e g. caterpillars) consume more nonnative (introduced from other places) oak leaf material in areas with diverse native plant communities than in less diverse communities.
But a new Yale-led study shows the critical importance of earthworms beetles and other tiny creatures to the structure of grasslands and the valuable ecosystem services they provide.
and resistance to insect pests and diseases but whether or not diverse forests are adapted also better to deal with drought stress remains unknown.
#Mountain pine beetles get bad rap for wildfires, study saysmountain pine beetles get a bad rap and understandably so.
The grain-of-rice-sized insects are responsible for killing pine trees over tens of millions of acres in the Western U s. and Canada over the last decade.
But contrary to popular belief these pests may not be to blame for more severe wildfires like those that have swept recently through the region.
Instead weather and topography play a greater role in the ecological severity of fires than these bark-boring beetles.
whether fires that burn in areas impacted by mountain pine beetles are more ecologically severe than in those not attacked by the native bug.
While the findings may exonerate the insect scapegoats they should also help ecosystem managers better respond to changes in the face of climate-driven disturbances like drought and warmer temperatures.
The phenomenon of more beetles has meant more dead trees and some have grown concerned about how beetle attacks
The burrows the beetles carve under the bark of pines called galleries choke off water and nutrient circulation in the trees.
Fortunately for the team among the burned areas studied were pine stands that had not been attacked by beetles.
Others suffered a range of mortality from the beetles; in some stands beetles killed nearly 90 percent of the trees prior to wildfire.
The fires that raged also ran the spectrum of severity allowing the researchers to compare a number of variables.
and stripped sections of bark from over 10000 trees to determine what killed them beetles
or Fire beetle galleries can remain visible under the bark even after fire. As they sifted through the blackened trees
and windy--did areas with more beetle-killed trees show signs of more ecologically severe fires such as more deeply burned trunks
By counting the number of post-fire tree seedlings in their plots the researchers found very little beetle-related impact.
#Preference for built-up habitats could explain rapid spread of tree bumblebee in UKTHE strikingly rapid spread of the Tree Bumblebee in Britain could be occurring
A new study published today shows that Tree Bumblebees are associated with built-up areas and that these areas form a large part of their habitat use.
These markedly different habitat and foraging preferences set this species apart from other common British bumblebee species
--which could explain how Tree Bumblebees have managed to colonize much of the UK while many other bumblebee species have been declining.
The Tree Bumblebee (Bombus hypnorum) has spread to nearly all of England and Wales since its first appearance in southern England in 2001.
The research team recorded the bumblebee species and the flowering plants visited by the bees at a large number of sites across southern Norfolk including both urban and rural sites over a three month period.
When combined with landscape mapping data these observations revealed that the Tree Bumblebee was much more likely to be found in built-up areas and to a lesser extent areas with woodland nearby.
In contrast none of the other five bumblebee species studied shared the combination of favoured landscape features found in the Tree Bumblebee.
Additionally the Tree Bumblebee preferred to forage on a set of flowering plants different to the sets of plants favoured by the other bumblebee species being more likely to use some species of flowering trees
and thistles but less likely to use some common herbaceous flowers. The results are the first evidence that in its new range in the UK the Tree Bumblebee is associated with built-up areas such as towns and villages and that these areas form a large part of its habitat use.
An association between Tree Bumblebees and human habitation has previously been suspected from natural history observations. Along with an association with trees it is likely to stem from the Tree Bumblebee's habit of nesting in cavities above the ground
which is unusual among British bumblebees. Lead author Liam Crowther from UEA's School of Biological sciences said:
This research implies that the Tree Bumblebee's remarkable success is due in part to favouring a suite of resources different to those used by the bumblebee species that are already widespread in the UK.
While an association with human habitation has been suspected for some time this study provides clear evidence of this link
and suggests that urban and suburban areas may be facilitating the Tree Bumblebee's remarkably rapid natural colonization of the UK.
The Tree Bumblebee was recorded first in the UK in the New Forest in 2001 and has expanded since its range approximately 600 km northwards through most of England
and Wales and into southern Scotland a rate of expansion of nearly 50 km per yearin continental Europe and Asia however its range extends from western France to Japan and as far north as the Kola Peninsula in arctic
and seed production collect insects survey mammals quantify carbon stocks and flows within the ecosystem take soil samples
and the insects that feed on them. But sugars may also be part of a deadly game of tag between plant and insect according to scientists at the Max Planck Institute for Chemical Ecology.
Grasses and crops such as maize attach sugars to chemical defenses called benzoxazinoids to protect themselves from being poisoned by their own protective agents.
