The arrival of summer, unfortunately, means the arrival of mosquito season. For most people in the United States, mosquitoes are simply a nuisance. In some people, however, they can cause “Skeeter Syndrome,” or a severe allergic reaction that can sometimes include anaphylactic shock. Mosquitoes are as fascinating as they are potentially dangerous. Considering the following facts about mosquitoes:
1)Number of Mosquito Species in the World
There are over 3500 species of mosquito in the world. Luckily, only a couple hundred of these feed on human blood; the others suck blood from other animals, like birds, reptiles, amphibians, and different mammals.
2)Number of Mosquito Species in the US
At least 175 species of mosquito are found in the United States. Unfortunately, they include members of such dangerous genera as Aedes, Anopheles, and Culex.
3)States with Least and Most Mosquito Species
The happy state of West Virginia has the fewest mosquito species with only 26. By contrast, Texas has been cursed with 85 species. Florida has the second-highest number of species with 80.
4)Order and Family
Mosquitoes belong to Diptera or the order of the true flies. They also belong to their own family, Culicidae. The word “mosquito” comes from the Spanish words for “little fly.”
Mosquitoes generally can’t fly very far, fast, or high. Their top speed is around 1.5 miles per hour, and they typically stay within several hundred feet of their hatching grounds. Similarly, mosquitoes can usually fly only one to three miles, but some salt marsh species have been known to travel as far as 40 miles. Most mosquitoes also don’t fly any higher than 25 feet – but some mosquitoes have been found in the Himalayas at altitudes of 8,000 feet!
6)Mosquitoes Take Siestas
Mosquitoes are least active in the afternoon. The insects rest in relatively cool places to avoid the heat.
7) How to Tell Males From Females
Look at the antennae. Male mosquitoes have feathery antennae that let them track the wingbeats of the females. A female mosquito’s antennae are far plainer and more sparsely feathered.
8) Mosquitoes Are Ancient
Mosquitoes first appeared in the Jurassic period; scientists have found fossilized mosquitoes that are 210 million years old. They have also been mentioned in historical records. Aristotle (384 – 322 BC) wrote about the mosquito – and philosophically wondered what its reason for being was.
9) About the Proboscis
Mosquitoes don’t have teeth; instead, they have a proboscis, which is a long, serrated and pointed mouthpart. A mosquito uses the proboscis to pierce its victim’s skin. After finding a capillary, the mosquito uses one of two tubes to suck out blood. It can drink up to three times its own weight in blood.
10) Why Only Female Mosquitoes Suck Blood
While both male and female mosquitoes feed on plant nectar to get the sugar they need to eat, only female mosquitoes suck blood. They can drink three milligrams or 3 millionths of a liter every time they bite somebody. Female mosquitoes need the iron and protein in the blood to make their eggs.
11) Why Mosquito Bites Itch
A female mosquito’s saliva contains a chemical that prevents the victim’s blood from clotting. The mosquito’s saliva also triggers an allergic reaction from the victim’s immune system, which is why mosquito bites cause itchy welts.
12) How Mosquitoes Find Victims
Mosquitoes can sense the humidity and heat given off by the human body, and they are attracted to the lactic acid, octenol, and carbon dioxide in human sweat and breath. Mosquitoes may be especially attracted to people who drink beer.
13)Stages of Life
Mosquitoes have a life cycle with four stages: Egg, larvae, pupa, and adult. Mosquitoes can reach maturity in as little as five days, depending on their species and the temperature. Their life expectancy can range from two weeks to six months, again depending on species and environmental conditions.
14)Where Mosquitoes Hatch
Mosquitoes need to hatch in water, and different species need different types of water, ranging from relatively pristine to grossly polluted. Most mosquito species lay their eggs in clumps called rafts that float on the water’s surface. There is usually about 50 to 100 eggs in a raft. Female mosquitoes lay about three rafts before dying.
A few species lay single eggs in moist soil in areas prone to flooding.
15) How Long Eggs Take To Hatch
While eggs laid in water hatch within three days, eggs laid on land can remain dormant for a year until there’s enough rain for the larvae to live in.
