Feeds:
Posts
Comments

Archive for the ‘Biological control’ Category

Science

Watch how battles with bats give moths their flashy tails

Bats and their prey are in a constant arms race. Whereas the winged mammals home in on insects with frighteningly accurate sonar, some of their prey—such as the tiger moth—fight back with sonar clicks and even jamming signals. Now, in a series of bat-moth skirmishes (above), scientists have shown how other moths create an “acoustic illusion,” with long wing-tails that fool bats into striking the wrong place. The finding helps explain why some moths have such showy tails, and it may also provide inspiration for drones of the future.

Moth tails vary from species to species: Some have big lobes at the bottom of the hindwing instead of a distinctive tail; others have just a short protrusion. Still others have long tails that are thin strands with twisted cuplike ends. In 2015, sensory ecologist Jesse Barber of Boise State University in Idaho and colleagues discovered that some silk moths use their tails to confuse bat predators. Now, graduate student Juliette Rubin has shown just what makes the tails such effective deterrents.

Working with three species of silk moths—luna, African moon, and polyphemus—Rubin shortened or cut off some of their hindwings and glued longer or differently shaped tails to others. She then tied the moths to a string hanging from the top of a large cage and released a big brown bat (Eptesicus fuscus) inside. She used high-speed cameras and microphones to record the ensuing fight.

Moths with no tails (such as polyphemus) were easy quarry for the bats, escaping only about 27% of the time, Rubin, Barber, and colleagues report today in Science Advances. But when Rubin enlarged the polyphemus hindwing lobe, twice as many escaped the bat’s sonar, or echolocation system.

Bats going after long-tailed African moon moths got a mouthful of tail 75% of the time as the moths flitted away. Shorten the tail, and the African moon moths escaped only 45% of the time. With no tail at all, that percentage dropped to 34%. When Rubin’s colleagues Chris Hamilton and Akito Kawahara at the Florida Museum of Natural History in Gainesville built a family tree of silk moths and their relatives, they realized that long tails had evolved independently several times. That’s further evidence that they are an important life-saving feature for these moths.

“The authors have demonstrated a powerful approach for understanding the diversity of moth shapes,” says Aaron Corcoran, an animal ecologist at Wake Forest University in Winston-Salem, North Carolina, who was not involved with the work. “There appear to be many different ways to trick a bat’s echolocation system.” The study also revealed how hard it was for bats to work around this deception, he adds. “The fact that the bats in the study never learned how to catch these moths, despite ample time to do so, shows how hard-wired this blind spot is in the bat’s perception.”

The findings could benefit other fields such as robotics, says Martin How, a sensory ecologist at the University of Bristol in the United Kingdom. Because the study examined the bat-moth dogfights at such a fine scale, the results could help engineers design the “bio-inspired technologies of the future,” he says, including deftly flying drones.

*Correction, 5 July, 1:45 p.m.: This article has been updated to reflect that although Juliette Rubin was the lead author of the paper, some of the work was done by other researchers.

Read Full Post »

moroccoworldnews-logo-top

Morocco to Provide Biofriendly Pest Control

By Hajare El Khaldi

Rabat- The biological pest control group, Biobest, announced the launch of its new, EUR 1.2 million “state-of-the-art” facility, which will boost Morocco’s aphid biocontrol capacity, on April 24.

Aiming to satisfy the strong demand for zero-residue products and tackle the rising problem of pesticide resistance, the Belgium-based company fully equipped the 2,000 square-meter vertical livestock facility with air-conditioned rooms, thus preparing to ensure a “flexible” and “reliable” supply to its customers.

“Aphids remain one of the most challenging pests to control with biological methods,” declared Biobest, which offers producers around the world a full range of “natural enemies” for agricultural pest problems, as well as the necessary technical advice for a successful pests control.

While synthetic chemical pesticides are effective in protecting crops, they have proven to cause acute and chronic health effects, in addition to upsetting the natural equilibrium of agricultural systems and the environment.

Biobest provides an alternative solution that uses microbial biopesticides to work against certain pests without harming other organisms.

“The success of biocontrol against aphids does not depend on a miracle product, we recommend strategies that combine different aids in an effective way,” says Biobest sales manager, Marc Mertens, “the midge Aphidoletes has an important role to play, given its great predatory ability, since its effectively gets rid of emerging aphid infestations. It forms a powerful tandem with different parasitoid wasp species. We continue to work in expanding our range of solutions, and our consultants know how to help producers best combine the most effective IPM solutions in different crops and climates.”

