ART. 9 DIGGER WASPS OF GENUS PODALONIA FERNALD 25 



The male has long been sought for, and following Cresson's guess, 

 many have found it in argentifrons , but the female of this last-named 

 species, sometimes confused with luduosa^ is now known, and argen- 

 tifrons is therefore eliminated from consideration. 



In the United States National Museum collection there is a pair 

 of Podalonias, the neck of the female gripped by the mandibles of 

 the male as in mating. The female is certainly luctuosa, while the 

 male is violaceipennis, having several of the abdominal segments 

 bright ferruginous. The pair was taken in "Sept. Placer Lake Cal." 

 and was in the Riley collection. 



This pair has given me much trouble. P. luctuosa, and molaceipennis 

 are both very widely distributed and about 400 males of violaceipen' 

 nis were available for study, to find, if possible, whether there were 

 really two extremely similiar species in the lot. Many weeks of 

 comparison have given no results in this direction, and the compar- 

 ison of the male of the pair (even of the genitalia) with the males of 

 several pairs in which the female was undoubtedly violaceipennis, also 

 revealed no differences. The conclusion I have finally reached is, 

 that the female violaceipennis is sometimes dimorphic, luctuosa being 

 one of the female forms, and that in very rare instances the male 

 also becomes entirely black. The only alternative to this, which I 

 €an see, is that in the case of the pair from Placer Lake the male 

 made a mistake in the species of female and that true males of luctu- 

 osa are so rare that only one has thus far come to my attention — a 

 view which seems hardly probable. 



In support of the view that we have here a case of color dimorphism 

 in at least one sex (dichromorphism?), the case of Podalonia hirsuta 

 (Scopoli) of Europe should be considered. Here, according to Kohl ^ 

 the female usually with ferruginous on the abdomen, is sometimes 

 entirely black. Kohl states that the two should not be considered 

 separate as there is complete agreement in sculpture and plastic rela- 

 tions, and an almost complete lack of black-bodied males. In Cor- 

 sica the red-bodied females are almost entirely absent, while one 

 finds no black males of the same. Elsewhere he states that among 

 several hundred males examined, he found only two black-bodied 

 ones. 



P. hirsuta is very similar to our violaceipennis in every way and 

 there is even a slight possibility that it may prove to be the same spe- 

 cies. In the female the pulvillus is rudimentary or absent. This is 

 true with our luctuosa but not with our female of violaceipennis, so 

 that on this point the comparison fails. On the whole it seems best 



« Cresson, Proc. Ent. Soc. Phila., vol. 4, p. 462, 1865, and others. 



' Verb. k. k. zool.-bot. Ges. Wien, vol. 39, p. 21 and p. 275, 1889: Ann. k. t. Naturhist. Mus., Wien, 

 vol. 21, pp. 276-280, 1906. 