16)What Wrigglers Are
Mosquito larvae are called “wrigglers” for their movements in water. Wrigglers generally spend their time suspended upside down in the water. Wrigglers are cold-blooded, so the temperature of the water determines the rate of their growth. The warmer the water is, the faster they will grow.
17)What Wrigglers Eat
Wrigglers eat various microorganisms in the water. While many will feed on bacteria and/or algae, some wrigglers will eat each other.
18) Pupa Stage and Emergence
A wriggler will generally molt four times before becoming a “tumbler” or pupa. Tumblers don’t eat; they just swim around with their flippers. When the adult mosquito has fully developed, they will use air pressure to make the cocoon split open, so they can emerge. The new adult will rest on the water until their bodies and wings harden.
As soon as they’re able to fly, the newly-minted adult will start looking for a mate. Some adult males, however, may have to wait a day for their reproductive organs to finish developing. After tracking a female down by the sound of her wingbeats, the male will mate with her. The male mosquito dies three or five days after mating. Female mosquitoes lay eggs once every three days, and they usually lay their eggs at night.
20) Some Mosquitoes Hibernate
While most mosquitoes have short life expectancies of only a few weeks and die shortly after mating and/or laying eggs, a few species can survive the winter. They do so by going into a state called diapause that resembles hibernation. As the days get shorter, they look for warm places like sewer drains where they will not be in danger of freezing. They then enter a state of suspended animation and live off their fat stores. A mosquito can survive being in diapause for several months.
Mosquitoes and Disease
21)Deadliness of Mosquitoes
Mosquitoes have caused more humans deaths than any other animal on the planet by transmitting a variety of disease-causing parasites and viruses. Malaria, the most common disease transmitted by mosquitoes, causes about a million deaths every year, with most of the victims being children in Africa. Some reports say that a child dies from malaria every 40 seconds.
22)Other Diseases Caused By Mosquitoes
Other diseases transmitted by mosquitoes include the following:
• Zika virus
• Yellow Fever
• West Nile Virus
• Dog Heartworm
23)Death of Alexander the Great
Some researchers believe that Alexander the Great died from malaria in 323 BC. While it’s not definite, historians do know that the king died from a fever that lasted for ten days.
24)The Washingtons and Malaria
President George Washington and his First Lady Martha both suffered from malaria. Washington had contracted the disease in adolescence. During his second Presidential term, he had a reaction to the quinine used to treat him that left him with severe hearing loss.
25)Dr. Walter Reed
In 1898, Dr. Walter Reed investigated the causes of typhoid fever and yellow fever during the Spanish-American War. Back then, people believed that yellow fever was spread by contaminated bedding and clothes, but Reed found it was actually transmitted by mosquitoes. His discovery soon led to yellow fever being controlled in the United States
26) Last Yellow Fever Outbreak
The last outbreak of yellow fever in the US occurred in New Orleans in 1905. The authorities tried to control the outbreak by fumigating every ship that came into port. Unfortunately, a smuggler with a shipload of bananas managed to slip through. By June, Italian immigrants who worked on banana boats started to fall ill.
27)First Appearance of the West Nile Virus in the US
The West Nile Virus (WNV) first appeared in North America in 1999. It infected both humans and horses at the Cornell Environmental Risk Analysis Program in New York. Seven people and nine horses died. Since then, it has spread throughout the continental United States, Canada, Mexico, and parts of the Caribbean.
28)Birds Were Originally Blamed For the West Nile Virus
People initially blamed birds for the spread of the West Nile Virus in the US. Researchers in 2010, however, found that mosquitoes were the vectors. Since then, they have found that over 60 species of mosquito can carry the West Nile Virus, and they can infect 300 vertebrate species. In the most typical scenario, a Culex species will infect a common bird species, like the house sparrow or American robin.
Researchers have traced the chikungunya virus to a drought in Kenya that occurred in 2004. So far, most of the cases seen in US citizens have involved people traveling from places with infected mosquitoes, but there have been a few cases of people in Florida, Puerto Rico, and the US Virgin Islands contracting chikungunya from local mosquitoes.
