Sentences with word «damselfly»

In the absence of mortality threat, growth rates of damselflies increased with warming until about 23.5 °C and then began to decline, a typical unimodal response to changes in temperature.

Researchers have seen other species resort to parthenogenesis when isolated, such as damselflies in the Azores.

Their results imply that males, but not females, pay a high cost when using color to communicate with other damselflies, both in terms of predation risk and visibility to prey.

He details the intimate activities of reptiles with two penises, male damselflies that can scrape out the sperm from a female's previous partner, 70 - ton sauropods whose unique anatomy meant only one position was physiologically feasible, and Amazonian catfish, which rely on oral sex to fertilize their eggs.

We measured and evaluated how temperature and predation risk affected growth rates of predaceous damselfly nymphs (Enallagma vesperum, Odonata: Coenagrionidae).

All the other giant damselflies live in South America.

This month, dragonfly and damselfly larvae will start to emerge from the water as adults.

Using damselfly nymphs (Lestes congener) hatched in the lab, researchers put nymphs of various sizes in two different temperature environments, one a balmy 18 ° Celsius and the other a toastier 24 ° Celsius.

As youngsters, damselflies sometimes engage in good old - fashioned cannibalism, when larger nymphs make a meal out of smaller ones.

While temperature doesn't typically affect when damselflies hatch, it does affect how fast they grow.

The researchers, who release their findings in the Proceedings of the National Academy of Sciences, did not see a similar reduction in trematode infections in the presence of larval damselflies, which are intraguild predators, meaning they attacked and killed not only the parasites but also the tadpole hosts.

Observations revealed that D. villosus took a far greater toll on the other species in its tank than did G. duebeni, killing and mangling large numbers of blue - tailed damselflies, water boatmen, fish leeches and water hoglice.

Researchers from the Universities of Turku and Helsinki, Finland, are the first in the world to discover which species adult dragonflies and damselflies prey upon, as modern laboratory techniques enabled the study of the insects» diet.

One is the African damselfly Coryphagrion grandis (see picture), which has a body up to 12 centimetres long.

As a result, it is rare to find more than one larva in a single tree hole, says damselfly expert Viola Clausnitzer.

When her team took a closer look at dragonfly and damselfly antennae with an electron microscope, they spotted tiny bulbs in pits that resembled olfactory sensilla.

Groups of cockroaches have consistently shy and bold members, whereas damselflies have shown differences in risk tolerance that stay the same from grubhood to adulthood.

They brought damselflies into the lab and measured how much they ate and grew at different temperatures and how that changed when a fish predator was nearby.

Helicopter damselflies specialise in plucking orb - weaving spiders from their webs.

Thanks to Laurel Symes for help with damselfly identification; Danny O'Donnell, Zach Wood, Lauren Bonvini, Kathy Culler, and Bret Manning for help with lab and field work; and Craig Layne and Sam Fey for help with Daphnia rearing.

First, we conducted growth trials at five temperatures crossed with two levels of predation risk (fish predator present versus absent) and measured growth rates, consumption rates, assimilation efficiencies, and production efficiencies of 107 individual damselflies.

I also keep notes on my bird life list, butterfly life list, reptile life list, dragonflies and damselflies list and amphibian life list.

«One of our most surprising findings was that male damselflies are unable to discriminate the wing coloration of perching females.

Damselflies live in coastal forests that once formed a continuous belt in east Africa but are now fragmented, forcing the creatures into small, vulnerable populations.

A new study from a group of researchers at Uppsala University has studied the conspicuous wing coloration of two species of damselflies.

This implies that males, but not females, pay a high cost when they use color to communicate with other damselflies, both in terms of predation risk and visibility to prey.

Also, naturalists discover 60 new species of dragonfly and damselfly in Africa, the National Institutes of Health reveals its first agency - wide strategic plan in more than 20 years, and the U.S. National Science Foundation plans a massive overhaul of its McMurdo research station in Antarctica.

Better yet, on the dust - jacket of David Attenborough's splendid Life in the Undergrowth, a creature that turns out to be a damselfly appears to be sizing up the reader as it pauses, front legs arrested in a judo - like stance, perhaps interrupted at tea.

We can see a damselfly, but who knows what the damselfly sees?

Based on this effective model, the Dragonfly Monitoring Network was created with the aim of gaining a greater knowledge of the distribution and abundance of dragonfly and damselfly species in the Chicago region and, eventually, to expand the network across Illinois and beyond.

Other wildlife found here include a variety of amphibians, reptiles, and mammals such as painted turtles, Fowler's toads, red fox, river otters, and at least 24 species of dragonflies and damselflies.

Dragonflies and damselflies may mate while flying together in mid air in «tandem flights.»

So a team at the University of Toronto tested whether a warmer world would also be a damselfly - eat - damselfly one.

Kuntner and colleagues staked out 46 webs and found that most of the prey was small insects like beetles, damselflies, dragonflies and wasps.

Damselflies in the hotter setting displayed bigger differences in body size, higher activity levels and increased cannibalism rates.

Reeves says it is possible that building larger, less - appetising decoys may be a way for the spiders to evade their damselfly predators, which would otherwise pluck them from their webs.

She's eager to show off its treasures: iridescent beetles from South America, bugs with plantlike bodies, damselflies and dragonflies from around the world.

We hypothesize that females use this to reduce male harassment, which is very intense in damselflies.

In the new paper the researchers studied the conspicuous wing coloration of two species of damselflies, which are predated by birds and prey on small flies.

Using electrophysiology, they first determined the color vision of the damselflies and found that they see well in UV as well as in the human visible range.

The researchers found that males are very conspicuous to bird predators, to other damselflies, and to prey, while females remain predominantly cryptic (i.e. hard to see against the background).

Dragonflies and damselflies, i.e. the odonates, are numerous and quite large insects.

The conspicuous wing coloration is used in color communication between the sexes and between different species of damselflies.

Dragonflies and damselflies have shrunk since the time when some had wingspans of 70 centimetres, some 300 million years ago, perhaps because the atmosphere nowadays has less oxygen to power such monstrous insects.

When Rebora's team exposed the suspected sensilla to scents, they emitted nerve pulses, supporting the idea that damselflies and dragonflies perceive odors.

Their signals would have to actually affect behavior in dragonflies and damselflies.

Once believed to lack a sense of smell, dragonflies and damselflies, such as Ischnura elegans (pictured), possess olfactory bulbs in their antennae that may help them track prey.

Because dragonflies and their close cousins, damselflies, don't possess glomeruli or any higher order smell centers in their brains, most scientists believed these insects were unable to smell anything at all.

Damselflies gravitated to the spot of the screen just on the other side of the fruit fly cluster, providing the first evidence that scents guide damselfly and dragonfly behavior, the team reports this month in the Journal of Insect Physiology.

To ensure their experiments were relevant to fruit flies» real - world experiences, Card teamed with fellow Janelia group leader Anthony Leonardo to record and analyze the trajectories and acceleration of damselflies — natural predators of the fruit fly — as they attacked.