261 



Work connected with Insect and Fungous Pests and their Control. — 



Rept. Agric. Dept., Dominica, 1919-20, Barbados, 1920, p. 19. 



An outbreak of Orthezia insignis on lime trees in certain districts 

 of Dominica was the only occurrence of importance during the year. 

 This Coccid is generally distributed in the island, but has not often 

 been reported in serious abundance. In the outbreak in question the 

 limes were growing in exhausted hillside soil, and consequently, though 

 spraying might do some good, it would only divert attention from what 

 is really needed — the improvement of the soil conditions, and perhaps 

 also protection from wind. 



In a case where the hurricanes of 1915 and 1916 had destroyed a 

 wind-break, lime trees had suffered severely from the wind, and the 

 trees had been attacked by Chionaspis citri and Lepidosaphes beckii. 

 The latter scale had, however, been completely overcome by the red- 

 headed fungus [Sphacyostilbe coccophila) . 



Food-plants of the Pink BoUworm. — Agric. News, Barbados, xx, no, 

 491, 19th February 1921, p. 58. 



The pink bollworm [Platyedra gossypiella], which was found in 

 Montserrat a few months ago, has been recorded as feeding on okra 

 [Hibiscus esculentus]. As it also feeds on Indian hemp [H. canna- 

 binus). and as all Malvaceous plants that produce seeds large enough 

 seem attractive to it, they should be included in the schedule of cotton 

 destruction planned by the Government for Montserrat [R.A.E., 

 A, ix, 99]. 



Williams (C. B.). Report on the Froghopper Blight of Sugar-cane in 



Trinidad. — Mem. Dept. Agric. Trinidad & Tobago, Trinidad,. 

 no. 1, January 1921, 170 pp., 11 plates, 32 figs. 



Sugar-cane in Trinidad is cultivated over some 78 square miles, and 

 for many years has been considerably damaged by outbreaks of frog- 

 hopper blight, which consists of browning and drjing-up of the 

 leaves and a consequent check to the growth of the plant. Tomaspis 

 saccharina (sugar-cane froghopper) is almost invariably abundant in 

 blighted fields, as well as various root fungi, and both have been 

 held responsible in varying degrees for the damage. The injury 

 usually appears about six weeks to two months after the wet season 

 begins" ; the canes stop growing, and the leaves wilt and are streaked 

 with brown marks. They show some recovery after a few weeks, but 

 are frequently subject to a second, and perhaps a third, attack at 

 intervals of about two months. The nature of the blight and its- 

 connection with T. saccharina are discussed. Each puncture of the 

 froghopper on a leaf causes an injury that spreads ; the roots are 

 damaged by the sucking of the nymphs, by the root fungi usually 

 associated with the blight, and by the unfavourable soil conditions 

 nearly always found in fields liable to attack, and injur}- to other 

 parts of the cane occurs as a natural consequence. The greatest 

 intensity of the blight is about two to three weeks after the maximum 

 abundance of froghoppers, but the total damage varies greatly from 

 year to year and from place to place. 



The various froghoppers occurring in other countries are enumerated.- 

 T. saccharina is only known from Trinidad, Grenada and possibly St. 

 Vincent ; it is almost certainlv native to Trinidad. Feeding on the 



