THE COCCIDAE OF SOUTHWESTERN UNITED STATES 23 



Genus LACHNODIUS Maskell. 



This genus was based upon the fact that the anal ring bears numer- 

 ous (twenty or more) setae instead of the six to eight commonly found 

 in members of the Pseudococcus group. I have at hand a specimen 

 from Australia, determined by Froggatt as L. eucalypti (Maskell), the 

 type of the genus. Also, through the kindness of Mr. E. E. Green, I 

 have specimens of L. greeni Vays. and a manuscript species o'f Green. I 

 am also recording an apparently new species that I shall refer to this 

 genus. 



If the specimen purporting to be L. eucalypti be correctly deter- 

 mined, none of the other three species at hand can be referred to this 

 genus. The anal ring possesses numerous setae, but the margin of the 

 body is beset with a continuous, single row of short, sharp spines and 

 the derm bears 8-shaped pores. I have been unable to detect with 

 certainty whether the dorsal ostioles are present or not. I am inclined 

 to think that they are not. 



The other three species are unquestionably of the Pseudococcus group 

 and should probably be separated from Pseudococcus. Being unable to 

 determine the real nature of the genus Lachnodius I shall regard them 

 as belonging to this genus and base the following characterization of the 

 group upon them. 



Pseudococcine forms in which the anal ring typically possesses more 

 than six setae, sometimes as many as twenty or more. In cases where 

 the number of setae on the ring is reduced the ring is surrounded by a 

 cluster of setae. Anal ring tending to be set well away from the margin. 

 Cerarii consisting typically of irregular patches of spines and pores; 

 varying in number from eight to fifteen. Antennae seven to eight-seg- 

 mented. First stage larva with six-segmented antennae and with six 

 hairs on the anal ring. 



Lachnodius salicis n. sp. 

 Fig. 7. 



Type host and locality. From Salix sp., Sabino Canyon, Tucson, 

 Ariz., June 25, 1918. 



'Habit. Occurring in cracks in the bark, attended by ants and con- 

 cealed beneath a covering of papery consistency made by the ants. All 

 the specimens found were bare of secretion (doubtless because of the at- 

 tentions of the ants) except for a slight marginal fringe on the abdomen, 

 and were of a chocolate color. So well were they concealed in the 

 cracks that it was only the presence of the swarms of ants that led to 

 their discovery. 



