335 



very long hair directed downward and curving slightly forward, and 

 about the middle there is a similar hair, as shown in Figure 9. In- 

 ternally there are 2 strong rods connected with the mandibles, and 

 attached to the posterior margin of the dorsal sclerite is a strong rod, 

 dilated posteriorly, which runs to the posterior margin of the first 

 thoracic segment internally. Thoracic segments each with a long 

 curved hair near the middle on sides, prothoracic respiratory organ 

 short, located close to posterior margin of segment. Abdomen with 

 segments as in Figure 10, the pattern shown being probably caused by 

 the spines of the pupa showing through ; surface without hairs except 

 on last segment, where there are 2 pairs, one on the dorsum and the 

 other on the venter; apex bifid (Fig. 10, a). 



Pupa. (PI. LXXXI, Figs. 11 and 12). — Length, 9 mm. Yellowish 

 white. Surface of integument of body slightly wrinkled. Head and 

 thorax in lateral aspect as in Figure 15, thorn on wing base remark- 

 ably long and slender. Thoracic respiratory organ tubelike, the ab- 

 dominal spiracles almost identical with it in form, their apices present- 

 ing to the eye the appearance of small rounded openings. Apex of ab- 

 domen with 2 long curved spines directed sHghtly upward (Fig. 13). 



This species was found by D. K. McMillan, the field assistant of 

 this office for northern Illinois, commonly in truck gardens infested 

 with wirew^orms, upon which it feeds in the larval stage. I have seen 

 the larvae occasionally in wheat fields, and the adult is represented in 

 the laboratory collection from the following localities : Algonquin, 

 June to August (Nason) ; Havana, August 18, 1904 (Hart and 

 Brown) ; Piper City, July 27, 1888 (Marten) ; Grand Tower, August 

 25, 1889 (Hart) ; Urbana, July 21, 1899 (Hart), and June 14, 1915, 

 on flowers of wild parsnip (Hart and Malloch) ; Champaign, July 14, 

 1899 (Hart); McHenry, July 31, 1884 (Webster); Philo, June 3, 

 1887, from pupa found in sod corn (Hart); West Union, May 24, 

 1884; Waterman, July 27, 1883 (Webster); Monticello, June 28, 

 19 14 (Hart and Malloch), — all in Illinois; Jamesburg, N. J., July 4, 

 1893. 



The larvae of this family are recognizable by the peculiar sub- 

 division of the abdominal segments, as shown in the figure (10) here- 

 with, which gives them the appearance of having 20 segments. In 

 some other families there is a similar subdivision, for example in 

 Mycetophilidce (see Mycetobia, PI. LXXX, Fig. 12), but the subdivi- 

 sion is of a different character, the short portion of the segments being 

 appreciably shorter than the anterior portion is in Psilocephala. This 

 species and probably allied species are no doubt of considerable eco- 



