One species of adolescent mosquito can suddenly launch its head forward from its body, stretching out its neck in a thin cord, to bite another juvenile. And that’s just one of the ways that young mosquitoes kill other mosquitoes, a new study shows.
For decades, scientist and cinematographer Robert Hancock and his colleagues have filmed attacks by these psorophora ciliata and two other types of predatory mosquito larvae with unusual details. Launch heads evolved independently in two of the types, he and his colleagues say in his new study.
The third predator, a species of you know mosquito larva, use its other end. Hanging head down in the water, you only need 15 milliseconds to grab prey with a hooked sweep of the breathing tube on its predatory buttresearchers report Oct. 4 in Annals of the Entomological Society of America.
The most dramatic jump in the film may be the stretch of the neck by the psorophora larva. He could power up this lunge by squeezing a blast of liquid at his head. When Hancock looks at the mosquito’s body, segmented a bit like a string of alphabetic beads, he can see two segments creaking inward “accordion-like,” as if spewing liquid forward as the head shoots out.
Throwing the head to reach the prey is one thing, but grabbing it is another problem. The newly posted video offers a clear view of a pair of brushes, one on each side of the head, that help with grip. As the head approaches its victim, the brushes fan out in what researchers call a “flimsy basket-shaped arrangement” that folds around the doomed prey.
Such an attack can scare people into thinking of mosquito bites as stealthy hypodermic bloodsuckers. That’s the adult morsel of females who crave a nutritional supplement for egg laying. Mosquito eggs, however, hatch in water and the larvae do not assume their flying dandelion form for weeks. During the aquatic phase, these larvae do not look or feed like adult forms at all.
The larvae do not bite people, and many simply filter out edible crumbs floating in the water. Carnivores, however, jump so fast that the human brain cannot analyze it. Hancock has been fascinated ever since he was in a class in the 1980s seeing just a blur through the microscope as he tried to describe feeding behavior. the toxorhinquitas The mosquitoes that later thwarted him turned out to be one of the groups that developed head-throwing larvae.
“If there’s one mosquito that all you mosquito haters might not love, it’s toxorhinquitassays Hancock, now at Metropolitan State University of Denver. As iridescent adults, they are vegan, feeding primarily on flower nectar. For the larvae, everything is meat, mainly other mosquitoes. Also, he says, “They are big and beautiful.”
The new study found that the pitch does not extend as far as the length of the head, but toxorhinquitas Vigorously attacks the prey larva. In the videos, “By the time you watched it, there was like half a maggot…while pushing this thing around like it was a hot dog eating contest,” says Hancock.
He and his colleagues also captured on video a third type of carnivorous mosquito, you know, which are more flexitarian than carnivorous. They still eat their meat from the head part, but the danger of snagging comes from the rear, videos from the researchers show. Like many mosquito larvae, they often hang upside down in the water, absorbing oxygen through a flexible siphon. It turns out that the breathing tube works as a kind of food hook, capable of snagging a target in just a few milliseconds.
“What’s up with you know it’s that they’re probably more like killers because they don’t actually ingest or consume whole prey larvae like the other two,” says Hancock. Feeding tests show that the insects get at least some nutrition from the bites.
A human watching the grub hunt may wonder why we spend so much money and chemistry trying to kill pests when their own tiny relatives do it so brilliantly. For one thing, mosquito larvae stay underwater, says entomologist Don Yee of the University of Southern Mississippi in Hattiesburg, who was not involved in the study. The two groups of neck stretchers cannot rise into the air and fly to the next water-filled tire or hole in the tree. There, a toxorhinquitas, for example, “would probably consume all the other larvae,” he says. “[H]However, there may be hundreds of such containers in the area.”
In contrast, stretching the neck psorophora mosquitoes live in larger bodies of water and could theoretically have a greater effect in reducing mosquito numbers, says Yee. But under natural circumstances, predators are unlikely to wipe out mosquito populations the way humans would like. Yee compares it to the African savannah. In the photos, “you can see how many wildebeest there are. The lions can’t really control them.” In the wild, after all, predators that thrive don’t kill off their own prey.