230 SCIENCE PROGRESS 



larvse bore into and feed on the roots of the flax plants, but do 

 not appear to cause any appreciable hindrance to growth. 

 H. B. Weiss {Amer. Nat., 56, 159-65) summarises the feeding- 

 habits of N. American Coleoptera, and estimates about 26 per 

 cent, are phytophagous, 44 per cent, saprophagous, and 27 per 

 cent, predaceous. He concludes that about three-fourths of 

 the species are apparently engaged in what may be termed 

 useful activity. The external anatomy of the Elaterid genus 

 Melanotus forms the subject of a paper by R. H. Van Zwalu- 

 wenburg (Proc. Ent. Soc. Washington, 24, 12-29). R- Jeannel 

 {Arch. Zool. Exp., 69, 509-42) has an illustrated paper on the 

 larvae of cavernicolous beetles of the group Trechini, describing 

 this stage in numerous species. 



Hemiptera. — J. Davidson {Ann. App. Biol., 9, 35-145) 

 has a further contribution deahng with the biology of Aphis 

 rumicis. The reproduction of this species was tested on 

 eighteen varieties of field beans and the results compared with 

 the reproduction on Prolific Longpod broad beans. Five 

 plants of each variety were tested, and the total number of 

 aphids produced on each plant from one apterous viviparous 

 female in fourteen days was counted. The mean values of 

 infestation were found to range from 37 to 1,037, ^i^d they 

 allow of the varieties being grouped into classes representing 

 various grades of susceptibility, ranging from 98 per cent, to 

 3 per cent. Several additions to the Aphid fauna of Great 

 Britain have been made during the last few months. F. V. 

 Theobald {Bull. Ent. Res., February) describes a new genus 

 and species, Laingia psammce, off marram grass and meadow 

 foxtail in Kent. In Ent. Month. Mag., June, the same author 

 records Trilobaphis caricis ger. et sp. nov. off Carex near Bangor 

 and F. Laing {ibid., July) brings to notice three species not 

 previously known from our islands. 



Hymenoptera. — M. D. Haviland {Parasitology, 14, 167-73) 

 describes the larval stages of Dacnusa areolaris, a Braconid 

 endoparasite of Diptera of the group Phytomyzinae. The 

 newly hatched larva is enclosed in a trophic membrane which 

 is subsequently cast off ; the caudate larva undergoes two 

 ecdyses before assuming the typical grub-like stage. The 

 same authoress {Q.J. M.S., 66, 321-38) discusses the meta- 

 morphosis of some Chalcid hyperparasites of Aphides and 

 also certain general questions relative to insect parasitism. 

 Among Hymenoptera it is suggested that this mode of life 

 arose from an earlier inquiline existence. A. B. Gahan {Proc, 

 Ent. Soc, Washington, 24, 33-58) contributes a useful list of 

 the species of phytophagous Chalcids (other than fig insects) 

 known to date, and discusses the evolution of the plant-feeding 

 habit within the group. H. Shapley {Proc. Nat. Acad, Sci. 



