28 INSECTS INJURIOUS TO SUBTROPICAL FRUITS. 



NATURAL CONTROL. 



Rains. — The heavy summer rains that occur in Florida are directly 

 responsible for the destruction of large numbers of this thrips. 



The author did not observe any natural enemies feeding on tliis 

 thrips. However, as Triylilefs insidiosus Say feeds quite commonly 

 on Heliothrips fasciatus in California, it will probably be found to 

 attack the present species. 



ARTIFICIAL CONTROL. 



Where this insect becomes sufficiently abundant to cause injury 

 to the mango and avocado, it can be controlled by careful spraying 

 with a nicotine extract. IVIi*. Edward Simmons, at the subtropical 

 gardens of the Bureau of Plant Industry, has controlled it during 

 the last two years by spraying according to the following formula : 



Blackleaf tobacco extract gallon . . 1 



Whale-oil soap pound . . 1 



Water gallons. . 50 



First dissolve the soap in a quantity of water, then add the black- 

 leaf tobacco extract and full amount of water and thoroughly mix. 

 This spray should be applied to the trees at a good pressure, so as to 

 thoroughly coat the surface and underside of the leaves. 



Another formula that will give equally good results is the following: 

 Take 1 part of blacldeaf tobacco extract containing 40 per cent 

 nicotine solution to 1,500 to 2,000 parts of water and add 1 pound 

 of whale-oil soap to ever}^ 50 gallons of the mixture and thoroughly 

 spray the foliage. 



BIBLIOGRAPHY. 



1. Broadway, W. E.— Government Gazette of Grenada, no. 139, 1898. 

 The blight of cacao was reported as caused by an insect, but no name was used. 



2. Maxwell-Lefroy, H.— West Indian Bulletin, vol. 2, no. 3, pp. 175-180, 188-190, 

 figs. 1-2, 1901. 



Account of injury to cacao by tliis thrips and remedies recommended. There was no de^scription 

 of the insect itself. 



3. GiARD, A.— Bul. Soc. i^nt. France, pp. 263-265, 1901. 



Original description of female of this thrips under name Physophus rubrocincta, an insect injurious 

 to cacao in Guadeloupe, French West Indies. 



4. Elot, a.— Revue des Cultures Coloniales, Paris, pp. 358-361, 1901. 



Under the name Physophus rubrocinctus the author give^ an economic account of this insect in 

 Guadeloupe. 



5. Editorial.— West Indian Bulletin, vol. 2, pp. 288-289, 1902. 



Short article reviewing that of Elot on Physophus rubrocinctus. 



6. Fawcett, W.— Bul. Bot. Dept. Jamaica, vol. 9, pt. 5, pp. 70-71, 1902. 



Editorial on the article by Maxwell-Lefroy on the cacao thrips. 



7. Anon. — Government Gazette of Grenada, December 31, 1902. 



Brief mention of the cacao thrips. 



8. .Vnon. — Agricultural News for We.st Indie.s, vol. 2, p. 66, 1903. 



Thrips on cacao. 



