LECANIIN^. 



FEMALE. 



The form of the adult insects comprising this exten- 

 sive sub-family varies considerably ; and their habits 

 are also very dissimilar. In Aclerda the adult female 

 (PI. XXXVI, fig. 5) is apodous, and the antennae are 

 mere rudimentary stumps. Physokermes (PL LVIII, 

 figs. 3-5) is also another aberrant genus of this 

 division of the Coccidas. In its larval stage it exactly 

 resembles a Lecanium or a Pulvinaria ; but the adult 

 insect loses all trace of antennae and legs, the 

 body becomes intussuscepted, and two large internal 

 chambers or pouches are formed for the reception of 



c 



FIG. 1. Adult female Lecanium after treatment with potash, x 20 : a, 

 mentum ; b, rostral filaments forming the sucking- tube ; cccc, ventral 

 channel leading to spiracles ; d, anal plates or lobes (dorsal) ; e, anal 

 cleft ; /, marginal spines. 



the ova. The anal lobes also take the form of large 

 rounded cornicles. In all the remaining genera found 

 within the British Isles the antennas and legs are well 

 developed a fact all the more remarkable as very few 

 species possess the power of progression after the final 

 moult has been effected. The mentum (fig. 1 a in text) 

 is short and generally monomerous, and the loop -like 

 filaments forming the sucking- tube (fig. lb in text) 

 are either moderately long, or extremely short as in 



