In the annals of bad bugdom, ticks and fleas are often lumped together, though they have little in common, other than a propensity to bedevil dogs and cats. Fleas are insects, whereas ticks are arachnids. Back in the Jurassic Period, when fleas first appeared, Pangea was still breaking apart and dinosaurs were on the menu. Jurassic fleas were peanut-sized and had nasty, syringe-like beaks that could drill through archaeopteryx hide. They could not jump.
By comparison, today’s fleas are generally a mere one to two millimeters (tip of a sharpened pencil to tip of a new crayon). They have springy back legs that propel them up to 200 times their own body length, at an acceleration rate roughly equal to that of an Apollo rocket. And their piercing mouthparts are only as long as they need to be to pierce mammalian, avian or reptilian skin.
The flat, beaky and bristly cat flea is the most common flea species in the US, while the dog flea reigns supreme in Europe. Both are happy to feed on the other’s namesake, and neither, fortunately, shows a propensity for people. We’re just not hairy enough to suit their needs—though there is a human flea, which prefers the blood of people and pigs.
A flea’s life
Cat fleas go through a complicated metamorphosis, starting with an egg that falls off its parent’s hairy host and then hatches into a light-phobic larvae that squiggles off to a nearby warm, moist and dark corner. There, it feeds on…this is kind of gross… adult flea poop—which is, natch, dried blood.
The larvae metamorphose four times before spinning a cocoon and entering a pupal stage. They emerge at the exact moment a convenient host comes into range and immediately leap on board and start feeding.
Cat fleas like to wander and bite, rather than embed in one place like ticks. They use their saliva to soften the host’s skin, making it easier to penetrate and slurp. As with mosquitoes, it’s their saliva that’s allergenic, causing the host to itch and scratch. And scratch. And scratch. Due to a hard, slippery body and handy, Velcro-like bristles, though, fleas seldom get scratched off.
After a nice blood meal, it’s mating time. And yow!, mate they do. Males can copulate up to 48 times in eight hours, while the less lusty females get it on a mere 27 times or so. To keep from being blasted into space by the female’s rocket-booster leaps mid-coitus, the male employs toilet-plunger-like suckers to hang on.
And by the way, to say that someone is hung like a flea is extravagant praise; the male’s penis is around 2.5 times the length of its body, making it the John Holmes of the insect world.
Given the opportunity, a cat flea will spend its entire life (up to 133 days) feeding on one host, with the females laying and shedding 20 to 40 eggs each day. That’s over 5,000 eggs per flea.
The good, the bad and the itchy
Fleas are, of course, infamous for spreading the bubonic plague, aka the Black Death, that felled nearly 60% of the European population during the 14th century. At that time, it was mostly spread by the Oriental rat flea.
The plague is still around; in the U.S., it most often occurs in the Southwest, spread by the rock squirrel flea. A young Colorado girl was infected with it last summer after coming into contact with a dead squirrel. She, like the vast majority of people infected with the bubonic plague these days, survived.
The good news is, cat fleas don’t normally spread bubonic plague, though they can transmit murine typhus and tapeworms.
The even better news is, there are no cat fleas in Utah. (Or dog or human fleas, for that matter.)
Cat fleas, like fireflies, like low altitude, high temperatures and drippy, sweaty humidity. Flea eggs need relative humidity of at least 70–75% to hatch and the larvae require at least 50% to survive.
If you travel to a flea-hospitable climate where your pet becomes afflicted, don’t use toxic flea medications. The vast majority contain organophosphates and carbamates, which are neurotoxins. Why risk nausea, convulsions and respiratory arrest (in both pets and the people who come into contact with them)? Instead, check out PETA’s recommendations for safe pest control: www.peta.org/issues/Companion-Animals/flea-control-safe-solutions.aspx
The bottom line: Don’t worry about your pet getting cat or dog fleas in Utah.
But do beware of dead squirrels, prairie dogs and other potential rodential bearers of bubonic plague.
Next month:
The Truth About Ticks.