Then when an insect starts feeding a plant enzyme removes the sugar to deploy the active toxin.
The Max Planck scientists have discovered now why this defensive strategy fails to work against Spodoptera larvae.
After the plant removes the sugar the insect reattaches it but in the opposite stereochemical configuration.
which explains the success of Spodoptera species. Plants usually defend themselves against insect feeding by producing toxins or deterrents.
However many insects have become adapted to plant defenses and can feed on plant tissues containing toxins or deterrents without the expected negative effects.
Insects overcome plant defenses by the rapid excretion sequestration or detoxification of toxic substances Not only have contributed such adaptations to the vast diversification of insects in the course of evolution they also support the success of agricultural pests specialized on certain crop plants that jeopardize crop yields every year.
With the abundance of maize grown throughout the world it is not surprising that the crop has many insect pests including larvae of the Genus spodoptera.
In North and South america the fall armyworm Spodoptera frugiperda is an important maize pest causing considerable damage.
Like all cereals and other members of the grass family maize plants defend themselves with chemistry.
The plant also produces an enzyme active in caterpillar guts which cleaves DIMBOA-glucoside to release the sugar.
The free DIMBOA formed as a result causes many insects to die or cease growing but not the fall armyworm.
A group of researchers led by Daniel Giddings Vassã£o and Jonathan Gershenzon from the Department of Biochemistry at the Max Planck Institute for Chemical Ecology in Jena Germany have discovered recently a previously unknown detoxification strategy in these pest insects.
Caterpillars of the fall armyworm and two other Spodoptera species deploy a gut enzyme that catalyzes the attachment of a sugar to the toxic free DIMBOA.
The sugar group is reattached in a mirror-image orientation (forming a (2s)- DIMBOA-glucoside) so that the plant enzyme cannot remove it a second time.
We were surprised that the difference between the insect metabolite and the original plant compound was simply the stereochemical configuration of one atom.
The crucial change however is the fact that the insect metabolite is no longer reactive to the plant enzyme
The elegance of such a mechanism comes from its simplicity yet it saves the insects from being poisoned said Felipe Wouters who performed the experiments for his doctoral thesis at the institute summarizing the results.
Like his colleague Daniel Giddings Vassã£o Felipe Wouters is from Brazil where fall armyworm caused major losses of the maize yield before Bt maize was introduced.
According to a Reuters report this summer Brazilian farmers are complaining that Bt is not protecting the plants against the fall armyworm any longer.
The increasing resistance of pest insects to Bt is another reason to look deeper into the natural insect adaptations against plant defenses.
If we can better understand how much this gut enzyme has helped the fall armyworm to become such a dangerous pest on maize we may be able to use this to our advantage by impairing this insect enzyme
Plant-insect interactions involve very complex and dynamic metabolic processes. The importance of the three-dimensional structure of molecules and the stereospecificity of chemical reactions is overlooked often.
These insects can teach us humans a lot about an important chemical concept the idea that a compound
and the encoding genes that are responsible for the detoxification process in the fall armyworm. They also want to look for equivalent enzymes in related species and compare these.
If the researchers can obtain a more comprehensive picture of how benzoxazinoids are metabolized in pest insects they may be able to design better strategies to reduce pest damage.
Every morning the cherry grower sprinkles the spores into a specially designed dispenser that has been fitted in front of the hive.
and the number of managed hives. This will help prepare Australia for the expected incursion of the Varroa mite
and termite guts for microbes that can efficiently break down plant cell walls for the production of next-generation biofuels
and termite gut it looks like we can actually make some contributions ourselves he said. And our bugs seem to have some enzymes that are even better than those in the cow rumen.
Story Source: The above story is provided based on materials by University of Illinois at Urbana-Champaign.
#Mown grass smell sends SOS for help in resisting insect attacksthe smell of cut grass in recent years has been identified as the plantâ##s way of signalling distress
but new research says the aroma also summons beneficial insects to the rescue. â#oewhen there is need for protection the plant signals the environment via the emission of volatile organic compounds which are recognized as a feeding queue for parasitic wasps to come to the plant that is being eaten
#whether by blade of a mower or jaws of a predatory insect â#by producing defensive proteins
To test how it functions in plant during insect attacks Kolomiets and his team used a mutant corn plant that could not produce the green leaf volatiles mown-grass smell when cut or torn.
And thatâ##s when they observed that the parasitic wasps didnâ##t pay attention to plants without the green leaf volatile. â#oethere are actually two roles for this moleculeâ#he said. â#oefirst it activates the jasmonate hormone
which involves activation of defenses against insects on the plant. Then this molecule since it is a volatile attracts parasitic wasps.
