Sunburst Diving Beetle (Thermonectus marmoratus)

Sunburst Diving Beetle
A Sunburst Diving Beetle (Thermonectus marmoratus) in captivity at the Butterfly Pavilion, Westminster, Colorado, USA. November 10, 2012.

This last month has been very busy for me (partly due to my awesome entomology class), so here’s a quick interlude before I return to the Iceland photos. Today I stopped by the Butterfly Pavilion in Westminster, Colorado, to see the newly remodeled Crawl-A-See-Em exhibit. The Butterfly Pavilion, in addition to butterflies, also exhibits many other invertebrates, ranging from ocean invertebrates like lobsters and jellies to terrestrial invertebrates like bees and probably the most famous resident of the Butterfly Pavilion, Rosie the Chilean Rose-haired Tarantula (or rather, an army of Rosies). The Crawl-A-See-Em focuses on terrestrial invertebrates other than butterflies, and I was excited to see the changes.

While the old Crawl-A-See-Em was always a mixture of animals on permanent exhibit and rotating special exhibits according to what the zookeepers were able to collect in the wild or order from dealers, it didn’t really have a coherent theme. Parts of it were habitat-themed; others were taxonomically themed.

The new Crawl-A-See-Em is arranged by habitat type, which I think gives the room a much better flow. While many of the same familiar animals were there, the most exciting change for me was the addition of a tank highlighting aquatic insects, containing Sunburst Diving Beetles (Thermonectus marmoratus) and some fantastic giant water bugs (family Belostomatidae). I’ve never seen either of these species in the wild, and the tank made them easy to observe.

Predaceous diving beetles (family Dytiscidae) are one of my favorite beetle groups. They have several adaptations for their aquatic lifestyle, including fringed hind legs that work something like oars, as well as a physical gill for respiration. In the picture below, you can see an air bubble at the tip of the abdomen, which is the physical gill. Diving beetles have to surface regularly to renew this air bubble.

Sunburst Diving Beetle (Thermonectus marmoratus)

Apparently as larvae they also have eyes with two retinas and two focal planes, effectively functioning as bifocals–the only known example of bifocal vision in insects.

I kind of want some now, although after my ill-fated attempt at dragonfly larva-rearing this fall, I’m not sure I’m ready to attempt to keep an aquarium again.


Why milkweed is the best plant: wasps!

Potter or mason wasp (Subfamily Eumeninae)
A potter or mason wasp (Subfamily Eumeninae) feeding on milkweed nectar, Barr Lake State Park, Colorado, USA. July 1, 2012.

Not only is milkweed food for adorable monarch butterfly caterpillars, but the right patch of milkweed can attract a host of interesting pollinators. After we checked out the burrowing owls the other weekend, we stopped at Barr Lake State Park for brunch, and I had to check out this fine stand of pink milkweed in full flower.

I’m kicking myself now for not taking some pictures of the actual plant. For one thing, it might have helped with identification, as some milkweed-loving insects are adapted to specific species, plus it’s generally a good habit to get into. In my defense, I was really excited about the wasps.

Because really, look at this gorgeous green-eyed square-headed wasp (Tachytes sp.). Who wouldn’t get excited?

Square-headed wasp (Tachytes sp.)

There was a thread-waisted wasp (Prionyx sp.) gamely flying around feeding despite missing at least one and a half legs (it’s rough sometimes, being an insect):

Thread-waisted wasp (Family Sphecidae)

And a bunch of attractive yellow-spotted scoliid wasps, probably Scolia nobilitata:

Scoliid wasp (Scolia nobilitata)

But the mystery was this milkweed beetle (Tetraopes sp.):

Milkweed beetle (Tetraopes pilosus)

Most milkweed beetles are bright red and black–like many insects which feed on milkweed, including monarch caterpillars and milkweed bugs, they exhibit aposematic coloring. Milkweed contains toxins that make it unpalatable to many animals, and aposematic coloring indicates to predators that insects like milkweed beetles are also unpalatable.

There are a few species of milkweed beetle that sometimes exhibit pale forms, but the only one I know of that’s this pale is Tetraopes pilosus. T. pilosus does live in Colorado…so what’s the catch? Remember, earlier I mentioned that a lot of insects that eat milkweed are host-plant specific, and milkweed beetles may fall into this category. T. pilosus feeds on Asclepias arenaria and A. tuberosa, both white-flowered, less showy species, that are commonly found in sandhills.

