631 



The remedial measures against P. poecilopiera have been based 

 on the recommendations of Lesne [R.A.E., A, ii, 404 ; iv, 304]. Birds 

 appear to be the only effective natural enemies. 



The Chrysomelids have two or three generations a 3-ear, and measures 

 against them include the collection of adults at night and spraying 

 with nicotine or arsenic against the larvae. The most satisfactory 

 spray for general purposes is that recommended by Guenaux [R.A.E., 

 A, vi, 134], and consists of tobacco extract containing \ lb. nicotine, 

 I lb. carbonate of soda, 2J lb. black soap, 1 qt. methylated spirit and 

 25 gals, water. The arsenical spray recommended consists of \ lb. 

 sodium arsenate in 2| gals, water mixed with 1| lb. lead acetate in 

 2| gals, water, the total being made up to 25 gals, with water. 



VoGELWEiD (V.). La devastation des houblonnieres du Bas-Rhin 



par le Tetranyclms tclarius, L. — Bull. .4,s\soc. Philomalhique 

 d' Alsace et de Lorraine, Savcrne, vi (1921), pt. 3, 1922, pp. 71-89, 

 3 figs. 



In July 1921 serious complaints were received of the abundance of 

 Tefranychiis telarius, L. (red spider) in the hop fields around Strasburg, 

 the entire crop being threatened with destruction. The history, 

 description and distribution of the mites are dealt with. Both 

 T. telarius and T. althaeae, Hanst., were present, and the colours vary 

 between N'ellow and green, found chiefly on haricot beans, and orange 

 varieties, found on beets. Both kinds are found together on hops, the 

 yellow-green predominating. It seems likely that the variation in colour 

 is merely produced by the choice of food-plant, as either form is equally 

 adaptable to either beans or beets. Hops infested by the mites are 

 retarded in growth and turn yellowish and then red. The leaves 

 dry, roll up and fall. Infestation takes places from the soil, and the 

 mites travel gradually to the top of the plants, the webs giving them 

 a grey appearance. It has been noticed that the mites do not occur 

 on hops when Aphids are present, the latter having been observed 

 to attack them and suck the juices from their bodies. A study of 

 former records of infestation shows that the mites are always par- 

 ticularly abundant in an unusually dry season ; they can withstand 

 severe cold, but cannot live in a moist atmosphere, and while there 

 are normally four or five generations in a year, a particularly dry 

 season may produce six or seven. Coccinellids are very useful in 

 reducing the numbers, and sprays of nicotine, black soap and spirits 

 of wine are efficacious if used at the correct periods in the life-cycle. 



(N.). Note sur les d^gats causes a la vigne par la larve d'une noctuelle. 



— Prog. Agric. & Vitic., Montpellier, Ixxviii, no. 44, 29th October 

 1922, pp. 430-431. 



The larvae of Laphygma {Caradrina) exigua, Hb., have been doing 

 considerable damage in vineyards, where they attack the parenchyma 

 of the young leaves and sometimes injure the fruit. As this moth can 

 live on various plants, it is important to clear away all weeds and 

 to practise clean cultivation for a space of four or five yards around a 

 vineyard. The spray recommended consists of 2\ lb. cresyl, 2i lb. 

 soft soap, 1 lb. sodium carbonate (commercial crystals), 2\ lb. paraffin 

 and 50 gals, water. Another formula is 5 lb. black soap and 1 gill 

 ordinary carbolic acid in 10 gals, water. Care should be taken to 

 spray the mixture lightly over the surface of the leaves and to reach 

 the base of the stems and underneath the leaves, where the larvae 

 are generally found. 