This project is expected to reinforce the company’s position as a leading supplier for integrated pest management solutions in Morocco and to underline the Moroccan franchise’s role within the global production network, asserted the managing director of Biobest Morocco, Karim Jerate.

Founded in 1987, Biobest offers biofriendly solutions to producers in more than 60 countries, Through its subsidiaries, the company has productions sites, sales personnel, and technical support strategically located around the world for efficient global service.

“With several production sites around the globe, our goal is to offer a flexible response capability to producers in different parts of the world. Our Moroccan team has done a remarkable job completing the construction of this new production plant on time and according to the required specifications,” said Biobest Chief Operating Officer, Karel Blockmans.

Read Full Post »

Science

How one parasitic wasp becomes the victim—of another parasitic wasp

Karma is a real pest for parasitoids, tiny parasitic wasps that lay their eggs on caterpillars. That’s because the way they protect their hungry young from the caterpillar’s immune system sends out a chemical calling card that lures other parasites, which feast on the offspring, according to a new study.

For the parasitoid’s brood, a caterpillar is a walking nursery and buffet. But that brood is on the menu for wasps called hyperparasitoids, which lay their eggs on the parasitoid offspring. Researchers previously found that hyperparasitoids sniff out their victims using the distinctive aroma a plant emits when being munched by a parasitized caterpillar.

What’s ultimately responsible for the release of this odor, scientists report today in the Proceedings of the National Academy of Sciences, is a virus that parasitoids squirt into a caterpillar to suppress its immune system and shield their offspring. When the researchers injected caterpillars with the virus and let the insects gnaw on wild cabbage plants, they found that the scent of the plants was particularly attractive to the hyperparasitoid Lysibia nana (above, laying its eggs on the parasitoid’s cocoons). The study suggests the virus changes the chemical composition of the caterpillars’ saliva, which in turn causes the plant to release molecules that are wasp-nip for hyperparasitoids.

Read Full Post »

Cornell University

Cornell Chronicle

Graduate student Ricardo Perez-Alvarez checks cabbage plants for insect pests.

Landscapes surrounding farms affect insect pests, crop yields, study finds

A cabbage looper, a pest of cabbage plants.

Landscapes that surround agricultural lands strongly influence the dynamics of beneficial insects as well as insect pests on farms, which in turn affect crop yields.

Such were the findings of a Cornell study of New York farmlands, published April 4 in the journal Ecological Applications.

Many previous studies on how landscapes surrounding farms affect insect pests and crops have only considered one pest at a time. This study examined the effects of three cabbage pests – aphids, flea beetles and leaf-feeding caterpillars – wasps that feed on caterpillars, and crop yields. It also looked at three different types of landscapes that surround farms: agricultural lands, meadows and semi-natural areas (including shrublands, types of forests and woody wetlands).

“By considering multiple insect pests, [our study design] represented a more realistic situation for what farmers experience, we were able to disentangle some of these complexities,” said Ricardo Perez-Alvarez, the paper’s first author and a graduate student in the lab of Katja Poveda, professor of entomology and the paper’s senior author.

In the study, the researchers set up 22 experimental cabbage plots on farms across the Finger Lakes region of New York from June to September in 2014 and 2015. The details and management of each plot were the same, with no pesticides or insecticides used. Throughout the growing season, the researchers measured plant damage by each pest, density and abundance of parasitoid wasps, and they recorded crop yields at the end of each season.

The researchers expected that landscapes with a higher proportion of cropland and lower habitat diversity would lead to more specialist pests and a reduction in crop yields, according to the paper. Instead, they found that yields and the number of pests were best explained by the presence of non-crop habitats, such as meadows, in the landscape.

Specifically, when the proportion of meadows surrounding farms was high, the amount of infestation from cabbage leaf-eating caterpillars was lower, likely because of increased parasitism from wasps. On the other hand, these same plots experienced more infestation from flea beetles and aphids. The findings suggest that while some beneficial insects increased as a result of the non-crop habitats, so did the number of certain pests.

