LARVAE OF APHODIINAE — JERATH 49 



Description: Maximum width of head capsule of third-stage larva 

 1.09X1.19 mm. Cranium light yellow, surface smooth except for 

 three depressions in a line on each side on the frons, 6-8 dorsoepi- 

 cranial setae and 3-5 microsensUlae on each side. 



Protophoba of epipharynx with 13-16 microsensillae. Maxillary 

 stridulatory area with an irregular row of 12-16 conical teeth. Galea 

 dorsally with four stout setae. Lacinia dorsally with a row of five 

 or six long setae near the mesal edge and a seta posteriorly. 



Dorsal annulets of abdominal segments 1-5 with setation as fol- 

 lows: each prescutum with 12-14 short setae, each scutum with 6-8 

 long setae and 20-25 short setae on each side, and each scutellum 

 with 16-18 short setae. 



Raster with teges of 25-37 hamate setae curved at their distal ends. 



Tribe Aphodiini 



This tribe is represented in the United States by only three of the 

 many known genera in the world. The genus Oxyomus Laporte occurs 

 only in the Eastern States; the genus Xerospsamobeus Saylor is known 

 only from California. In contrast, more than 100 species of the genus 

 Ajphodius lUiger occur in the United States. 



Species dealt with in this study include Oxyomus silvestris (Scopoli), 

 the only species of this genus known in the United States, and 19 

 species of the genus Aphodius. Two of these species of Aphodius are 

 from Australia, where they are pests in pastures. Six specimens were 

 reared by the author. The others were borrowed from the U.S. 

 National Museum and the personal collection of Paul O. Ritcher. 



Larvae of this tribe may be characterized as follows : Frons, on each 

 side, with two short posterior frontal setae and a microsensilla, a 

 long seta at each anterior angle, a single long exterior frontal seta 

 and a microsensilla, and a single short anterior frontal seta and a 

 microsensilla. Frontal sutures distinct. Clypeus marked into large 

 sclerotized postclypeus and a small weakly sclerotized preclypeus; 

 clypeus with three setae on each side. Maxillary stridulatory area 

 with conical teeth; palpifer differentiated. Anal lobes whitish, with- 

 out setae; lower anal lobe emarginate, partially divided into sublobes, 

 never completely divided. 



Larval key to Oxyomus and Aphodius 



Left mandible with S1+2, S, and S4 (fig. 26) ; galea dorsally with four stout setae 

 (fig. 40); 9th and 10th abdominal segments strongly tapering in a concave 



curve (fig. 79) Oxyomus Laporte 



Left mandible with S1+2 and Ss (fig. 23) ; galea dorsally with five or more stout 



setae (fig. 41); 9th and 10th abdominal segment slightly tapering in a concave 



curve Aphodius lUiger 