30)The Gates Foundation’s Mission
The Bill & Melinda Gates Foundation has made it one of its missions to eradicate malaria throughout the world. As the malaria parasite is becoming resistant to current medications and treatments, the Foundation is funding research for new drugs. It is also funding research for new insecticides, as mosquitoes are becoming resistant to the current insecticides.
31)Mosquito-Borne Diseases in the US
The US eradicated malaria within its borders only as recently as 1951, but it is still plagued by other mosquito-borne diseases like chikungunya and West Nile Virus.
Some scientists want to go even further and eradicate mosquitoes altogether. While some believe this would be beneficial, others worry about the impacts on the ecosystem, for many creatures eat mosquitoes. A partial list of their predators includes fish, frogs, spiders, salamanders, and other insects.
Defenses Against Mosquitoes
33)Effective Mosquito Repellents
According to the Centers for Disease Control and Prevention (CDC), the only insect repellents that work against mosquitoes are those containing any of the following ingredients:
• Oil of lemon eucalyptus or its synthetic variant para-menthane-diol (PMD)
Insecticide-treated nets (ITNs) can reduce malaria in children and pregnant women by as much as 50 percent. The nets, which hang over beds, have to be replaced every few years.
35) Sources of Standing Water
All mosquitoes have aquatic young that need standing water. The water source doesn’t have to be big – in fact, some mosquitoes will lay eggs in something as small as a bottlecap filled with water. Common mosquito breeding grounds can include old tires, bird baths, pet food dishes, decorative ponds with no fish, drainage ditches, clogged rain gutters, and longstanding mud puddles.
36)Getting Rid of Standing Water
There are many ways to eliminate potential mosquito breeding grounds:
• Throw out old tires, used flower pots, buckets, etc.
• Dump water out of items like bird feeders and wading pools at least once a week
• Stock garden ponds with fish that will eat the mosquito larvae
• Store things like boats or wheelbarrows upside down if they are outside or keep them indoors
• Clean out ditches and roof gutters to keep them from clogging
Types of Mosquitoes
Mosquitos in the genus Anopheles can carry Plasmodium, the protozoan that causes malaria. About 40 percent of the world’s population, particularly people living in sub-tropical and tropical regions, are vulnerable to malaria.
38) Anopheles gambiae
Anopheles gambiae is the most important carrier of Plasmodium in sub-Saharan Africa. It is especially notorious as the carrier of P. falciparum, the most dangerous species of malaria parasite. A. gambiae is actually a complex of at least seven different species of mosquito that look identical to each other. The various species do show different behavioral traits. For example, two of the species lay their eggs in saltwater, while the others lay their eggs in freshwater.
39)Yellow Fever Mosquito
The Yellow Fever mosquito (Aedes aegypti), which is considered one of the most widespread mosquito species in the world, originated in Africa. It has since spread to every continent in the world, except Antarctica, for it can live in temperate, subtropical, and tropical climates. In addition to yellow fever, it can also transmit Zika virus, dengue fever, chikungunya, and other diseases.
40)Asian Tiger Mosquito
The forest or Asian tiger mosquito (Aedes albopictus) comes from Southeast Asia. It can transmit many of the same diseases as the Yellow Fever mosquito, plus some parasitic nematodes, including Dirofilaria immitis, which causes heartworm in dogs and other mammals. It has spread to the Americas, the Caribbean, Africa, the Middle East, and Europe over the past 50 years. The Global Invasive Species Database puts the Asian tiger mosquito on its list of “100 of the World’s Worst Invasive Species.”
41)Northern House Mosquito
The most common mosquito species in the US is Culex pipiens, which has the benign-sounding common name of “northern house mosquito.” It is, however, the primary vector of the West Nile Virus.
Mosquitoes are an ubiquitous and unpleasant aspect of summer and its warm weather. The best way to keep them from ruining outdoor fun is to deny them places for egg-laying and to use the appropriate insect repellents.