By considering the collective effect of multiple pest species on crop yields, management schemes need to consider joint effects of pest species to be effective, Perez-Alvarez said. Still, more detailed study is needed to better understand these dynamics. “There were some landscapes where the presence of meadows can have an overall positive effect from crop production, but in other areas, meadows can have a negative effect,” he said, perhaps due to the characteristics of the insect fauna that live in those areas.

“There is not a universal solution,” he added.

Brian Nault, professor of entomology, is a co-author of the study.

The study was supported by U.S. Department of Agriculture’s National Institute of Food and Agriculture via the Cornell University Agricultural Experiment Station.


Story Contacts

Krishna Ramanujan

Read Full Post »

Ghana News Agency

http://www.ghananewsagency.org/science/ghana-to-focus-on-bio-rational-products-for-management-of-faw-131321

fall-armyworm-frontal-MER-563x744

Ghana to focus on bio-rational products for management of FAW

By Belinda Ayamgha, GNA

Accra, April 13, GNA – The Ministry of Food and Agriculture says it has shifted its focus from synthetic insecticides to bio-rational products, for the management of the Fall Armyworm (FAW) infestation, as part of its short, medium and long-term management measures.

The focus on bio-rational products is to ensure minimum pest resistance by the FAW, which is higher with the use of synthetic insecticides.

Dr Mrs Felicia Ansah, Director of Plant Protection and Regulatory Services at MoFA, said this when she briefed Journalists on the current situation of the FAW problem.

She noted that the FAW had come to stay, as it could not be completely eradicated but managed, as in the case of Brazil, which had been managing the FAW infestation for the past 40 years, and was currently one of the biggest exporters of maize.

Ghana had thus modelled its management measures after the Brazilian experience.

These measures, she said, include the deployment of pheromone trap catches in various locations across the country to ascertain the levels of infestation, training of MoFA staff and farmers on scouting, early detection and sustainable management of the pest in the event of an outbreak.

She explained that the best way to manage the infestation on farms was to detect the pests early at the larvae stage, and not when they became full grown moths. That is when they did the most damage to crops.

Other measures being undertaken by the Ministry are the distribution of pesticides to all district offices in the country where farmers can access in FAW infestations, the formation and training of Nnoboa Spraying Teams in farming communities and intensification of public awareness creation for farmers and the general public.

According to Dr Ansah, Ghana had commenced scouting of natural enemies of the FAW, which once identified, will be reared to help reduce the population of the pests.

“In the long term, only biological control agents, microbial insecticides and botanicals/organic products will be used to manage FAW in Ghana,” she said.

She said a total of 249,054 hectares of maize were affected and sprayed, out of which 234,807 hectares recovered and 14, 247 totally destroyed in the previous season, adding that there was a likelihood for more infestations in the 2018 farming season.

Dr Ansah stressed the need for the media to be circumspect in how they reported issues around the FAW infestation as it had implications for trade.

She urged the media to collaborate with the Ministry to educate farmers on how to manage the FAW.

She said the pockets of FAW infestations being currently experienced in some districts in the Ashanti, Brong-Ahafo, Eastern, Volta and Western Regions had been blown out of proportion as it was a pre-season production infestation.

“We would like you to appreciate that this is a Phytosanitary or Public Plant Health Issue, with trade implications and must be communicated in a professional manner. Media coverage should rather be geared towards improving the knowledge and skills of our farmers,” she said.

GNA

 

 

 

Read Full Post »

Daily News Blog

Predatory Birds Can Successfully Replace Pesticide Use in Agriculture

(Beyond Pesticides, March 8, 2018) Simple approaches that increase populations of vertebrate predators, like bats and falcons on farms, can reduce pesticide use, increase on-farm productivity, and conserve wildlife, according to a literature review published by researchers at Michigan State University in the journal Agriculture, Ecosystems and Environment.  The review encompasses 48 studies published over the last 150 years on the effect of human interventions to enhance natural ecosystem services. Results point not only to new methods to improve on-farm pest management, but also potential ways to engage farmers and citizen scientists in implementing these win-win strategies.

Researchers looked at a number of methods tested in the scientific literature that would increase on-farm populations of vertebrate pest predators. Broadly, discrete approaches such as installing structures like nest boxes, perches, and artificial roosts were investigated alongside more wide-ranging systems aimed at altering habitat and increasing landscape complexity. The latter includes methods such as installing field borders, increasing tree cover, reintroducing native species, and eliminating invasives.

