Handbook of Medical Entomology

CHAPTER II

ARTHROPODS WHICH ARE DIRECTLY POISONOUS 6-56

The Araneida, or Spiders. The tarantulas. Bird spiders. Spiders of the genus Latrodectus. Other venomous spiders. Summary. The Pedipalpida, or whip-scorpions. The Scorpionida, or true scorpions. The Solpugida, or solpugids. The Acarina, or mites and ticks. The Myriapoda, or centipedes and millipedes. The Hexapoda, or true insects. Piercing or biting insects poisonous to man. Hemiptera, or true bugs. The Notonectidae or back-swimmers. Belostomidae or giant water-bugs. Reduviidae, or assassin bugs. Other Hemiptera reported as poisonous to man. Diptera; the midges, mosquitoes and flies. Stinging insects. Apis mellifica, the honey bee. Other stinging forms. Nettling insects. Lepidoptera, or butterflies and moths. Relief from poisoning by nettling larvae. Vescicating insects and those possessing other poisons in their blood plasma. The blister beetles. Other cryptotoxic insects.

CHAPTER III

PARASITIC ARTHROPODS AFFECTING MAN 57-130

Acarina, or mites. The Trombidiidae, or harvest mites. The Ixodoidea, or ticks. Argasidae. Ixodidae. Treatment of tick bites. The mites. Dermanyssidae. Tarsonemidae. Sarcoptidae, the itch mites. Demodecidae, the follicle mites. Hexapoda, or true insects. Siphunculata, or sucking lice. Hemiptera. The bed-bug. Other bed-bugs. Parasitic Diptera, or flies. Psychodidae, or moth flies. Phlebotominae. Culicidae, or mosquitoes. Simuliidae, or black-flies. Chironomidae, or midges. Tabanidae, or horse-flies. Leptidae or snipe-flies. Oestridae, or bot-flies. Muscidae, the stable-fly and others. Siphonaptera, or fleas. The fleas affecting man, the dog, cat, and rat. The true chiggers, or chigoes.

CHAPTER IV

ACCIDENTAL OR FACULTATIVE PARASITES 131-143

Acarina, or mites. Myriapoda, or centipedes and millipedes. Lepidopterous larvae. Coleoptera, or beetles. Dipterous larvae causing myiasis. Piophila casei, the cheese skipper. Chrysomyia macellaria, the screw-worm fly. Calliphorinae, the bluebottles. Muscinae, the house or typhoid fly, and others. Anthomyiidae, the lesser house-fly and others. Sarcophagidae, the flesh-flies.

CHAPTER V

ARTHROPODS AS SIMPLE CARRIERS OF DISEASE 144-163

The house or typhoid fly as a carrier of disease. Stomoxys calcitrans, the stable-fly. Other arthropods which may serve as simple carriers of pathogenic organisms.

CHAPTER VI

ARTHROPODS AS DIRECT INOCULATORS OF DISEASE GERMS 164-174

Some illustrations of direct inoculations of disease germs by arthropods. The role of fleas in the transmission of the plague.

CHAPTER VII

ARTHROPODS AS ESSENTIAL HOSTS OF PATHOGENIC ORGANISMS 175-185

Insects as intermediate hosts of tape-worms. Arthropods as intermediate hosts of nematode worms. Filariasis and mosquitoes. Other nematode parasites of man and animals.

CHAPTER VIII

ARTHROPODS AS ESSENTIAL HOSTS OF PATHOGENIC PROTOZOA 186-211

Mosquitoes and malaria. Mosquitoes and yellow fever.

CHAPTER IX

ARTHROPODS AS ESSENTIAL HOSTS OF PATHOGENIC PROTOZOA 212-229

Insects and trypanosomiases. Fleas and lice as carriers of Trypanosoma lewisi. Tsetse-flies and nagana. Tsetse-flies and sleeping sickness in man. South American trypanosomiasis. Leishmanioses and insects. Ticks and diseases of man and animals. Cattle tick and Texas fever. Ticks and Rocky Mountain Spotted fever of man.

CHAPTER X. Arthropods As Essential Hosts of Pathogenic Protozoa

ARTHROPODS AS ESSENTIAL HOSTS OF PATHOGENIC PROTOZOA (CONTINUED) 230-240

Arthropods and Spirochaetoses of man and animals. African relapsing fever of man. European relapsing fever. North African relapsing fever of man. Other types of relapsing fever of man. Spirochaetosis of fowls. Other spirochaete diseases of animals. Typhus fever and lice.

CHAPTER XI. Some Possible, but Imperfectly Known Cases of

SOME POSSIBLE, BUT IMPERFECTLY KNOWN CASES OF ARTHROPOD TRANSMISSION OF DISEASE 241-256

Infantile paralysis, or acute anterior poliomyelitis. Pellagra. Leprosy. Verruga peruviana. Cancer.

