154 



THE AGRICULTURAL NEWS. 



M\T IS, 1918. 



INSECT NOTES. 



THE VALUE OF ZOOLOGY TO HUMAN 



WELFARE. 



The above title lorined the subject for discussion by 

 some of the leading zoologists of the United States at a 

 special symposium lield under the auspices of the American 

 Association for the Advancement of Science during its last 

 annual meeting at Pittsburg in December 1917. Each 

 speaker had been assigned one general topic relating to that 

 branch of zoology in which he himself is a specialist, and it 

 was hoped that the contributions by the various .'speakers 

 might more or less supplement each other. The present 

 symposium was also intended to supplement a former discus- 

 sion on the same general subject held at the Philadelphia 

 meeting of the above Association in IKHl-"). Since the 

 time allotted to each speaker was necessarily limited, the 

 various aspects of the subject could only be touched upon 

 briefly by the different speakers. The whole subject is ime 

 of general interest, and some of the different topics will be 

 referred to later. 



Among the speakers on the present occasion was 

 Dr. L. O. Howard. Chief of the Bureau of l']ntomology at 

 Washington, who di.scussed the subject from the point of 

 view of the economic entomologist, and alluded to the 

 'work that those zoologists who .study insects have 

 done and are doing for the welfare of humanity.' A brief 

 .sketch of this paper, which was published in Si'itiicc for 

 April 1, 1!J18, is given here. 



Dr. 1 1 owaid begins by slating that the Class Insecta 

 includes a host of species which are most keenly competing 

 with the human speciis in the struggle for existence. Insects 

 have their origin in an early period of the earth's history, 

 dating back to Carboniferous or perhaps to Silurian times. 

 They have persisted and flourished by adapting themselves 

 to almost all conceivable conditions, until at the present time 

 they are tlie chief competitors with the human race for the 

 control of the earth. 



The unceasing straggle between insects and man is 

 vividly sketched in the following words: 'Man labours for 

 months to produce a food crop — he must .share it with many 

 •species of in.sects. He builds himself a house with infinite 

 toil — it iriust harbor insects as well. He makes garments 

 for himcelf — without great care on his part they are eaten 

 by insects. His harvested food is destroyed by them; his 

 blood is sucked by then; ; he sickens and dies from a multi- 

 plication of disea.se genus which they have introduced by 

 their bites, or with which they have contaminati'd his food, 

 and after his death they consume his body.' 



The relations between in.sects and the food crops of 

 man is then discussed by Dr. Howard. This subject has 

 'become one of vital importance at thi- present tinii'. 

 In peace times it was estimated that the damag(^ 

 caused by insects to the food products of the I'nited 

 States amounted to approximately •Sl,.'!0(*,000 per year 

 or roughly, about 10 per cent, of the whole. This estimate, 

 as expressed in terms of money, is open to iriticisin. 



a-^ Dr. Howard points out, for the obvious rea.son that a fall 

 in production is followed by an increase in price. The lo^s^ 

 liowever. may be estimated ju>t as well in terms of human 

 food, and consei|uently of human vit.ility. The writer con- 

 tinues: '.V loss of ID (ler cent, of the possible food, and not 

 considering the cjuestion of waste, means strictly that a given 

 number of people must live on a ration of 90 per cent, of 

 the possible: not necessarily that ID per cent, of the |)eople 

 must die of .starvation.' 



It has been estimated that the flureau of Entomolotiy 

 sKves the United States over .■<2l',000,000 annually, but this 

 estimate is probably far. too small. 



In addition to the insect enemies of growing crops there 

 are a large number of species which attack stored food pro- 

 ducts of all kinds, and the problem of preserving stored 

 foodstuffs from tlie attacks of insects has become •>! 

 the greatest importance in the i)resent crisis. As an 

 instance of the importance of this i|uestion of food pre- 

 servation from insects at the present time, the writer 

 mentions that .Mr. Maxwell-Lcfroy has been sent from 

 England to Australia to study the condition of the Australian 

 wheat awaiting export to the United State.s, and to prevent 

 damage by ir..sects which attack stored grains. The United 

 Slates has sent large supplies of milled grain to England, and 

 in order to save the long transportation, the Australian wheal 

 is to go direct to San Francisco for use in America. So thnt 

 much depends on the success of Mr. Lefroys work in 

 Australia. 



Dr. Howard then touches upon 'the enormous problem 

 of medical zoology', in which the entomologist has a most 

 important interest. 'It is true' he continues, 'that most of 

 the important discoveries concerning the carriage of disease by 

 insects have lieen made by medical men, and not by 

 entomologists. But even in these ca.ses, the discovery once 

 made, the entonmlogist, with his training in methods of 

 investigating the life history and habits of in.sects, plays 

 the important part in the investigation of every point 

 in the life-history, habits, and behaviour of the insect carrier, 

 and in the perfection of the methods for its destruction.' 



The wiiter considers that the prevention of insect-borne 

 diseases is a matter fnr the economic entomologist and not for 

 the medical man; or at the very least, for the individual who 

 does not yet exist, namely, the medical man trained as an 

 entomologist. At pre.seni the entomologist forms a link 

 between the medical man ami the sanitary engineer. 



J.CH. 



Investigation of Thymol Yield of Wild 



Thyme. - In the .l^^ricKltuntl .\;7.'.v, April 20, 1918, i 

 ijuery was nude as to the possible utility of Coicus ninhoiii- 

 Inis, known generally in the West Indies as wild 

 thyme, as a .source of thymol. 



With reference to this subje<l .Mr. A. E. Collens 

 Superintendent of Agriculture, .\nligua, states that he 

 investigated this plant, known in Trinid::d as Spanish thyme, 

 for thymol content at the Oovernment Laboratory there in 

 191 1. A reference to this appeared in the annual report .>f 

 the Officer in Charge of Special Investig-ations for that year. 

 The amount of oil recovered was too small for any definite 

 investigation— the freshly gathered herb, which contained 

 practically 90 per cent, of moisture, yielding less than 0'2 

 per cent, of oil. Mr. Collens goes on to say that it may 

 perha[)s still be of interest to examine local .specimens as 

 the oil content may be considerably influenced by climatic 

 conditions, and a comparatively dry climate, stich as that of 

 .NntigUA, may lead to an increased yield. 



