Posts Tagged 'invertebrates'

The Canary on the Windshield

Or rather, the lack of one. The canary in this case is all the dead bugs people used to have to wipe off their windshields. Michael McCarthy, who titled his book on the great decline of life on earth during our watch The Moth Snowstorm, writes about being old enough to remember all those dead bugs. But this doesn’t happen anymore.

Yesterday, I read of a new study that found that insect populations in Europe have plummeted over the last 27 years.

Here’s the news item.

Here’s the study.

Here’s the abstract:

“Global declines in insects have sparked wide interest among scientists, politicians, and the general public. Loss of insect diversity and abundance is expected to provoke cascading effects on food webs and to jeopardize ecosystem services. Our understanding of the extent and underlying causes of this decline is based on the abundance of single species or taxonomic groups only, rather than changes in insect biomass which is more relevant for ecological functioning. Here, we used a standardized protocol to measure total insect biomass using Malaise traps, deployed over 27 years in 63 nature protection areas in Germany (96 unique location-year combinations) to infer on the status and trend of local entomofauna. Our analysis estimates a seasonal decline of 76%, and mid-summer decline of 82% in flying insect biomass over the 27 years of study. We show that this decline is apparent regardless of habitat type, while changes in weather, land use, and habitat characteristics cannot explain this overall decline. This yet unrecognized loss of insect biomass must be taken into account in evaluating declines in abundance of species depending on insects as a food source, and ecosystem functioning in the European landscape.”

OF COURSE it’s pesticides and habitat destruction, for f’s sake! Will this, one day not too soon, be like those images of aurochs painted in caves?

Familiar Bluet

Enallagma civile, the last damselfly of the year? This picture was taken on 9/24.This one on 10/6: tandem flight and egg-laying in Green-Wood’s Sylvan Water. I assume the larvae will overwinter.

Insects

Harmonia axyridis, the Multi-colored Asian Lady Beetle, is known in the UK as the Harlequin Lady Beetle. “Harlequin” is a better common name than MALB, which is a mouthful and has a whiff of racial baggage to it, particularly when added to invasive. This one was one of two spotted in Denmark, the only lady bugs seen on this trip. The Swedes, meanwhile, really seem to like their spiders. There were many webbing the inn we stayed in. There were more than a few indoors. All fine with me. And here’s a neighbor in the Bronx, on a window-spanning web right in front of a fan blowing out. Has been hanging out for more than a month now. One of the biggest orb weavers I’ve ever seen, a good 2″ from toe to toe. Yellow-collared Scape Moth (Cisseps fulvicollis) back in Brooklyn. First time I’ve noticed the red tongue.

Bombus Away

After a lingering slog of humidity, things have gotten cooler and drier here in the Borough of Kings. Today’s high is forecast to be 69, not the most optimal for insects. Their season is passing. I saw this bumblebee yesterday working a chicory, of the few flowering plants in Sunset Park now. The bumble was a bit sluggish. This large grub — 1.5″ long; I took it for a caterpillar at distance — was upside down but nonetheless moving with rhythmic pulsations. I gently rolled it over, thinking it would prefer to use its minor appendages, but it was having none of that and returned to this position. Then we both moved on to our destinies, whatever those might be. Yet I, for one, feel fairly sure that I will awaken tomorrow as a giant beetle…

So Many Monarchs

Have you noticed what a good year it is for Monarch Butterflies? There have been lots of positive reports from around the city and further afield about the large numbers of Danaus plexippus being seen. On Saturday, I walked from Sunset Park to Park Slope and back again to pick up some baked goods. I was distracted: over two hours, I counted 51 Monarchs, the majority of them overhead, heading south towards Mexico along 5th Avenue. Detouring into Green-Wood, I found fourteen. Not one was in the pretty plantings, all exotica, at the neo-gothic gate at 25th Street — a good argument for pollinator-friendly plantings. Because up in the native meadow patch — the prototype of a much larger hillside native meadow project — there were at least half a dozen winking their enormous velvety wings. And in the extraordinarily productive low-growing Buddleja patch by Valley Water there were at least seven more. (Yes, this one spoils that native plant theory…) Normally, I only see one or two Monarchs around these candy purple flowers, which have been swarming with Painted Ladies (Vanessa cardui) for a solid month and a half. Portrait of a Lady. There has also been a single Common Buckeye (Junonia coenia) in this patch, as well as a whole crowd of skippers (and European Hornets trying to tackle everything). Note that small gap in the hind-wing of this individual; I’ve been seeing this one for a while now. Why go somewhere else to feed?

Scandonata

So they have the same meadow hawk problem over there. These Sympetrum dragonflies are hard to ID in camera. Looks like S. vulgatum or S. striolatum are the options. Found around the moat of the Kastellet in Copenhagen, where the word for them is Hedelibel, or darter. The following mating damselflies were spotted in the same placid waters:Looks like the Small Red-eyed Damselfly (Erythromma viridulum). Lille Rødøjet Vandnymfe in Danish.

In Sweden, we didn’t have great dragonfly weather, but a big blue mosaic darner of the Aneshna genus, one of the Mosaiksländor in Swedish, was present on the sunny days. We were told that a week before many thousands had moved through, with lots of perching in the evening, but damned if I could get one of these to stop flying for a second for a photograph. With the Hobbies slicing and dicing the airspace overhead, they might have been wiser to take breathers on a perch under something occasionally. Really quite remarkable to watch the falcons zipping low over the golf courses and dunes to snag dragons, which they then eviscerated and gobbled up in the air. Not a lot of meat even on a big darner, so the Hobbies did it again and again.

Darners

The mosaic darners of the genus Aeshna are some of our largest dragonflies. There are 20 similar looking species in North America, so they can be a bear to identify. This looks like a Shadow Darner (Aeshna umbrosa), photographed recently in Westchester Co. They run about 2.9″ long.

Shadow Darners can be seen well into the fall. They are one of the last Odonata flying around here. The only other time I’ve seen one was in late October.

Our usual darner is the 3″-long Common Green Darner. Migratory, they can sometimes be seen in good numbers over meadows this time of year.

But our biggest darner is the 3.4″ Swamp Darner (Epiaeschna heros). That link is to the time I watched one lay her eggs in rotting wood in Prospect Park.I don’t run into Swamp Darners often. Recently, though, we found this dead one in the NYBG on the bridge over the Bronx River. Talk about ol’ blue eyes.


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