142 



EEPOKT OF THE ENTOjrOLOGICAL SECTION 



Technique for 

 poisoning with 

 carbon 

 bisulphide 



" These pieces of wood had not been touched at the time of the third examination, 

 and were as <i;ood and perfect as they were three years ago at the time they were planted. 



" Soapa. — Nothing can be said in favour of soap in solution with water or mixed 

 with other chemicals, as all pieces of wood were eaten. 



"Copper sulphate fBliiestone) . — Only those pieces of wood which had been thoroughly 

 soaked in an absolute copper sulphate solution withstood the attacks of the termites, 

 whereas those pieces which were only slightly treated were eaten. 



" Native woods. — Of all the various native woods which had been used in this test, and 

 which are not treated with any chemicals, the following remained untouched for three years: — 



Six pieces of leadwood {Gomiretvm prophijrulepis) 



Three pieces black ironwood (Olea lanrifolia) 



One piece vaalbosch {Brachijleena discolor)." 



Besides devouring dead wood, white ants not infrequently attack living plants and 

 trees, especially those which from some cause are in a sickly condition. Trees newly 

 transplanted, and cuttings, are often killed before they can become established. In June, 

 1908, Messrs. William Cooper & Nephews, of Berkhamsted, England, furnished these 

 Laboratories with two 14 lb. tins of the soil fumigant Apterite for purpose of experiment. 

 Of these, one tin was handed to Mr. P. S. Sillitoe, Supt. of Gardens, who very kindly 

 undertook to test its value against white ants. The results he obtained were by no means 

 satisfactory, as it neither killed nor drove away the white ants, and in one case a bed of 

 eucalyptus seedlings appeared to be adversely affected by it. The other tin was very 

 kindly taken by Capt. R. C. G. Owen, C.M.G, Governor of Mongalla, who used it to protect 

 newly transplanted trees, and met with great success. 



The Bl.\ck Gaeden Ant 

 Aphienog aster harhara, L. 

 Plate IX., figs. 3 and 4 



This is the large black ant which so frequently selects as a site for its nest some 

 prominent position in a garden, such as a path or a tennis lawn. The nest appears as 

 a low mound with several holes or entrances, from which well-marked tracks lead off in 

 all directions. The ants are very fond of dura grain, and if the nest is situated near a 

 granary they will remove very considerable quantities of this corn every night, to store 

 away in their subterranean chambers. In gardens they damage growing plants by biting 

 off and carrying aw-ay the leaves. 



In cotton fields the localities of their nests are marked by bare patches, devoid of 

 vegetation. One such patch on the Government Experimental Farm at Halfyia, in 1909, 

 conrprised some tw'enty-four square yards. 



Uemedial measure. — The best method of dealing with these insects is to poison them 

 with carbon bisulphide, which should be used in the following way : Moisten the surface 

 soil above the nest by pouring one or more buckets of water over it. Make two or three 

 holes into the nest with a crowbar or pointed stick, to a depth of about eighteen inches 

 (45 cm.), pour into each of these holes and into the entrance holes, one or two ounces 

 of carbon bisulphide, and spread a wet blanket over the nest to prevent the fumes from 

 escaping. After five minutes remove the blanket and apply a lighted match or piece of 

 rag at .the end of a stick to the mouths of the holes — the vapour will explode, shattering 

 the nest and driving poisoirous fumes into every corner of it. As soon as the dull rejjort, 

 made by the exj^losion, is lieard, the blanket should be replaced over the nest and left 

 for half-an-hour. 



