357 



Naphtha residue (Mazut) emulsion, containing 6'66% of naphtha 

 and 0'2% soft soap, proved very effective and resulted in the destruction 

 of 90 per cent, of scale-insects, and is also quite harmless to the plants. 

 Even a 5% solution of lysol was ineffective against scale-insects, 

 but 10% carbolineum destroyed some 90% of a species of Cerojilastes in 

 winter. 



Most of the pests of citrus trees have not yet been finally identified. 

 The most common pest present in all nurseries and orchards are mites 

 of the genus Tetranychus ; they chiefly attack Citrus trifoliata, but 

 all other varieties also suffer. All the above-named insecticides, even 

 in weak solutions, were effective against mites, but the eggs proved 

 more difficult to destroy, the most effective remedies against them 

 being lime-sulphur and Scalecide. Coccidae were numerous, includ- 

 ing : — Coccus {Lecanium) hesperidum, against the young larvae of 

 which all the above insecticides proved effective, though the older ones 

 were affected only by strong lye, oil or lime-sulphur solutions ; against 

 Chrysomphalus {Aspidiotus) aurantii, Scalecide gave the best results, 

 though even this was not entirely effective. Against Mytilaspis sp., 

 one of the most injurious species, Scalecide, lime-sulphur, soda-naphtha 

 and tobacco-lye proved of some value, though several sprayings are 

 necessary and the trunlc and infested branches must also be smeared 

 \\dth a mixture of 2-3 parts by volume of 3 per cent, milk of lime and 

 one part of carbolineum ; with 1 lb. carbolic and 1 lb. soft soap in 

 2-3 gallons of water ; with the mixture recommended by Trabut, 

 composed of 35% lime, 20% caustic soda and 45% flowers of sulphur ; 

 or with that used by F. F. Penkov consisting of 2 lb. of lime, 4 lb. of 

 carbolineum and 8 lb. of lye ashes. Against Ceroplastes sp., which 

 attacks tea as well as citrus, none of the insecticides had any effect on 

 the adults, though the larvae were most affected by Scalecide. 

 Three other species of unidentified Coccids occurred in this locality, 

 one of which was also found on tea. 



Aphids on citrus can be eff'ectively controlled with kerosene and 

 carbolic emulsion, soft soap, or a decoction of quassia containing 

 1'3% of soft soap. 



Baltruk (N.). BopbOa cii kpobhhom TJien Ha HepHOMopcKOM-b no6e- 

 peWbM KaBKasa. [The Control of the Woolly Aphis on the Black- 

 Sea Coast of Caucasia.] — « PycCHJe Cy6TponMKM.» [Russian 

 Subtropics], Batum, no. 11-12, 1916, pp. 117-119. [Received 

 18th June 1917.] 



The following notes on the control of the woolly aphis [Eriosoma 

 lunigerum] are given. In autumn, after the fall of the leaves, 8-10 lb. 

 of freshly slaked lime is dug into the soil round each tree ; this 

 should be done every 3-5 years, the trunks being washed with lime 

 annually. In February or March, before the buds have unfolded, the 

 trees are further treated with kerosene emulsion and lye or with milk 

 of lime and iron sulphate. Kerosene emulsion with lye is prepared by 

 boiling 3 lb. of soft soap in 4 pints of water till the soap has dissolved ; 

 15 pints of kerosene are then added and the whole is added to the lye, 

 prepared separately by boiling about 3 gallons of dry ashes in 4 or 5 

 gallons of water and diluting it with 35 gallons of water ; another 

 8 crallons of water are added to the mixture and it must be used the 



