Dec., '04] ENTOMOLOGICAL NEWS. 339 



In the small material collected on the fly at sunset in Giant 

 Forest and Sierra Camp I found many minute specimens new 

 to my collection, of which I shall give a later report when 



worked up. 







Formica sanguinea, subsp. rubicunda, Em. and Xeno- 



dusa cava Lee. ; 



or the discovery of pseudogynes in a district of Xenodusa cava Lee. 



By PROF. H. MUCKERMANN, S.J., 



Sacred Heart College, Prairie du Chien, Wis. 



It may be known to the reader that in 1895 E. Wasmann, 

 S.J., advanced the hypothesis that the so-called pseudogynes 

 1/^877? : : false, AWT? female, in the colonies of Formica 

 sanguinea owe their existence and development to the rearing 

 of the beetle Lomechusa strumosa F. The morphological char- 

 acteristics of these pseudogynes will be easily understood from 

 the accompanying figures. In the case ot common workers 

 (Figs. 3 and 2c) we find the prouotum strongly developed, 

 whilst the mesonotum is but small. The- normal female 

 (Fig. 2a), on the contrary, has a small pronotum and a 

 strongly developed mesonotum. The pseudogyne (Fig. 4 and 

 2b) combines with the size and abdomen of a worker the 

 mesonotum of a female ; it makes the impression of a deformed 

 female as well as of a deformed worker. A pscudogyne is a 

 frustrate creature, a ruined existence. Not being able to lay 

 eggs or to perform the functions of workers, it is a useless bur- 

 den of the colony and tends to finally degenerate the species. 



After a careful research of five years, during which he exam- 

 ined and studied with the closest attention no less than 410 

 colonies of Formica sanguinea, Wasmann succeeded in raising 

 the following four propositions to established theses : 



1. The districts of pseudogynes always coincide with the 

 districts of Lomechusa strumosa. 



2. The colonies of Formica sanguinea containing pseudogynes 

 are always the centres of the districts of Lomechusa strumosa. 



3. Without the districts of Lomechusa strumosa, there are no 

 pseudogynes to be found in the colonies of F. sanguinea. 



4. No pseudogynes exist in colonies of Formica sanguinea, 

 where Lomechusa strumosa is found in the imago stage, but 

 they exist only in those colonies in which the larvae of Lome- 

 chusa strumosa are reared for a number of years. 



The above propositions Wasmann succeeded in verifying not 

 only for Formica sanguinea and Lomcchnsa strumosa, but also 

 for Formica rufa L. and Atemeles pubicollis Bris, or Lomechusa 

 strumosa ; for Formica rujibarbis F. and Atcmclcs paradox us 



