339 



[Bitsseola fitsca] by treating the plants with a dip called " Little's 

 Fluid Sheep Dip," diluted at the rate of one measure of dip to 100 

 measures of water. This was applied from a wine bottle, with a quill 

 through the cork, so that a small quantity of the diluted dip can be 

 well shaken into the heart of the plant. The amount should vary 

 according to the size of the plant, about a teaspoonful being enough for 

 an 18-in. plant. 



Beneficial Insects. — Minist. Agric. & Fisheries, London, Misc. Pubns. 

 no. 37, 1922, 11 pp., 2 plates. Price 4d. net. 



A general account is given of the five kinds of insects that are 

 beneficial to the farmer, namely, Coccinellids, the various families 

 of parasitic Hymenoptera, Tachinids, Syrphids and Chrysopids, and 

 of their manner of attacking Aphids, Coccids and other injurious 

 insects. The destruction of these beneficial insects should be avoided 

 whenever possible ; new kinds of parasitic or predacious insects 

 should be introduced into countries where they do not already occur ; 

 and those already established should be increased in numbers by 

 every possible means. The last method is not often very successful, 

 except in a few instances, such as in the United States, where 

 Coccinellids are brought down from the hills to the valleys before the 

 time of their normal migration. 



In the case of the apple blossom weevil, Anthonomus pomonmi, L., 

 which is one of the most serious apple pests in England, if the " capped " 

 blossoms are collected before the beetles have emerged and kept under 

 muslin cages, many Ichneumonid parasites [Pimpla pomorum, Ratz.) 

 may be obtained. This method has been successful in France. 



Rhynehart (J. G.). On the Life-history and Bionomics of the Flax 

 Flea-beetle [Longitarsus panniliis, Payk.), with Descriptions of 

 the hitherto unknown Larval and Pupal Stages. — Sci. Proc. R. 

 Dublin Soc, Dublin, xvi, no. 39, 13th April 1922, pp. 497-541, 

 2 figs., 5 plates. 



The investigations here recorded were begun in 1920 with a view 

 to finding a suitable check on the ravages of Longitarsus parvulus, 

 Payk. (flax flea-beetle). Particulars are given of the life-history, 

 synonymy and distribution of this species. In Ireland it is 

 common all over Ulster, and of recent years has become a pest in 

 flax-growing districts in Co. Cork. 



The principal damage is caused by the adults, which feed on the 

 cotyledons and growing points of seedlings, which are either killed 

 and stunted or become branched. Newly emerged adults in August 

 attack old flax stalks. The larvae feed on the youngest parts of the 

 roots. The occurrence of this Chrysomelid as a pest and the range 

 of its food-plants are discussed. Cultivated flax is the favoured food- 

 plant, but clovers, grasses and species of wild flax are also attacked. 

 It is usually thought that dry, warm weather in May, after weather 

 not conducive to the thorough cultivation of seed-beds, will give rise 

 to serious attacks. The author considers that the prevailing weather 

 in May or June will determine to a large extent the infestation of the 

 following spring. 



A full description is given of the immature stages. Hibernation 

 occurs in the adult stage beneath grass near dry fences, in crevices in 

 walls, etc. in October or late September, the beetles emerging in April. 



(6782) z 2 



