58 PROCEEDINGS OF THE NATIONAL MUSEUM vol. loe 



Remarks: Members of this species are abundantly found on hog- 

 peanut (Amphicarpa bracteata (L.) Fernald). 



Rivellia michiganensis, new species 



Figure 4,a-d 



Holotype: Male. Body length about 4.0 mm. 



Head: Frons dark reddish brown; upper fronto-orbital plates and 

 ©cellar triangle black. Face with dorsal half pruinose, ventral half 

 shining, smooth, black; parafacials and part of orbits ventral to each 

 eye brownish yellow. Antenna long, definitely surpassing oral mar- 

 gin; with first and second segments yellowish brown; third segment 

 almost entirely black, only a narrow posterior strip on inside brownish 

 yellow, the tip rounded, from lateral view somewhat constricted be- 

 fore tip. Anteclypeus black. Palpi brown. Postcranium black, 

 pruinose. 



Thorax : Mesonotum black ; strong humeral and posterior dorsocen- 

 tral setae present. Scutellum and postscutellum concolorous with 

 mesonotum. Pleura black, mostly shining. Mesoplem-on with scat- 

 tered pale setae on posterior half; pruinose area at dorsal posterior 

 corner in form of right triangle, one side reaching two-thirds distance 

 to ventral posterior corner and the other side reaching two-thirds 

 distance to anterior spiracle. Sternopleuron with narrow pruinose 

 strip on ventral margin and a narrower strip on posterior margin ; disc 

 with scattered pale setae. Disc of pteropleuron with scattered pale 

 setae, one black seta present ventral to subalar. Hj'poplem'on with 

 disc shining, borders narrowly pruinose. Laterotergite completely 

 and densely pruinose. The prosternum cannot be seen in the type. 



Thoracic appendages: Front legs: Wholly yellow. Middle legs: 

 Coxae and femora black; tibiae with somewhat less than basal half 

 black, remainder yellowish; tarsi yellow. Hind legs: Coxae, femora, 

 and tibiae black; tarsi j^ellow. 



Wing (fig. 4,a) length 2.9 mm., width 1.4 mm. Bands black. First 

 and second bands widely separated at costal margin ; third and fourth 

 bands definitely separated at costal margin. Fourth band broad, 

 width at tip of third vein subequal to length of posterior crossvein. 

 The part of first basal cell contiguous to second basal cell completely 

 hyaline. Section of fourth vein proximad of anterior crossvein with 

 slight bend. Halteres with pedicel brownish yellow, capitulum dark 

 brown. 



Abdomen: Tergites shming, rugose, black. Disc of fu'st tergite 

 with pale setae. Genitalia (fig. 4,c,c?) with apical part of aedeagus 

 consisting of, from lateral view, a heart-shaped base and two fila- 

 mentous terminal tubes which are subequal in length to length of basal 



