20 MISC. PUBLICATION 5 00, U. S. DEPT. OF AGRICULTURE 



The Subfamily RHOPALOPSYLLINAE Oudemans 



Fronto-epicranial groove usually poorly developed. Frontal notch present,, 

 also frontal tubercle, although the latter may protrude but slightly beyond 

 the surface of the front. Antennal club long or short, symmetrical or asym- 

 metrical. Labial palpus 4- or 5-segmented. Eyes unreduced and pigmented or 

 reduced and pale. Pronotal comb absent. Antepygidial bristles present. Ab- 

 domen in gravid females not greatly distended. Parasitic on both birds and 

 mammals. 



This subfamily contains three genera, only one of which (Rhopa- 

 lopsyllus) is represented in North America. 



Rhopalopsyllinae was established by Oudemans (59) in 1909 for 

 the single genus Rhopalopsyllus Baker, 1905. In it the present writ- 

 ers place two additional genera, Parapsyllus Enderlein, 1903, and 

 Tetrapsyllus Jordan, 1931. Members of this subfamily are confined 

 to the Southern Hemisphere, except for a few species of Rhopa- 

 lopsyllus. 



In the characters of the head, thorax, and tarsi the Rhopalopsyl- 

 linae show relationships with the Pulicidae. They differ from the 

 latter rather markedly in the characters of the abdomen. Further- 

 more, in the Rhopalopsyllinae the posterior borders of the labial 

 palpi usually are well sclerotized, while in the Pulicidae usually they 

 are either poorly sclerotized or membranous. 



Wagner (86, p. 70) places the three genera of this subfamily in 

 two subfamilies, leaving only the type genus in the Rhopalopsyllinae. 

 Such a division hardly appears justified on the ground of either 

 morphological characters or geographical distribution. Furthermore, 

 the genera Parapsyllus Enderlein and Tetrapsyllus Jordan, included 

 in the proposed subfamily Parapsyllinae, really differ more between 

 themselves than the two together differ from Rhopalopsyllus Baker, 

 and if the subfamily Rhopalopsyllinae, as here used, is to be broken 

 up, it should be divided into three subfamilies. This number could 

 hardly be justified. 



The genus Rhopalopsyllus Baker is the only North American genus 

 of this subfamily. 



The Genus Rhopalopsyllus Baker 



(Fig. 4, B) 



Rhopalopsyllus Baker, 1905, U. S. Natl. Mus. Proc. 29: 129. Type, Pulex lutzii 



Baker (by original designation). 

 Rothschildella Enderlein, 1912, Zool. Anz. 40: 72. Monotypic. Type, Roth- 



schildella cryptoctenes Enderlein. 



Frontal tubercle angulate apically, varying much in size and sometimes en- 

 tirely contained in frontal notch. Antennal club short, asymmetrical, with seg- 

 mentation less marked on front side. Upper margin of antennal groove with a 

 long comb of closely set microsetae. Eyes well developed and well pigment ed. 

 Labial palpus 5-segmented, varying much in length. Postantennal region of 

 head with 3 rows of setae, the posterior row being submarginal. Upper scler- 

 ite of metepisternum separated from the metanotum by an inner sclerotized 

 ridge. Abdomen of gravid female not greatly enlarged. Sternum VIII of 

 abdomen of male enlarged, but otherwise little modified ; sternum IX extending 

 distally as a single, median, unbranched, setigerous process. 



This genus was divided into three genera by Jordan (4-6) in 1939. 

 The chief characters used for this division are: The shape of the 

 prosternum, the length of the mesosternum in comparison with its 



