While insect grooming has been observed and documented for over one hundred years, we present the first quantitative analysis of this highly dynamic process. Pollinating insects, like honey bees, purposely cover themselves with millions of pollen particles that, if left ungroomed, would make sensing and controlled flight difficult. How do they get clean? We show that the hairs on insect eyes are tuned to the pollen they collect; namely, the hairs are spaced so that they suspend pollen above the body for easy removal by the forelegs. In turn, hair spacing on the foreleg dictates the leg's ability to store the pollen removed during each swipe. In tests with wax-covered honey bees, we show that hairy forelegs are necessary for pollen removal. Moreover, the viscous fluid found on the surface of pollen grains, or pollenkitt, greatly enhances adhesion. We find that bees accumulate twice as much pollen if pollenkitt is present. This study may help further understand pollination, as well as inform designs for mechanically-sensitive functional surfaces with micro- and nano-structures that are easier to keep clean.
The swinging of a mammal's tail has long been thought to deter biting insects, which, in cows, can drain up to 0.3 liters of blood per day. How effective is a mammal's tail at repelling insects? In this combined experimental and theoretical study, we filmed horses, zebras, elephants, giraffes and dogs swinging their tails. The tail swings at triple the frequency of a gravity-driven pendulum, and requires 27 times more power input. Tails can also be used like a whip to directly strike at insects. This whip-like effect requires substantial torques from the base of the tail on the order of 10 1-10 2 N m, comparable to the torque of a sedan, but still within the physical limits of the mammal. Based on our findings, we designed and built a mammal tail simulator to simulate the swinging of the tail. The simulator generates mild breezes of 1 m s-1 , comparable to a mosquito's flight speed, and sufficient to deter up to 50% of mosquitoes from landing. This study may help us determine new mosquito-repelling strategies that do not depend on chemicals.
Honey bees ( Apis mellifera ) carry pollen back to their hive by mixing it with nectar and forming it into a pellet. The pellet must be firmly attached to their legs during flight, but also easily removable when deposited in the hive. How does the honey bee achieve these contrary aims? In this experimental study, we film honey bees removing pollen pellets and find they peel them off at speeds 2–10 times slower than their typical grooming speeds. Using a self-built pollen scraper, we find that slow removal speeds reduce the force and work required to remove the pellet under shear stress. Creep tests on individual pollen pellets revealed that pollen pellets are viscoelastic materials characterized by a Maxwell model with long relaxation times. The relaxation time enables the pellet to remain a solid during both transport and removal. We hope that this work inspires further research into viscoelastic materials in nature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.