122 



THE AGRICULTURAL NEWS. 



Ai'RiL 12, 1913. 



INSECT NOTES. 



ROOT BORERS AND OTHER GRUBS 

 IN WEST INDIAN SOILS. 



As was promised in the last issue ol the AijricuU'ural 

 Jicirf, the account of boring insects belonging to the group 

 iiliVLCoijhoia. is now continued as follows: — 



The root borer of the sugar cane in the Leeward Islands 

 (H.'/jp/il/ialmiis i.<i(7'jV«s). Reference: Agricultural Kefs, 

 Vol. XI, p. 298. 



In a few instances in Antigua and frequently in 

 one locality in St, Kitts a weevil grub has been found 

 •attacking mature canes in a manner exactly similar to 

 that in which the larvae of Diaprepes alibreviatits attack the 

 .same plant in Barbados. The larva found in the Leeward 

 Lsland.* is similar in general appearance to that which occurs 

 JQ Harbados, but Diaprepes is not known to exist either in 

 J5t. Kitts or Antigua. In these islands, however, a weevil 

 yE.iopjhllialiiius c-siirieiis) is to be found very commonly among 

 '-.be le:ives of pigeon peas, castor and French silk cotton 

 (t'alohofis sp.) Exophthalmus compared with Diaprepes 

 is somewhat smaller, and of a uniform greyish brown colour 

 'in contrast to the handsome markings of the latter. The 

 relationshiji as adult and larva of the same species, between 

 •his weevil and the root borer of the cane iu the Leeward 

 Islands has not been proved, but the evidence so far available 

 .strongly indicates this relationship. 



The eggs are laid in the same manner as, and greatly 

 resemble those of 1 liaprepes, and when deposited on leaves of 

 castor, are protected by a fold of the leaf stuck down in the 

 same manner as in the case of Diaprei)es. The eggs of Exoph- 

 thalmus have not been ob.-ierved on leaves of .sugarcane. 



E.'Oplillialiinis esuriiiis occurs in St. Kitts, Nevis, 

 Antigua, Montserrat and l)ominica. 



The extent of the injury caused by the attack.s of root 

 borer on canes in Antigua and St. Kitts is not known, but 

 the fact that planters generally are not aware of the presence 

 <,i this insect in their fields, would indicate that this is not 

 great at the present time, although it is probably greater than 

 is suspected. The first observations recording the attacks of 

 this insect ajipear to have been made by the Entomologist 

 <>a the statf of the Imperial 1 )epartment of Agriculture, in 

 Antigua in 1911, and in St. Kitts in 1912. It is very 

 probable that thi.s insect will prove a more serious pe.sl in 

 later years than it has done in the past, and also that when 

 planter.s learn to recognize this form of injury, it will be 

 found in many instances to arcount for what has in the past 

 ■jften been attributed to the effects of drought and the 

 ravages of fungus disease. The insect now known as 

 J'^opldlialtiius c.mritns was formerly referred to in the 

 publications of the Imperial Department of Agriculture as 

 J-'picaerus raridiis, especially with reference to its occurrence 

 in Montserrat where it is abundant, and has attracted attention 

 from the fact that the adults are often to be found on lime 

 trees, feeding on the leaves. This insect is known in 

 .Montserrat by the common name of hard-back. 



No para.site ot the root borer in the Leeward Islands is 

 known. The method.-^ of control to be used against this 

 insect in the event of a severe attack would be the same as 

 -hose suggested in the case of /)i>i/Trj,rs a'jOrci iaius in 

 Barbados. 



The fiddler beetle {FraepoJcs niiulus). Jtelerences: 



'.l;/rHiiltiind Ki'Wi, \'ol, IV, p. 316: Jlull'/in of the DejKtrt- 



,i-nt o'J.'//(C(///i(7(, Jamaica, November lUO.'J, October 1905. 



The fiddler beetle is a large weevil, marked with black 

 •nd white stripes on the wing covers (one variety has a red 



stripe down the middle, of the back). The larvae attack the- 

 roots of orange trees in Jamaica, often girdling them am* 

 thus causing their death. This is similar in kind to the- 

 attack of l)iaprepes grubs on cacao in St. Lucia, already 

 mentioned. 



^'arious methods Jjave l^een suggested for dealing witb 

 the fiddler beetle, chief among which are the following: 

 Avoid planting too deep, and do not cultivate provisions or 

 similar crops between the orange trees, since the open nature 

 ot well tilled soil otlers easy opportunity for the beetles to 

 penetrate into the ground and gain access to the roots. 

 l-'rom what is known, however, of the strength of similar 

 insects in both larval and adult conditions, and their ability 

 to penetrate hard, closely packed soil, this last would .seem: 

 to be only a mild preventive. 



The fiddler beetle is said to be parasitized by a large- 

 black wasp {El)s atrata). This insect belongs to the Scoliidafc, 

 a family of solitary, burrowing wasps, which lay their eggs 

 on or in the bodies of certain soil-inhabiting grubs, after 

 these have been partially paralyzed by stinging. 



The golden weevil or orange leaf weevil {Diajoepet 

 spenc/leri). References: Aaiicultural A'eff, Vol. II [, p. 202: 

 Annual Reports, Porto Rico Experiment Station, ly05, 1906, 

 1907. 



This insect in size and shape is very similar tCK- 

 I) ahbreviaiu^, the root borer beetle in Barbados, but its 

 bright golden 3-el!ow colouring distingiii-hes it at once. 

 D. .y't'ii^/leri seem.s to be known only in St. Vincent and 

 I'orto Rico, and in both these places only the adults are- 

 recorded. The larvae and their food and feeding habit are- 

 apparently unknown in St. Vincent. In Porto Rico, the- 

 larvae attack the roots of the orange, and also feed on roots 

 of guavo, avocado, mango and rose. The adults are notice- 

 able from their habit of feeding on the leaves of certain plants,, 

 among them limes and other citrus trees, pigeon peas, castor 

 and several cruciferous plants. In Porto Itico, the injury tc 

 orange trees caused by this insect has been especially notice- 

 able on young trees newly planted out, and at times this has 

 been sutficiently severe to render advisable spraying witb 

 arsenate of lead. 



In the Virgin Islands, a small yellow weevil (see A;iricul- 

 iiiral N'eics, Vol. XI [, p. 42) seemingly related to IHaprfjtes 

 .yienc/leri is known to occur, and in .Montserrat one specimens 

 of a species has been found, closely related to D. a/'breviatitf. 

 Nothing more appears to be known of these two insects 



In the next issue of the A'lricullural Xci".* the continua- 

 tion of the present subject will concern the family of beetles 

 known as hardbacks. 



THE BALSAM TREE OF VIRGIN 



GORDA. 



The attention cff this Department was first called to the 

 interesting characteristics of the Balsam tree by the Hon. 

 W. H Porter, 'J'reasurer of Dominica, who wrote in August 

 1912 as follows: 'There grows at the famous natural baths at 

 Virgin ( Jorda (in the Virgin Islands) a small tree known locally 

 as balsam which resembles in character 'cashew', and is to my 

 knowledge well over fifty years old. It grow.-- amongst the 

 enormous boulders which forms the "baths" (at some distance, 

 as far as I can ascertain, above the ground) and has ar. 

 enormous root system striking down to the sandy soi3 

 beneath The leaves are rather fleshy when growing, and 

 visitors to- the baths usually record the event on the leaves^ 

 for the benefit of persons coming after. I plucked some 

 such inscribed leaves, still green and fresh eighteen months 

 after the date appearing on them. In the dry climate ot 



