107 



Rosenberg (L.). Die Heuschrecken in Palastina. [Locusts in 

 Palestine.] — Tropenpflanzer, Berlin, xviii, no. 12, December 

 1915, pp. 657-669, 3 figs. [Received 6th January 1921.] 



The serious outbreak of locusts in Palestine in 1915 is described. 

 The Jewish settlements suffered a loss of about £120,000. Among 

 the measures adopted was the use of a flour paste placed on the 

 ground, locusts coming into contact with it being suffocated owing 

 to its sealing their stigmata. In a more fiuid form this paste can be 

 applied to tree-trunks. 



MoRSTATT (H.). Pflanzenkrankheiten in den Tropen, [Plant Diseases 

 in the Tropics.] — Tropenpfla)izer, Berlin, xxiii, no. 4, April 1920, 

 pp. 114-117. [Received 6th January 1921.] 



The remarkable injury that is sometimes done to crops in the 

 tropics is due to the fact that their cultivation is a new departure. 

 Such a disaster as the destruction of coffee [by Hemileia vastatrix] 

 in Ceylon cannot be ascribed to dangers peculiar to tropical conditions. 

 Fungi always accompany plants, but in the case of insects it is feasible 

 to prevent the importation of a given species with a known life-history, 

 but it is not possible to predict what enemies a plant will find in its 

 new home, and what their effect on it will be. 



Friederichs (K.). Weberameisen und Pflanzenschutz. [Wea\'er 

 Ants and Plant Protection.] — Tropenpflanzer, Berlin, xxiii 

 no. 5-6, May-June 1920, pp. 142-150. .'Received 6th January 

 1921.] 



This paper is published in view of an Ordinance issued at Rabaul 

 (New Guinea) on 26th August 1919, respecting the palm leaf beetles, 

 Proniecotheca antiqua and P. opacicollis. These Hispids cannot be 

 classed among the more dangerous pests of coconut, as their infesta- 

 tion is very local, and most of the larvae are parasitised by Chalcids, 

 as has also been recorded by Knowles and Jepson in Fiji. In Samoa 

 the author recommended arsenical sprays, and the above Ordinance 

 also advises arsenicals, and the removal and destruction of the leaflets 

 containing larval mines. All these measures are considered unneces- 

 sary, however, owing to the extent of parasitism. If the parasites 

 are absent, they can be introduced. 



An interesting feature of the Ordinance is the recommendation 

 to employ the ted tree ant (called " karakum " by the natives) by estab- 

 lishing large numbers in the plantations. This can only refer to weaver 

 ants of the genus Oecophylla. 



Many travellers in eastern Asia, have reported the use of ants 

 against plant pests. Escherich states that as far back as the 12th 

 century this was the case in China, where a special class of workers 

 existed for this purpose. Raciborski mentions that nests of large 

 red ants are tied in mango trees in Java to protect the fruits against 

 Sternochetiis ( Cryptorrhynchus) mangiferae. 



When, early in 1914, the author was studjdng Oryctes rhinoceros 

 (rhinoceros beetle) in Cochin China and Cambodia, he found that the 

 presence of ants, of which Oecophylla smaragdina was the commonest, 

 did ensure the absence of many insect pests, though leaf-eating 

 Lamellicorn beetles are not interfered with, as they feed at night. 



