Sonic Hypcnnctamorphic Beetles 35 



Diodontus (?) spp. (Pemphredonidae). 



These wasps were also very small. They were taken August 

 17, 1903, and September 8, 1903. Like Crabro they were hover- 

 ing around the holes. 



Psen sp. (Mimesidae). 



Three small specimens of this genus were also taken hovering 

 around the holes on the same dates as Crabro. 



Spogostylum (Argyramoeba) analis Say (?) (Bombyliidae). 



Flies of this species are very numerous at the holes. They 

 have often been seen to suddenly dart down at a hole, insert the 

 abdomen, and then quickly fly away. Often they made mistakes, 

 alighting at Cicindela holes, and it was very noticeable that they 

 made haste to remove themselves, usually escaping before the 

 Cicindela larva had reached the top of its hole. This fact would 

 indicate that oviposition must be almost instantaneous. Willis- 

 ton in his Manual of N. A. Dipt era states that this genus is 

 parasitic on Pelopaeus, Megachilc, Ccnionus, Osniia, and Cali- 

 codonw. The present species is probably an Epinomia parasite, 

 to judge from its great numbers. 



Mutillasp. (sens latum). 



A small female of the siiuillima group of Fox (Trans. Am. 

 Ent. Soc, XXV, 226) was found on September 7, 1903, crawl- 

 ing around among the holes. It is undoubtedly a parasite on 

 some of the bees dwelling here. It is 4^ mm. long. Head large, 

 slightly wider than thorax, eyes hemispherical, faceted. An- 

 tennae with all joints short, scape equaling first three joints of 

 flagellum; first and second flagellar joints subequal, hardly as 

 long as broad ; third and fourth subequal, not twice as long as 

 first or second ; mandibles evidently not toothed, but broadly 

 sulcate beneath. Thorax one and one-half times longer than 

 broad, sides parallel, narrowed behind middle slightly. First 

 abdominal apically sessile ; abdominal segments after first api- 

 cally fringed with yellowish pubescence ; pygidium longitudinally 

 striate, with pygidial area. Reddish brown; pubescence sparse, 

 whitish ; abdominal segments after second, black, immaculate ; 

 eyes, mandibles, apical half of antennae and legs externally also 



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