LIFE-IIISTOllY OF A MONOPHLEBTJS. 159 



on the underside of leaves — Sal, BauJiinia, and other large leaves 

 being those usually aSected. The adults also feed upon the 

 female MonopMehus, attacking them in a similar manner to 

 that of the grubs and anywhere on their dorsal or ventral 

 surfaces (fig. 9). They do not, so far as my observations showed, 

 fly up and alight upon a scale, but usually crawl up to it and 

 then make a short rush. In feeding they pierce through the 

 skin, and a drop or two of the yellow liquid comes out, but never 

 a stream. They do not kill their host outright, as they appear 

 to be full-fed in half an hour (and often do not remain more 

 than five to ten minutes), by w^hich time they have absorbed but 

 a small quantity of the body-contents. Whilst the beetle is 

 feeding upon it, the scale either continues to remain with its beak 

 buried in the tissues of the Sal-twig or it may move about with 

 the beetle attached to it, but it does not appear to be incon- 

 venienced to any great extent, and only shows signs of feeling 

 when the beetle first pierces through the skin. The scales 

 would, however, appear to be killed off in time, or to have their 

 vitality greatly reduced, through this constant tapping by 

 different beetles. Individuals which have been so tapped show 

 numbers of small white and yellow spots, the places at which the 

 beetles have pierced them. They lose their fresh white powdery 

 appearance, become much shrivelled, are dirty brown or whity- 

 black in colour, and move about very slowly. It is probable 

 that those which do not die under this constant sapping of their 

 body-contents are so reduced in vitality that their egg-laying 

 capacity becomes considerably impaired, and even if eggs are 

 laid, their fertility is probably doubtful. The female Vedalia 

 would appear to commence oviposition at about the same time 

 as the MonopTilebus. 



A careful study of this attack showed me that the Vedalia 

 did not begin to multiply in any serious proportions until the 

 female scale had undergone its third moult. The numerous 

 empty white papery skins of this moult, attached by the sticky 

 secretion in large numbers to every twig and branch, were 

 evidence of the fact that the coccid had reached this stage of 

 development before its decimation commenced. These skins re- 

 mained in situ upon the branches for several weeks owing to the 

 exceptionally dry year experienced in 1902, practically no rain of 

 importance falling duriug this period. A. single heavy tliunder- 