They come to the plant that is being chewed up by insect herbivores and lay eggs in the caterpillarâ##s body. â#oewe have proven that
when you delete these volatiles parasitic wasps are attracted no longer to that planteven when an insect chews on the leaf.
So this volatile is required to attract parasitoids. We have provided genetic evidence that green leafy volatiles have this dual function â#in the plant they activate production of insecticidal compounds
but also they have indirect defense capability because they send an SOS-type signal that results in attraction of parasitic wasps. â#Kolomiets tested the phenomena both in the lab
and in the field. â#oewe did not have to do any artificial infestation because we had plenty of insectsâ#he said. â#oewe have discovered that even under the field conditions
when thereâ##s enough insect pressure then the plants are more susceptible to insect damage
We have found that this gene is required for many many different physiological processes such as drought toleranceâ#he said. â#oewe observed that mutant plants are drought susceptible as well as susceptible to insect feeding.
and how it works. â#Such findings may help plant breeders know how to develop new varieties that are more resistant to insects and drought he noted.
and tossed by the wind a field of soybean plants presents a challenge for an Asian lady beetle on the hunt for aphids.
That's good news for hungry lady beetles according to research Barton published in the September issue of the journal Ecology.
Lady beetles eat a major soybean pest the soybean aphid. Barton grew plots of soybeans in alfalfa fields protecting some with wind blocks
He found two-thirds more lady beetles in the plots hidden from the wind and twice as many soybean aphids on the plants growing in the open.
Wind has no direct effect on the aphids tiny insects that hug the plants and anchor themselves while feeding with a needle-like mouthpart called a stylet.
The aphids appear on the plants whether it's windy or not and we showed that in lab experiments Barton says.
But when you add the predators with the wind block the beetles eat something like twice as many aphids.
In his lab trials--simulating wind with fans and windless movement with a machine that tugged on tethered plants to shake
and bend them--a stilled soybean plant represented a smorgasbord for the lady beetle. How do you do your duty as a predator if you're entire world is moving around?
and it eats less than half as many aphids in an hour. Slower natural wind speeds could reduce the amount of pesticide required to keep soybean aphids from wrecking harvests.
And the wind research may present other opportunities for pest control. By growing trees or not harvesting them around a field you may be able to have an indirect effect on the number of aphids on your soybean plants says Barton who wonders what other close animal relationships may be disrupted by shifting winds.
The mechanism may be different for other predators but it's not hard to start thinking about effects he says.
#Peacocks train is not such a drag afterall: Flight unchanged with and without plumagethe magnificent plumage of the peacock may not be quite the sacrifice to love that it appears to be University of Leeds researchers have discovered.
Dr Graham Askew from the University's School of Biomedical sciences filmed five Indian peacocks taking off using two high-speed video cameras to try to work out
what price male birds pay for carrying the spectacular iridescent feathers they use in displays to attract females.
The train of the peacock is one of the most iconic examples of sexual selection in the animal kingdom.
The results do not mean that having an ornate train carries no costs for peacocks.
Together with her colleague from GÃ rlitz Dr. John M. C. Hutchinson and a colleague from the United states Department of agriculture (USDA-APHIS) the scientist has studied the distribution of these mollusks
and totally eco-friendly sound and odor devices to fight off insects from their cultivated fields.
These areas are an important resource for pollinators and it now seems they even have an impact on the yield of the cultivated crops.
The European grape berry moth and the cicada Scaphoideus titanus are considered to be the major pests of cultivated grape.
Camilla Moonen and her team focus on natural pollinators like the wild bee. In experiments they are investigating
whether natural pollinators contribute a higher yield quality. Both of these studies have shown that modern agriculture can still learn from nature
athletes in sports such as cricket long jump triple jump and pole vault and found the vertical objects sportspeople see at the end of the runway significantly impact their performance.
#Femme fatale emerald ash borer decoy lures, kills malesan international team of researchers has designed decoys that mimic female emerald ash borer beetles
Specifically we coated a dead female beetle with a vapor of nickel and used the'nickelized'shell to fabricate two matching molds in the shape of a resting beetle said Akhlesh Lakhtakia Charles Godfrey Binder professor of engineering science and mechanics
The finished bioreplicated decoys retained the surface texture of the beetle at the nanoscale. Additionally we painted some decoys a metallic green.
and shape of emerald ash borers but did not attempt to duplicate the surface texture of the insects.
