THE CITRUS MEALY BUG 305 



above, is another similar pair. On the sides of the head are the two dark e)'es, 

 the same as seen in the immature stage." 



"Mating with the half grown females occurs soon after the males issue. 

 Someone has said that the anal filaments are used for mating, but observation 

 in several cases has not shown this to be the case, the filaments merely e.x- 

 tending backward out of the way." 



In the Canadian Entomologist, Vol. xxxix, No. 8, pp. 284-287 (1907), 

 Robert Matheson presents the following most important article ; 



The life-history of the male of Dactylopius citri {Pseudococcus citri) 

 has been worked out by Reed in 1890 at Cornell University. His results arc 

 embodied in an unpublished thesis., Berlese, '93, in "Le Cocciniglie Italiane 

 Viventi Sugli Agrumi," pp. 23-33, has given a more detailed account of tiie 

 male's life cycle. It may be well to give here a brief summary of their 

 work before describing the transformations of the female. 



MALE STAGES. 



The young nymphs moult for the first time in from 10 to 22 days after 

 hatching. During the first stage it is impossible to separate the males from 

 the females by their external characters, and only just previous to this moult 

 can they be distinguished. Berlese has shown that, that the future mouth-parts 

 of the female which is about to shed its skin, are coiled spirally just beneath 

 the transparent cuticle. In the males no developing" mouth-parts can be 

 observed, and those which they possess disappear at the time of the tirst 

 moiUt. These facts can be observed just before the moult. 



The cast skins usually remain attached to the caudal extreniit}- of the 

 male nymphs. In the second stage the male nymphs are sluggish in their 

 movements. They usually seek out some secluded spot and, in about ten 

 days, begin spinning their cocoons. The spinning of the cocoon occupies about 

 two days, and, shortly after its completion, the second moult occurs. This 

 cast skin is, in a day or two, pushed out at the caudal end of the cocoon 

 It is during the second stage that the beginning of the wings and haltercs 

 may be noted. They appear as small papillae on the mesothoracic and meta- 

 thoracic segments. 



The third moult occurs five days after the second, and in a week later 

 they moult for the last time. The perfect winged insects emerge from the 

 cocoon in from three to four days after the fourth moult. 



FEMALE STAGES. 



The life-history of the female is in marked contrast to that of the male. 

 Neither Reed nor Berlese, nor any previous worker, succeeded in determining 

 the number of moults in the female. Reed supposed there were three, whereas 

 Berlese, reasoning from analogy with the male, considered there must be at 

 least four. 



As is generally known, each female lays from loO to 200 eggs. These 

 eggs are enclosed in a waxy secretion, produced by hypodermal glands. These 

 irlands are situated on the ventral surface of the abdominal segments. The 



