Dec, '04] ENTOMOLOGICAL NEWS. 339 



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

 Forest and Sierra Camp I found manj- 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 

 j/fcvSiys = false, X.VVTJ = female, in the colonies of Forynica 

 sangidnca owe their existence and development to the rearing 

 of the beetle Lomechusa stmmosa F. The morphological char- 

 acteristics of these pseudog3'nes will be easily understood from 

 the accompanying figures. In the case of common workers 

 (Figs. 3 and 2c) we find the pronotum 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 pseiidogyne (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 pseiidogyne 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 Lottiec/iusa strumosa. 



2 . The colonies of Formica safiguitiea containing pseudogynes 

 are always the centres of the districts of Lomechusa strtimosa. 



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

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



4. No pseudogynes exist in colonies of Formica sa7iguinea, 

 where Loinechusa strumosa is found in the imago stage, but 

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

 chusa striimosa are reare.d for a number of 3'ears. 



The above propositions Wasmann succeeded in verif3'ing not 

 only for Formica sa7iguinea and Lomechusa strumosa, but also 

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

 strum,osa ; for Formica nifibarbis F. and Atem,eles paradoxus 



