160 f'^"'^' 



A THIRD NEW BRITISH PLASTOSCIARA (DIPTERA, SCIARIDAE.) 



BY F. W, EDWAEDS, F.E.S. 



The species described below has been received for identification hj 

 M;\ Edward R. Speyer, Research Entumologist to the Nursery and 

 Market G-arden Industries Development Society. The specimens wero 

 obtained from the West End Nurseries, West Worthing, 25.V.1922, 

 being reared in very large numbers from larvae attacking cucumber roots 

 and stems. 



On a previous occasion Mr. Speyer had obtained quantities of 

 Pnyxia scahiei (Hopkins), damaging cucumber seedlings at Cheshunt. 

 He suggested that the Worthing species might be the .same, with a winged 

 form of the female corresponding to the long-Avinged males of P. scabiei. 

 An examination of the material, however, showed that this could not be 

 the case, the species differing in very many respects from P. scahiei and 

 being referable apparently to the genus Plastosciara. From the two 

 known British species of this genus the Worthing insect differs in its 

 much smaller size as well as in venational and other details. Although 

 it may possibly have been described previously as a Sciarn, it will be 

 easier and more satisfactory to treat it as a new species, than to attempt 

 to apply to it any one of the old incomplete descriptions. The spii-it 

 material sent by Mr. Speyer comprised some hundreds of females and 

 about a dozen males. 



Plastosciara 2)Grniciosa, sp. n. 



Head black. Eyes bare, rather large, forming a distinct though narrow 

 dorsal bridge, the portion from each eye being narrowed almost to a point, the 

 points touching. Labium very small and short, not so large as one palp. 

 Palpi pale, 2-segmeuted, apart from tlie very small and hardly distinguishable 

 palpiger ; first segment nearly globular, considerably enlarged in the 5> much 

 less so in the S '■, second segment very minute, each with a few short hairs. 

 Antennae black, the flagellar segments with rather dense, uniform hair which 

 is about as long as the diameter of the segments. First anil last flagellar seg- 

 ments each a little longer than any of the others, the remaining segments in 

 the S each a little over half as long again as broad, and provided with a 

 distinct week, which is fully one-third as long as the remaining portion of the 

 segment ; in the 5 these segments are very little longer than broad, and Lave 

 shorter necks. Thorax blackish-brown, somewhat shining. Pleurae with 

 rather extensive pale membranous areas. Scutellum with two distinct mar- 

 ginal bristles and some finer hairs ; mesonotal hair short, dark and inconspicuous. 

 Abdomen with the membranous parts whitish, the chitinised parts dark brown. 

 In the S all the tergites are uniformly chitinised ; in the '^ tergites 1 and 2 

 are membranous at the base, 3 and 4 uniformly cliitinised, 5 with a tendency 

 to weakening of the chitin in the middle, 6 and 7 chitinised only on the apical 



