13S 



THE AGRICULTURAL NEWS. 



May 6, 1905. 





INSECT NOTE. 



Termites or White Ants. 



Few insects in the tropics do greater damage to 

 property tban the termites or, as they are more commonly 

 called, 'wood ants,' or ' white ants.' 



In reality the termites are not ants, as the term is 

 usually applied, but are more closely related to the dragon- 

 flies. They have, however, a social arrangement in their 

 coh'nies similar to that found among the true ants, and it is 

 proV.aMe that for this reason these insects were called- ant<. 



There are many instances of the destructiveness of the 

 termites, and probably every resident in the tropics has liad 

 prciof of the rapidity with which these insects work. They 

 arc rdl miners in habit and carefully avoid the light. "When 

 it becomes necessary to come to the surface of the ground or 

 to travel on the outside of tree trunks or timbers, they build 

 covered ways in which they travel. They live upon the fine 

 particles of the material in which they tunnel. In addition 

 to destroying timbers and other wood-work of houses. 

 bridges, posts, fences, furniture, picture-frames, books aud 

 papers, they also attack living plants. In Florida, orange 

 and other trees have been damaged by termites girdling them 

 below the surface of the ground ; in ( icorgla they have 

 injured potatos in the ground ; and in Rarbado.s, Ipomoea 

 plants have been destroyed by them. 



Termites are very difticult to combat especialh- after 

 they are established. It the location of the nest is known, 

 the insects can be killed by the use of creosote or any 

 creC'Sote mixture, kerosene, or carbon bisulphide. The 

 co\ered ways should be destroyed wherever seen. 



Timbers for posts or for use in buildings should be 

 treated with tar, creosote, or some other preservathe. 

 wherever they are to come in contact with the earth or 

 masonry walls. Chairs should not be allowed to lean up 

 against the walls of the houses, and books, picture-frames. 

 etc.. should be freipiently examined and exposed to light and 

 air. and when found infested with tliese pests, they should be 

 pioiiptly treated as suggested above. 



IMMUNITY OF BARBADOS FROM 

 MALARIA. 



A note appeared in tho hist issue of tlie A'ji-i- 

 ctdlu7\il Neu's in wbicli it was mriitionod that 

 a theory had been propounde<l by Mi: V. Kendrick 

 (libbons, of Collynns, Barbado.s. tlial the iinuiunity of 

 Barbado.s from malaria was due to the presence 

 in the swamps and ponds of tlie island of large 

 numbers of tiny fish, known as ' millions.' Tlie 

 A I'djilirlc-i mosquito, the carrier of tiie malaria 

 parasite, is not present in Barbados; tlie conuuon 

 inosqnitcs found in tliat island are Ct'Ir.r /('-liu""-'^ and 

 iStci/iimyiii /((■•<ci<il'i. The following is a letter tliat has 

 been received on tliis subji-ct from Mr. (libbons: — 



In your issue <>f Aiirll L'-, you call attention ti> 

 a weak point in my theory, which you saj- aj^pears to 



have escaped notice. The particular weak point alluded 

 to exists only because the writer assumes that the habits 

 of the Anopheles, the Ctdex fatii/ans and Ste'joinyia fasciata 

 are snnllar, which does not appear to be the case. I do 

 not attribute any selective action to the ' millions,' our ])onds 

 and swamps are free from the larvae of the CuUcidae 

 generally, if any variety deposit their eggs therein, no doubt 

 their larvae are destroyed by the fi.sh as effectually as are the 

 larvae of the AiKi/'Iir/c): : assuming the Anoj'lii'fcs Is imported 

 here, which I think highly probable, there is nothing in my 

 idea, if it is not, and the immunity of Barbados from malaria 

 is due to something else. Hut while the Cnfcr and Stcijonu/ia 

 avail themselves of tanks and other recei>tacles for water, to 

 deposit their eggs in, where the 'millions' do not naturally 

 exist, and so perpetuate their species, the Aiiophrfcs do not 

 appear to do so. To quote ^Major W. M. Hodder, R.E — 

 by the by, whose phamphlet on the Dcstrm-tion of 

 Mvsijuitus is reviewed in this very issue — who states 

 in his chapter on the habits of moscjultos, that the Culex 

 'breed lu gutter.s, water tanks, and filthy pools in back-yards 

 with equal facility. Their larvae can be found in the 

 gutters of high buildings or on the ground level. So 

 far as my observation goes, .such is not the case with 

 the Anopheles; they do not deposit their eggs anywhere 

 except close to the ground level. I have examined 

 hundreds of tanks i or 5 feet above the ground, but in 

 not one single instance have their larvae been found therein, 

 although the tanks wei-e actually stan<liiig on the ground 

 vliere these mosqultos lived.' 



It is obvious if the habit of the Awfihrlcg only permit 

 them to deposit their eggs in water on the ground level, and 

 that water abounds with fish which destroy their larvae, that 

 that variety of mosqultos must be exterminated lu that 

 locality. 



Mr. Gibbons is of the opinion that the note in the 

 Agrlcidfurid Neirs, to which he refers, indicates that 

 the writer assumed that the habits of the various kinds 

 of moscpiitos arc similar, and goes on to j)rove that this 

 is not the case. Literature on this subject shows that 

 observations made in different parts of the world 

 indicate that AixijiJtcles is very rarely found in vessels 

 of water, fiower pots, and such receptacles in which 

 Cuter is usuall}^ to be seen. This point of difference 

 appears to be generally recognized. The point of 

 difference upon which Mr. Gibbons lays special stress, 

 however, is that Anapheles is not found more than 

 a few feet above the ground-level. If Major Hodder's 

 observations on this point are borne out in other parts 

 of the World, the criticism w'ould therefore be disposed of. 

 Mr. Gibbons' argument is that Culfx and 

 Sfcyoitv/ia have not been exterminated in Barbados 

 because they breed in jolaces in which the 'millions' 

 are not likely to be found. That may certainly be the 

 case. But the further argument that these fish are 

 more or less certain to be found in all places that the 

 Anoplid<< would be likely to select as breeding places 

 would appear to admit of considerable doubt. We are 

 of opinion that there ai'e many pools and ponds in 

 Barbados in which Anoi^idcK might breed — ponds in 

 which tlvj 'millions' would not be found. Of the 

 natural breeding places of Anopheles, Howard states in 

 his M(>>:ijV.'l<'-< of the United Statefi: ' Anopiheles will 

 always be found to breed most abundantly in fair!}- 

 permanent stagnant pools of water uninluthited hi/ 

 P.d'\ but more or less covered with srcen scum.' . 



