A HISTORY OF HERTFORDSHIRE Cephus troglodyta pallipes pygmajus tabidus Janus connectens Xyela pusilla Ichneumon rufipes pumilus crassicornis (' I believe at Hertford ') fulvipes candidatus iridipennis submarginatus primatorius flavolineatus ornatorius laboratorius occisorius equitatorius castanopyga ? troglodytes ruficoxatus mutabilis Ichneumon mitigosus ruficollis Ischnus porrectorius Stilpnus blandus Mesoleptus submarginatus melanocephalus sticticus spheginus gracilis Tryphon praerogator nanus anceps mesoleptoides erythropalpus parvulus quadrilineatus Exochus mansuetor Cryptus cyanator assertorius brevicornis Phygadeuon exiguus Megastigmus dorsalis Diptera. Mr. Verrall in his List of British Diptera divides the order into two great sections, the Orthorrhapha and the Cyclorrhapha. The old sub-order Aphaniptera has been done away with, and the Puliddte or ' fleas ' have been included among the Nematocera, one of the sub-sections of the Orthorrhapha. The Hon. N. Charles Rothschild, who has made the family a special study, enumerates twenty-five species of Pulicidae belonging to six genera which have been found within a radius of five miles of Tring, and doubtless two others Ceratophyllus columbee from the domestic pigeon and C. styx from the sand martin which have not yet been detected are also present. Typhlopsylla pentacantbus was first taken by Mr. Albert Piffard of Feldon, Boxmoor, and was described by Mr. Rothschild. The capture of T. dasycnemus near Tring gives, so far as is known, the only British record for this species, and Ceratophyllus mustelts and C. penidlliger are here recorded for the first time. The following is the Hon. N. Charles Rothschild's list of Tring Puliddte : Hystrichopsylla talpae Ceratophyllus sciurorum gallinae hirundinis (from house martin) fasciatus mustelae penicilliger Ceratopsylla elongatus (from noctule bat) jubatus octactenus (from Natterer's bat) pentactenus hexactenus (from long-eared bat) Pulex irritans canis felis goniocephalus erinacei Typhlopsylla gracilis pentacanthus agyrtes sub-sp. nobilis (from water vole) bisoctemdentatus, Wagner dasycnemus (from common shrew) Ctenopsylla musculi spectabilis (one specimen) The Hessian Fly (Ceddomyia destructor) has a special county interest, as this pest was first recognized in Britain at Revell's Hall, Hertford, in July, 1886. The barley crops at that place were found to be badly ' root-fallen ' and much injured. On examination the presence of pupae resembling linseed was detected in the joints of the stem, and on specimens being submitted to Miss E. A. Ormerod she identified the pupae as those of the Hessian Fly, a minute insect which commits serious ravages in America and on the continent of Europe. Infestations were subsequently reported from other farms in the same neighbourhood, from Ware and Hitchin in this county, and from numerous other localities in the British Isles. An investigation of the parasites which were reared from some of the Hertfordshire specimens enabled Miss Ormerod to draw the conclusion that the pest had been imported from the east of Europe. 1 A carefully prepared paper on the subject was written by Mr. F. Maule Camp- bell, F.L.S., F.Z.S., the then President of the Hertfordshire Natural History Society.* & 1 Manual of Injurious Insects, E. A. Ormerod, p. 89. 8 Trans. Herts Nat. Hist. Soc., vol. iv. p. 1 80. 170 Diplosis
