CICADINA (cont.) JASSIDAE Athysanus, Burm. communis, J. Sahl. sordidus, Ztt. obscurellus, Kbm. obsoletus, Kbm. Deltocephalus, Burm. striifrons, Kbm. Falmouth pascuellus, Fall. distinguendus, Flor. socialis, Flor. Truro sabulicola, Curt. striatus, L. normani, Scott. Allygus, Fieb. mixtus, Fabr. Thamnotettix, Ztt. prasina, Fall. Par; Falmouth subfuscula, Fall. spendidula, Fabr. crocea, H. S. attenuata, Germ. Limotettix, J. Sahl. striola, Fall. quadrinotata, Fabr. nigricornis, J. Sahl. Botut Fleming INSECTS CICADINA (coat.) JASSIDAE (cont.) Cicadula, Fieb. sexnotata, Fall. TYPHLOCYBIDAB Alebra, Fieb. albostriella, Fall. Kybos, Fieb. smaragdula, Fall. Chlorita, Fieb. flavescens, Fabr. viridula, Fall. Euptcryx, Curt. vittatus, L. urticea, Fabr. strachydearum, Hardy melissae, Curt. Scilfy (Dale) auratus, L. filicum, Newm. Mittook (Mrs. Clark) pulchellus, Fall. Typhlocyba, Germ. sexpunctata, Fall. ulmi, L. tenerrima, H. S. aurovittata, Dougl. CICADINA (cont.) TYPHLOCYBIDAE (cont.) Typhlocyba douglasi, Edw. rosae, L. quercus, Fabr. geometrica, Schr. Zygina, Fieb. flammigera, Geoff. parvula, Boh. PSYLLINA PSYLLI DAE Psylla, F. Loew simulans, Forst. pyricola, Forst. peregrina, Forst Arytaena, Scott genistae, Latr. Truro TRIOZIDAE Trioza, Forst. galli, Forst. urticae, L. crithmi, F. Loew albiventris, Forst. APHIDES The work of identifying the insect pests of the county at the Technical Schools has necessitated a considerable amount of attention being given to the commoner aphides, and in 1901 and 1902 an attempt was made to collect and identify every species observed in the county. The efforts in this direction were not altogether successful, and it is probable that one or two of the species kept under observation for some time are not described in Buckton's Monograph. The peculiarities of the physiological processes involved make the study of the order very complicated, and the extensive morphological differences among members of the same species greatly increase the difficulties of identification. The parthenogenetic production of apterous young for few or many generations in suc- cession, and for the most part of the female sex only ; the occasional appearance of winged individuals, sometimes in considerable numbers ; the frequent remarkable disproportion in numbers between the sexes when the males do appear ; the occurrence of viviparous and oviparous broods ; the difference of sex organs in the same sex and species ; the extraordinary changes in life habits in successive generations and the consequent formation of so-called parallel series, are all so many difficulties in the way of accurate diagnosis. The following notes, however, deal only with those species about the identification of which there is no reasonable doubt. Siphonophora rosae is, of course, ubiquitous. S. granaria in some years appears on wheat about Launceston, but is much more troublesome locally on grass than on grain. In 1 90 1 S. phi did considerable damage on garden peas about Bodmin. In 1902 almost every nettle in the neighbour- hood of Truro carried a large colony of 5. urticae. S. dirhoda, S. lactucae, S. ruii, and S. rosarum are at times abundant locally, while S. jaceae and S. sonchi are widely spread and common. S. scabiosae has been found plentifully near Falmouth, and S. chelidonit in the neighbourhood of Truro on bramble. S. alliariae was common in 1902 at Newquay on nipplewort. S. fragariae attacked the strawberries about Truro, Falmouth, and Penzance in 1 900, and in places did considerable mischief. S. hieracii and S. millefolii seem to be rather local. 5. circumflexa was found on Ixia sparaxis and other Cape bulbs at Tresco, Scilly. S. pelargonli has been taken on various plants, but especially on shrubby calceolarias, at Truro. S. carnosa was plentiful at St. Clement, Truro, in 1902 on nettles, and appears to be widely spread. S. longipennis was fairly common in 1901 on Poa annua close to the Falmouth Docks. S. convolvuli has been taken at Miramar, Truro, on periwinkle and on various bindweeds. S. avellanae is widely distributed in the Truro district and elsewhere. S. tanaceti has been obtained on tansy in the Looe valley, and on feverfew in gardens about Truro. S. artemisiae occurs on mugwort about St. Ives. S. so/idaginis was common in 1902 on golden-rod at Bishop's Wood, Truro, and on anthemis and groundsel at Millook. S. tusstlaginis is occasionally 243
