3U 



THE AGRICQLTURAL NEWS. 



September 28, 1912. 



INSECT NOTES. 



ENTOMOLOGY IN TRINIDAD. 



At the meeting of the Board of Agriculture, Trinidad, 

 In July last its Entomolgist presented a report coveriDg his 

 ■work during the time since the previous meeting. The 

 report dealt principally with matters relating to the occur- 

 rence of the froghopper {I'o/iia^/n's varia, Fabr.) on a number 

 of estates, and showed the difference in the abundance of 

 •this pest where different treatments had been applied. In 

 those localities where the fields were burned after the canes 

 had been cut and the surrounding traces were also burned, 

 there were few froghoppers and only a small amount of spittle 

 to be seen. In those fields which were burned over while the 

 canes were still standing there were at the time of the report 

 more froghoppers than under the preceding conditions. In 

 those localities where no burning was done, that is where 

 infe.sted fields and traces had gone untreated, froghoppers 

 were numerous, spittle masses were abundant and the canes 

 ■were beginning to show signs of injury already. 



The froghopper fungus {Metanliizium amsopliae) 

 ■appeared to be doing good work on the two estates where 

 spores had been distiibuted in the previous year. The use 

 of lime and sulphur applied dry was being tried as a remedy, 

 but it was too early to say what the result of the trials 

 ■would be. 



The Mexican predaceous bug (Castolus) had been dis- 

 tributed to seven estates, where they had been observed 

 .since their liberation in the field. These in.sects seemed 

 quite at home, and were found to be attacking the adult 

 froghoppers. 



^ Attacks of the cotton worms and the corn ear worm 

 are recorded, and it was suggested that these insects could 

 be killed by the use of arsenate of lead, applied either as 

 a dust, or as a spray. 



A note was also given on the ufe of formalin for the 

 destruction of house-Hies. The method suggested was as 

 follows: 1 part of formalin in k mixture with 6 parts of 

 condensed milk and water. This is exposed in saucers. 

 A few pieces of bread are put into the mixture to provide 

 places for the ffies to alight and feed. This method is 

 .similar to that mentioned in the Afjrkultural Juries, Vol. XI 

 p. 58, where an account was given of the successful use of this 

 method in South Carolina. In this latter instance formalin 

 was used in water and in a mixture of milk and water. It is 

 mentioned that in Portof-.Spain the principal breeding 

 places for the house-fiy are horse manure heaps. Careful 

 attention to the removal of their breeding places will have 

 greater effect in i educing the numbers of these insects than 

 .any methods of killing or capturipg the adult tty. 



The A.ssistant Entomologist reported on the method of 

 trapping the cacao beetle by m«ans of pieces of thick bark 

 from the trunks of the Chataigne Maron {Pacliira aquatica) 

 placed in the forks of the cacao tree or against its trunk. 

 The eggs of the beetle are laid in these pieces of trap bark, 

 which dries in a short time and causes the death of the eggs 

 or of the young larvae which niity have hatched from them. 

 (See also ]]'esi India,) Jiulht.in, Vol. XII, p. 311.) 



At the meeting of the Board in August and September 

 the froghopper situation was di.scussed at length, and at the 

 (lose of the latter of these meetings a committee was 

 • ppointed to investigate the whole matter of froghopper 

 rontrol in that island. 



During the discussion of the question of the abundance 

 ■f the froghopper a diversity of opinion was shown to he held 



by members of the" Board. Certain influential planters 

 maintained that no improvement was to be seen on those- 

 estates where the recommendations of the Board's officers had 

 been carried out. The officers of the Board however showed 

 that the introduced Mexican bug was actively engaged in 

 destroying the froghoppers and that the fungus was more 

 abundant where the spores had been distributed than in 

 other localities. The long continued drought earlier in the- 

 year had helped to make the froghopper conditions very 

 bad, but experiments and trials in methods of control were 

 being continued. 



The Director of Agriculture stated to the meeting that 

 he was making trials of nitrolim, a nitrogenous manure- 

 which he hoped would prove of value as possessing certain 

 insecticidal properties,' which would be effective against the- 

 froghopper. 



The result of the pfforts in Trinidad to control the frog- 

 hopper will be awaited with much interest in all sugar-pro- 

 ducing countries where this pest is likely to occur. The 

 experiments with the froghopper fungus and the Mexican 

 predaceous l)ug as natural enemies of the froghopper are 

 likely to have important results. The practice of cleaii 

 cultivation, and the burning of trash and the grass on the- 

 traces, are also likely to result in definite improvement when 

 they have been tried over a series of years on a fairly large 

 scale. 



The question as to whether the froghopper fungus wilfr 

 attack the ^Mexican bug and thus interfere with its pre- 

 daceous activity is one that time alone will answer. 



The Brown Hardback.— In a recent number of 

 the Ac/rictiltiaal ]\'ews(see\o\. XI, p. 298), mention was made 

 of the brown hardback {Plu/talnn smithi, Arrow.) which has^ 

 appeared in such extraordinary numbers in Mauritius. In the 

 BuUetin Agrirole, ^lauritius, for May 1912, a brief account of 

 the occurrence of this insect is given, with mention of the prin- 

 cipal points in its lifehistory. This information is takecs. 

 from a report submitted to the Government by M. D. 

 d'Emmerez de Charmoy. It is shown that the life-cycle of 

 this insect occupies a period of from 405 to 648 daj-s, of 

 which from 265 to 333 days are spent in the egg, larvaS 

 and pupal stages. 



As already stated in the A(jricultuval Noes, the total 

 number of beetles collected in the campaign against this pest 

 from August 1911 to April 1912 amounted to over 26- 

 million. The greatest number captured in any one day, or 

 rather night, was nearly three million, taken on December 14. 

 In the report under consideration, the weights are given for 

 these enormous numbers of insects. It appears that the 

 total capture was equal to a weight of 15 metric tons, 800 

 kilos , or about 20 long tons. The weight of the insects 

 captured on December 14 was 700 kilos., or about 1,540 If>. 



Antis;ua at the Canadian National Exhibi- 

 tion. — Mr. H. A. Tempany, B.Sc, Superintendent of Agri- 

 culture for the Leeward Islands, has sent information to the 

 effect that the material representing Antigua on the occasions 

 of the present holding of this exhibition comprised eighty- 

 nine separate exhibits, including samples of sugar, molasses, 

 cotton, and lime juice and other minor products, together 

 with native curios, picture post cards, and ornamental andl 

 decorative material. A small illustrated pamphlet, dealinsi 

 with useful general matters relating to Antigua, was also» 

 issued by the Permanent Exhiliition Conmiittee for distribu- 

 tion at the exhibition. 



