Posts Tagged 'beetles'

Two-Spotted Sightings

My first ladybug of the year was spotted on the weekend. It was, no surprise, a Multicolored Asian, Harmonia axyridis, which you should expect to see just about everywhere. I also saw very small lady beetle I’m not yet sure of the identification of. But on Monday, I saw half a dozen Two-spotted, Adalia bicunctata, which made me very happy. (See the essay I wrote about these for Humans & Nature.) Adalia bipunctataThis is the classic form.

Adalia bipunctataThis is the black form. Yes, that’s a human neck it’s on.

VLB in BBP

Pyrrhalta viburniTwo of the gardeners at Brooklyn Bridge Park showed me the evidence of Viburnum Leaf Beetle that they were hunting down. The pits in the twig are egg cavities, dug into the tree by the mature beetle. The tiny larvae can just be seen.

The destructive invasive beetle is rampant through most city parks, but is so far kept at bay in BBP, which has multiple species of viburnum growing. Here’s what the damage looks like when it runs wild.

Still Hanging On

In early November, I found four adult Two-spotted Ladybeetles (Adalia bipunctata). Adalia bipunctataAnd without looking very hard. I just stood under the tree and looked up.Adalia bipunctata

Early Stages

larva1This is some kind of Lacewing larva. It was found predating under the Catalpa leaves, where the ladybugs are still to be found, too, deep into October. larva2On the rocks below the trees, a lady bug pupa.

Nicrophorus

NicrophorusA carrion beeetle, also known as a sexton beetle, of the genus Nicrophorus, from the Greek for “carrier of the dead.” Found this on a mammal corpse on a path at Dead Horse Bay. The carcass was in curious state; some exposed bones were already whitened, but the main part of the body still had leathery skin/fur and did not smell pleasant. (Nothing like the Götterdämmerung of rotted chicken used to bait for carrion beetles here, though.) Not sure what the animal was: didn’t look big enough for adult raccoon; perhaps a feral cat, of which there are plenty in the phragmites.

So these Nicrophorus beetles — there are some 15 species in the U.S. — are remarkable for providing not just a nest egg of carrion for their young, but sticking around to help feed the wee larvae when they are just starting out as squirmy little rotten-flesh eaters.

The mites — you can spot two adults and see some young ones clustering on the beetle body as well — are symbionts, not parasites. Sources of carrion are extremely variable and unpredictable: so the beetles range throughout the landscape searching for it, carrying the mites (of at least four families), who eat fly larvae and couldn’t get around so well otherwise; the fly larvae is competition for the beetle larvae.

Nicrophorus marginatus is the most wide-spread of these beetles, but it’s very similar looking to N. obscurus and N. guttula, and they evidently can’t be separated based on overall appearance according to Bugguide.

Still Going Strong, But Hurry Up!

IMG_4439These 2-spotted ladybug larvae were still active on Thursday. Time to pupate, kids!

Now, here’s something I’m not so sure about: Pupation and eggs generally seem to be set on leaves. These leaves will shortly fall to the ground, many to blow away to who knows where (into the harbor in some cases, in this situation). This seems a real chancy way of surviving the winter. Are there special end of season approaches to getting the genes through the cold months?

More Two-Spotted Ladybugs

catalpaThe Catalpa trees grow and the big heart-shaped leaves attract aphids, lots of aphids. The aphids, tiny little white sucking machines, coat the leaves with their “dew” — what goes in must come out in some form — which in turn attracts ants and wasps. The aphids themselves attract ladybugs, hungry little beasts. All the dark things on the leaf above are early-stage instars of lady beetle larvae, which look absolutely nothing like the shiny, round adults. Adalia bipunctataThis photo and the one below are shot with my camera’s macro through a 10x loupe. The ‘gator-like larval stage ladybug — see the two spots on its side, like the adult Two-spotted — is surrounded by aphids; these aphids are so small they can barely be seen with the naked eye. catalpa2I don’t know if these are instals of A. bipunctata, but suspect so. I doubt that’s my hair, since I was wearing a hat. Adalia bipunctataThis one is so plump I suspect it’s close to pupating.

I have read that some localities ban Catalpas because they are messy trees, dropping foot-long, dried bean-pod-like seed pods, dripping with sticky goo, swarming with insects. But let’s hear it for mess! Nature is messy, complicated, interrelated. It is not a lawn or vast monocultural farm field soaked in poisons, which, as we keep learning over and over again, do tend to move from the insects and plants they are aimed against to fish and reptiles and birds and mammals, including the very people who apply the toxins and the rest of us. Quelle surprise! Adalia bipunctataLuckily, Brooklyn Bridge Park has had the vision to plant Catalpas all over the place. And almost every one of these trees has Two-spotted ladybugs in them. Remember, this is a species that isn’t being seen as much as it used to be. Above and below, Two-spotted pairs are engaged in making more of their kind.Adalia bipunctataRemember, too, that while the standard Adalia bipunctata is red-orange with two black spots, there are melanistic variations that are black with four red spots (or squares as in the side markings here), among other patterns.Adalia bipunctataHere’s what the loupe/camera set up view looks like before cropping. Rest of my left-hand fingers are supporting the leaf from underneath. I’m amazed these came out this well. Adalia bipunctataI wrote most of this post some weeks again, but a cursory look yesterday found three adult TSLs underneath some awfully bedraggled looking Catalpa leaves. Three cheers for bedraggled!

For my first discovery of these rare beetles two years ago on these trees, see here.


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