Daily Account #7- Insects

5/3- today we learned about insects with uw biology lecturer evan sugden. he talked about how insects are the most biodiverse thing on the planet, so in terms of biodiversity and evolution, we might say that earth is planet of the insects.

their roles in the natural world are also diverse and extremely important, from being a foundation for food webs, integral to waste recycling (as demonstrated by flies, termites, and dung beetles among others), soil formation, vegetation control (caterpillars, leafbeatles), and plant reproduction (via pollination by bees, butterflies, moths, etc.).

at this point professor sugden shifted to talking about their relevance to the human world, though i would question why in this discussion he separated the human world from the natural world. not only because we are part of nature, but because the services insects provide in the "natural world" directly impact the well-being of humans. though i can see that the next points he makes are more directly related to human activity. these include competition for food and fiber (crop and forest pests), disease vectors (such as malaria. but is this not true then for other animals? are they only disease vectors for diseases that affect humans?), biocontrol, and food and medicine.

in terms of diversity, insects make up about ten million known species, while spiders and mites comprise about one million. something i didn't know was that beetles represent a third of all insects, and hence one fifth of all animals! that's actually pretty mind-boggling.

beetles tend to be nocturnal, and many are extremely small, even the size of a pinhead. but even the smallest are very important in the web of life. sugden also talked about collection techniques, noting that pitfall traps are the best for beetles. he also talked about how the immature forms of beetles, namely larva, are actually where most of their interaction with the environment happens. once they have matured, their main purpose is to disperse and reproduce.

i also learned that all butterflies are moths, and that there are roughly ten times as many moths as butterflies. moths are nocturnal and less conspicuous, while butterflies are day-flying and most are showy. they're also usually not pests, except for the cabbage butterfly. they are best collected by hand nets, caught and then released.

bees are specialized pollen-feeding wasps. i didn't realize the pollen was their protein source, but they still drink nectar for energy (which is how the flower attracts them, and how they get fuel for flight). they are the most tightly evolved species with plants as pollinators. they collect the pollen to feed the larvae in the hive.
bumblebees are the most conspicuous and important pollinators in this area. they usually live in the ground in undisturbed habitat- since this is increasingly hard to find, some species are now endangered. all bee populations are under distress/decline.
they are very negatively affected by pesticides, which are increasingly used in potent levels by homeowners in gardens.
honey bees are not native (native to the Old World only), but have become naturalized wherever they've been introduced. they are the most efficient way to pollinate crops because you can move their hives around.
male bees don't sting, but any female will (when they feel they need to protect their larvae). honeybees die after stinging, while bumblebees can sting several times.
the most fascinating thing for me was how worker bees choose who will be their queen bee, collectively, and feed her differently/more intensively so that she develops the proper sexual organs- but all larvae start out the same.

Posted on June 3, 2012 07:01 AM by akumar