62 



Zoologica: N. Y. Zoological Society 



[III; 3 



FIG. 10. PSEVDOCOCCVS BROMELIAE BOUCHE. 

 Adult female treated with caustic potash to show the open- 

 ings of the anterior and posterior ostioles, anal orifice, etc. 



The specimen is mounted dorsal surface uppermost. 



§ulc (1909) made a histological and physiological study of 

 the anterior and posterior ostioles in Pseudococcus farinosus De 

 Geer. When the female of this insect was stroked with a brush, 

 each of the ostioles suddenly emitted a droplet of orange-yellow 

 liquid, which partly adhered to the brush and partly rolled off 

 from the wax-powdered dorsal surface. The liquid was found to 

 consist of cells and a few blood-corpuscles, gulc concludes that 

 the organs are repugnatorial, and that their secretion is employed 

 like that of the cornicles of aphids for gluing up the appendages 

 of insect enemies. His account of the function of the secretion 

 is by no means convincing, since it might also be regarded as an 

 exudate, derived directly from the fat-body, like the exudates 

 produced by various termitophiles and myrmecophiles (C/. 

 Wheeler 1918), and hence employed for allurement instead of 

 repulsion. 



Returning to a consideration of the Coccidotrophus in the 

 Tachigalia petioles, we find that the beetle often remains motion- 

 less for hours at a time, in a food-groove, which just fits its long 

 slender body. If at other times, when it is moving about, it 



