330 



THE AC.IHCULTURAL NEWS. 



OCTOBER ( .t, 1915. 



INSECT NOTES. 



THE ACROBAT ANT. 



Amongsl the matters receiving consideration on the pari 

 of the Entomologist of the Imperial Depar! nl of Agricul- 

 ture during his recent visit to Grenada was the small ant 

 known as the Acrobat ant (Cremattogaster sp.\ which it 

 is suggested may possiblj become troublesome in cai 10 

 fields in that colony. This insect, or perhaps a closely 

 related species "I the same genus, was described in the Agri- 

 cultural Newf, Vol. XIII, p. 298, for Si r 12, 1914. 



The acrobat ant i- a small black or very dark-brown ant 

 which lives "ii trees and other places, and is characterized by 

 the habit as it were of turning up its abdomen over its 



This insect was found to be abundant in different parts 

 nl the island, and. from what could be learnt, during a recei 

 visit to Grenada by the Entomologist of this Department, 

 the opinion was formed that it is well known to planters and 

 that it occurs all over the island. 



It was noticed that the insect often occurs in great 

 abundance on a small, well delincd area, and that at 

 a distance of a few yards there are.none to he found Not 

 many places were seen in Grenada where the acrobat ant 

 was actually doing much harm, but from what was discovered 

 in other ways, and from what is known of the Barbados 

 acrobat ant, the insect is to be regarded as possessing bti 

 possibilities of becoming a cacao pest in the future. It 

 would seem likely that the acrobat ant may become the most 

 serious pest in Grenada. Some of the features in the 

 economy of this insect which make this outcome seem 

 possible are the following: — 



i."i WION OF THE NESTS. The nests of this species are 

 formed in crevices of the bark or wood of living 

 trees, in or upon dead trees, in fences and outbuildings. 

 Broken or splintered wood resulting from bad pruning, 

 loose bark from the same cause, a leaf adhering to the 

 surface of the bark — all these give nesting opportunities 

 to the acrobat ant, while the central pith in a cut branch or 

 the burrows or tunnels of boring insects are specially 

 attractive to them for the purpose. 



sizr: OF THE NEST OR colony. The acrobat ant lives 



in very small colonies. Often the nest is no more than the 

 collection of a tew workers, eggs, larvae, pupae, and of course 

 one or more egg laying females located under a leaf or portion 

 of bark. The destruction of nests or colonies when they air 

 90 Small, SO numerous, and SO well protected, would p 



enormous difficulties in attempting measures < f control. 



method of i K i : i > i n < . . This species of ant damages 

 directly. The ants get into cuts made by pruning, and into 

 wounds made by boring insects, especially when the bast ;nnl 

 cambium are exposed, and they seem to feed there in such 

 a manner as to prevent these cuts and wounds from healing 

 over. 



iSSOCIATlon nun other iNsKiis. In nearly every 

 instance where the acrobat ant was noticed On cacao in 



Grenada, it was associated with the mealybug {Pieudo 

 dtri), and inmost cases where the mealy-bug was seen the 

 acrobat ant was also present 



The only remedial measures which seem practical at 

 present have lo do with better pruning and care of the oacao 

 trees with a view of eliminating breeding places of the ant as 

 far as possible, and of preventing the dama ;e resulting From 

 the feeding of the ants on cambium and bast tissues. 



The cara,o tree would seem to lee protected from this ant 

 by nature, since its hard, smooth bark offers very little i 

 tunity for its neMs. Trees with a rough scajj bark, like 

 mahogany for instance, are very suitable lor this purpose. 



In this connexion it in 13 be stated that while on certain 



estates evidences of excellent pruning methods and g I care 



of trees were Been, other cacao trees wen- observed which were 

 much neglected in this respect: dead stubs, cavitiesof all sizes 

 resulting from borer attacks which had been neglected or 

 badly treated, or from the lotting out of cut stubs or broken 

 bran, lies, being much in evidence. This condition is favourable 

 to the an f. and all well-directed effort toward better care ot the 



trees will have an effect in reducing the numbers of this insect. 



It was judged from what was seen that the cacao 



planters require some dressing for wounds made in pruning, 



more efficient than anything they have at present. The 



Sects o good pruning are lost to some extent because the 



dressing used does not protect the wood until it heals over, 

 and the wood rots out: cavities are thus produced which tend 

 to shorten the life of the tree. At the present time, lead 

 paint, coal tar, and rosin oil, to which tar is added to urn- 

 colour, aie the' wound dressings used on cacao toes. It is 

 suggested that trials might be made with Solignutn carboli- 

 neuui and similar wound preservativi -. 



HAH. 



NOTES FROM CROWN COLONY REPORTS. 



The Annual Reports on the Crown Colonies for 1913-1 I 

 have just been received. Most of the information contained 

 therein dealing with West Indian agriculture has already 

 appeared in past numbers of this Journal. Most of the fol- 

 lowing matters, however, have so far not received attention. 

 In the report on British Guiana it is stated that there is 

 room for considerable development in regard to fisheries in 



everal directions, especially in sea fishing, curing with the 

 aid of ice and smoking. Salt cod, herrings, and mackerel are 

 imported in quantity but no colony fishes are cured. During 



MM.". 1 1. Ssl glue or isinglass from the gilbaker was export- 

 ed to the amount of 15,197 lb. value £1,286 \:u. |7. 



In connexion with the export of agricultural produce from 

 British Honduras, the report on that colony states that all 



the bananas exported went to the United States, the rum to 

 the Republic of Honduras, the sugar to Mexico, and the 

 tortoise shell to the United Kingdom. It may be noted that 

 938 barrels of grape, fruit and 8 barrels of oranges were 



exported to the United States. They were not in isider- 



able shipments of sponges and tortoise sholl, the amount 

 being in 1912, 10,488 It', and 3,627 lb., respectively. There 

 was a large decrease iii the export of sponges in 1913 but an 

 increase in the turtle shipments. 



Interesting li_ givi n in the Trinidad and Tobago 



report concerning the export of mineral oil. In 191 1 the value 

 of the exports was £32,839, which rose to £75^20 in 1913. 



A considerable quantity was consumed locally, either as fuel 

 in 'he sugar factories or, alter having been refined, a- petrol 

 and kerosene. A section of interest in the Report is thai 

 devoted to the subject of Crown land. It is stated that 

 the price of Crown land is i"-' It's, per acre, including 

 the cost of SUrvej and other charges, and it is sold to 

 the applicant without competition. The work of reafforest- 



ing the Crown reserves ( tinuc to be actively carried 



on, and the operations of the department are growing 

 so extensively that it has been Found necessarj to make 

 provision for the appointment ol an assistant forest Officei 

 An interesting feature of the statistics in the Grenada 

 report is the information showing the distribution of e 

 The United Kingdom and British Coionies took 62 and - 

 per cent., respectively. To the. United Slates 24 p 



the exports was sent. At the i lusion of the report the 



Colonial Secretary adds the following note of warning: 

 Grenada depends for its prosperity, almost for its existence 



