INSECTS AFFECTING MAN MP21 COOPERATIVE EXTENSION SERVICE College of Agriculture The University of Wyoming DEPARTMENT OF PLANT SCIENCES Trade or brand names used in this publication are used only for the purpose of educational information. The information given herein is supplied with the understanding that no discrimination is intended, and no endorsement information of products by the Agricultural Research Service, Federal Extension Service, or State Cooperative Extension Service is implied. Nor does it imply approval of products to the exclusion of others which may also be suitable. Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30,1914, in cooperation with the U.S. Department of Agriculture, Glen Whipple, Director, Cooperative Extension Service, University of Wyoming Laramie, WY. 82071. Persons seeking admission, employment or access to programs of the University of Wyoming shall be considered without regard to race, color, national origin, sex, age, religion, political belief, handicap, or veteran status. INSECTS AFFECTING MAN Fred A. Lawson Professor of Entomology and Everett Spackman Extension Entomologist with minor revisions by Mark A. Ferrell Extension Pesticide Coordinator (September 1996) TABLE OF CONTENTS INTRODUCTION .............................................................1 BASIC RELATIONSHIPS ......................................................1 PARASITIC RELATIONSHIPS..................................................1 Lice......................................................................1 Head Louse ............................................................1 Human Body Louse......................................................1 Pubic Louse............................................................1 Fleas.....................................................................2 Bed Bug..................................................................2 Kissing Bug...............................................................2 Blood Sucking or Biting Flies .................................................3 Mosquitoes.............................................................3 Black Flies.............................................................3 Punkies (no-see-ums) .....................................................3 Horse Fly..............................................................4 Stable Fly..............................................................4 Horn Fly...............................................................4 Snipe Fly ..............................................................5 Non-biting Flies ............................................................5 House Fly..............................................................5 Lesser House Fly........................................................5 Latrine Fly.............................................................5 Myiasis...................................................................5 Obligate myiasis.........................................................5 Accidental myiasis.......................................................5 Stinging Insects ............................................................6 Paper Nest Wasps .......................................................6 Yellow Jacket...........................................................6 Bald Faced Hornet .......................................................6 Mud Daubers...........................................................7 Digger Wasps...........................................................7 Honey Bee .............................................................7 Bumble Bees ...........................................................7 Velvet Ants ............................................................7 Ants ..................................................................7 Blister Beetles .............................................................8 Other Arthropods ...........................................................8 Black Widow Spider .....................................................8 Brown Recluse Spider....................................................8 Scorpions..............................................................9 Ticks..................................................................9 Stinging Caterpillars ........................................................9 LIST OF FIGURES...........................................................10 APPENDIX.................................................................11 INSECTS AFFECTING MAN INTRODUCTION The insects included here are those which, in one germs as they crawl about on people and their food and way or another, have a direct effect upon or within dishes. They may also be a severe annoyance to man humans. Many of these utilize the blood of man as a by their presence and activities. Many other forms primary source of food; others feed on humans in lieu attack man only in self defense; some bite (spiders, of other vertebrate hosts which serve equally well. ants, etc.) while others sting when disturbed. Other species do not suck blood but spread BASIC RELATIONSHIPS Certain blood sucking ectoparasites of man are so blood but are adapted to life with man or his domestic closely adapted that they cannot live on another host. animals and, in passing back and forth between habitats, Other blood sucking types use man as a temporary host, spread filth and disease. Another relationship exits visiting man only in response to the need for food. The when man and insects share the same habitat. The remainder of the insect's time is spent resting, digesting insect may bite or sting defensively when man intrudes. the blood meal, and producing eggs. Some blood Man, in turn, responds by trying to control the insect sucking insects prefer livestock or other vertebrates as with chemicals or other control measures. a source of food but will use man when the opportunity exists. Other insects do not feed on PARASITIC RELATIONSHIPS Lice prolonged feeding by this protected population of lice. Three types of lice are so well adapted to life with man that they normally are unable to survive on another Human Body Louse (Fig. 2): The body louse is a close host. Two of these are full-time residents on man's relative of the head louse. The two can be forced to body. The other lives in man's clothing and is entirely interchange habits and replace each other. The body dependent upon him for food, temperature and louse inhabits the clothing of man in places where it humidity. binds tightly against the skin. Lice prefer to live in seams and folds of the clothing but incase of a heavy Head Louse (Fig. 1): These insects mostly live on the infestation will remain on the body of the host. They head of the human host, particularly in the hair above are spread mainly through contact with infected people the ears and on top of the head. On occasion they may or their clothing. become established in other densely hairy areas of the These lice are about the same size a head lice but body. These lice are basically gray colored. However, have a more consistently gray color. Each female they may vary with the hair color of the host. They are produces about 300 eggs, deposited on fibers in the 1/12 to 1/8th inch long, slender and have pointed heads seams of clothing. Garments worn for long periods and a claw-clamp on each leg. A louse attaches to the without cleaning become heavily infested with eggs. hair of the head with the leg clamps and are difficult to and lice. Hatching occurs after 5 to 7 days. Young lice dislodge. When hair is shed the attached lice or eggs immediately begin sucking blood and mature about drop off with the hair. Loose hairs can stick inside a hat three weeks after eggs are laid. Populations build providing a means of infesting another head when the rapidly, and as many as 10,000 eggs and 10,000 plus hat is placed on another head. lice have been found on an infested shirt. Infestations spread easily through exchange of head High populations of body lice and heavy feeding wear or combs and scarves. Populations begin to build may cause severe blood loss, along with eventual up in late fall and early winter, particularly on people hardening and pigmentation of the punctured skin whose habits are unsanitary. Increased sped among (vagabond's disease). The lice also transmit disease school children often occurs after Christmas, when new organisms causing typhus fever, murine typhus fever, head wear may be traded back and forth passing eggs trench fever, and relapsing fever. and lice to new victims. Each female produces 50 to 150 eggs, which are Pubic Louse (Fig. 2): This insect, also called the crab glued to the hair near the base. Young lice hatch in 5 to louse and the crotch cricket, can be recognized by its 10 days and develop rapidly. Egg to adult may take resemblance to a minute crab. It is very small, 1/12 only three weeks. Adults and all sizes of young live in inch or less in length and is almost as wide as long. The the hair and on the scalp. legs are long and extend outward from the body. They Eggs are glued to hairs a slight distance above the also have a clamping-claw for clinging to the hair of the scalp sealing off a small space within which the lice live hose. The front of the head is more blunt than in either by sucking blood or lymph. The egg layer is called a the head or body lice. The body also is more distinctly false scalp and inhibits removal of the lice. Sever warty and hairy. These lice are relatively stationary