230 



Chalcid parasites of the eggs in Spain, which are described. These 

 include Anastatus bifasciatus, Schedius kuwanae, Atoposomoidea 

 ogimae, and a new species of Tyndarichus. 



Fontanel (P.). La Guerre aux Coquerelles. [Cockroach Extermina- 

 tion.] — Nat. Canad., Quebec, xlv, nos. 6, 7, 8; December 1918, 

 January-February 1919; pp. 86-93, 104-110, 117-126. 



The gases used for the destruction of cockroaches {Blatta germanica) 

 inchide chlorine and hydrocyanic acid. The former, being readily 

 soluble in water, must be kept away from food and from metallic 

 kitchen utensils. Hydrocyanic acid gas may be generated by using 

 potassium cyanide 1 oz., sulphuric acid 2 oz., and water 4 oz., these 

 quantities being sufficient for the fumigation of 100 cubic ft. It 

 should be used only when fumigating a completely infested house, 

 and as the eggs are not destroyed by it, the treatment should be re- 

 peated a month later. ' 



Of other remedies, pyrethrum powder is recommended, if it can 

 be obtained freshly prepared and pure ; but the most efficient mixture 

 consists of wheaten flour 5 oz. and potassium cyanide 1 oz., intimately 

 mixed in a mortar. This usually kills in less than 5 minutes and 

 often in less than 1 minute, while even the odour has been known 

 to kill in less than 15 seconds cockroaches passing over it. The 

 efficacy of powdered poisons lies in their being brought into contact 

 with the insect which swallows them in cleaning its limbs and antennae, 

 as is its invariable habit. Another recommended formula that can 

 be used in cases where the presence of a powerful poison is inadvisable, 

 consists of chocolate 1 oz. and borax 1 oz., or cocoa ^ oz., sugar | oz., 

 and borax 1 oz 



Finally, after having killed the adults, it is necessary to destroy 

 the bodies, since the eggs being laid in cases, they may be mature 

 and almost ready for extrusion at the time of the death of the adult, 

 in which case they may hatch out as though the insect were viviparous. 



De Koolvlieg {Chortophila brassicae, Bch.). [The Cabbage Root 

 Maggot.] — Meded. Phytopathologischen Dienst, Wageningen, no. 8, 

 1919, 18 pp., 13 figs. 



The life-history of Phorbia {Chortophila) brassicae, Bch., in Holland 

 is described, and tarred paper collars are suggested as the best means 

 of protecting the plants [see this Review, Ser. A, v, p. 171]. Some 

 of the figures illustrate a punch used for cutting the collars from 

 a roll of tarred paper, a collar ready for appHcation, and cabbages 

 equipped with tMs protection. 



ScHOEVERS (T. A. C.) Wat nu in den Boomgaard gedaan kan worden 

 ter Bestrijding van Ziekten en Plagen. [Measures that may be 

 taken in the Orchard at this Period of the Year against Diseases 

 and Pests.] — Tijdschr. Plantenziekten, Wageningen, xxv, no. 1, 

 January 1919; Bijblad pp. 1-4. 



The title of this popular article intended for owners of orchards 

 indicates its scope. 



