> I-l'Ni'.I PARASITIC UPON ALEYRODES CITRI. 



sects other Aschersonias, which, as far as we know, he has not identified. 

 I'mf. II. II. Hume sent to the author in 1906 a species of Aschcrsonia found 

 mi what appeared to he an Alcyrodcs on the leaves of Hc.v Dahoon. It is 

 (|iiite probable that further observation will reveal a number of other species 

 >f fungi parasitic u])nn insects of these two orders in Florida and the ad- 

 joining S:au--. 



AI.KYKDDES CITRI. 



ffhis insect, the larval and pupal stages of which are parasitized by the 

 fungi to he discussed later, has been a serious pest of orange groves in 

 Florida and the adjoining States for a number of years. It had been ob- 

 served by C. Y. Riley in 1878 in the greenhouses at the United States De- 

 partment of Agriculture at Washington. In 1885, Mr. Ashmead wrote an 

 account of it for the "Florida Despatch", in which he gave it the name of 

 Alc\rodcs citri. In 1895, Riley and Howard 11 first described this species 

 in "Insect Life". In this publication it is reported as having been received 

 from Mississippi. Louisiana, North Carolina and many points in Florida, 

 (xainesville and Crescent City are places mentioned at which it had been 

 studied by Jas. Yoyle and H. G. Hubbard, before 1893. It is also stated that 

 during the years 1892 and 189;? it had so multiplied in parts of Louisiana and 

 Florida as to deserve immediate attention. It is of interest here to note that 

 it was about this time. IS!):?, that Webber discovered the first fungus para- 

 site of this insect. 



This insect is not a true fly, as the name might imply, but belongs to 

 the Order I lemiptera, which also includes the plant lice and scale insects. 

 Tlie following summary of the life-history of Aleyrodes citri is from Bul- 

 letin ss nf the Florida Agricultural Experiment Station, by E. W. Berger : 

 There are three well-defined broods of the whitefly, with an interval of several 

 da\s t.. several weeks hetweeii each brood, when few or none are seen on the wing. 

 The first brood generally appears some time during March, April or May; the second 

 during June. Jul\ or August; and the third during September and October. 



Larvae and pupae of the whitelly are to be found on the under surfaces of the 

 leave-, and seldom elsewhere. The larvae are scale-like and closely appressed against 

 tile leaf. They vary in si/e from the very young, just visible to the unaided eye, to the 

 fully matured larvae which measure about one-sixteenth of an inch in length. 



The larvae are white and translucent with a tinge of yellow, and almost invisible 



upon the leal. The pupa (Fig. :. X... s) is the transformation stage from the larva 



to the adult winged tly. The pupae are readily visible as yellowish-white, plump, oval 



b-,di,.^with a dark reddish sp.,t on the back. From the pupa emerges the adult winged 



Tin- little white cases, with a T-shaped split on the back, found on the under 



; a leal, are tin- empty pupa cases from which the adults have emerged (Fig. 



No, in). The eggs <Fi. ,. N08, 3 and ft) are JUS1 visible to the unaided eye as a 

 upon the nndrr surface ,,f ,h e leaves. An ordinary hand lens will show 

 them as little egf-shaped bodies iniu-h resembling grains of wheat. * * * 



