330 



THE AGRICULTURAL NEWS. 



October 11, 1913. 



INSECT NOTES. 



HOW TICKS ARE KILLED IN THE 

 DIPPING OF CATTLE. 



The Ar/riciiltutal .Joiirmil of Ihe Unimi nf South Ajtica 

 ior July 1913, contains an interesting article by H. E. Laws, 

 B.Sc, F.I.C., giving the conclusions arrived at after a series 

 of experiments designed to demonstrate the manner in 

 which ticks are affected by the soluble poison (arsenic) in 

 the dipping mixtures with which tick-infested cattle are 

 treated in t'lat country. 



Three theories have been advanced by different inve.sti 

 gators: The.se are (1) that the tick absorbs the poison through 

 its skin while the animal is passing through the dipping 

 bath; (2) that the absorption of the poison through the skin 

 of the tick takes place after dipping; (3) that the beast 

 absorbs the poison into its .skin, and the tick sucks in the 

 poison with the juices extracted in the process of feeding. 



The experiments are stated to demonstrate conclu- 

 sively, that the method expressed in theory (3) is the one 

 by means of which the poison in the dipping solution is 

 communicated to the tick, and that it is impossible that the 

 poipon should be absorbed in the manner suggested in 

 theories (1) and (2). 



The conclusions seem to be supported by the fact that 

 ticks do not gain weight during the process of dipping or 

 immediately afterward — indicating that no absorption takes 

 place at those times; and further, that when soluble arsenic 

 solutions are injected subcutaneously into cattle, the ticks at 

 the point of injection and within a short radius (about 

 6 inches) are killed, and a sul:)sequent analysis demonstrates 

 the presence of arsenic within the bodies of the ticks. 



It is shown, moreover, that the arsenic taken up by the 

 skin of the cattle does not enter the blood stream, being 

 retained in the lymphatic parts, whence it is extracted by the 

 ticks with the juices of the skin. 



The most efficient arsenic-containing dip is one which 

 penetrates to the skin uniformly on all parts of the body, 

 and it has been found that when the arsenic solution is 

 combined with an oil emulsion this result is best achieved. 



The Same arguments in favour of the arsenic and 

 emulsion combination would apply in the case of animals 

 treated by spraying, as well as by dipping. 



It will be noted that these tests were made entirely 

 with reference to solutions acting as internal poisons, and 

 the results would not be applicable in connexion with the 

 use of mixtures having a purely external effect, i e. contact 

 poisons, of which kerosene oil is a good example. 



■SUGAR-CANE PESTS IN QUEENSLAND. 



The Queensland Department of Agriculture and 

 Stock has recently issued Bulletin No. I, entitled The 

 Cultivation of Cane Upon Old Lands, by H. T. Easterly, 

 General Superintendent of Sugar-cane Experiment 

 Stations. 



The subject is dealt with under two heads : (1) res- 

 toration of old land, and (2) planting, subsequent 

 cultivation, methods of ratooning, and ajiplication of 

 manures. Under the second of these heads, the pests 

 and diseases of cane are discussed in a brief note, which 

 is reproduced below. The account of the severity of 

 "the liltacks of the scarabaeid beetles is of interest in 



connexion with that of the root borers and other 

 grubs in West Indian soils, which appeared in the 

 Ayrlculliiral Newii, Nos. 2S.5-290, and which is now 

 being issued as No. 7.S of this Department's Pamphlet 

 Series: — 



The sugar-cane plant in Queensland is subject to many 

 pests and diseases The most serious of these, at the present 

 time, is the grub pest. The larvae of Lepidiota and other 

 scarabaeid beetles attack the roots of the cane, causing the 

 stool ultimately to -fall and |erish. Thousands of tons of 

 cane, particularly in the north, have been destroyed every 

 year, and a high price, per It)., is now paid for the beetle. In 

 Mackay, over 1-5 tons of beetles have been captured within 

 so fhort a time as two months, and destroyed. The weevil 

 horer {Sjihenophorm oOsciirns) and the moth borer {Dintraea 

 saccharalis) do a certain amount of damage, but have not so 

 far called for urgent repressive measures. The gumming 

 disease of the cane caused by Bacillus vascularHm, Cobb, is 

 at times a very serious trouble, both in the field and ia 

 the mill, but so fur as the writer's experience goes, gumming 

 of the cane is not found to any extent north of Mackay, 

 and appears most prevalent in cooler climates. Sets showing 

 gum should never be planted. Certain varieties of cane, par- 

 ticularly the older sorts, such as Rose Bamboo and Striped 

 Singapore, are particularly liable to the disease, while in the 

 best of the New Guinea canes no traces of it have been 

 found, though the^ poorer kinds are far from immune. 

 An entomologist, in the person of Mr. A. A. Girault, is at 

 the present time investigating the grub pest, but until his 

 enquiries bear fruit, the methods of grub and beetle 

 destruction are the best that can be undertaken at the 

 present time. One thing appears evident — that where the 

 grubs and beetles have been systematically destroyed over 

 a period of years, the pest is doing little or no damage. 



Nematodes and fungoid diseases attacking roots are 

 also causing alarm in places. The liming of the soil, change 

 of plants, and rotation of crops are the surest and safest 

 methods for the elimination of these troubles. 



SUCCESSFUL TRANSPORTATION OF 

 MILLIONS TO THE EAST. 



Another attempt is now being made to introduce 

 Millions {Girardinus poecilloides, de Filippi) into the Feder- 

 ated Malay States, in connexion with the work of mosquito 

 control in that Colony. 



Early in June of this year a consignment of these small 

 fish was sent from Barbados by the Imperial Department of 

 Agriculture by the R.M.S. 'Tagus'. In England the fish 

 were transferred to the P. it O. S.S. 'Xyanza' which arrived 

 at Kuala Lumpur at the und of July. The consignment 

 consisted of 12 cases, each case being composed of 

 a wooden bo.\ containing a kerosene tin properly packed in 

 shavings, which acted as a cushion and as a protection 

 against extreme changes of temperature. These cases were 

 described in an article entitled 'Millions and Mosquitoes' in 

 the H'tst Indian Bulletin, Vol. IX, pp. 382-90 and in 

 Pamphlet No. .55 on the same subject. 



According to newspaper accounts, this consignment of 

 millions arrived in excellent condition, the 12 cases con- 

 taining over 1,000 living fi.sh. It would seem that with this 

 number to serve as a start, and with the experience gained 

 in dealing with a previous lot, a fair degree of success 

 might be looked for in establishing millions in the Federated 

 Malay States. 