While I can’t identify this milkweed for certain, I think it was probably A. speciosa, and definitely not either of the host plants for T. pilosus. It was growing at the edge of a grassy meadow near a lake, about as far from sandhill country as a habitat can be.

But the beetle really can’t be anything other than T. pilosus, and was identified as such by Michael C. Thomas over at BugGuide. So my best guess here is that milkweed beetles are not quite that host- or habitat-specific. If anyone has some insight on this, I’d love to hear it!

(Thanks to John S. Ascher, Michael C. Thomas, Ken Wolgemuth, and Eric R. Eaton at BugGuide for identification help. Remaining errors are mine.)

This is not a photograph of a Burrowing Owl

Two-spotted Melyrid (Collops bipunctatus)
Two-spotted Melyrid (Collops bipunctatus) beetle, somewhat out of its expected habitat in Brighton, Colorado, USA. July 1, 2012.

At the beginning of July I went on a trip sponsored by the Boulder Audubon Society to look for nesting Burrowing Owls (Athene cunicularia) up in Brighton, Colorado. As you can see, this is not a photo of a burrowing owl.

We did see a lot of burrowing owls–several colonies–but mostly barely within scope range, and I still had trouble telling the difference between owls and prairie dogs half the time. The last colony we visited we did see one lovely individual about 20 feet from the road, but that wasn’t close enough to get even the mediocre photo I got in Oklahoma in 2010.

But I enjoyed seeing them, and I was able to photograph quite a lot of interesting insect life, such as the above gorgeous little flower beetle, somewhat unexpectedly crawling around on a gravelly roadside with no flowers in sight, and a lot of darkling beetles (Family Tenebrionidae). The flower beetle was moving along at a good clip, perhaps feeling a little exposed, so I wasn’t able to get a very good picture.

And here’s a fairly small robberfly (Family Asilidae):

Robberfly (Family Asilidae)

But I think the most exciting thing was probably finding a cooperative tiger beetle! I am in awe of Ted MacRae of Beetles in the Bush, who specializes in photographing tiger beetles–I find them to be incredibly frustrating and uncooperative insects. They’re fast and flighty, and half the time when they do run towards me instead of away, it’s so they can hide under my shoe. I cannot take photos of insects that are hiding under my shoe. In general, a lot of ground-dwelling beetles seem be in constant motion, so I expect I will continue to focus the majority of my insect photography efforts on dragonflies.

Tiger beetles are a pretty amazing group of animals, and I’m always excited to see one, even when they are not cooperative photography subjects. I believe this is the Punctured Tiger Beetle (Cicindela punctulata), and part of why it was so cooperative is that it had found a squashed individual of the ubiquitous darkling beetles, which it was busily trying to consume:

Punctured Tiger Beetle (Cicindela punctulata) scavenging a darkling beetle (Family Tenebrionidae)

I love how tiger beetles are pretty much made of long, long legs and chompy jaws of death:

Punctured Tiger Beetle (Cicindela punctulata)

I also spotted one bright metallic green tiger beetle, which I was not able to get any focused shots of, but which I am fairly sure was a green southwestern form C. punctulata.

After the owls we stopped at Barr Lake State Park for a lovely brunch, and I found some flowering milkweed that was absolutely covered with interesting insects…but that’s a topic for another post.

(Thanks to Ron M. and Michael C. Thomas at BugGuide for identification help. Remaining errors are mine.)

Bug hunting at Chatfield State Park

Spider wasp (Family Pompilidae)
A wasp (Order Hymenoptera) at the Audubon Nature Center at Chatfield, Littleton, Colorado. June 30, 2012.

This morning I went on an entomology walk through the Audubon Society of Greater Denver, led by time-traveling Victorian naturalist Professor J. Phineas Michealson (Michael Weissman, a local entomologist). I go on these sorts of trips to learn more about animals and see some interesting things, not for serious photography, which is basically impossible in a large group unless the whole group is serious macro photographers. And, well, I’m not.

But I saw some awesome animals and took some photos I’m fairly happy with (not always at the same time).

Before the walk even started, I found a very small praying mantis nymph, probably a European Mantis (Mantis religiosa), although I didn’t get a look at its armpits. I’ve never actually seen a native mantis in Colorado, though, and all the other mantises we saw today were European. European Mantises come in different color morphs, but this one is so pale I suspect it was freshly molted.

