Name Distributed to elementary school students within the boundaries of... Greater Los Angeles County Vector Control District District Headquarters: 12545 Florence Avenue, Santa Fe Springs, CA 90670, 562-944-9656 Sylmar Branch: 16320 Foothill Boulevard, Sylmar, CA 91342, 818-364-9589
Hi, I m a Vector Inspector from the Greater Los Angeles County Vector Control District. I patrol your neighborhood, looking for vectors. When I find them, I do what s necessary to control them so that people like you don t get bitten or sick. Look for this magnifying glass for clues throughout this book. I bet you re wondering... What s a Vector? A vector is an animal, usually an insect, that carries diseases. (It can make people or other animals sick.) We also control two nuisance insects: Black flies bother people by biting them. Thousands of tiny midges are very pesky. - 1 -
What s the Most Dangerous Vector? It s the mosquito! Throughout the world, over two million people die every year from diseases carried by mosquitoes. The Greater Los Angeles County Vector Control District works to keep mosquitoes under control in your community and protect the public s health. Let s investigate... Is this a mosquito that s carrying diseases? Does she really carry diseases in a suitcase? Follow me as we for clues... What do mosquitoes look like? What makes them so dangerous? Where do they live? How can we control them? - 2 -
What s a Mosquito? HEAD THORAX ABDOMEN Wings Antennae Spiracle Compound eye Legs Anatomy is the study of the body parts that make up an animal. A mosquito is an insect and all insects have three major body parts to their bodies: HEAD, THORAX and ABDOMEN. The soft body tissues inside an insect are protected and supported by a rigid outer covering called an exoskeleton. Located on the head are: two compound eyes that allow insects to see in every direction at once and a pair of antennae. The thorax has 6 jointed legs, with 3 on each side. If the insect has wings, they are attached at the top of the thorax. Insects that fly have either 2 or 4 wings. The mosquito has 2 wings. The last body region, the abdomen, is long and segmented. Breathing holes, called spiracles, are located on both sides of each segment. for these body parts in the mosquito diagram above. - 3 -
Why Are Mosquitoes So Dangerous? Look at the two heads below. Both have long, thread-like antennae that sense sounds and odors. Under the antennae are the palpi. Palpi are used to taste and feel. The proboscis under the palpi is long and thin. This is the mosquito s piercing and sucking mouthpart. One of these mosquitoes is a male and feeds only on plant juices with its proboscis. The female may drink plant juices too. But, she is the dangerous insect (the actual vector) because she sucks blood with her proboscis as well. Antennae Palpi Proboscis Mosquito Heads and Mouthparts Male or female, which one is which? Do you know why the female drinks blood? - 4 -
Mosquito Word Search Fill in the correct word or words for each description, using one letter for each space. Circle these words in the puzzle below. Look up, down, across and backwards. B I P L A P J O S X W E F J Z D U H R P E F D U V K Y I N X A R O H T E S J L A W N S I C S O B O R P O Z M P A F Q L C V S Q L H W J I R T O U G K T I U M K U S M D E D N Y F I T P N P C L G F C L R J Y H O F D A N T E N N A E U T E U S D Q O Y X S N Y T Y E G P T A P J D A N M L R U Z C I Z E R I O C S M H O R T Y Q O T A B D O M E N E U J C S T K N Y H D R L N A P Q M I R S O A F W A R H W J Y V K T Z H N I F V L T M U P E C 1. senses sounds and odors 2. breathing holes on each side of the abdomen 3. the long segmented body region 4. with this, insects can see in all directions at once 5. used to taste and feel 6. the major body region behind the head 7. attached to the top of the thorax 8. females use this to suck blood 9. antennae and palpi are attached to this major body region 10. three on each side of the thorax 11. the study of the body parts that make up an animal - 5 -
How Does the Female Mosquito Drink Blood? Her proboscis is inserted through the epidermis (the outermost layer of the skin) to a blood capillary (a tiny blood vessel that carries the blood between the smallest arteries and veins.) The outer covering stays on top of the skin as the 6 stylets are pushed underneath. 6 Stylets Outer Covering Epidermis Capillary Proboscis Cross-Section Outer Covering Feeding Tube As she inserts her proboscis, she injects saliva into the wound with the hypopharynx. Mosquito saliva contains an anesthetic which numbs the wound. Her saliva also contains an anticoagulant which thins the blood to make it easier to suck up. She draws blood with the feeding tube upon reaching a capillary. Hypopharynx Hypopharynx Lancets Lancets Feeding Tube Cutting Lancets The four outer stylets are sharp, cutting lancets that cut through tissue, while the two tubes in the middle reach the blood supply. So, how do mosquitoes make people sick? - 6 - Look on page 7
