ENTOMOLOGY 119 



It occurs very commonly in greenhouses, and has been carried 

 to every quarter of the globe. The insect is mealy white in color, the 

 female attaining a length of nearly a quarter of an inch when fully 

 adult. The edge of the body is surrounded by a large number of 

 short waxy filaments. This insect is active in all stages and the eggs 

 are laid in and protected by a cottony or waxy secretion, the female 

 insect as this is developed being gradually forced from the bark, as 

 in the case of the fluted scale. The adult winged male is light olive 

 brown. 



This species is somewhat gregarious and occurs in masses in the 

 angles of the branches and leaf petioles and about the stem of the 

 fruit. The remedies are the emulsions and oily washes, repeated as 

 often as necessary to reach the young as they hatch. 



The White Fly. The white fly of Florida and the Gulf region 

 is not a scale insect, but belongs to a closely allied family. In gen- 

 eral appearance and habits, however, at least in its economic features, 

 it exactly duplicates the true scale insects. For many years this very 

 interesting insect has been known to infest the orange trees of Florida 

 and Louisiana and also to be a common pest on the orange in green- 

 houses. It has been found also on a number of plants other than 

 orange, such as viburnum, cape jasmine, and the aquatic oak of the 

 South. These other food plants are of significance only in indicating 

 that it may be harbored in situations near orchards in which efforts 

 have been made to exterminate it. The first careful description of 

 this insect and general account of its habits was given by Riley and 

 Howard in 1893, and from their article the data following are largely 

 derived. 



The white fly is limited, economically, to the citrus plantings of 

 Florida and the Gulf region. It is widely distributed in greenhouses, 

 as already noted, and has undoubtedly been carried to California on 

 many occasions, but has never gained a foothold out-of-doors. The 

 dry hot season of southern California probably accounts for this, and 

 may prevent its ever becoming troublesome in that region. Its origin 

 is unknown. It first came into prominence about 1885, but probably 

 had been present in greater or less numbers for a much longer period," 

 and perhaps is native to Florida. 



While closely resembling a scale insect in its early stages, the 

 white fly in the adult stage emerges, in both sexes, as a minute white 

 gnat, having four chalky wings of a fine granular texture, from 

 which fact it is frequently called the "mealy wing." This active adult 

 condition gives the white fly a distinct advantage over scale insects in 

 means of spread. 



The damage occasioned by it is greatly increased by the secretion, 

 in the larval and pupal stages, of a honey-dew similar to that secreted 

 by the true scale insects. This is in enormous amount, and the .<ooty 

 mold which develops in it frequently covers the entire upper surface 

 of the leaves and produces very serious effects on the vitality of tho 

 plant; the fruit does not ripen properly, is deficient in quality and 

 size, and keeps poorly, involving in addition the expense of washing 

 before it can be marketed, 