European Mantis (Mantis religiosa)

In the parking lot I found a Brown Scarab Beetle (Phyllophaga lanceolata), which was not very cooperative. It would not stop moving, so I wasn’t able to get a very good photo:

Brown Scarab Beetle (Phyllophaga lanceolata)

We started out in the non-native garden, where the most common insect was the non-native European Honeybee (Apis mellifera). There were a few small native bees, including some gorgeous sweatbees that I couldn’t get any pictures of, and some native bumblebees, but by far the highlight for me here (and for the entire morning), was a little metallic green animal I at first thought was a beetle. I was thinking primarily about focusing (unsuccessfully, alas), so I didn’t noticed until I examined my photos at home that it was actually a jumping spider, Tutelina elegans Sassacus papenhoei! This is probably the most beautiful spider I’ve ever seen–I can’t believe it lives in dry, utterly non-tropical Colorado.

Jumping spider (Sassacus papenhoei), female

There were also some very colorful, very tiny, very hard to photograph leafhoppers (Family Cicadellidae). I find it amazing how beautiful and colorful these tiny, often-overlooked insects are.

Leafhopper (Family Cicadellidae)

We then headed out on the trails, where we quickly came across a fuzzy tiger moth caterpillar (Family Arctiinae). Caterpillars in this family are often called “woolly bears.” Anyone have any idea what species this might be? It looks to me like it might be a Virginia Tiger Moth (Spilosoma virginica), but fuzzy caterpillars often look the same to me.

Tiger moth caterpillar (Family Arctiinae)

There were a few more European Mantis nymphs here, as well as an old already-hatched ootheca (egg case). It’s a little unusual to see one laid on a rock rather than a plant.

European Mantis (Mantis religiosa)

Mantis egg case (ootheca)

Our guide Professor Phineas was a bit aghast at speaking so much of insect reproduction in the company of the fairer sex, but as a good naturalist, felt compelled to answer our many questions about the workings of the insect world.

Victorian naturalist Professor J. Phineas Michealson

Another beautiful, annoyingly out of focus sharpshooter (Cuerna sp.):

Sharpshooter (Cuerna sp.)

Down at the wetlands–the wetlands at Chatfield, like most wetlands in the Colorado Front Range, are artificial–we found quite a different assortment of animals. This invasive American Bullfrog (Lithobates catesbeianus) may not be welcome, but it is rather handsome.

American Bullfrog (Lithobates catesbeianus)

To my great joy, I spotted a species of dragonfly I haven’t seen before, the beautiful (and surprisingly cooperative) Eight-spotted Skimmer (Libellula forensis).

Eight-spotted Skimmer (Libellula forensis), male

Eight-spotted Skimmers and Twelve-Spotted Skimmers (Libellula pulchella) were by far the most common species I spotted, which surprised me a little. There were also some Blue-eyed Darners, one Common Green Darner (Anax junius), Widow Skimmers, assorted damselflies, and possibly a Black Saddlebags (Tramea lanceata, although I wasn’t entirely sure about that one).

Twelve-spotted Skimmers are probably my second-favorite dragonfly, and not very cooperative photography subjects. Today I was able to get a few decent photos of them, but I may have to go back with less of a crowd to try to get good photos. Until then, these will have to suffice.

Twelve-spotted Skimmer (Libellula pulchella)

Twelve-spotted Skimmer (Libellula pulchella)

We did a little dip-netting in hopes of finding dragonfly larvae, but only came up with a very very tiny crawdad.

Baby crawdad (Superfamily Astacoidea)

And here is another adorable tiger moth, I think perhaps a different species (although caterpillars can look quite different at different instars–life stages–so it’s hard to say):

Tiger moth caterpillar (Family Arctiinae)

Quite a lot of animals to see in only about two hours. It’s interesting to contemplate how unnatural this created habitat is–highly biodiverse in some respects, but unnatural. A number of the species we saw today were non-native, including the European Mantises, Cabbage Whites (Pieris rapae), and the American Bullfrog. While these artificial wetlands provide excellent habitat for birds (some of whom were not found in Colorado historically), dragonflies, and other water-loving animals, they are certainly not good habitat for the prairie species which lived here historically.

As our guide mentioned several times, Chatfield is a wonderful place for teaching about nature, but it’s not natural.