According to Domingue the light-scattering properties of the beetle's shell--which the team experimentally demonstrated using a white laser--made the nano-bioreplicated decoys more lifelike and therefore more attractive to males than the non-textured 3d printed decoy.
Beetles appear to be able to recognize this feature of the decoys and are attracted strongly to it.
thus enabling us to figure out how these destructive beetles find each other to mate and how we can exploit this behavior
in order to help APHIS meet its goals of early detection and mitigation of invasive pests he said.
and assessed immediately by APHIS personnel rather than waiting days or weeks until a trap might usually be checked said Baker.
In addition the team has been investigating the use of the decoys to attract other insect species some
and sheep industries in the United states an estimated $125 million annually manages to survive the winter by reproducing in the insect that transmits it report veterinary scientists at the University of California Davis. The findings solve a century-old mystery
By conducting this epidemiological study on a commercial dairy farm in Northern California we were able to demonstrate that the virus overwinters in female midges that had fed on an infected animal during the previous season said lead author Christie Mayo a veterinarian
About bluetonguebluetongue disease first identified during the 1800s in southern Africa is transmitted by the Culicoides biting midge a tiny gnat sometimes referred to as a no-seeum.
when midges are abundant in late summer and fall but there has been speculation over how the virus survives through the winter.
and the biting-midge populations plummet transmission appears to cease for more than six months but the virus reappears
when temperatures warm the following season Findings from California dairythe researchers monitored cows and midges on a Northern California dairy farm for more than a year.
They documented for the first time the presence of genetic material for the bluetongue virus in female midges that were collected during two consecutive winter seasons.
The bluetongue virus was widespread in both the dairy cows and the midges from August to November.
Surprisingly however the researchers discovered that the virus was also present in female midges captured in February of both 2013 and 2014.
The researchers concluded that those long-lived female midges had been infected with the bluetongue virus during the previous warm-weather season.
Different species specialize in keeping different pest insects under control in pollinating the many flowering trees and other plants in tropical landscapes and then in dispersing their seeds.
For example farmers in the United states and Australia have used planting of pest-friendly refuges to delay evolution of insect resistance to genetically engineered corn and cotton.
Providing refuges of conventional plants has been especially effective for suppressing resistance in the pink bollworm an invasive pest of cotton.
#Unusual host preference of a moth species could be useful for biological controla team of Iranian researchers from the Rice Research Institute of Iran have discovered that Gynnodomorpha permixtana a well-known moth species from Europe
The importance of this adaptation for biological control of problematic weeds in rice fields and the biology of the moth on new host plant have been described in the open access journal Nota Lepidopterologica.
Their studies have revealed that the larvae of a certain moth species feeding on the fruits
After this discovery the moth was sent for identification to Dr Leif Aarvik from the Natural history Museum University of Oslo who have diagnosed the species as the commonly known G. permixtana
'To our surprise it looks like this moth chose new host plant in Iran. This moth was reported in 2009 from the northern regions of the country
but its host plant was unknown. Its usual host plants such as water-plantain also grow in Iran
That made this moth host range and biology in Iran rather mysterious at that point and the recent discovery of arrowheads as its preferred host in the region brings even more peculiarity in the story.'
and quantity climatic conditions synchronization physiological conditions in both insect and food plant genetic modifications etc.
and change in different environmental conditions so an insect can change its choice of food plant on the basis of seeking the most beneficial complex of factors.
Singularly and combined these factors lower the toxicity threshold of fungicides for springtails. The study by scientists from the LOEWE Biodiversity and Climate Research Centre (Bik-F) the Goethe University and the ECT Oekotoxikologie Gmbh was published in the September issue of the journal Applied Soil Ecology.
Springtails are tiny about 10 mm large creatures which participate in essential soil functions. Its numerous species include Folsomia candidaand Sinella curviseta
If springtails are affected therefore soil fertility will be affected too. As the new study shows low soil moisture (i e. 30%of the water holding capacity) leads to significant reduction of springtail juveniles.
We experimented with two different species of springtails. Both of them--but especially Folsomia candida--might have difficulties to produce enough offspring to keep a population stable in dry soil says Cornelia Bandow an ecologist at ECT Ecotoxicology Gmbh who conducts research for the German Biodiversity
and Climate Research Centre (Bik-F). Extreme climate conditions may also alter the effect of pesticides on soil organisms.
