kayell/insects

Who is Killing Nature's Precious Bees?

From the page: "How important are bees? One-third of the food we eat comes
from crops that need animal pollinators. "Without the services of managed honeybees, provided by migratory beekeepers, billions of dollars' worth of crops across the United States would fail." Unfortunately, as we pointed out before,
there was a there was a 57% decline in bee colonies in the US between 1985 and 1997. One of the things responsible for that decline is the use of pesticides by farmers in their fields and by consumers around their homes and gardens."

The number of home gardeners busily and indiscriminitely "dusting" their veg gardens with carbaryl aka Sevin always amazes me. I've had people who claimed to be "organic" tell me they use Sevin. I've talked to people who dust Sevin for plant diseases and fertility problems and plain old drought. "It must be safe, my grandma used it." Then they cry because their squash, and cucumbers and so on won't set fruit. Duh. And grrrrrrrrrrrrrrrrrrrrr.

From the page: "This man's bees are in grave danger. So is our food supply. Why something so small matters so much.
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As he moves through the bee yard, Anderson can tell at a glance how each colony is doing. If all is well, the frames of honeycomb will be thick with bees giving forth a contented hum. But sometimes half the frames are bare and the bees just don't sound right. Sometimes the ground beneath a hive box is covered with bee carcasses.

Since Anderson began, in 1976, raising healthy bees has become more and more difficult. In the 1980s, two non-native species of parasitic mite infested North American honeybees. One of the species, Varroa destructor, has proved especially deadly. Meanwhile, safe pastures where bees can forage without being poisoned by pesticides are becoming increasingly rare."

A traditional folk remedy, known among people in Mississippi's hill country for at least a century, may provide some relief without all the worries of DEET and other harsh chemicals. Scientists at the United States Department of Agriculture-Agriculture Research Service housed at the National Center for Natural Products Research at the University of Mississippi have isolated compounds in the American beautyberry plant, Callicarpa americana, that may keep chomping insects away.

From the page:
"Managing the Japanese Beetle

A Homeowner's Handbook"

From the page: "The world is filled with cues that could influence the daily feeding patterns of an organism. Many plants, for example, respond to foraging damage by releasing specialized chemical signals - volatile organic compounds that evaporate in the air - that attract the forager's natural enemies. This strategy is obviously no use against a cow, but proves effective when the offender is a caterpillar and the summoned predator is a wasp. Just how much control such biotic factors exert over a forager's daily routine has remained an open question.


But in a new study in the open access journal PLoS Biology, Kaori Shiojiri, Rika Ozawa, and Junji Takabayashi show that plant signals can indeed regulate herbivore behavior.

When the larvae of beet armyworms (Spodoptera exigua) feed on corn, the plant releases volatile compounds that act as a magnet for parasitic wasps (Cotesia marginiventris), which deposit their eggs in the larvae. Production of volatile chemicals increases during the day (when wasps are active) and decreases at night, suggesting that variations in production might affect the daily activity patterns of foraging larvae, with low production sending the signal that the coast is clear. To test this hypothesis, Shiojiri et al. exposed larvae of a corn-munching nocturnal caterpillar, Mythimna separata, to volatile compounds from corn and varied the light and dark conditions for both corn and insect. Corn infested with M. separata releases volatiles that attract parasitic wasps (C. kariyai). "

Heartbreaking
From the page: "The number of butterflies migrating through the state has fallen to a nearly 40-year low as populations already hurt by habitat loss and climate change encountered a cold, wet spring, researchers said."

Scientists had known that honeybee scouts "waggle dance" to report on food. Seeley and his colleagues, however, have confirmed that they dance to report on real estate, too, as part of their group decision-making process.

The better the housing site, the stronger the waggle dance, the researchers found, and that prompts other scouts to visit a recommended site. If they agree it's a good choice, they also dance to advertise the site and revisit it frequently. Scouts committed to different sites compete to attract uncommitted scouts to their sites, the researchers have discovered, but because the bees grade their recruitment signals in relation to site quality, the scouts build up most rapidly at the best site.

As soon as 15 or more bees are at any one site, the researchers found, the scouts signal to the waiting bees in the swarm that it's time to warm up their flight muscles in preparation for takeoff. Each scout does so by scrambling through the swarm cluster and briefly pressing its vibrating thorax against the other bees to stimulate them to activate their wing muscles. Once every bee has its thorax warmed to 95 degrees Fahrenheit, the swarm lifts off toward its new home.