367 



out by Mr. A. A. Rumsay, Assistant Chemist, Department of Agricul- 

 ture, N.S.W. The specific gravity of hme-sulphur solutions as an 

 index of sulphur and lime content, the ascertaining of the specific 

 gravity by means of either the Baume or Twaddell hydrometer, 

 and the method of diluting stock solutions, are concisely and clearly 

 dealt with. The hydrometer is described, and there is included a 

 table, ranging from 2° to 35° Be. (2-8° to 64° Twaddell), which shows 

 the number of gallons and pints of water required to each gallon of 

 stock solution of varying density in order to produce sprays of 

 " summer " strength of approximately 1° Be., " winter " strength 

 of about 3|° Be. and " Citrus trees " strength of about 1|° Be. 

 Experience AAath Ume-sulphur at the various departmental orchards 

 has shown that, for winter application, 1 in 7 is the greatest strength 

 that should be apphed. 



Urich (F. W.). Entomologist's Report. — Minutes of Meeting of the 

 Trinidad Bd. Agric. no. 2. 17th February 1915, p. 8. 



During a visit to the Mitan district no cacao beetles {Stirasloma 

 depressum) were observed and thrips were only present in numbers 

 too small to cause injury. At Chatham, on the contrar}^, cacao beetles 

 were very numerous. Parasol ants {Atta cejyhahtes) having been 

 proclaimed a pest under the Plant Protection Ordinance, it should 

 be noted that the best time to destroy their nests is from February 

 to May, or just before the rains commence. It is necessary to destroy 

 the nests before the flying forms appear, or they will scatter and found 

 new colonies. 



Urich (F. W.). Cassava Insects. — Bull. Depl. Agric, Trinidad and 

 Tobago, Port-of -Spain, Trinidad, xiv, no. 2, 1915, pp. 38-40. 



Lonchaea sp., the bud maggot, is the most important insect pest 

 of cassava. The eggs are laid on the buds, and the larva bores into 

 the soft tissues of the growing point, which it completely destroys. 

 Pupation takes place in the ground. In Cuba, the larval period 

 occupies 23 days, the pupal period, 26 days. The best control measure 

 seems to be to cut and burn infested shoots. A small mite frequently 

 causes the leaves to become dwarfed and spotted ; the under surface 

 of the leaves should be sprayed with a weak solution of lime-sulphur. 

 Erinnyis ello, the cassava hawk-moth, is kept in check by natural 

 enemies ; Telenomus sp. destroys the egg, while Microgaster sp. is 

 parasitic in the larva. Lasiopteryx sp., the gall midge, deposits its 

 eggs in the cassava leaves, but is kept in check by Hymenopterous 

 parasites. Corynothrips sp. has been found on the underside of young 

 leaves, but not in sufficient numbers to cause any damage. It is 

 controlled by a parasitic fungus, probably an Entomophthora. The 

 cassava lace-wing bug and parasol ants {Alia cephalotes) have been 

 recorded on cassava, but only the latter do serious damage. In 

 Cuba, the follomng pests are important : — -The Longicorn beetle, 

 Lagochirus obsoletus, burroAxnug into the growing stems, and the 

 larvae of Lonchaea chalybea and Erinnyis ello. In St. Vincent, 

 Corythuca sp., Frankliniella sp. and Corynothrips have been observed 

 on cassava ; in Southern Nigeria, a locust, Zonocerus variegatus, has 

 been known to defohate the plants. 