The more discrete approaches provided a simpler, more accessible, and less expensive method of pest management when compared to approaches that require more wide-ranging landscape changes, though the benefits of those activities were not negligible. Nest boxes were found to successfully increase the abundance of predator species. Populations of western bluebirds increased by a factor of 10 when nest boxes were installed as part of a study on California vineyards, and vineyards without the nest boxes saw significantly higher pest levels when compared to those with bluebird boxes. In Europe, apple orchards that installed nest boxes for the native great tit bird saw 50% less pest damage than orchards that did not install the structures. Likewise, the installation of artificial bat roosts around Spanish rice fields led to significant declines in major moth pests over a 10 year period. When perches were installed around Australian soybean fields, raptors and other predatory birds caused a statistically significant decline in mouse populations.

The creation of field borders – strips of non-crop flowers and plants – did represent a successful method of improving populations of vertebrate pest predators. Studies reviewed found that bird abundance around these strips grew as the distance between cropland and forested areas increased, indicating potentially significant benefits of this practice for otherwise monotypic row crop farms.

In considering research on the addition of tree cover, studies have found mixed results. While some work indicates higher populations of various birds on farms of shade-grown coffee, other show species richness to be greater in sun-grown fields. That being said, studies generally indicate that increasing tree cover is likely to improve vertebrate pest control services.

Reintroducing native species can be a multifaceted, costly undertaking, and as a result of misperceptions about large carnivores, is more successful when the species is smaller, well-known, and non-threatening for people and farmers. A case study following the introduction of the New Zealand falcon into region known for its grape production found that the predators reduced fruit loss from pest bird species.

Both structural and landscape-level strategies can interact with one another. In one example, nest boxes installed to promote kestrel populations in Michigan were displaced by the widespread and invasive European starling. Although the solution to this problem is as simple as removing the nests, it indicates broader efforts may be necessary to maintain discrete approaches.

In sum, these methods provide a myriad of benefits. The economic value of vertebrate predators in reducing pests is significant. Bats alone contribute millions of dollars in pest-controlling ecosystem services – one study reviewed found that the loss of bats in Indonesian cacao fields would decrease yields by over 700 lb per hectare, a loss of $730 per year per hectare. The falcons reintroduced to New Zealand grape fields saved farmers there between $234 and $326 as a result of decreased pest bird consumption of fruit. In addition to monetary benefits, structures like nest boxes help conserve species by enhancing local populations, as occurred with the reintroduction of kestrels in Michigan.

Critically, these strategies help replace the over $15.2 billion American farmers spent purchasing pesticides in 2016. However, as researchers indicate, the true cost of pesticide use, through the poisoning of humans and animals, the displacement of pest predators, and contamination of our environment may increase that number by over $10 billion.

This review provides sound evidence in favor of farmers implementing simple, environmentally sustainable pest management methods. Researchers note the need to further investigate ways to engage farmers and citizens to participate in these activities, potentially through social networks, games such as the Ebird mobile app, and other tools. “Now that we’ve bundled these studies, we really need to set a research agenda to quantify best practices and make the results accessible to key stakeholders, such as farmers and environmentalists,” said lead author of the study Catherine Lindell, PhD to the National Science Foundation.

For more information on the benefits of not only vertebrate predators, but a wide range of wildlife species in reducing pesticide use, see Beyond Pesticides’ Wildlife Program page.

All unattributed positions and opinions in this piece are those of Beyond Pesticides.

Source: National Science Foundation, Agriculture, Ecosystems and Environment

Read Full Post »

SE farm press

 

Auburn University
An Auburn University researcher surveys a soybean field. Auburn entomologists have discovered and identified a tiny wasp, Ooencyrtus nezarae, which kills the crop-destroying bugs.

Researchers discover another natural enemy of the kudzu bug

Though only about the size of a pinhead, the newly detected parasitoid wasp can do plenty of damage to the kudzu bug.

Paul L. Hollis | Mar 14, 2018

Auburn University entomologists have discovered and identified a tiny wasp that could provide a huge benefit to soybean producers and other farmers.

