THE AGRICULTURAL NEWS. 



Febkuaky 20, 1909. 



INSECT NOTES. 



Flower-bud Maggot of Cotton at Antigua. 



It will be rciiiemhered that the insect resjion-sible 

 for Hdwrr-ltml (lin|i|pnig of cotton at Antigu.a has again 

 made its appearance in the present season. Some 

 account ofthe insect, with illustrations, appeared in the 

 Agricultural Neirs of January 9 last, and in the same 

 issue it was mentioned that Mr. Ballou, Entomologist 

 to this Department, had gone to Antigua for the 

 purpose of making investigations in connexion with the 

 attack of this pest. 



The following is Mr. Ballou's report on his visit: — 



One object of the work of investigation was to discover 

 if possible the plant or plants other than cotton (wild or 

 cultiviited) in which the tlower-bud maggot may live and 

 breed. In the report on my visit to Antigua in November, 

 it was stated that both Mr. Jennnett and myself had made 

 careful search for this insect, but did not succeed in finding 

 it, though Sea Island cotton was e.xamined in several fields, 

 and the wild cotton at -Judges (Blizzards). 



On my arrival at Antigua, one of the first things I did 

 was to pay a visit of examination to the wild cotton mentioned 

 al>ove, and the tiower-bud maggot was at once found, and in 

 considerable i|uautity. 



Examination of other plants then in blossom in the 

 immediate vicinity led to tlie discovery of a Cecidomyiid 

 larva in the tlo\ver-buds of the Privet or ' Wild Coft'ee ' 

 (Chrnihiuh-on iwuleatiim). I was not able to determine 

 whether this was the same as the flower bud maggot of the 

 cotton by comparing the maggots, so I collected a large 

 quantity of flowers and buds of the plant from the hedge 

 surrounding the Hotanic Station. These were placed in 

 breeding jars at the laboratory, and from them I reared two 

 (or three) different Cecidomyiid flies, one of which is 

 apparently identical with the fly which is the adult of the 

 flower-bud maggot of the cotton. 



In order to obtain further proof as to the identity of this 

 insect, e.xperiments have been .started at the Botanic Station, 

 with the object of producing an attack of fluwer-Vxid maggot 

 on cotton directly from the insect in the flowers and buds (if 

 the Privet. This experiment is not flnished. 



In connexion with this portion of my work the flowers 

 and flower-buds (in some cases two or three lots) of some 

 eighty-four ditt'erent plants have been examined. I am 

 indebted to Mr. Jackson for having mo.st of these collected 

 by persons connected with the Botanic- Station. 



The exi)erimeuts started during my visit to Antigua 

 last year gave no definite results, perhaps because the attack 

 of the flower-bud maggot was on the decrease at the time the 

 experiments were started, and perhai)s because of the drought 

 which set in soon after, and stopped the flowering of the plants. 

 .Similar trials have been started again and are at present in 

 progress. These may give residts later which will suggest 

 <lireit remedial measures. 



The experiments are established in two jilaces. There 

 are five [ilots in the field of cotton at the Old Hospital, each 

 About y\f acre, which rcceiveil the following api)licatioiis of 

 manure : No. 1, suli>hate of ammonia ; No. 2, sulphate of 

 ]K)tash ; No. ."5, Vaporite ; No. 4, nitrate of soda ; No. 5, 

 "V'i-phosphale. These plots were established with the consent 

 r)f Mr. Fishre, who detailed Oflicer Maynard to assist in 

 carrying out the work. At McKinnons there are seven 



plots established with the consent and co-operation of 

 Mr. J. Koden, and the active assistance of Mr. Halpike. 

 These plots are about J^ acre, and received a[iplications of 

 manure as follows ; — No. 1, sidphate of pota.sh ; No 2,. 

 sulphate of ammonia ; No. 3, nitrate of soda ; No. 4, super- 

 phosphate ; No. .5, Vaporite ; No. 6, Vi-phosphate : No. 7^ 

 salt. In both these series the applications consisted of 20 tti.. 

 of each substance, except in the case of No. 7 at .Mc Kinnons,, 

 where only 10 tt). of salt were apjilied. 



Previous to my arrival in Antigua, Dr. Watts had giveni 

 Mr. Robert Goodwin 100 B). of Vaporite for use at Greys,, 

 where the flower-bud maggot had made serious attack. This- 

 was applied to 1 acre of cotton, and at the time of my visit 

 to this estate (Feb. 2), the cotton field treated with Vaporite 

 showed a greater proportion of flowers than any other field 

 on that estate, and it was decided that it would be worth' 

 while to make more extended trial of this material. With- 

 this end in view, Mr. Tempany, Acting Su|ierintendent of 

 Agriculture, sent out a circular letter to a limited number of 

 representative planters asking if they wished to make a trial 

 of Va|)orite and ottering lOu It), of this material to each one,. 

 with directions for applying it. 



In combating insects closely related to the flower-bud 

 maggot it has been found that applications of mineral ferti- 

 lizers have had a decidedly benertcaal efi:'ect, not only front 

 their usefulness as manures, but from the ettect ofthe mineral 

 salts in solution in the soil. How much ettect these may 

 have on the flower-bud maggot is very problematical, but 

 they are considered worth the trial. 



I noticed that the parasitic Hymenoptera which were 

 abundant in Feliruary and March 190S, w-ere much less- 

 numerous during .January 1909. 



In nearly all the cotton fields I visited, I noticed that 

 the youngest bolls then existing on many of the plants must 

 have been formed about the middle of Decendier. That is to- 

 say, the attack of the flower-bud maggot nnist have become 

 sufficiently severe about that time to jirevent the later 

 development of flowers and bolls, and for the most 

 part there had been no bolls developed from that time- 

 up to the first week in February. In most cotton fields 

 1 noticed that the fallen flower-buds were not so numerous 

 as the small bolls or ' form.s,' which appeared to have- 

 drop|ied within I wo or three days of the opening of the flower 

 and the shedding of the corolla. I do not feel sure th.it 

 I should be quite correct to lay all that to the charge of the 

 rtower-bud maggot. The shedding of the corolla is a 

 perfectly normal circumstance, but the dropping of bolls is 

 abnormal. Whether these bolls were dropped because they 

 were unfertilized I cannot say, but I believe that this was 

 the reason in many cases. Further, I cannot say whether 

 they w-ere unfertilized because the flower-buds from which 

 the bolls were being developed stitt'ered attacks from 

 the flower-bud maggot, but this was probably the reason in 

 most cases. 



As already stated, very fi-w liolls were developed from the 

 middle of December to the first week of February, aud as 

 a (oiisequence the top of the (dantsfor some 12 to 18 inches, 

 with the developing laterals from this amount of growth, was 

 ipiite unprodnctivi- of bolls, and I believe that most of this. 

 was due to tin- l|ouri--bud maggot. 



In past years the drop(iing of these very small bolls has 

 been ascribed to the weather, and in a .sen.se this may be 

 correct, for there seems to be a definite relation between 

 certain weather conditions and the attacks of the flower-bud 



