUS INSECTS FOR 1905 



In spite of the beneficial work of the larvae of certain Hover- 

 ing Flies (Catabomba pyrastri, Linn., and Syrphus grossulariae, 

 Meig.), and Ladybird beetles, once they attack a plant, they seem 

 to flourish. 



None of the remedies I know of are of any value except 

 where employed on a small scale. For gardens or where grown on 

 small areas, three or four weekly applications of J Ib. of soft 

 soap to I gallon of water will usually keep the plants clear. 



All cruciferous weeds should, of course, be destroyed. 



THE SNOW OR GHOST FLY. 



Aleyrodes vaporarium, Westw. 



The Snow or Ghost Fly, known also as the White Fly and 

 Mealy Wing, belongs to a family of the Hemiptera known as the 

 Aleyrodidae, which are related on the one hand to the Cocctdae, or 

 scale insects, and the Aphididae, or plant-lice, on the other. 



Generally speaking, this insect has not been sufficiently plenti- 

 ful in the Midland Counties to constitute a pest of any seriousness 

 for many years past, but early in 1905 it made its appearance in 

 large numbers, and has caused much loss to horticulturists and 

 others. One species, A. citri, Riley and Howard, has proved a 

 serious pest in the orange and lemon groves of the Southern States 

 of America, whilst in our own country A. brassicae has often 

 proved very troublesome. 



The present species was described by Westwood in 1856, but 

 he stated that the antennae were six- jointed. Britton* in 1903 

 gave a much fuller account, together with the habits and life- 

 history of the insect. 



PLANTS ATTACKED. 



I have taken this species on, or it has been reported to me as 

 attacking, the following plants: Tomatoes, chrysanthemums, 

 asters, cucumbers, vegetable marrows, lettuce, roses, and numerous 

 plants under glass. 



LIFE-HISTORY AND HABITS. 



Throughout life, in all stages, the Snow Fly frequents the 

 under surface of the leaves of different plants. The eggs are laid 

 first on the lower leaves, later on those above, and so on until the 

 top of the plant is reached. As Dr. Britton remarks : " Thus the 

 lower leaves of large and badly-infested plants are usually com- 

 pletely covered on their under surfaces with the empty skins from 

 which the adults have emerged. These leaves are the first to 

 wither and drop. Those next higher up on the plant will show 

 nymphs and pupae; still higher we shall find younger and newly- 

 hatched nymphs, while on the upper leaves the adults will be 

 mating and the females laying eggs." 



* Second Rpt. State Entom. of Connecticut, 1903, p. 148. 



