INSECTS APID/E (continued} APID.AE (continued] Megachile argentata, Fabr. St. Osyth, Psithyrus, Lep. Southcnd rupestris, Fabr. Osmia, Pz. vestalis, Fourc. rufa, L. barbutellus, Kirb. pilicornis, Smith campestris, Pz. cacrulcscens, L. quadricolor, Lcp. fulvivcntris, Pz. Bombus, Latr. bicolor, Schr. venustus, Smith spinulosa, Kirb. agrorum, Fabr. Stelis, Pz. hortorum, L. aterrima, Pz. v. harrisellus, Kirb. phoeoptera, Kirb. latreillellus, Kirb. Anthidium, Fabr. sylvarum, L. manicatum, L. derhamellus, Kirb. Eucera, Scop. lapidarius, L. longicornis, L. lapponicus, Fabr. Mclecta, Latr. pratorum, L. luctuosa, Scop. cullumanus, Kirb. Seuthend (F. Smith) armata, Pz. tcrrestris, L. Anthophora, Latr. v. lucorum, Smith retusa, L. Apis, L. pilipes, Fabr. mellifica, L. furcata, Pz. PHYTOPHAGA The Phytophagous Hymenoptera comprise the Sawflies (Tenthre- dinida] and their allies, and the great majority of the Gallflies (Cynipidce). The females of these insects have the ovipositor modified into a saw or borer, and in some cases into an instrument which combines the properties of saw, lance and file all in one ; for they vary considerably in their structure according to the work which they have to do, such species as deposit their ova in hard woody substances requiring stronger implements than those which simply make incisions between upper and lower leaf surfaces. As the name implies they are as a rule plant feeders in the larval state, and the majority feed up during the summer and autumn and appear in the perfect state during the following spring, but some are to be met with much later in the season, and Emphytus serotinus is often abundant on herbage under oak trees during fine weather in October. The early species may be found on leaves and at the flowers of various plants, the Umbelliferce being especially attractive to them. Angelica sy/vestris is also a great favourite with those which appear in the late summer and autumn. So far as our present knowledge goes, we have about 400 Sawflies in Britain, but many of them are extremely local or excessively rare, and as the great majority of the individuals are females they are not nearly so much in evidence as many other insects, and consequently they rarely do much damage to vegetation in ordinary seasons. Occasionally however certain among them appear in immense numbers and prove harmful to particular crops. Prominent among these is the Turnip Sawfly, Athalia spinarum, of which vast migratory swarms sometimes invade our shores, and dispersing themselves over considerable tracts of country proceed to lay their eggs on the turnip leaves, and the i 105 14
