beneficial insect species

See Fire Ants Create Towers From Their Own Bodies

To gain insights on how to program swarms of tiny robots, scientists are studying one of nature’s most cohesive species—fire ants.

When the insects work together, they’re a force to be reckoned with. The small creatures are capable of using their bodies to create towering structures of more than 30 stacked ants and buoying themselves into a raft so buoyant it stays afloat even when a human hand forces it under water.

Researchers at the Georgia Institute of Technology have been working for years to analyze how ants socially and physically form such elaborate globs without a leader or a discernable overall plan.

In a study recently published in the journal Royal Society Open Science, high-speed cameras show ants banding together to form a tower around a slippery rod. The coordination results in a bell-shaped structure, similar to that of the Eiffel tower.

Scientists had previously observed ants creating these towering structures from their own bodies, and the video offers a fresh look at the phenomenon.

The process to create these towers is less of a delicate dance and more trial and error. According to the study, an individual ant is capable of supporting as many as three other ants, which it connects to using sticky pads on its feet.

If an ant takes on more weight than it can bear, the ants fall away from the tower like a cascading avalanche. By continuously scrambling over each other, the ants are able to eventually build a solid base, building on each other from the bottom up.

Scientists believe this behavior is used as a temporary structure after events like floods. Scaling tall structures allows them to hunt for empty spaces in which they can create new homes.

Because the ants are continuously sinking, they must repeatedly climb over each other until they reach shelter, making their towers dynamic rather than static.

“The ants are circulating like a water fountain, in reverse,” one of the study’s authors told Nature.

Unsinkable Ants
The dynamics of their static structures was discovered by the same research group in 2014 when they studied how ants formed such robust raft structures.

By swirling a bunch of ants into a cup, the ants naturally formed a dough-like ball by grabbing onto each other with their sticky legs. Forming perpendicular to one another, the ants were able to evenly distribute their weight, creating a raft that floated even when one of the researchers fully submerged it in water.

While not known to be particularly intelligent as individuals, ants are adept at collectively working and communicating through a complex system of pheromones and sounds inaudible to the human ear.

Researchers hope that small robots can be programmed to form rafts and bridges of their own.

“Imagine robots that need to construct a barrier or patch a hole during a disaster response,” one of the 2014 study’s authors told Nature.

Source: NATIONAL GEOGRAPHIC

Radiohead has newly discovered ants species named after it

A new species of ant, discovered in the Venezuelan Amazon, has been named after Radiohead in honour of their contributions to music and conservation efforts.

As noted by Phys.org, Ana Ješovnik and Ted R. Schultz — of Washington’s Smithsonian Institution’s Ant Lab — discovered three species of ants while collecting data for a study. One of those — the Sericomyrmex radioheadi — was named after the upcoming Glastonbury headliner.

“We wanted to honour their music,” Ješovnik, said. “But more importantly, we wanted to acknowledge the conservation efforts of the band members, especially in raising climate-change awareness.”

Sericomyrmex literally translates to ‘silky ants’, a fungus-farming species that are reportedly ‘less well-known relatives of the famous leaf-cutter ants’. The Radioheadi breed has a white, crystal-like layer covering their bodies.

Earlier this month, a species of shrimp were named after Pink Floyd; the Synalpheus Pinkfloydi have large pink claws capably of killing small fish.

Source:INDEPENDENT

Insects that help feed the world

The Cream Striped Owl moth is usually a sub-tropical and bushveld baby, with a range that extends up to equatorial Africa, according to my insect book, Field Guide to Insects of South Africa (Picker, Griffiths, Weaving, Struik 2002). They do seem to have been creeping slowly into Highveld areas for some time – I took the picture below of a slightly tattered individual in Cullinan in 2010.

There was one fluttering in my bathroom last night, a large member of a vast dancing throng of wings, ranging from almost translucent cream to rich sepia. I’ve never understood why people find moths scary; I know some superstitions hold that moths are signs of death (if that were the case, few families would survive an ordinary summer evening!) but to me, they’re signs of life. When not distracted by our lights, they do important nightshift work.

Many moth species are crucial pollinators, drawn by the night’s rich, sweet fragrances and nectars to flowering plants like Struthiola ciliate, a fynbos shrub, picking up pollen to transfer to the next plant they visit.

Despite the rightful focus on honeybees-as-pollinators, all sorts of wild animals are vital to both agriculture and wild plants. Flies are perhaps second to bees in the pollination stakes, visiting apple trees, cashews, onions and coriander, to give a tiny sample.

Wasps are important pollinators too (avos are among their beneficiaries), as are beetles and bumblebees (apparently they love canola).

Other nightshift pollinators are also often maligned. Bats trigger grils down the spine for many, but the fruit bat, with its appealing dog-like face, is the major pollinator of the baobab, for example. Mice also attract the ‘eeurrgh’ reaction, yet in recent years, scientists have discovered that some Protea species are pollinated by scurrying little rodents out at night.

If you like chocolate, you can thank those most-cursed creatures, the midges (what we call muggies), daytime workers spreading pollen from one cacao flower to another in cocoa plantations, according to Adrienne Mason in Planet Ark: Preserving Earth’s Biodiversity.

One in every three bites of food made possible by pollinators.

The staple crops of the world (wheat, maize, rice and other grasses) are wind-pollinated, but many of our other food crops are dependent on living creatures, from ants to birds, to reproduce. “87 out of 115 leading global food crops are dependent on animal pollination. One in three bites of food you take was made possible by the work of pollinators,” Mason writes.

