497 



within reasonable limits coconut cultivation must be centralised. 

 Trap-heaps, collection, the removal of breeding-places, and possibly 

 the introduction of natural enemies are the other measures advocated. 



Fahringer (J.). Beitrage zur Kenntnis der Lebensweise einiger 

 Schmarotzerwespen unter besonderer Beracksichtigung ihrer 

 Bedeutung fiir biolog. Bekampfung von Schadlingen. [Contri- 

 butions to a Knowledge of the Habits of some Parasitic 

 Hymenoptera with special regard to their Importance in the 

 Biological Control of Injurious Insects.] — Zeitschr. angew. Ent., 

 Berlin, viii, no. 2, May 1922, pp. 325-388. 



The results of fifteen years' breeding experiments by the author and 

 the late Dr. F. Tolg are given as regards 316 species of Hymenopterous 

 parasites of Central or Southern European insects and Arachnids, 

 including forest and agricultural pests. The species dealt with com- 

 prise 71 Ichneumonids, 2 Evaniids, 36 Braconids, 2 Proctotrupids 

 and 3 Cynipids. Notes are given on the best methods for keeping 

 and breeding such insects, with a list of 316 hosts and the parasites 

 attacking them. 



Thiem (H.). Zur Biologie und Bekampfung des geiurchten Dickmaul- 

 russlers {Otiorhynchus sulcatus, ¥.). [A Contribution to the 

 Biology and Control of 0. sulcatus.] — Zeitschr. angew. Ent., 

 Berlin, viii, no. 2, May 1922, pp. 389-402. 



In Germany, Otiorrhynchus sulcatus, F., is, on occasions, a pest 

 capable of considerable injury to grape-vines, berry fruits and green- 

 house plants, following migration or introduction in earth, turf or humus. 

 It has not been recognised as an important forest pest, but in the 

 districts chiefly affected there is a well-grounded belief that the weevils 

 migrate from oak forests to neighbouring vineyards. Though con- 

 siderable, the recorded damage to Taxus, Rhododendron, Camellia, 

 gooseberries and strawberries is slight compared with that to vineyards. 

 In 1920, 4,000 out of 6,000 young grafted vines were destroyed at 

 Berncastel-Cues. The roots are eaten, ringed or bitten through, and 

 numerous grooves are gnawed on the stem to a height of 8-12 in. 

 Eight-year-old vines have been destroyed ; old vines are not attacked, 

 possibly on account of some chemical or mechanical change in their 

 bark. The adults feed on the newly opened buds in early sprijig. 

 Young berries and their stalks and shallow roots are also attacked by 

 them. Both the weevils and their larvae will eat a great variety of 

 plants with soft tissues. Stable manure, in which the larvae often 

 occur, forms a source of food, and the abundant manuring often 

 practised in attempting to save the vines by inducing vigorous growth 

 is therefore not advisable. The slight importance of the larvae m 

 forests may be due to the fact that they prefer humus to roots. Oak 

 roots seem to be avoided. 



The weevils that appear in early spring and in summer apparently 

 become mature only in the following year, ovipositing in July and 

 August (perhaps also in September) and again in spring after a second 

 hibernation. Larvae hatched from the spring oviposition yield adults 

 in July ; those from July eggs may perhaps hibernate as pupae, while 

 later eggs yield hibernating larvae. The assumption of two annual 

 generations is therefore incorrect. On feehng the warmth in spring 

 the larvae at a depth work upwards to pupate. The appearance of 



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