410 



THE AGRICCTLTURAL NEWS. 



December 21, 1912. 



INSECT NOTES, 



TICKS. 

 PART II; 



A.s was promised, the subject of ticks is continued from 

 the last number of the Ayricultural 3'evs, bj' further 

 <juotation from the Bulletin mentioned there, namely No. lOG 

 •of the Bureau of Entomology of the United States 

 J»epartment of Agriculture. 



'Owing to the fact that very few entomologists or 

 zoologists have had experience with the systematic collection 

 •of ticks, a few suggestions along this line may prove of value. 

 The writers have found that in many instances zoologists 

 liave received and handled specimens of skins and living 

 animals to which ticks were attached and seen but were not 

 preserved. The ease with which this class of parasites may 

 ~be preserved should encourage zoologists to keep on the 

 lookout for them and to collect all specimens seen. 



'Persons who collect specimens of ticks should record the 

 host, point of attachment, date and locality. All parts of the 

 lost, including the inside of the ears, should be closely 

 examined. Upon the discovery of a female, and before 

 jemoving it, the collector should .search closely f')r the male, 

 which may be attached near by. A pair of forceps will be 

 iound useful in removing the smaller ticks. Those with 

 ^hort mouth-parts are readily removed without injury, but 

 ."many, particularly those of the genus Ixoiles, are usually so 

 "firmly attached that ihv body of the tick will be separated 

 iviim the capitulum unless the latter is firmly grasped. Some 

 ixodologists have recommended the application of a penetra- 

 ting oil and waiting for the tick to loosen its hold, but this 

 ■will seldom be found necessary. 



'In collecting ticks from small animals which have been 

 shot or trapped, a supply of small cotton bags should be at 

 hand into which the host can be placed as soon as shot 

 and the bag firmly tied to prevent the escape of the ticks. 

 If the host animal is too large to be bagged it should be 

 examined at once over some white surface, such as white 

 cctton cloth spread over the ground. The importance of 

 immediate examination is emphasized, as the writers have 

 found that larvae of the rabbit tick, and of other species with 

 short hypostomes, commence to leave the host within a few 

 minutes after the animal is killed. Ticks with long hypos- 

 tomes, such as Ixodes, are sometimes unable to detach them- 

 selves and therefore remain upon the animal. In a number of 

 instances living and dead ticks have been found clinging to 

 the skins of animals which have been nailed on a wall for 

 several days. 



'The collection of ticks from herbage, on which they are 

 awaiting a host, may best be done by dragging a white cloth, 

 preferably of wool, over bushes, grass, etc. An ordinary in- 

 sect beating net may also be employed. Fruitful results have 

 been found to attend the examination of the dens of animals, 

 nests and regular roosting places of birds, and the ground in 

 the vicinity of resting and watering places of mammals. Pill 

 boxes have been found to be satisfactory receptacles for the 

 ticks when collected. 



'In preserving we have usually used 80 per cent, alcohol 

 or a mixture consisting of 60 parts alcohol, 1 part formalin, 

 and 39 parts water. Adult specimens, particularly males 

 with bright colour markings, should be mounted on pins as 

 well as preserved in alcohol. For microscopical study speci- 

 mens should be mounted in Canada balsam on slides. The 



contents of the body should first be teased out in hot water^. 

 through a slit made at the posterior end of the body. Speci- 

 mens can then be readily cleared by boiling in a lO per cent, 

 solution of caustic potash, care being taken that the clearing- 

 be not carried too far. T'h.e method employed by Dr. C. W. 

 Stiles consists in soaking the specimens in from 2 to 5 per 

 cent, caustic potash solution for periods varying from twelve 

 to ninety-six hours, after which all the soft body content 

 is remoied, and after passing the specimens through water, 

 the alcohols, and xylol oc other clearing agents the specimens 

 are mounted in balsam. 1 



BASIC SLAG AS AN INSECTICIDE. 



The following article appeared in the Journal of 

 the Nev: Zealand Dcparlmevt of Agricidtv.re for Sep- 

 tember 1(3, 1912. The employment of the manure in 

 this way is interesting, particularly in view of the 

 experimental use of nitrolim (calcium cyanamide) in 

 Trinidad against the froghopper; only it must be 

 remembered that the probable manner of action ditTers 

 in the two cases. 



Basic slag, that one-time residual waste of the steeH 

 blast furnace — the dross formed in the removal of phosphorus 

 from iron ore — is not only proving a fertilizer of great value 

 in this country, as well as an excellent corrective of acidity 

 in the soil, but it is well known that root crops manured 

 with slag are not affected with certain diseases which are 

 often present when other manures are used. 



Now, according to an investigation in France, basic slag 

 is proving of distinct value in the destruction of the plant 

 louse. In Europe this insect has been very destructive, 

 especially to sugar beet. All mixtures or liquors used for 

 spraying plants as a protection against these insects have^ 

 been applied in vain. The 'false brown rust' or 'curl' ot" 

 the peach is caused by the plant lice, and it cannot be success- 

 fully fought because neither liquors nor powders can be made 

 to reach the little animals. When the beet plant is attacked, 

 the leaf curls up and protects the insect against any treat- 

 ment the farmer may apply. 



It has been found that by the application of large 

 quantities of nitrates a,fter rains, the beet is stimulated to 

 push out new leaves, which take the place of those destroyed 

 by the plant lice. But this method has its dangers, since 

 an excess of nitrogen in the soil may be just as harmful to- 

 the plants as the action of the insects. 



J. P. 'U'agner, a sugar-beet expert, recently told the 

 National Society of Agriculture of France of a successful! 

 attempt to fight these insects by means of basic slag. He 

 spread about 1,4005). of the basic slag to the acre on fields 

 that were infested with the plant louse. Not only did this 

 treatment prevent the insects from attacking the leaves, but 

 they were driven away from leaves they had already attacked. 

 On another field the slag was applied in larger quantities. 

 Every plant was already attacked by the insects when the 

 dross was applied. Within eight days all the insects had. 

 disappeared, and the plants recovered their healthy appear- 

 ance and colour. 



The method by T>:hich the basic slag operated in these 

 cases is not known. '\Vagner thinks that the compound forms 

 a thin layer on the leaf, spreading out over the whole surface, 

 and that it is either distasteful or injurious to the insect. 

 It is well knowB that many lime compounds are injurious to 

 animals with soft, naked skins, such as snails, caterpillars,, 

 naked larvae; but it has not been shown that a similar effect 

 is actually produced in the treatment against plant lice with 

 basic slag. 



