Dragonflies

Photo courtesy of Katie Bradshaw (SCB Citizen).

The past couple weeks I have received numerous calls and inquiries about dragonflies. It is common for adult dragonflies to make an appearance this time of year. The last couple years, there has been more rain than the 10-year average in the panhandle of Nebraska. Due to an increase in habitat and food, dragonflies have done well. In fact, they have done so well that some people are actually concerned about their large numbers. However, what some people do not realize is that dragonflies are predacious. Fortunately, they feed on pest insects that also benefit from all of the rain that we have had, such as, mosquitoes and biting flies. They scoop them out of the air with the long setae that coat their legs. So, you see, it's a natural phenomenon and could be considered a balanced ecosystem process that benefits us greatly through the reduction of disease vectors -- dragonflies provide ecosystem services.

Sometimes entomology can be a little herpetological...

Johan on the "Panhandle R&E Entomology Field Machine".

I have a graduate student doing some pretty cool work with root aphids and sugar beets. We were engaged in a round of aphid infestation in his sugar beet field plots today. However, earlier this week, we collected pitfall trap samples and noticed that they catch vertebrates as well -- tiger salamanders (n = 1) and toads (n = 2) so far. Yes, I too was surprised to find amphibians in a sugar beet field in western Nebraska. I wouldn't exactly describe the climate here as humid.

Sarah, with her awesome bullsnake handling skills.

An annoyed bullsnake.

Anyway, the amphibians seemed to almost force themselves through the funnels and into the cups of the traps. This is surprising considering that the funnel holes are about 1-inch in diameter and are supposed to keep larger vertebrates out. I have assumed that they are somehow after a short-term cool-off in the killing solution in the trap cups. However, maybe they are on the run from bullsnakes. So far, just one. But, kudos to my helpful student worker, Sarah, who bravely handled our reptilian loiterer. Johan, on the other hand, is not a big fan of snakes (and that isn't actually the reason he is on top of the "field machine"). I was just glad that it wasn't a rattlesnake.

Dust. It isn't an insect, but I'm sure it affects them.

Ok. So, this isn't insect related, but this kind of weather certainly can have a major impact on crops and entomological studies. Most of the Midwest doesn't experience this kind of weather. However, extreme weather seems to define this region. The top image is a storm front that blew in today. Note the rather large wall of dust that is moving in with it. The bottom video shows the result as the front passed over. I would guess that there was about 15-20 minutes of nothing but dust before a drop of rain fell.

'Miller moths" [continued]

The army cutworm moths (A.K.A., miller moths) continue their increase. Last night an extremely large number of them began settling in the North Platte Valley. Today I took some footage of me spooking the moths out from their resting sites under the overhang at the Panhandle Research and Extension Center. Sorry for the jittery video, I was taking the video with my phone.

'miller' moths

The army cutworm (Euxoa auxiliaris) flght has been producing a steadying flush of moths over the past month. Any day that provides a bit of sun and warmth, one can find these moths about. However, we have been quite cold and rainy for the last month as well. Therefore it is difficult to say whether or not we are experiencing a larger flush of moths relative to last year. On the others hand I do seem to be finding more of them in my garage, in windows, and in public restrooms (see photo) than last year. Perhaps this week, since it is supposed to get much warmer and be free from precipitation, may reveal the true abundance of what the locals call 'miller moths' this year.

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Mountain pine beetles

The mountain pine beetle, Dendroctonus ponderosae, is native to the western United States. Like many of our pests (e.g., grasshoppers, army cutworms, Russian wheat aphids, etc.) in the High Plains and Rocky Mountain regions, these insects can go through outbreak periods. During the past couple years these regions have suffered from devastating numbers of this insect attacking pine trees. The symptoms can be easy to spot...

When the beetles enter a tree, the burrow they create results in the formation of a "pitch tube"; the results of tree sap exudate (see above). The above tree has been attacked many times and there are many exit holes in the pitch tubes. However, this sapping process is part of a tree's defense system and if the tree is healthy...

It will actually drive the insect out of the burrow, entrapping it and ejecting it from the tree (see above)...

A very healthy tree can defend itself well against numerous pine beetle attackers (see above). If you examine a pine tree with a few pitch tubes with beetles in them, there is a good chance the tree will survive that year's attack and some insecticidal treatments and tree-health improvements could save the tree. However, if a tree has many pitch tubes without any beetles, it is likely that the tree is not going to survive and should probably be removed.

Linnean games UNL

Our 2011 ESA Linnean Games team.

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