54 OHIO BIOLOGICAL SURVEY 



( Rumex crispns L-J broad leaf dock, (Riiiiie.v obtiisifolius L.j common burdock, 

 ( Arctium iiiiuiis Schk. ) and on thistle ( Canfiiiis sp. ). The larvae prey upon Aphis 

 ruinicis and other apliids which commonly cluster on the flower spikes, tender stems, 

 or on the under side of the large leaves of the above plants. 



Puparium — Approximate dimensions: length 5.3 mm., height 2.2 mm., width 2.4 

 mm. The long, segmental spines, contrasted with the short dorsals or their apparent 

 absence on the principal segments, and the short, posterior respiratory appendage 

 with its prominent spoon-shaped spurs at the end, dorsallj', should serve easily to dis- 

 tinguish the species in this stage. Duration in pupal stage from five to fifteen days, 

 passed on the host-plant of the larva, among the flower spikes, on leaves, or in leaf 

 axils. 



Adult — Length 5.6 mm. A blackish species usually with much red on the abdo- 

 men. The pile of the eyes mostly grouped in two vertical stripes, separated by a dis- 

 tinct vertical glabrous stripe (Figs. 29-30). Face in the male wholly pure, light, 

 sulphury yellow. Front of female narrowed above (Fig. 30). Thorax in front with 

 two whitish, pollinose stripes. 



Paragus tibialis Fallen 

 (Plate III, Figs. 31-38.) 



Seethe Ohio Naturalist, Vol. XII, No. r, pp. 401-404, Nov., 1911. 



Larva — Length about 7.5 mm. Color light yellowish-brown with some darker 

 markings. Segmental prominences and spines smaller than in larva of P. bicolor, the 

 dorsal ones in segments 6. 11 less reduced proportionately, being about one-third as 

 large as the median and dorso-lateral ones. 



The most convenient means for separation of the two species in the 

 larval stage is in the length of the posterior breathing appendage. This 

 in P. tibialis ranges from about 0.4 to 0.65 or 0.7 mm. with an average 

 of about 0.5 mm. as compared with P. bicolor where the length is near 

 0.3 mm. The width at the tip is about 0.25 to 0.3 mm. as in P. bicolor. 

 The appendage besides being di.stinctly longer is somewhat more bifurcate 

 at the tip in P. tibialis and the general surface is slightly more depressed, 

 between the spiracular elevations. The dorsal spiractilar spine is also 

 noticeably longer. This will be made clearer by reference to Figs. 25, 

 26, 33 and 34. 



L,arvae and pupae were taken from burdock (^Arctium viinus) preying 

 on an unidentified aphid. 



Puparium — Approximate dimensions. Length 4.3 mm. width 1.8 mm. height 

 1.75 mm. The puparium is strongly attenuated posteriorly to the respiratory append- 

 age both by depression and compression. The characters of the posterior respiratory 

 appendage and of the segmental spines remain essentially as in the larva. Duration 

 in the pupal stage 5. 11 days. 



Adult — A small black species 3-5 mm. long, sometimes with reddish on the abdo- 

 men. A median black band on the face of both male and female. The pile of eyes 

 not massed in two vertical stripes. Front of female not much narrowed above, (Fig. 

 38). No yellow on the scutellum. 



