The Unseen Arms Race: Plants & Insects

There’s a war going on. One in our own backyards, right under our noses, but goes unnoticed.

It is the ongoing battle of insect versus plant.

Plants have a serious disadvantage when it comes to protecting themselves. They can’t move. They root wherever nature, or we, put them. If things change in the environment and conditions become less than favorable, they’re stuck. The same goes for predators, all the insects and animals looking to make a meal out of them. So how do you defend yourself when you’re immobile?

 

You develop spines, spikes or thorns, unpalatable hairs on leaves, bitter-tasting toxins and other chemical defenses, among others, anything to make you a less desirable target. The goal? To survive and reproduce.

Yet this isn’t the end. Just by developing ways of deterring predators it doesn’t mean you’re safe because the insects and animals attacking you are doing their own adapting, finding ways around them.

It’s this battle that leads to changes in both plant and animal species until they balance each other out, when one can’t outcompete the other.

It also leads to specialization, which is sometimes very beneficial to the plants. This is especially true with our pollinating insects. Flowering plants and insects have co-evolved, or adapted through time together, to best suit each other. The plants have created the best ways to lure in particular insects. These insects in return, have found the best ways to collect the plant’s pollen and nectar. The result is an ecological win-win, the plants get pollinated, the insects get food for themselves and their larvae. Both species benefit and thrive. There are good examples of this beneficial co-existence in this blog post by the Washington Native Plant Society.

So the next time you take a stroll through a park or a garden, take a closer look. There’s a lot going on all around you, all the time.

Article by Jennifer Hunnell, Michigan Arbor Day Alliance

Research Shows Insect Invention…Plastics in Hives???

A recent study has demonstrated the resourcefulness of insects.

Human activities affect several aspects of nature, sometimes in good ways, sometimes in bad ones. But how do the creatures that live in our constructed urban environments continue to live, and even thrive, there when their environment has been so drastically altered? Well, apparently certain bees are repurposing our creature comforts and using them to their advantage.

 

Urban bees using plastic to build hives

Date:

February 11, 2014

Source:

University of Guelph

Summary:

Once the snow melts, bees will be back in business — pollinating, making honey and keeping busy doing bee things. For at least two urban bee species, that means making nests out of plastic waste. A new study reveals that some bees use bits of plastic bags and plastic building materials to construct their nests.

 Megachile rotundata, an alfalfa leafcutting bee.

 Credit: Photo by Peggy Greb / USDA Agricultural Research Service

Once the snow melts, Canada’s bee population will be back in business — pollinating, making honey and keeping busy doing bee things. For at least two urban bee species, that means making nests out of plastic waste.

A new study by a University of Guelph graduate and a U of G scientist reveals that some bees use bits of plastic bags and plastic building materials to construct their nests. The research was published recently in the journal Ecosphere.

It’s an important discovery because it shows bees’ resourcefulness and flexibility in adapting to a human-dominated world, says lead author Scott MacIvor, a doctoral student at York University and a 2008 U of G graduate.

“Plastic waste pervades the global landscape,” said MacIvor. Although researchers have shown adverse impacts of the material on species and the ecosystem, few scientists have observed insects adapting to a plastic-rich environment, he said.

“We found two solitary bee species using plastic in place of natural nest building materials, which suggests innovative use of common urban materials.

Figuring out that the bees were using plastics in place of natural materials took some detective work by U of G’s Andrew Moore, supervisor of analytical microscopy at Laboratory Services.

Moore analyzed a grey “goo” that MacIvor discovered in the nests of one kind of bee, Megachile campanulae, which uses plant resins to build its nests,

“Scott thought it might be chewing gum originally,” Moore said. His team uses a scanning electron microscope to take highly detailed pictures of items, x-ray microanalysis to determine the elements in the sample and infrared microscopy to identify polymers. They can distinguish the finest detail on the surface of an animal hair.

Turns out that M. campanulae was occasionally replacing plant resins with polyurethane-based exterior building sealant, such as caulking, in its brood cells–created in a nest to rear larva.

The researchers also discovered another kind of bee, Megachile rotundata, an alfalfa leafcutter, was using pieces of polyethylene-based plastic bags to construct its brood cells. The glossy plastic replaced almost one-quarter of the cut leaves normally used to build each cell.

Markings showed that the bees chewed the plastic differently than they did leaves, suggesting that the insects had not incidentally collected plastic. Nor were leaves hard to find for the bees in the study.

“The plastic materials had been gathered by the bees, and then worked — chewed up and spit out like gum — to form something new that they could use,” Moore said.

In both cases, larvae successfully developed from the plastic-lined nests. In fact, the bees emerged parasite-free, suggesting plastic nests may physically impede parasites, the study said.

The nests containing plastic were among more than 200 artificial nest boxes monitored by MacIvor as part of a large-scale investigation of the ecology of urban bees and wasps, a project involving numerous citizen scientists.

The nest boxes are located in Toronto and the surrounding region in backyards, community gardens and parks and on green roofs. They are used by a variety of bee species.

“The novel use of plastics in the nests of bees could reflect the ecologically adaptive traits necessary for survival in an increasingly human-dominated environment,” MacIvor said.

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Story Source:

The above story is based on materials provided by University of Guelph. Note: Materials may be edited for content and length.

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Journal Reference:

1. J. Scott MacIvor, Andrew E. Moore. Bees collect polyurethane and polyethylene plastics as novel nest materials. Ecosphere, 2013; 4 (12): art155 DOI: 10.1890/ES13-00308.1