404 



DE Stefaxi (T.). Lotta contro la Mosca delle Ulive. [Measures 

 against the 01i\'e V\y.\ — AUcvauicnti, Palermo, ii, no. 6, 1st June 

 1921, pp. 170-171. 



This article describes the losses clue to the olive fly, Dae us oleae, 

 Rossi, and the well-known Berlese method of poison-baits. 



B[olle] (G.). La Lotta contro il Bruco Geometra dei Ciliegi. 



[Measures against the Cherry Geometrid.] — Allevamenti, Palermo, 

 ii, no. 6, p. 171. 



Very good results against the winter moth, Cheimatobia hriimata, 

 infesting cherry trees have been obtained by using the American 

 banding specially prepared for this insect. It is imperative to band 

 the trees immediately the first autumn frosts are expected. The 

 adhesive should be spread on paper tied round the trunk, the width 

 of the band being 6 in. It must be renewed when it ceases to be tacky, 

 and left in ])osition until May. 



CoKTi (A.). Lyctocoris campestris, F., un Nemico ignorato del Baco 

 da Seta. [L. campestris, a hitherto unknown Enemy of the 

 Silkworm.] — Atti Soe. Ital. Sci. Nat. in Milano, Ix, no. 1, 1921, 

 pp 1-10. 



In some Venetian localities a bug, Lyctoeoris campestris, F., has 

 killed large numbers of silkworms, attacking them through the walls 

 of the cocoons. 



Davidson {].). Biological Studies o£ Aphis nmiicis, L. 1746. — Ann. 

 App. Biol., Cambridge, viii, no. 1, June 1921, pp. 51-65, 1 chart, 

 7 tables. 



The experiments made in 1914 and interrupted by the war were 

 resumed in 1920, with the object of obtaining a numerical expression 

 of the infestation of plants by Aphis rumicis and of the relative 

 susceptibility of its various food-plants [R. A.E., A, ii, 660]. For the 

 1914 experiments described in the present paper the Aphids were reared 

 in captivity from the eggs through successive viviparous partheno- 

 genetic generations. The original eggs were taken from Euonymus 

 europaeus. Thus the history of the Aphids was known, as also was 

 the exact generation with which the plants were infested. An early 

 viviparous parthenogenetic generation found on E. europaeus was used 

 for the 1920 observations. The difficulties arising through variation 

 in temperature were partly overcome by carrying out the infestations 

 as far as possible in each series on the same day. The technique 

 employed is described, also the influence of food-plants on the characters 

 of the species. 



Of the various plants tested, rapid de\-elopment was maintained on 

 broad beans, while on peas, mangels, sugar-beet, red beet and poppies, 

 the figures were considerably lower and infestation somewhat slower. 

 On dwarf French beans the colony died out, and on Carter's Canadian 

 wonder bean only a few dwarfed indi\'iduals produced a few young. 

 The sap from certain plant cells forms the food of the Aphids. and the 

 hydrogen-ion concentration of this sap in relation to the relative 

 susceptibility of plants to Aphid attack should be investigated. 



Research as to the relative intensity of reproduction on different 

 varieties of the same species is being continued, with the view to the 

 possibility of breeding a resistant strain. It is possible that reproduc- 



