Roger Drummond - Ticks and what you can do about them

Ticks and What You Can Do About Them

1st EDITION May 1990
2nd EDITION April 1998
3rd EDITION March 2004
2nd printing March 2008
3rd printing August 2009

Copyright 1990, 1998, 2004 by Roger Drummond, Ph.D.

Book design: Andreas Schueller
Book editors: Jessica Benner, Elaine Merrill

ISBN 978-0-89997-353-1

Manufactured in the United States of America

Published by: Wilderness Press
PO Box 43673
Birmingham, AL 35243
(800) 443-7227; FAX (205) 326-1012
info@wildernesspress.com
www.wildernesspress.com

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All rights reserved. No part of this book may be reproduced in any form, or by any means electronic, mechanical, recording, or otherwise, without written permission from the publisher, except for brief quotations used in reviews.

SAFETY NOTICE: Although Wilderness Press and the author have made every attempt to ensure that the information in this book is accurate at press time, they are not responsible for any loss, damage, injury, or inconvenience that may occur as a result of using this book. The information contained here is no substitute for professional advice or training. Readers are encouraged to seek medical help whenever possible.

The author wishes to thank persons who provided information, help, and advice for any or all of the three editions of this book. Dr. Glen Needham, Institute of Acarology, The Ohio State University, Columbus, Ohio, provided the picture of the mouthparts, and reviewed a draft. EcoHealth, Inc., Boston, Mass., provided the plate of the actual size of the blacklegged tick. Dr. Willy Burgdorfer, Dike Drummond, M.D., Don Drummond, Dr. Lance Durden, Dr. John George, Maud Jennings, Dr. Sam Junkin, Dr. Robert Lane, Dr. Robert Miller, Dr. Dan Sonenshine, Richard Stewart, David Weld, and Rita Wilson read final drafts. Special thanks to Joe Fleming for his insightful review of this third edition. Roslyn Bullas, Managing Editor, Elaine Merrill, Editor, Jessica Benner, Editorial Assistant, and Andreas Schueller, Designer, all ofWilderness Press, provided constructive editorial advice. My most helpful advice, comments, and criticism came from Ellen Drummond, friend, companion, and wife.

Have you or members of your family found a tick crawling on or attached to you or them? Do you want to know how to remove an attached tick? Have you become aware of the diseases, especially Lyme disease and Rocky Mountain spotted fever, carried by ticks? Do you live in an area or are you planning to visit an area that has ticks? Have you read an article about ticks and the diseases they carry and want to know more? Are you looking for ways to keep ticks from getting on you and your family? Are you or your community looking for ways to control ticks and have you heard or read about new methods and materials used to control ticks on mice and deer? This book gives detailed information on how you can protect yourself from ticks, how you can remove attached ticks safely, and how you can control ticks.

This book tells about tickswhat they are, how and where they live, the diseases they carry, and the problems they cause.

Nature and all outdoors are to be enjoyed. As with any part of life, this enjoyment is not without its risks. One of these risks is the presence of ticks and tick-carried diseases. A tick bite can cause severe irritation and even paralysis. If you know more about ticks and how you can protect yourself and your family from them, you and they can enjoy the outdoors with a greatly reduced risk of contacting ticks and suffering from tick-carried diseases. The first six chapters of this book give information on ticks and the diseases they carry. The last three chapters provide practical measures you can take to reduce the risks from ticks and tick-carried diseases.

Ticks are part of a large group of animals that have jointed legs and skeletons located on the outside of their bodies. This group, called arthropods, includes insects, crustaceans, myriapods, and arachnids. Arachnids, in turn, include spiders, scorpions, mites, and ticks. Scientists have described more than 850 kinds of ticks in the world and 100 of these carry organisms that cause diseases of wildlife, livestock, pets, and people.

Ticks only food is the blood they suck from their hosts (usually warmblooded animals).

The front part of a tick consists of the head area which contains the mouthparts. The mouthparts have a central structure, the hypostome, which is shaped like a harpoon, flat on the top and curved on the bottom, with many recurved barbs, and two chelicerae which have sharp teeth on their front ends. it difficult to remove once it has attached. The teeth on the chelicerae then cut blood vessels under the skin, causing the blood to form a pool. To keep the blood from clotting, ticks inject saliva containing an anticoagulant into the pool of blood. The tick then sucks this blood into its gut through the hypostome. The saliva may also contain disease organisms, so removing a tick as soon as you discover it is important to avoiding getting a tick-carried disease.

The rear part of a tick consists of the body, which is designed to expand as the tick takes in blood. When a tick feeds, the ticks gut enlarges as it receives blood, and the accordion-like skin of the ticks body grows and unfolds as the gut increases in size. Some female ticks can increase their size 20-50 times and their weight more than 200 times as they feed. Male ticks increase only slightly.

Some females feed once and lay all their eggs in a single mass containing thousands of eggs, while others feed several times and lay eggs in several small batches after each feeding.

Ticks go through four stages in their life cycleadult, egg, larva, and nymph. The adult stage consists of sexually mature, eight-legged male and female ticks. The adult sexes usually differ in color, size, and appearance: females are usually larger and more colorful than males. Females and males emit chemicals, called sex pheromones, to attract the opposite sex. These pheromones allow adults to find each other and act as an aid to mating. Adults find hosts, attach, suck blood, and mate. Some adults attach and suck blood only once; others do so several times. Mating may take place on or off a host and before or after feeding.

Fully fed, mated females lay eggs. Females die after laying all their eggs. Males usually feed slightly and live to mate several females.

Eggs hatch into very tiny six-legged larvae, often called seed ticks. A larva finds a host, attaches, and sucks blood until full. When full, it detaches and drops to the ground. After a week or so, the larva changes form, in a process called molting, and becomes a nymph. A nymph is larger than a larva, has eight legs, but still does not have sex organs. The nymph breaks out of the larval skin, finds a host, attaches, and sucks blood. Some nymphs feed several times and molt to another nymph before finally feeding, dropping off the host, and then molting to an adult. Other nymphs feed only once, drop off, and molt to an adult. The adult breaks out of the nymphal skin and finds a host.

Ticks have a unique system for finding hosts. They have sense organs on their front legs that detect carbon dioxide, host odors, and heat given off by warmblooded animals. Using these sense organs, ticks locate and can crawl to hosts. Researchers and health officials use this behavior to collect ticks. They place a small block of dry ice on a cloth, the dry ice sublimates to carbon dioxide, the ticks detect the carbon dioxide and crawl to the cloth. Some ticks may crawl 10-15 or more feet to a source of carbon dioxide. Ticks do not fly to or jump onto their hosts; they are only found on or near the ground.