I can actually feel the bite of this mosquito. Mosquitos are the bane of summertime existence in coastal Texas, as they increasingly are in other areas due to climate change and urbanization. Did you know only females bite and feed on blood, which they need to nourish their eggs? That’s how we know the mosquito above is female. We also know she just started her meal, because her abdomen would be engorged otherwise. See the photo below to see what I mean. If you’re wondering, both males and females feed on nectar, plant juices, and honeydew, which is the sugary secretion of tiny insects like aphids.
Mosquitos don’t bug just humans; they bite other animals, including reptiles and birds. They pick up diseases from infected victims and pass them on.
Researching mosquitos got me thinking about other insects. Honestly, I’d forgotten a few things over the years, so I decided to review their basic characteristics.
The natural place to start is with their segmented bodies. In fact, the word “insect” derives from Latin and Greek words meaning “with a notched or divided body.” Insect bodies divide into three parts: the abdomen, thorax, and head.
Besides the digestive tract, an insect’s abdomen includes its reproductive organs, and respiratory and circulatory systems. Legs and wings attach to the thorax. The head comprises the eyes, antennae, and mouth. Insects with stingers, like bees and wasps, carry them at the rear of their abdomens. With the mosquito, the head delivers all the damage. That’s where we find the proboscis, which contains a complex system of needles that pierces the victim’s skin, sucks out the blood, and leaves behind hitch-hiking viruses like yellow fever, malaria, and west nile.
As support and protection, a rigid exoskeleton encases an insect’s body. If you’ve ever plucked the discarded shell of a Cicada from a branch, you’ve been up close and personal with an exoskeleton. Entomologists call these remains “exuviae.” Cicadas live most their lives as underground “nymphs”–juveniles that look like adults except for the wings. When they finally emerge from the ground as adults, they shed their outgrown exoskeletons. The process is called moulting, and almost all insects do it at least once in their lives.
Adult insects have three pairs of jointed legs attached to the thorax. Just as different types of insects have their own unique abilities, so do their legs. Cursorial legs on cockroaches are best for running, while the Saltatorial legs of grasshoppers excel at jumping. Aquatic insects like diving beetles rely on Natatorial legs to paddle efficiently. Fossorial legs help Mole Crickets burrow through dirt. Finally, predators like the Praying Mantis wield Raptorial legs to grip other insects.
All insects have a pair of antennae, which they use to sense smell. Olfaction helps them to avoid predators, to find food or a mate, or to locate a place to lay their eggs. With at least twice the odor receptors of other insects, ants top the insect mound with their ability to smell. (In another win, ants are the most numerous insects in the world, with 10 billion billion individuals. That’s a one with 18 zeros.)
Most insects have compound eyes, which absorb light through thousands of tiny lenses, each focused in a slightly different direction. While the single, large lens in the human eye produces much sharper images, the compound eye enables a far greater viewing angle. The insect sees much more of its surroundings at a single glance. What this means practically is that we see a fly clearly enough to swipe at it, but the fly has already seen our hand, even if coming from almost directly behind it, and swerved to safety.
All insects hatch from eggs, although in a few rare cases the female retains the eggs in her body until they hatch. Once hatched, most insects don’t emerge as tiny versions of their parents (like reptiles, birds, and mammals), but as larvae or young nymphs. From there they progress through additional life stages, a process known as Metamorphosis.
For paper wasps, the first three stages take place inside the nest, with adults emerging fully formed.
Houseflies search for warm, moist, and dark places to lay their eggs. A pile of fresh cow manure is ideal. Like butterflies, Houseflies develop through egg, larva, and pupa stages before emerging as adults.
Nearly all insects have wings and fly, with most having two pairs of functional wings. Flies and mosquitoes are exceptions. They have halteres, club-like organs that act as vibrating gyroscopes to maintain stable flight. There are over 800 types of flying insects.
Many insects contribute to pollination, with bees and butterflies being the most prominent. As they buzz and float from flower to flower in search of nectar, they transfer sticky grains of pollen from the anther of a flower to the stigma, thus fertilizing the plant so it can reproduce. But bees and butterflies aren’t the only pollinators. Wasps, flies, mosquitoes, beetles, and even ants pollinate.
I hope your knowledge of insects is now back to where it once was. I’ve enjoyed the review.
“Aedes Albopictus (Asian Tiger Mosquito).” Wikipedia.
“Calliphora Vomitoria (Blue Bottle Fly).” Wikipedia.
“Four-spotted chaser (dragonfly).” Wikipedia.
“Four-spotted chase.” British Dragonfly Society.
“Friday 5: Five Types of Insect Legs.” The Dragonfly Woman. 10 Dec 2010.
“Green Darner Dragonflies.” Columbus Audubon.
Hadley, Debbie. “7 Insect Pollinators That Aren’t Bees or Butterflies.” ThoughtCo. 20 July 2019.
“How to Identify Different Types of Bees.” Treehugger.
“Insect Olfaction.” Wikipedia.
“Metamorphosis (Insects).” Wikipedia.
“Mosquito.” Field Guide to Common Texas Insects: Texas A&M Agrilife Extension.
Quiros, Gabriella. “Watch: Mosquitoes Use 6 Needles to Suck Your Blood.” NPR. 7 June 2016.
Salisbury, David. “Ants Have an Exceptionally High-def Sense of Smell.” Research News at Vanderbilt. 10 Sep 2012.
“What is Pollination?” U.S. Forest Service.