252 



stirred with a stick. This mixture is then added to the rest of the water. 

 The whitewashing is done in winter, after pruning, special attention being 

 given to the current year's growth and to the lower side of the stems. 



Baer (W.). Die Tachinen als Schmarotzer der schadlichen Insekten. 

 Ihre Lebensweise, wirtschaftliche Bedeutung und systematische 

 Kennzeiclinung. [Tachinids as Parasites of Injurious Insects. 

 Their Life-history, Economic Importance and Systematic 

 Characters.] — Zeitschr. angew. Ent., Berlin, vii, nos. 1 & 2, Septem- 

 ber 1920 and February 1921, pp. 97--163 and 349-423, 30 figs. 



The general section of this paper has already been noticed [R. A.E., 

 A, ix, 61] ; the present part is an attempt to meet a growing demand 

 for a key to the Central European Tachinidae and for a systematic 

 work on these flies that would also be suitable for a non-specialist. 



After discussing the morphology of these flies, a systematic review of 

 the subfamilies is given, followed by a key to the Central European 

 genera. 



The various genera of Tachinidae are listed, specific keys being 

 included where required. Brief notes are given regarding each species, 

 its occurrence, and its hosts. A systematic list of the hosts, with their 

 Tachinid parasites, follows. 



WiLLE (J.). Chlorpiki'in in der Schadlingsbekampfung, insbesondere 

 im Kampf gegen den Komkafer [Calandra granaria, L.). 

 [Chloropicrin against Pests, especially C. granaria.] — Zeitschr, 

 angew. Ent., Berlin, vii, no. 2, February 1921, pp. 296-310. 



As a result of a series of experiments chloropicrin (CClgNOo) is 

 recommended against Calandra granaria, L., which is killed in six 

 hours if a strength of 30 c.c. of the liquid per cubic metre of space is 

 used. When the weevils are in heaps or bags of grain, 40 c.c. must 

 be allowed to act for 24 hours if the destruction of all stages is to be 

 absolutely ensured. As slight traces of this substance irritate the eye, 

 nose and respiratory organs, the operators should be protected by an 

 ordinary gas mask with a special respirator of large capacit}'. The 

 germinating quality of fumigated grain is reduced about 30 per cent., 

 but this is not a drawback in practice, because infested grain is seldom 

 used as seed. The baking quality of the grain and flour is not affected. 

 Feeding experiments with mice and rabbits showed that treated corn 

 can be used with impunity. Metals are acted upon by chloropicrin 

 in the presence of aqueous vapour ; in the absence of humidity they 

 remain unchanged. Fabrics and colours do not suffer in any way. 

 The fumes disappear in about six hours, so that large buildings may 

 be expected to be habitable in 24 hours at the outside. 



In the case of other insect pests, the cockroaches, Blattella {Phyllo- 

 dromia) germanica. Blatta (Periplaneta) orientalis and B. (P.) americana. 

 were kiUed in two hours, 10 c.c. per cubic metre being used. The 

 various stages of the flour beetle, Tenehrio molitor, were more resistant, 

 especially the pupae, six hours at 20 c.c. being necessary. The meal 

 moth, Ephestia kuhniella, succumbed to an exposure of four hours, 

 30 c.c. being used. The hed-hn^, Cimex lectidarius, was more resistant 

 by comparison ; adults and larvae were killed in six hours with 20 c.c, 

 but 30 c.c. acting for two hours failed to destroy individuals inside 

 rolled-up carpets. Compared with hydrocyanic acid gas, chloropicrin 

 is slow in penetrating obstacles to diffusion and is more readily 

 absorbed by fabrics. 



