78 THE REPOET OE THE No. 36 



ALEYRODIDiE OF ONTARIO. 

 Prof. T. D. Jarvis, O.A.C, Guelph. 



There are at the present time three species of Aleyrodidse found in Ontario: 

 Aleyrodicus asarumis (Shinier) on the Wild Ginger (Asarum canadense) and 

 the WMte Baneberry (Adea alba) ; Aleyrodes forbesii (Ashmead) on Soft 

 Maple (Acer saccharinum) and Red Maple (Acer ruhrwm) ; Aleyrodes vaporari- 

 ORUM (Westwood) on Salvia, Solanum, Coleus, Coreopsis, Cucurhita, Cuphse, 

 Fuchsia, Hibiscus, Lycopersicum, Monarda, Rosa, Rudbeckia, Helianthus, 

 Tropseolum, Verbena, Zinna, Digitalis, Pelargonium, Phlox, Cobea, Dahlia, Ribes, 

 Fragaria, Solidago, Aster, Smilax, Polemonium, Delphinium, Achillea, Calliopsis, 

 Chrysanthemum, Callistemma, Campanula, Antirrhinum, Berberis, Aquilegia, 

 Lonicera, Nicotiana, etc. 



Those who have made a special study of thisi group believe that the White Fly 

 had it? origin in some part of South America, the Neotropical region, where they 

 formed the genus Aleurodicus, which except through human agency have remained 

 there ever since. A branch belonging to the genus Aleyrodes has spread over the 

 greater part of the world. 



Aleyrodicus asarumis is a very common species in Ontario and was noticed in 

 1903 on a species of Wild Ginger at Guelph. Aleyrodes forbesii was first observed 

 in the fall of 1907 up the River Speed from Guelph where the nymphs were found 

 rather abundantly on the leaves of Soft Maple. Aleyrodes vaporariorum, which is 

 most interesting and of greatest economic importance, is believed to be a native of 

 Florida or Mexico; though it was first described and named by Westwood after it 

 had reached England in 1856. Since reaching the United States it has spread 

 gradually through the North-eastern part principally; and wherever introduced has 

 multiplied very rapidly. Previous to 1900 there are only one or two reports of the 

 species in Ontario. In 1903" it had appeared at the Ontario Agricultural College 

 greenhouse and by 1906 had become fully established. 



The White Fly or Mealy-wing Fly belongs to the Homopterous division of tlie 

 order Hemiptera, in which the four similar membranous wings are held roof-like 

 over the body. It is a member of the family Aleyrodidas, which consists of small, 

 active insects, easily recognizable by a characteristic, white, wax-like secretion, com- 

 pletely covering the wings and giving them the popular name Mealy-wings and 

 White Fly. The young Mealy-winged Flies look much like scale insects and liave 

 the same general habits. The larvae are flattened, oval, scale-like creatures found 

 stationary on the lower sides of leaves. Most species of them bear numerous wax 

 rods and copious secretions of wax all over their bodies. The pupa, also are charac- 

 terized by their secretions of wax; and the amount and disposition of the rods and 

 fringes on them are made use of very largely in the distinction of species in this 

 family. 



in their relationship with other insects the Aleyrodidse come nearest the Aphi- 

 didae and the Coccidge ; from the former they differ most markedly in being station- 

 ery during their immature stages, and from the latter in being winged in both sexes 

 of the adults and therefore capable of moving about rapidly. 



The life-history of the WTiite Fly (Aleyrodes vaporariorum) covers a period of 

 approximately five weeks; and the broods succeed each other constantly, the year 

 round. The eggs are oval, light green, changing to almost black in color, smooth 

 and with a short stalk from one end raising it off the leaf. They are deposited ir- 

 regularly on most kinds of leaves ; but on smooth leaves it is quite characteristic for 