This Is How It s Done... 1. If this wild bird is infected with an encephalitis virus, a mosquito can ingest the virus with her bloodmeal. 2. The Culex tarsalis mosquito s favorite meal is the blood of birds. If she bites this bird infected with an encephalitis virus, the blood with the virus will travel to the mosquito s stomach. Esophagus Stomach Virus Salivary Glands Feeding Tube 3. Proboscis The virus is small enough to escape through the stomach wall while the blood is being digested. The virus travels to the mosquito s salivary glands where it multiplies and grows. 4. If the mosquito needs another bloodmeal 7-10 days later and bites a human, the human will get the virus from the mosquito s saliva. 5. An infected human may become sick with flu-like symptoms When a female mosquito sucks blood from an infected animal, that blood might contain a virus. Some wild birds carry a virus that causes encephalitis. The most common encephalitis viruses in the Western USA are West Nile virus, St. Louis encephalitis and Western Equine encephalits. Even though birds and mosquitoes aren t affected by these viruses, humans and other animals can get very sick and even die from them. Mosquitoes can transmit many other diseases too, such as malaria, dengue fever, yellow fever, dog heartworm, just to name a few. - 7 -
Now You Know... Now you know why mosquitoes are so dangerous. But when they re not carrying diseases, mosquitoes can cause other problems as well... Mosquito bites can itch. Mosquitoes can spoil a party! When mosquitoes bother dairy cows, milk production goes down. Chickens get so upset, they won t lay eggs. No one likes mosquitoes! - 8 -
Why Are Mosquitoes Important? Answer these questions to test what you ve learned: Underline the correct answer - 1. What is the average size of a mosquito? 2 inches 1 inch 5/8 of an inch 2. Which mosquito is dangerous to humans? both male and female only the male only the female 3, What part(s) of the female proboscis is(are) used to cut through tissues? the outer covering the hypopharynx the 4 lancets 4. How does the mosquito get an encephalitis virus? she is born with it she sucks an infected bird s blood from other mosquitoes 5. Why don t you feel a mosquito biting you? because you re asleep her proboscis is too small to hurt she injects saliva to numb the wound 6. Once a mosquito is infected with a virus, how does she give it to a human? she injects saliva containing the virus the proboscis touches blood she injects blood containing the virus 7. Why are mosquitoes important? they are valuable to the ecosystem they are a great nuisance and can carry diseases they bother people - 9 -
Where Do Mosquitoes Come From? Look what I found swimming in this bucket full of water. What are they and how did they get there? Female mosquitoes lay their eggs in standing water (like the bucket of water) and any standing water will do! Why is standing water so important? (see the clue on page 25) - 10 -
The Mosquito Life Cycle An adult female will land on standing water to lay her eggs. She lays them one at a time and they clump together. We call this an egg raft because it floats on water eggs Egg Raft Adult Because the new adult has just come from the water, it rests on its pupal skin to dry and then flies off looking for food. Larvae hatch from the eggs and feed on small particles of food in the water. When disturbed, larvae wiggle to the bottom. That s why we call them wigglers. Wigglers grow and shed their skin four times. Larva Pupa Pupae, called tumblers, summersault through the water. They don t eat while they are in this stage. The pupa is actually in a cocoon under water. When the pupa reaches adulthood, it breaks out of its cocoon. - 11 -
Metamorphosis Have you ever heard this word before? Scientists call the change in shape and form of insects as they grow metamorphosis. Mosquitoes start their life as eggs in water. They hatch out as larvae ( wigglers ) and change into an entirely different shape and form, called pupae ( tumblers ). The first 3 stages of a mosquito s life cycle take place in water. In their last stage they change into adults and can fly. Fill in the puzzle below to test what you ve learned. Across: 4. where mosquito larvae and pupae live 6. the last stage of the mosquito s life cycle 7. a mosquito tumbler 8. the complete development of an organism through its life stages 10. laid by a female, they clump together to form a raft 7 4 1 3 6 2 5 Down: 1. the change in shape and form of an insect as it grows 2. the most dangerous insect on earth 3. larvae and pupae stay at the surface of the water to do this 5. larvae and pupae can only survive in this type of water 9. this mosquito wiggler feeds on tiny particles of food in the water 8 9 10-12 -
Be a Vector Inspector Let s inspect this backyard for mosquito breeding sources... - 13 -
How many possible breeding sources did you find? possible breeding sources - 14 -
