The monarch butterfly migration was in full swing earlier this month, and I got a pic of this one at Meadowlark Botanical Gardens in Virginia.
This is a photos of a Monarch butterfly, laying eggs on a milkweed plant. Happens all the time, but there is more to this relationship than simply a butterfly finding a good place for the young to grow up.
There is way more to this story than I can get into here, but two things are worth knowing. First, the milkweed plant contains toxic chemicals, and second, that even though monarch numbers have been way down in modern years just planting more milkweed isn't a perfect solution.
So, the milkweed plant is toxic, specifically containing cardenolides that are not fun to eat. But the larval butterflies, you know, caterpillars, eat up milkweed like crazy. In fact, it is pretty much all they eat, from at least of the 27 species of milkweed in North America.
And as for the toxins, well, they sequester them. This allows these cardenolides to stay in their body through metamorphosis and arrive in the adult butterflies, having no seeming effect on the animals. But you still won't like it if you eat these toxins, so chowing down on a monarch will likely induce vomiting or similar stomach distress. Animals that eat a monarch butterfly learn that this is not good food, and avoid them in the future. Nifty little strategy they've got going there. Side note: the very tasty Viceroy butterfly mimics a monarch's colors to not get eaten since it looks like the awful-tasting one.
So with the numbers of monarchs decreasing (mainly due to habitat loss and pesticide spraying), a grand plan was hatched to have gardeners plant more milkweed. Seems very reasonable, since milkweed makes for a nice garden plant and will attract the pretty butterflies. Well, all is not perfect here. Seems like most all of the available milkweed plants to gardeners in the US are tropical milkweeds, which have a problem.
Milkweed can carry a parasite that is hard on the butterflies, and they can pick it up during the caterpillar stage while eating the leaves. They then pass it on to the adults, which weakens them severely and can prevent them from having the strength to migrate (many go all the way to Mexico!). This whole problem has historically been kept in check by all the milkweeds dying off each winter along with most infected adults. Each year the unaffected adult butterflies return to relatively unaffected milkweed.
But tropical milkweed is different. In parts of the US, like southern Texas, it does not die out but survives the winter. This provides both for continuing the infection and also a side problem whereby some butterflies now do not continue their migration but just stop there as the milkweed remains present (and continues to infect them).
So, monarchs have had it tough lately, even with a large effort to help them out. And this is just a small snippet of the whole story, but certainly an interesting story to learn.
There are a number of species of these bluet damselflies, and I am not completely sure of these so just leaving it at genus level identification. This pair was flying and perching among a lot of spider webs, which did not seem to bother them.
This youngster did not seem quite so adept around the webs.
While I can not tell the species of a juvenile mantis, I really like these insects and so am putting up a photo of one (of several I saw) from Centre County, Pennsylvania.
My computer has been doing too many updates lately to blog properly. But to put something fun up here is a katydid. It is a juvenile and does not yet have its full wings, but still a nice looking insect.
This moth, the Polyphemus moth, is named after a Greek cyclops Polyphemus. Supposedly for the big eye spots on the underwings. But when the wings are open there are clearly two eyespots making a complete set. I leave it up to the reader to figure out that bit, although this one wouldn't open its wings completely for me.
Sometimes we do catch the larger moths in our bat mist nets. We take them out like we would a bat and release them. Pretty animals.
Leaf cutter ants are all over the place here at the FCRE. Here is a shot of them cutting up a banana leaf to haul off to their nest.
There are a multitude of mantids here, and no easy way to figure them all out as we haven't focused on them (yet). This beautiful animal was on one of the ornamental plants right outside my room this evening.
These wasps, known variously as spider hawks or spider wasps or for some tarantula hawks, are very neat animals. They capture large insects or spiders by stinging and paralyzing them, then place the victim in a hole in the ground, and lay an egg on it. The egg hatches and the larvae gets to eat some fresh food before morphing into an adult wasp and digging itself out of the ground.
Here is one dragging what looks like a tree cricket or larval katydid to it's hole near the top of the Firestone Center property.
And now your fun fact of the day. The Schmidt Pain Index goes from 0 (bite does not break skin) to 4 (really, really ouchie) and rates quite a number of insect bites as to how painful they are. This wasp rates a 4, as painful as anything pretty much can be.
And lastly, a short video from Borneo where I explain these spiders in a little more detail.
Another giant insect from last night. This long-horned beetle is about 3 inches long not counting those long antennae.
Keith Christenson - Wildlife Biologist