Though only about the size of a pinhead, the newly detected parasitoid wasp, Ooencyrtus nezarae, can do plenty of damage to the kudzu bug, a quarter-inch-long invasive pest of soybeans and other legume crops in the Southeast. Researchers in the lab of entomologist Henry Fadamiro, associate dean for research for the College of Agriculture and associate director of the Alabama Agricultural Experiment Station, were the first to detect the wasp’s presence in North America.

 The research team published its findings in a recent article in the Journal of Insect Science. Blessing Ademokoya, an Auburn graduate researcher at the time of the study and now a doctoral student at the University of Nebraska-Lincoln, is lead author of the article. Fadamiro and Rammohan Balusu, research fellow in the Department of Entomology and Plant Pathology, are co-authors,

as are Auburn research entomologist Charles Ray and Jason Mottern, entomologist at the USDA Smithsonian Institution in Washington, D.C. Ray and Mottern assisted in final identification of the wasp. O. nezarae is the second kudzu bug-attacking wasp to be identified in the U.S. The first, Paratelenomus saccharalis, was discovered in Georgia in 2013.”It is exciting to know that many natural enemies are in the field helping to keep kudzu bug populations under control,” Ademokoya said. “And, with this latest addition, we have a potential explanation for the decline observed in kudzu bug densities across several locations in the southeastern U.S.”

The kudzu bug, native to Asia, was first reported in the U.S. in 2009 in Georgia. Although it feeds on kudzu—an economically important invasive weed native to Asia and familiar to Southerners—it also devours soybeans and other legume crops, causing significant yield loss in highly infested fields.

A strong flyer and good hitchhiker, the pest rapidly expanded its numbers across many southern states, including Alabama, South Carolina, North Carolina, Florida, Tennessee, Mississippi, Virginia, Kentucky, Louisiana, Arizona, Maryland and Delaware. The population peaked in 2013.

The kudzu bug has emerged as the top yield-limiting pest of soybeans, which rank as the second most planted field crop in the United States with an estimated annual market value of approximately $39 billion.

In 2017, Alabama farmers harvested approximately 345,000 acres of soybeans with a production value of more than $150 million.

Potential long-term solution

O. nezarae, which was found during field surveys in Alabama, is reported to parasitize eggs from a variety of plant bug families in China.

“Until now, the distribution of O. nezarae has been limited to China, Japan, Thailand, South Korea and Brazil,” Fadamiro said. “This is the first report of the parasitoid in North America. The high rate of parasitism—82.8 to 100 percent—recorded in our study indicates that the parasitoid may serve as a potential long-term solution for managing kudzu bug.”

Despite O. nezarae’s high parasitism rate of kudzu bug, it has a short period of activity, and Fadamiro said continued research will be necessary to identify tactics for the use of the insect to biologically control the pest on farms.

“We need to conduct monitoring to know the distribution of the parasitoid in the United States and to determine its seasonal phenology in the field—when it is not active and when it is most active,” he said. “We also are interested in studying the nutritional ecology of this insect and strategies for its conservation in the field. We don’t want to spray toxic chemicals when it is most active.”

There are numerous ways to use natural enemies in production agriculture, Fadamiro said, including introducing them into areas where they are not already present and preserving them where they are naturally occurring. Farmers also can plant host flowering plants around a field so the nectar will attract and keep the beneficial insect in an area.

“If we conduct a survey and find the insects are only in central Alabama, then we can capture and relocate them to other areas of the state where the kudzu bug is a threat,” he said. “We want to make sure this finding is useful to the farmers who need it most.”

But there’s a risk in assuming that the known natural enemies of the kudzu bug will eliminate the threat, Fadamiro said.

“While the incidence of the kudzu bug has declined in recent years, there could be many factors involved, including weather conditions and other natural enemies, so we need to continue this work,” he said.

The research leading to the discovery of the parasitoid was supported by an Agriculture and Food Research Initiative Competitive Grant from the USDA National Institute of Food and Agriculture and by the Alabama Agricultural Experiment Station. It’s an example of Auburn’s commitment to development science-based advancements that meet pressing regional, national and global needs.

Auburn University

Auburn University entomologists have discovered and identified a tiny wasp that could provide a huge benefit to soybean producers and other farmers. Though only about the size of a pinhead, the newly detected parasitoid wasp, Ooencyrtus nezarae, can do plenty of damage to the kudzu bug, a quarter-inch-long invasive pest of soybeans and other legume crops in the Southeast.

Read Full Post »

Older Posts »