How Do We Control Mosquitoes? There s no way to eliminate mosquitoes entirely. But there are several different methods that help keep mosquitoes under control. Let s Investigate... Remember the backyard with all the mosquito breeding sources? One of the easiest ways to control mosquitoes is to eliminate breeding sources. This is called... Pour the water out! Keep containers upsidedown so water won t collect Physical Control What can you do when you can t eliminate a breeding source (a lake or unused swimming pool for example)? at the next page to see what we do at Vector Control - 15 -
Chemical Control When physical control is not possible, the Greater Los Angeles County Vector Control District uses chemical control. This product is an insect growth regulator. Larvae will eat it and they can t grow into adults. This product, a light oil, floats on the surface of the water and prevents larvae and pupae from breathing. These products, when used properly, are not harmful to the environment. If you are having a mosquito problem, call us... We ll come out to investigate and treat a breeding source if we find mosquitoes. What else can we do? - 16 - (turn to the next page)
Biological Control Using natural predators is another method our District relies on to control mosquitoes. This is a form of biological control. What s a predator? A predator is an animal that eats another animal in order to survive. The animal that the predator eats is called its prey. What predators are used to control mosquitoes? Mosquitoes have many predators, including fish, dragonflies, bats, frogs, etc. The predator must be able to survive in Southern California year-round and be easy to raise. Mosquitofish (Gambusia affinis) are very effective mosquito predators. Our District will give these fish to anyone who has a mosquito breeding source on their property: fish ponds, unused swimming pools or Jacuzzis. Wigglers and tumblers are our favorite food! Male Female - 17 - This is a life-size picture of a male and a female mosquitofish.
What Do You Know About Mosquito Control? Fill in the blanks with the proper control method. Adding mosquitofish to an unused swimming pool. control Empty flower pots outside must be stored so they can t hold water. control Fixing leaking faucets outside. The type of control used when other control methods won t work. control control - 18 -
Meet the Vector Inspectors Respirator Gloves Spraying Equipment Dipper Vector Vehicle Hovercraft Vector Control Specialist - 19 -
Here are some of their tools... Data Blood Testing Trap Emergent Jar Sentinel Chickens Microscope Vector Ecologist Turn to pages 21 & 22 to find out how they use their tools. - 20 -
The Greater Los Angeles County Vector Control District has many different types of Vector Inspectors. They all work toward keeping the community safe from vectors. Vector Control Specialist When Inspectors work with liquid products that evaporate easily, they wear a respirator to protect them from breathing fumes. Respirator Spraying Equipment Inspectors carry this hand tank as they walk along, spraying insect growth regulator into a breeding source. Every Inspector has a truck specially equipped for day-to-day vector control activities. Vector Vehicle Gloves When Inspectors handle products every day to control mosquitoes, it is necessary to wear gloves to protect their skin. Every Inspector must have a long handled dipper that allows them to get a sample from mosquito breeding sources. If they find wigglers or tumblers in their dipper sample they know they have to treat the source. Dipper Hovercraft When larvae and pupae hide in the water among the vegetation at the edge of a lake, this vehicle allows Inspectors to reach them from the water side of the growth. - 21 -
Vector Control Specialists control vectors in assigned geographic areas. Vector Ecologists monitor mosquito counts, species and disease transmission. Vector Ecologist Inspectors place traps in selected areas of the district to catch female mosquitoes. The mosquitoes are taken back to the lab so they can be counted, identified and tested for disease. Trap Since mosquitoes are so tiny, Inspectors have to use microscopes to identify them. Microscope Inspectors record their findings and use the information to predict mosquito-borne disease outbreaks and/or nuisance problems. Data Flocks of chickens are placed in locations where mosquitoes that can carry encephalitis like to live. If encephalitis is present in an area, the chickens are likely to be infected first from a mosquito. Sentinel Chickens Inspectors sample the blood from sentinel chickens and trapped wild birds every two weeks. They send the samples to a microbiologist to test for encephalitis. Blood Testing Inspectors place water and mosquito larvae in the bottom of this jar. It is designed so the mosquitoes can grow into pupae and then emerge as adults and fly up the plastic funnel into the top chamber. Emergent Jar - 22 -
