185 



ScHELLENBERG (A). Bericht uber eine Studienreise in deutsche 

 Weinbaugebiete (Baden, Rheingau, Mosel, Rheinhessen, und 

 Bayrische Pfalz). [A Report on a Tour of Study in the German 



Vine-growing Regions.] — Landiv. Jahrh. der Schweiz, Lucerne, 

 XXXV. no. 6, 1921, pp. 725-754, 4 figs. 



One section of this report deals with the efforts being made in 

 Germany to simpUfy the methods for combating the vine-moths, 

 Clysia {Conchylis) amhiguella, Hb., and Polychrosis hotrana, Schiff. 

 In Germany these moths require annual measures, and though Switzer- 

 land does not suffer to the same extent, there are certain western 

 Swiss districts where great damage is done, ks nicotine has risen 

 to about forty times its pre-war price in Germany, arsenicals are 

 being used, Urania green — which contains no lead — being generally 

 employed, combined with lime-copper. 



Staniland (L. N.). Hover Flies: Their Habits and Economic 



Importance. — Fruit Groiver, Fruiterer, Florist & Mkt. Gdnr., 

 London, hii, nos. 1365 & 1366, 26th January &. 2nd February 

 1922, pp. 143-144 & 185-187, 10 figs. 



In these investigations to determine the species of Syrphid flies 

 that are useful checks on Aphids, the species recorded are ■.—Melano- 

 stoma scalare, F., predacious on Macrosiphum rosae ; Lasiophthicus 

 {Catabomba) pyrastri, L., on Acyrthosiphon [Siphonophora) pisi ; 

 Syrphus ribesii, L., on Macrosiphum urticae, M. rosae, Hyalopterus 

 pruni, Aphis pomi and Phyllaphis fagi ; S. vitripennis, Mg., on M. 

 urticae, Aphis rumicis, A. pomi, H. pruni, Callipterus quercus and 

 Phyllaphis fagi ; S. corollae, F., on Aphis saliceti; S. luniger, Mg., 

 on A. rumicis; S. balteatus, DeG., on A. rumicis, H. pruni, M. 

 urticae and Callipterus quercus ; and 5. auricollis, Mg., on Cavariella 

 capreae. 



The eggs are laid singly on the surfaces of leaves wherever there 

 are Aphids. The largest number of eggs laid by Syrphus vitripennis 

 in captivity was ten. Eggs of 5. vitripennis hatched in four days, 

 and those of 5. luniger in two. The larvae feed within half an hour 

 of hatching. Experiments are described to determine the number of 

 Aphids one larva can destroy in its lifetime, and this may rise to 

 over 100 per diem when it is nearly mature. Pupation usually occurs 

 on the lower surface of a leaf, while the last brood often pupates among 

 dead grass and rubbish at the foot of the tree or plant. The winter 

 is passed in this stage. The adults emerge in summer in 14-16 

 days, and it is thought that there are at least three generations 

 a year. 



The larvae collected were but Httle parasitised, a few Proctotrupids 

 and an Ichneumonid, Bassus laetatorius, being bred from them. Some 

 examples of Syrphus cinctellus were badly attacked by a fungus. 



The author does not consider that any of the species mentioned, 

 with the possible exception of 5. balteatus, will check the woolly aphis 

 [Eriosoma lanigerum]. Plants or trees attacked by Aphids should be 

 examined for the presence of Syrphids, and if they are found, spraying 

 should not be resorted to, as this kills the parasites as well as the 

 Aphids. Syrphids can prevent Aphids becoming a serious pest if they 

 are sufficiently numerous and commence work early enough in the 

 year. They are particularly useful in checking waxy Aphids such as 

 Hyalopterus pruni, which are difficult to spray. 



(5980) N 