CHAPTER XII

KEYS TO THE ARTHROPODS NOXIOUS TO MAN 257-317

Crustacea. Myriapoda, or centipedes and millipedes. Arachnida (Orders of). Acarina or ticks. Hexapoda (Insecta). Siphunculata and Hemiptera (lice and true bugs). Diptera (mosquitoes, midges, and flies). Siphonaptera (fleas).

APPENDIX

Hydrocyanic acid gas against household insects 318-320 Proportion of ingredients. A single room as an example. Fumigating a large house. Precautions.

Lesions produced by the bite of the black-fly 321-326

BIBLIOGRAPHY 327-340

INDEX 341-348

CHAPTER I.. Introduction

INTRODUCTION

EARLY SUGGESTIONS REGARDING THE TRANSMISSION OF DISEASE BY INSECTS

Until very recent years insects and their allies have been considered as of economic importance merely in so far as they are an annoyance or direct menace to man, or his flocks and herds, or are injurious to his crops. It is only within the past fifteen years that there has sprung into prominence the knowledge that in another and much more insiduous manner, they may be the enemy of mankind, that they may be among the most important of the disseminators of disease. In this brief period, such knowledge has completely revolutionized our methods of control of certain diseases, and has become an important weapon in the fight for the conservation of health.

It is nowhere truer than in the case under consideration that however abrupt may be their coming into prominence, great movements and great discoveries do not arise suddenly. Centuries ago there was suggested the possibility that insects were concerned with the spread of disease, and from time to time there have appeared keen suggestions and logical hypotheses along this line, that lead us to marvel that the establishment of the truths should have been so long delayed.

One of the earliest of these references is by the Italian physician, Mercurialis, who lived from 1530 to 1607, during a period when Europe was being ravaged by the dread "black death", or plague. Concerning its transmission he wrote: "There can be no doubt that flies feed on the internal secretions of the diseased and dying, then, flying away, they deposit their excretions on the food in neighboring dwellings, and persons who eat of it are thus infected."

It would be difficult to formulate more clearly this aspect of the facts as we know them to-day, though it must always be borne in mind that we are prone to interpret such statements in the light of present-day knowledge. Mercurialis had no conception of the animate nature of contagion, and his statement was little more than a lucky guess.

Much more worthy of consideration is the approval which was given to his view by the German Jesuit, Athanasius Kircher in 1658. One cannot read carefully his works without believing that long before Leeuwenhook's discovery, Kircher had seen the larger species of bacteria. Moreover, he attributed the production of disease to these organisms and formulated, vaguely, to be sure, a theory of the animate nature of contagion. It has taken two and a half centuries to accumulate the facts to prove his hypothesis.

The theory of Mercurialis was not wholly lost sight of, for in the medical literature of the eighteenth century there are scattered references to flies as carriers of disease. Such a view seems even to have been more or less popularly accepted, in some cases. Gudger (1910), has pointed out that, as far back as 1769, Edward Bancroft, in "An Essay on the Natural History of Guiana in South America," wrote concerning the contagious skin-disease known as "Yaws": "It is usually believed that this disorder is communicated by the flies who have been feasting on a diseased object, to those persons who have sores, or scratches, which are uncovered; and from many observations, I think this is not improbable, as none ever receive this disorder whose skins are whole."

Approaching more closely the present epoch, we find that in 1848, Dr. Josiah Nott, of Mobile, Alabama, published a remarkable article on the cause of yellow fever, in which he presented "reasons for supposing its specific cause to exist in some form of insect life." As a matter of fact, the bearing of Nott's work on present day ideas of the insect transmission of disease has been very curiously overrated. The common interpretation of his theory has been deduced from a few isolated sentences, but his argument appears quite differently when the entire article is studied. It must be remembered that he wrote at a period before the epoch-making discoveries of Pasteur and before the recognition of micro-organisms as factors in the cause of disease. His article is a masterly refutation of the theory of "malarial" origin of "all the fevers of hot climates," but he uses the term "insect" as applicable to the lower forms of life, and specific references to "mosquitoes," "aphids," "cotton-worms," and others, are merely in the way of similes.

But, while Nott's ideas regarding the relation of insects to yellow fever were vague and indefinite, it was almost contemporaneously that the French physician, Louis Daniel Beauperthuy argued in the most explicit possible manner, that yellow fever and various others are transmitted by mosquitoes. In the light of the data which were available when he wrote, in 1853, it is not surprising that he erred by thinking that the source of the virus was decomposing matter which the mosquito took up and accidentally inoculated into man. Beauperthuy not only discussed the role of mosquitoes in the transmission of disease, but he taught, less clearly, that house-flies scatter pathogenic organisms. It seems that Boyce (1909) who quotes extensively from this pioneer work, does not go too far when he says "It is Dr. Beauperthuy whom we must regard as the father of the doctrine of insect-borne disease."

In this connection, mention must be made of the scholarly article by the American physician, A. F. A. King who, in 1883, brought together an all but conclusive mass of argument in support of his belief that malaria was caused by mosquitoes. At about the same time, Finley, of Havana, was forcefully presenting his view that the mosquito played the chief role in the spread of yellow fever.

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