A risk for springtails under field conditions may not be expected as the toxic threshold of pyrimethanil is far above the maximum concentrations that may occur in soil
#Mosquito fact and fictionone of Jason Pitts'favorite stories is about mosquitoes and their strange attraction to Limburger cheese.
and other mosquito-borne illnesses by developing new and improved attractants and repellants. In his spare time he collects interesting facts
In the 1990's Dutch biologists put Limburger cheese in a wind tunnel with malaria mosquitoes and were surprised to find that females were drawn to the smell he said.
and that is what attracted the mosquitoes. The researchers used this discovery to develop Limburger-based traps that mosquitoes find two to three times more attractive than humans.
Pitts has found that the story about the mosquitoes and Limburger is a real crowd pleaser.
He has discovered also that two topics almost always come up when people learn that he studies mosquitoes for a living.
People want to know more about the giant mosquitoes in their homes and they wonder why mosquitoes appear to bite some individuals more than others.
Times past counting people have told Pitts that they have giant mosquitoes at home and asked him
if they are the biggest mosquitoes in the world. He responds by asking just how big these giant mosquitoes are.
If the answer is two inches or more Pitts informs them that they aren't mosquitoes at all:
They are called crane flies also mosquito hawks. Crane flies are harmless. They don't bite and they don't eat mosquitoes as some people claim he tells them.
Pitts is certain of his ground because the world's largest mosquitoes have a wingspan of only an inch
and they are found right here in Tennessee. I've caught them in my backyard
but they are very hard to find. You really have to hunt for them Pitts said.
They are called elephant mosquitoes and they don't feed on blood. In fact their larvae feed on other mosquito larvae
so they can potentially help reduce the population size of other harmful mosquitoes. There are more than 3000 species of mosquitoes worldwide
but only 150 of them are found in North america Pitts said. We only know of around 40 species in Tennessee he reported.
The second question Pitts frequently gets is Why am I the one that mosquitoes always bite?
We have a general answer to that question: It has to do with individual variations in body odor
but right now we don't understand the specific combination of odorants that mosquitoes find most attractive Pitts said.
Also different species are attracted to different smells. The source of the aromatic compounds that produce body odor are bacterial colonies that exist on human skin particularly in dark moist areas such as the arm pits and between the toes.
Pitts and his colleagues have discovered that mosquito antennae are filled with hundreds of tiny odor receptors
which are tuned individually to detect specific odors. While they have identified dozens of aromatic compounds that trigger the mosquito's antennae the researchers haven't discovered one that acts as a super-attractant.
The experimental evidence strongly supports the conclusion that mosquitoes are attracted by blends of odors rather than a single odorant he explained.
Individual compounds on the other hand can act as powerful repellants. Natural repellants such as clove oil citronella lemon grass eucalyptus castor oil peppermint lavender and cedar oil all work to a limited extent Pitts said
but almost all of them are less effective than the synthetic repellant DEET and they need to be reapplied more frequently.
Actually odors combined with heat are the basis of the mosquitoes'short-range detection system Pitts said.
The pesky insects also have a long-range system that allows them to track down potential prey from more than 100 yards away.
The mosquitoes do so in part by sensing the carbon dioxide in human breath. When we exhale our breath contains four to five percent more carbon dioxide than the surrounding air
and mosquitos can detect this difference. As you exhale your breath is carried by air currents as a series of bubbles enriched in CO2 that can persist for some time Pitts said.
Female mosquito flight is activated by CO2 and she can dart upwind from bubble to bubble in pursuit of her target.
According to some studies mosquitoes are attracted more strongly to human breath after a person has downed a beer
Some people claim that mosquitoes can fly between raindrops. This may seem farfetched but actually has an element of truth.
A study using high-speed video has shown that mosquitoes don't exactly fly between drops so much as the raindrops bounce off them.
Surprisingly the mosquitoes'small size and flexible exoskeleton actually reduces the impact of the raindrops on the insects'bodies.
Many experts categorize mosquitoes as specialists. That is different species of mosquitoes prey on specific animal hosts.
For example the malaria mosquito Anopheles gambiae prefers to feed on humans while other species may prefer birds dogs sheep etc.
However Pitts argues that these insects are opportunists rather than true specialists. For example numerous studies of A. gambiae taken from African huts have found that virtually all the females collected contained human blood:
A finding consistent with the specialist label. But A. gambiae females prefer to rest indoors
This strongly suggests that Anopheles females are not specialists that require human blood but instead are opportunists--they may have preferences
Despite all the time and effort that researchers have spent studying mosquitoes there still is a tremendous amount that they don't understand Pitts said.
Mosquitoes have managed to survive for more than 46 million years--more than 100 times longer than man
Each year 700 million people worldwide suffer from mosquito-borne diseases and millions die. Story Source:
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