Bugs
Page 4
The mosquito feeds by landing on a larger animal, sticking its long, sharp proboscis into the animal’s skin. The proboscis tip is like a needle, and the mosquito feels around for a blood vessel. When it locates one, it plunges the proboscis into it.
Before the mosquito starts sucking the blood out, it injects saliva into its target. The saliva does various jobs. Most importantly it stops the blood clotting while the mosquito is feeding. It is the saliva that causes raised mosquito bite bumps. In infected mosquitoes, it is the saliva that carries malaria, and the saliva injection is what transmits the malaria disease.
Male mosquitoes can get enough nutrients from nectar and other juices from plants. Female mosquitoes require extra nutrients, including proteins, in order to develop eggs. This is why they need to feed on animal (or human) blood. Other types of mosquito can carry diseases in this way, but only the anopheles mosquito can carry malaria.
The tsetse fly – Glossina palpalis – is also a vector, and can transmit a disease called trypanosomiasis, commonly known as sleeping sickness. This is a very serious disease that is hard to treat, and it kills many people in central Africa.
Found in South and Central America, the female human botfly – Dermatobia hominis – catches and lays her eggs on a mosquito. When the mosquito is feeding on a human, the eggs are transferred and start developing into a larva inside the skin of their host. They then hatch out of the skin before pupating into an adult botfly. The hatch sites can become infected, and infestation of the brain has caused death in children.
The assassin bug – Triatoma infestans – carries the protozoa responsible for the tropical Chagas disease. The bug can transmit this when it feeds by biting and sucking blood from humans. There is no vaccine to protect against the disease, and it can lead to serious heart damage.
The South and Central American bullet ant – Paraponera clavata – has the most potent sting of any insect. The chemical in its sting is known as a NEUROTOXIN, and it causes extreme pain as well as swelling and paralysis.
BENEFICIAL BUGS
Many different types of bugs perform services that are beneficial for the ecosystem as a whole, and for humans in particular. Thousands of plant species rely on bugs to spread pollen to help them reproduce – those vitally important bugs include bees, flies, wasps, butterflies, moths and ants. Other bugs, such as ladybirds and hoverflies, feed on small insects that would otherwise destroy crops.
Ground beetles eat slugs and snails, dung beetles deal with animal waste, and many beetle and fly larvae consume dead or decaying plant material.
Plants have evolved bright colours and nectar-secreting glands to attract bugs, because they are so important to their existence. We should always remember how important they are to ours too.
The western honey bee – Apis mellifera – is the main species of domesticated bee, used for the production of honey. This species is also extremely important for crop pollination, with all sorts of fruit and vegetable plants relying on them for this service.
The sacred scarab beetle – Scarabaeus sacer – is a type of dung beetle found in southern Europe, the Middle East and North Africa. Dung beetles eat, move and bury animal waste, which benefits other animals, and also improves the nutrient levels and structure of the soil.
Ancient Egyptians saw sacred scarab beetles rolling balls of dung to their nest burrows, and so believed that the sun must be rolled across the sky by a scarab god!
The seven-spot ladybird – Coccinella septempunctata – is the most common ladybird in the UK. Both the adult ladybird and its larvae are voracious consumers of aphids. This in turn protects delicate young plants from aphid damage, which is why ladybirds are popular with gardeners!
GLOSSARY
ABDOMEN The third section of the bug’s body, containing the heart, the final section of the guts, the reproductive organs and the sting
ANAUTOGENY The requirement of some female bugs to consume blood before they are able to produce eggs
ANTENNAE Sensory organs that bugs use to detect smell, heat, wind and vibrations, and can also use as feelers
APHID Small true bugs that are plant pests
ARTHROPOD The largest animal phylum, arthropods are invertebrates with an exoskeleton and jointed legs
BINOMIAL Double-named system for naming species
CARNIVOROUS Meat-eating
CERCI Appendages at the rear of certain insects. Can be sensory, defensive or a vestigial structure
CHARACTERISTICS Defining features
CHITIN The strong protein that makes up insect exoskeleton and wings
CLASS Larger set in taxonomy e.g. insecta (insects)
COLONY A eusocial community
COMPOUND EYES Complex eyes with lots of separate lenses
EUSOCIAL A complex arrangement of living together and dividing labour
EXOSKELETON Hard outer skeleton
FAMILY Large set in taxonomy e.g. formicidae (ants)
FERTILE Having the ability to breed (have children)
GENUS A small set in taxonomy; the first half of the species name e.g. Myrmecia (bull ants)
HAEMOLYMPH A fluid similar to blood that transports nutrients and oxygen around the body
HEAD CAPSULE A hard structure containing the brain, mouthparts and sensory organs
HEXAPOD A set of arthropods with six legs
IMAGO The final (or adult) stage in the lifecycle of an insect
INVERTEBRATES A group of animals with no backbone
LABIUM The lower part of the front of an insect’s mouth
LARVA The second life stage of some insects, following the egg stage
MANDIBLES A pair of mouthparts that can be used to hold, cut or chew the insect’s food. Some insects (such as stag beetles) have very large mandibles, which they use for fighting
MAXILLARY PALPS A pair of appendages that certain bugs use for moving food towards the mouth
METAMORPHOSIS The transition of an insect from one life stage to another
NEUROTOXIN A powerful chemical found in certain bug stings that affects the nervous system of the creature (or person) stung by the bug
NYMPH A form of the larval stage of certain insects in which the insect looks like a smaller version of the adult
OCELLI A simple insect eye with just one lens
OLFACTORY RECEPTOR An apparatus that certain bugs use to smell and taste things, particularly food
OMMATIDIA The individual units that make up the compound eye
ORDER Larger set in taxonomy e.g. hymenoptera (bees, wasps and ants)
ORGANISM A living being, such as an animal, a plant or a bacterium
PATHOGEN A microorganism that causes disease
PHYLUM One of the largest sets in taxonomy e.g. arthropoda (arthropods)
PREDATOR An animal that preys on/eats others
PROBOSCIS An elongated tubular mouthpart used by certain bugs for feeding
PROTOZOA Tiny single-celled organisms
PUPA The life stage of an insect in between larva and imago. Not all insects go through the pupa stage
SIPHONING An eating technique used by bugs using a proboscis
SPECIES The smallest set of taxonomy e.g. Myrmecia gulosa (red bull ant)
TAXONOMY How scientists group organisms into sets
THORAX The second section of the bug’s body, which contains the first section of the bug’s gut and circulatory system. The legs and wings (if present) are attached to the exterior of the thorax
TYMPANEL ORGANS Hearing apparatus, rather like a drum, with a thin membrane that vibrates when exposed to sound
VECTOR An organism that carries an infectious pathogen without being affected by the disease itself
VESTIGIAL STRUCTURE A part of a bug’s anatomy which is genetically inherited but no longer serves any useful function
To my parents, Michael and Diana
First published in the United Kingdom in 2017 by
Pavilion Children’s Books
43 Great Ormond S
treet
London
WC1N 3HZ
An imprint of Pavilion Books Limited.
Publisher and Editor: Neil Dunnicliffe
Digital Editor: Renata Jukic
Art Director: Lee-May Lim
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise, without prior permission of the copyright owner.
Text and illustrations © Simon Tyler 2017
Bug Consultant: Rory Dimond, Buglife
The moral rights of the author and illustrator have been asserted
eISBN: 978-1-84365-376-9
A CIP catalogue record for this book is available from the British Library.
This book can be ordered directly from the publisher online
at www.pavilionbooks.com, or try your local bookshop.