501 



Various scattered notices of the sporadic occurrence of this gall 

 insect in Germany are here collected. The author's own observations 

 show that the galls are nvimerous where the turkey oak {Q. cerris) 

 occurs together with Q. pedunculata. This supports Beyerink's state- 

 ment that C. calicis can complete its life-cycle only when these two 

 oaks occur near one another. 



Wolff (M.) & Krausse (A.). Zur Schreibung von biologischen 



Formeln. [The Writing of Biological Formulae.] — Zeitschr. 

 angcw. Ent., Berlin, viii, no. 2, Ma}^ 1922, pp. 447-451. 



The authors explain the principles followed in their method of 

 writing formulae representing the life-history of insects ; this is 

 considered somewhat easier to read than the system worked out by 

 Rhumbler [R.A.E., A, viii, 269], which has been modified by Borner 

 [R.A.E., A, ix, 547] and by Prell [R.A.E., A, ix, 610]. 



Schubert (W.). Die Riibenwanze, Piesma capitata, Wolff. [The 

 Beet Bug, P. capitata.] — Zeitschr. angeiv. Ent., Berlin, viii, no. 2, 

 May 1922, pp. 451-452. 



Since about 1903 beet in Silesia and the whole of Eastern Germany 

 has been affected by a curl disease, previously unknown, due to a 

 Tingid bug, Piesma capitata, Wolff. The damage is so serious that, 

 particularly in 1910, some beet-growers contemplated giving up this 

 crop. The infestation must be due to a migration from wild plants 

 to the more attractive cultivated crop. The adult and the larva suck 

 all the aerial parts of the plant, especially the undersides of the leaves. 

 The adults are very sensitive to jarring, and the vibration caused by 

 footsteps sometimes suffices to make them drop to the ground, where 

 their grey-black colour renders them almost invisible. The injury at 

 first resembles the curl due to Aphids ; yellow spots then appear, the 

 leaves rot, the beet top becomes conical, and the roots remain of 

 small size. 



The hibernated generation oviposits at the end of April or early 

 in May, and the resulting individuals oviposit at the end of June 

 or early in July. This generation is full-grown by the end of August 

 and is the one that hibernates. The eggs are laid on leaves and leaf- 

 stems. Incubation requires 10 days. The larva moults five days after 

 hatching and twice again at five-day intervals. A description of the 

 larva and adult is given. P. capitata is most harmful in June and 

 July, and hot, dry weather seems very favourable to its development. 

 Up to now neither insecticides nor trap belts of potatoes round a field 

 have proved of use. 



DiNGLER (M.). Feinde des Engerlings unter den Wirbeltieren. [Verte- 

 brate Enemies of the Cockchafer Larva.] — Zeitschr. angeiv. Ent., 

 Berlin, viii, no. 2, May 1922, pp. 455-456. 



A number of observations by different workers show that rooks, 

 starlings and blackbirds destroy large numbers of cockchafer larvae 

 [Melolontha]. The mole does not seem to be of importance in this 

 respect. 



