\"ol. Xxix] ENTOMOLOGICAL NEWS 35I 



but one generation per year, at least in the vicinity of Stanford 

 University. There is upon the same host a species of Pseudo- 

 coccus (at present undetermined), and I suspect that this is 

 the reason for Essig's statement. However, there is no more 

 reason to assume that this is a form of E. lichtensioides than 

 to assume that the latter is a form of Phenacoccus artemi- 

 siae. 



King has recorded an apparent case of such seasonal di- 

 morphism in connection with his original description of Phena- 

 coccus acericola. He states that specimens of this species 

 taken in the summer had nine-segmented antennae, while speci- 

 mens taken in the autumn had eight-segmented antennae. It 

 happens that a species of Pscudococcus, that I identify as P. 

 comstocki (Kuwana), occurs on maple in the eastern states, 

 and there is every possibility that confusion has resulted from 

 this. 



The last case that I shall consider (chronologically it is the 

 first) is that of Pscudococcus trifolii (Forbes). This was 

 described from a form with seven-segmented antennae. Later 

 authors have regarded a form with eight-segmented antennae 

 as the "summer form" of this species. The whole matter has 

 been summed up by Forbes^, and consequently I need not 

 review the literature here. Through the kindness of Prof. 

 Forbes I have had the privilege of examining one of the origi- 

 nal co-types of this species and am, therefore, in a position to 

 form some conclusions in regard to the matter. 



The species described by Forbes proves to have six or seven 

 segments in the antennae and to have but one pair of cerarii. 

 These cerarii are on the anal lobes, and each contains two 

 conical spines and two or three small setae which are sur- 

 rounded by many scattered pores. The descriptions of the 

 "summer form" are all insufficient to permit the definite recog- 

 nition of the species, but there are certain points of value in 

 which all agree and which may be summed up somewhat as 

 follows : "A species with from fifteen to seventeen pairs of 

 waxy tassels ; with a crowded group of pores about the anal 



^Forbes, S. A. Kept. State Ent. 111., vol. 25, pp. 1 17-123. (1909). 



