This genus is characterized by the presence of a deep angular 

 emargination on the anterior margin of the head. Antennae of the male 

 with an appendage on the 3rd segment. Temporal lobes long, rounded 

 posteriorly, with a few setae. Prothorax subquadrangular with prominent 

 stigmata at the posterolateral angles; metathorax widest posteriorly and 

 wider than head. Abdomen elongate-oval, 9 segmented, the segments with- 

 out setae except at their posterolateral angles; 8th segment appearing 

 to be double. In this genus the abdomen is parallel sided, tapering 

 rapidly from the 7th segment to an acuminate point posteriorly in the 

 female but only gradually in the male to a wide, bilobed segment. Members 

 of this genus are quite long measuring 3 to 4 mm. Species of this genus 

 are uncommon in collections and distribution on hosts of the Anseriformes 

 is not well known. Carriker (1949a, 1954), and Timmerraann (1962), have 

 discussed the genus Acidoproctus . 



Aaidoproctus kelloggi (Carriker, 1902) 



Akidoproctus kelloggi Carriker, 1902. J. N. Y. Ent. Soc, 10: 



228, pi. 22, figs. 1-2. 

 Type host: Aytha valisineria (Wilson) — Canvasback. 



Head elongate cordate, rather broadly rounded in front with 6 

 short bristles on each side between the trabeculae and the clypeal 

 notch; 1 short bristle on each side just within the opening of the 

 notch; temples with 1 weak hair and 5 short bristles; occiput deeply 

 concave; eye prominent, convex and, contrary to Piaget's description, 

 has a large stiff bristle upon the dorsal surface. Prothorax short 

 quadrilateral, with rounded angles and convex sides. The metathorax 

 longer than the prothorax and nearly twice as wide; sides rounded and 

 widely diverging; posterior margin sharply angulated with a few weak 

 bristles; a pair of long hairs at the middle on each side and 3 at the 

 posterior angles. Abdomen elongate-oval, constricted posteriorly and 

 widest at the 2nd segment; lateral margins of each segment convex, more 

 so posteriorly. 



Measurements: (Carriker, 1902) 



o" 



Head Length .76 .77 



Head Width .64 .65 



Abdomen Width .80 .72 



Total Length 3.50 3.65 



This species was described from 5 males and 1 female collected 



from Aytha valisineva (Wilson) Lincoln, Nebraska, March 25, 1901. 



Specimens Host Locality Date Collector 



1 slide Aytha valisineria Mass. 



69 