While South Africa does not use ‘managed pollinators’ (beehives trucked between agricultural regions) nearly as intensively as the USA and Europe, 87% of the beehives in the Western Cape, where half the deciduous fruit in the country is grown, are ‘managed pollinators’ of fruit trees (the fruit industry was valued at R9 800m in 2014).

In 2008, Mike Allsopp and colleagues did a valuation of pollination services and arrived at these figures: “The contribution of managed honeybee pollination is found to be between US$28.0–122.8 million […]; the contribution of wild pollinators is found to be between US$49.1–310.9 million…” That’s a lot of money. And if insects and other animal pollinators died out, of course, the replacement cost would be much higher – we’d probably have to invest in those little robot pollinators!

No fear of that quite yet: Wits zoology and entomology Professor Marcus Byrne (famous for discovering that dung beetles use the Milky Way to navigate) is in the bush as I write. Following late but good rains, he notes that all is lush and green and singing with insect life, evidence of “the resilience of our fauna to not only what we do, in continually removing or degrading their habitat, but also their ability to bounce back from a serious drought”.

However, I would suggest that we do not test that ability to destruction. Even if you don’t give a damn about the aesthetics of nature, or the intrinsic worth of the lives around us, these ecosystems clearly have a raw commercial value and are crucial to our food security.

Hence “the importance of maintaining natural and other forage areas for the conservation of insect pollinators,” as Allsopp et al write, instead of creating bleak and rebarbative deserts, and using pesticides to kill all known insects dead.

For example, in our pesticide-free garden, leaves are piled onto beds as mulch, and dead branches are left to quietly decompose, providing micro-habitat that supports insects, bats and birds – evidenced by the quiet humming of life here compared to more manicured and pesticided environment like the townhouse complex down the road. The same difference can be seen on a walk from ploughed and disked farmland to adjacent veld.

The need for havens that support and protect biodiversity, specifically pollinators and pest controllers, should be as much part of land use management policies as water use is.

Rejoice in the fluttering moth-wings at night; manage birds, bats and rodents in your office parks, housing developments and municipal buildings without sprays and poisons; campaign against development of every last wild haven in your vicinity. We need them more than they need us.

Author: Mandi Smallhorne
Source: News24

Common insecticides are riskier than thought to predatory insects

Neonicotinoids — the most widely used class of insecticides — significantly reduce populations of predatory insects when used as seed coatings, according to researchers at Penn State. The team’s research challenges the previously held belief that neonicotinoid seed coatings have little to no effect on predatory insect populations. In fact, the work suggests that neonicotinoids reduce populations of insect predators as much as broadcast applications of commonly used pyrethroid insecticides.

“Predatory insects contribute billions of dollars a year to agriculture through the elimination of crop pest insects,” said Margaret Douglas, postdoctoral researcher in entomology, Penn State. “We have found that neonicotinoid seed coatings reduce populations of these natural enemies 10 to 20 percent.”

According to John Tooker, associate professor of entomology, Penn State, the use of neonicotinoids has risen dramatically in recent years, especially for large-acreage crop species like corn, soybeans and cotton. The insecticide is most often applied to seeds as a prophylactic coating. When the seeds are planted, the insecticide enters the soil where some of it is taken up by plant roots. The chemical then runs systemically through the plant, protecting young seedlings from insect pests.

“Applying insecticides to seeds rather than broadcasting them across a field was thought to reduce unwanted effects on natural enemies,” said Douglas. “But we found that seeds treated with neonicotinoid insecticides reduced populations of natural enemies by 10 to 20 percent in North American and European farming systems. Surprisingly, this effect was about the same as that associated with broadcast applications of pyrethroids.”

The team’s research appeared in the online journal PeerJ.

The team used a statistical method, called meta-analysis, to combine the results of more than 1,000 observations from 20 field studies across North America and Europe that tested the effects of seed-applied neonicotinoids on predatory insects. “Unfortunately, the available literature is difficult to interpret,” said Tooker. “Some studies show little influence of neonicotinoids presented as seed treatments on arthropod predators that are common in crop fields, whereas others show a strong influence of these seed treatments. By using a meta-analysis approach, we were able to combine the results of many studies to quantitatively reveal the overall influence of neonicotinoids on predator populations.”

Not only did the researchers find that neonicotinoid seed coatings significantly reduced natural enemy populations, they also found that the insecticide acted more strongly on insect predators than on spiders. In other words, spiders appeared to be less susceptible to neonicotinoids than insects, which is consistent with previous research.

“This result suggests that neonicotinoids are reducing populations of natural enemies at least partly through their toxic effects rather than simply by reducing the availability of their crop pest foods,” said Douglas. “After all, insects are more susceptible to these toxins than spiders, whereas the two groups should be similarly affected by a lack of food.” The researchers note that their results may help farmers and pest management professionals better weigh the costs and benefits of neonicotinoid seed treatments versus alternatives.

“Several governments have restricted the use of neonicotinoids out of concern for their possible effects on pollinators,” said Douglas. “But this raises the questions, ‘What will farmers do without these products? If they switch to broadcast applications of pyrethroids, will those products be better or worse for predatory insects?’ While our results do not speak to the pollinator issue, they do suggest that predatory insects are affected similarly by seed-applied neonicotinoids and broadcast pyrethroids.”

The answer to the problem, noted Tooker, lies in the application of integrated pest management (IPM), a strategy that uses a combination of techniques — which may or may not include the targeted use of insecticides — to control pests, rather than universally deploying prophylactic tactics like insecticidal seed coatings.

“Substantial research exists supporting the value of IPM for pest control,” he said. “It is the best chance we have of conserving beneficial insect species while maintaining productivity in our agricultural systems.”

Source: Science Daily