465 



recent experiments, which have convinced them that C. assimilis — 

 especially its young adult and its pod-eating larva — and other alhed 

 weevils are mainly responsible for the damage to rape. At the cul- 

 niinating point of the outbreak studied, the parasite, Trichofnaliis 

 fasciattis, Thor., was present. Besides C. assimilis, C. sulcicollis, 

 Payk., and C. napi, Sch., do damage to rape that has been hitherto 

 ascribed to M. aeneiis. The adults destroy the blossoms, the buds and 

 flower-organs such as the pistils. The larvae of C. napi also injure 

 parts of the flower. Other destroyers of the flowers are various beetles, 

 including the adults of Baris spp., and some Cecidomj'iids and 

 Thysanoptera. The damage due to flea-beetles is unimportant. 



The success of the rape crops depends chiefly on C. assimilis, the 

 food-plants of which are Cruciferae, particularly mustard ; the female 

 lays 1-3 eggs in the very young pods, the puncture closing up entirely. 

 Oviposition lasts right into June. Unripe seeds serve as food for the 

 larvae, which often destroy all the seeds in a pod. The infested pods 

 become discoloured, and are often deformed and open prematurely 

 from June onwards, causing the larvae to fall to the ground. Pupation 

 occurs at a depth of about U-2| inches in ploughed soil and lasts 2-4 

 weeks. The young adults usually appear before mid-July, and, 

 together with adults from the preceding year, they attack the buds 

 and flowers. The sexually immature adult hibernates in the stubble 

 or superficial ground layer, and usually emerges before mid- April. 

 In warm weather the adults have a very lively flight-period, and they 

 then disappear among the other Coleoptera infesting rape. 



In infestation by C. siilcicollis galls are found on the roots. 



The cultivation of mustard favours C. assimilis, the presence of 

 weeds and clay soils being other favourable factors. Deep ploughing 

 under of the stubble is the direct measure reconnnended. 



Van d. Vlist (P.). Een Paar minder bekende schadelijke Insekten. 



[Two less-known injurious Insects.] — Maandhl. nedcrland. pomolog. 

 Vereenig., 1921, pp. 46-47. (Abstract in Ccntralbl. Bakt., Paras., 

 Infektionskr., Jena, lite. Abt., Ivi, no. 17-22, 14th July 1922, 



p. 451.) 



The sawfly, Hoplocampa testudinea, has been recently a common 

 pest, causing the fall of young apples and pears. Spraying with 0-1 

 per cent. Paris green, the removal of infested fruits and digging up the 

 soil are the measures advocated. This spray may also be used against 

 the pear gall midge, Contarinia pyrivora, which chiefly attacks the late 

 varieties, but spraying with repellents just before blossoming seems 

 more promising. 



Wahl (B.). Zur Bekampfung des ApJelbliitenstechers. [A Con- 

 tribution to the Work against the Apple Blossom Weevil.] — 

 Wiener landw. Zeitg., Ixx, 1920, p. 12. (Abstract in Centralhl. 

 Bakt., Paras., Infektionskr., Jena, lite. Abt., Ivi, no. 17-22, 

 14th July 1922, p. 451.) 



None of the remedies advocated against Anihonomus pomorum are 

 sufficiently thorough. The method recommended by Kurtz, of strewing 

 gallnut meal (a waste product from tanneries) around the trees [R.A.E., 

 A, viii, 325], seems worthy of trial. It is also necessary to ascertain 

 what effect this repellent has on A. cinctus, which oviposits on the pear 

 in autumn. 