Hidden Message Word Search Circle these words in the puzzle. Look up, down, diagonally, across and backwards. Use the letters left over in the beginning of the puzzle to fill in the blanks below D T M H E M O C S M Q T U I T R to see the I O I O S T O H I E M R O S T E hidden message. P D A N S N G C E R R A P O U S CONTROL DATA DIPPER DISEASE ECOLOGIST ENCEPHALITIS MICROSCOPE MOSQUITOFISH PREDATOR PROBOSCIS RESPIRATOR TRAP TUMBLERS VECTOR VIRUS WIGGLERS P S I N T Q R S E C O P R T O P E N E R A O U R T H T C E C J I R W O N S J C I F A C P D P D R C L W C K J G O T A E Q A K Y A P R O B O S C I S O V Y T G K T L P S R E L G G I W F L O S Q O E S R E L B M U T C C I R E V R E N C E P H A L I T I S S I Y D O Y F N S V R W W E U A R H A Q N O N T K H I T Q L E U X T E A T S I G O L O C E S S Q A M J A Y V Q N A E F C I K U D L J D R D N H Q M I J D U T J N W E L Q - 23 -
Insect Anatomy Fill in the body part answers to the following questions and then draw an imaginary insect including these body parts. 1. All insects have three main body parts. They are the, and. 2. Insects see in all directions at once because they have eyes. 3. How many legs do all insects have? legs 4. How many antennae do all insects have? antennae 5. If insects fly, they can have either 2 or 4 of these. 6. Insects eat with different types of mouthparts: biting & chewing, piercing & sucking, biting & sucking and just sucking. The mosquito s piercing & sucking mouthpart is called a. Draw your imaginary insect here... (Don t forget to include all the body parts from above.) - 24 -
Page 4: The male has feathery antennae and palpi. The female has just a few hairs on her antennae and her palpi is hairless and shorter. The female mosquito sucks blood to make eggs. Blood is a good source of protein, which is necessary for the female to produce healthy offspring. Male Female Page 10: Larvae and pupae can t breathe under water. They have breathing tubes they place above the surface of the water to get air. If the water is moving too much, they can t get to the surface to breathe. Page 13 & 14: 5. 17. 16. 15. 14. 12 11. 10. 9. 8. 7. 6. 4. 3. 2. 1. 13. 20. 18. 19. There are 20 standing water sources in the picture. If female mosquitoes were to lay their eggs in all of them, think of the thousands of adult mosquitoes that could bite the people who live in this neighborhood! - 25 -
The Case Is Closed Congratulations, you have learned the most dangerous insect on earth is the mosquito! You know what they look like, where they come from and why they are so dangerous. You even know how to help us control mosquitoes. Be sure to tell your family what you ve learned and show them how to check for mosquito breeding sources where you live. If you or your family know someone with a mosquito problem, have them give us a call and we will send a Vector Inspector to give them assistance. Get a Vector Inspector Badge... You ve earned this honorary Inspector badge by completing this activity book and helping us control mosquitoes. - 26 -
Glossary Abdomen - the long, segmented major body region of an insect, located behind the head and thorax Anatomy - the study of the body parts that make up an animal Anesthetic - a numbing substance used to prevent pain Anticoagulant - a substance that stops blood from clotting so that it flows more easily Capillary - a tiny blood vessel that carries blood between the smallest arteries and veins Ecologist - a biologist that deals with the relations between living organisms and their environment Egg Raft - a group of mosquito eggs, stuck together and floating on water Encephalitis - inflammation of the brain Epidermis - the outermost layer of skin Exoskeleton - an insect s rigid outer covering which protects and supports the soft body tissues inside Hypopharynx - mouthpart of a mosquito, a very small tube that transfers saliva to the bite victim Lancets - 4 tiny, sharp, saw-like parts of a mosquito s proboscis that cut the skin of the bite victim Larva - mosquito larvae live in water and hatch from eggs, the 2nd stage in insect development Metamorphosis - the change in body form of an insect as it grows to adulthood Palpi - 2 feelers above the proboscis used to taste and feel Predator - an animal that eats another animal in order to survive Proboscis - the needle-like mouthparts of the mosquito, used for feeding Pupa - the non-feeding stage of an insect, after it was a larva and before becoming an adult Spiracles - small openings along an insect s abdomen used for breathing Stylets - the 6 slender parts of the mosquito s proboscis Surveillance - continuing investigation, collection and analysis of data to reveal emerging diseases Thorax - the middle section of an insect s body bearing six legs and wings (if it flies) Vector - an animal, usually an insect, that carries diseases Virus - a microscopic, infective agent that can cause diseases in animals and plants Written and designed by: Karen Walker Revised: 1/2007 Original Drawings by: Brent H. Walker, Karen H. Walker, David W. Pelsue and Raymond P. Wallace