The first individual is a male, as indicated by his terminal appendages. He is perched on a Swamp Rose (Rosa palustris) leaf. Nothing says “fall” like this little red devil against a background of fiery foliage!
The last individual is a male, perched on a cattail (Typha sp.) leaf near Swamp Rose and buttonbush (Cephalanthus sp.). The brown globes are the fruit of buttonbush.
My collection of field notes includes two text files that list lots of photos of both Blue-faced Meadowhawk (S. ambiguum) and Autumn Meadowhawk dragonflies that were never published in my photoblog.
The following photos were taken on 21 December 2015 at Huntley Meadows Park while field-testing a new Nissin i40 external flash unit with my Fujifilm X-T1 mirrorless digital camera and 55-200mm zoom lens (88-320mm, 35mm equivalent). The camera was set for “Forced Flash”: “Flash On, Fired” appears in the EXIF information for all shots.
The camera was set for Manual Mode: both Aperture and Shutter Speed were operator-selected; ISO was set to “Auto.” Notice the camera used ISO 800 for every shot. One obvious advantage of using a digital camera featuring a larger sensor — in this case, an APS-C sensor — is the camera can shoot relatively noise-free photos at higher ISOs.
Also notice the rich color in each photo, something for which the Fujifilm X-series of cameras is well-known.
Unknown blue-black berries. Alonso Abugattas, moderator of the “Capital Naturalist” Facebook group, speculates this is probably a species of greenbrier (Smilax sp.).
Turns out the growth is a gall caused by a parasitic wasp. Charley Eiseman, widely regarded as the go-to gall guy, said “It is likely a Diplolepis sp. gall.” Diplolepis is a genus of gall wasp in the Family Cynipidae.
Charley also said the only way to make a positive identification would be to collect a few galls in the hope of capturing some wasps when they emerged from the galls. In the interest of science, Kevin Munroe, manager at Huntley Meadows Park, kindly granted one-time permission for me to collect a few galls.
Waiting and watching
On 11 March 2014, three (3) insect galls — similar to one I photographed during Fall 2013 — were collected from Swamp Rose (Rosa palustris) plants located alongside the boardwalk in the hemi-marsh at Huntley Meadows Park. The largest gall was ~1.9 cm (~3/4 in) long. There was one small hole in the gall when it was collected; there were no holes in the other two galls.
The galls were stored indoors in a sealed Ziploc plastic bag for several weeks. I checked daily to see whether anything had emerged. At least once, moisture was wiped from inside the bag in order to prevent the galls from getting moldy.
04 April 2014
The following photograph is shown for scale: the insect galls (and later, tiny gall wasps) were stored in a Johnson Ziploc XL Sandwich bag; its dimensions are 7 in x 8 in (17.7 cm x 20.3 cm). I taped the plastic bag to the window of my apartment at the Beacon of Groveton in order to shoot still photos and video before sending the specimens to Charley Eiseman.
04 April 2014
Gall wasps began emerging from the galls on 03 April 2014. The preceding photos were shot on 04 April 2014, and the following movie was recorded on the same day. Individual specimens are ~2 mm (1/16 in) long.
Tech Tip: The preceding video looks better viewed in full-screen mode.
A closer look at what emerged from the galls
Charley Eiseman used a Canon EOS Rebel XSi, MP-E 65mm lens, and MT-24EX Twin Lite flash to shoot the following excellent macro photographs on 08 April 2014.
The first photo shows a gall wasp (~2.2 mm long) that was covered with “crumbs” from chewing its way out of the gall.
One parasitoid, shown below, emerged among tens of gall wasps: Eupelmus dryohizoxeni (female), 3 mm long. That’s right, this parasitoid feeds on the gall wasps that parasitize Swamp Rose — now there’s an interesting and unusual food chain!
The gall wasps collected at Huntley Meadows Park don’t seem to match any species in the scientific literature, so Charley Eiseman sent some specimens to an entomologist who specializes in micro-wasps. We are waiting patiently for the specialist to identify the species.
Editor’s Notes: Sincere thanks to Kevin Munroe for facilitating my amateur scientific investigation, and to Charley Eiseman for his extraordinary kindness in helping a virtual stranger!
The dictionary widget in Apple OS X defines “gall” as …
gall 3 |gôl|
noun
an abnormal growth formed on plants and trees, esp. oaks, in response to the presence of insect larvae, mites, or fungi.
• [ as modifier ] denoting insects or mites that produce such growths: gall flies.
The following photos show an unknown insect gall on Swamp Rose (Rosa palustris) spotted during a photowalk through the central wetland area at Huntley Meadows Park on 06 November 2013.
Closer view.
Wider view.
Charley Eiseman, widely regarded as the go-to gall guy, said “It is likely a Diplolepis sp. gall.” Diplolepis is a genus of gall wasp in the Family Cynipidae.
Thanks to Joshua Stuart Rose for providing a detailed answer to my questions, “What is the typical timeline for development of a gall like this one (including the life cycle of the insects living inside the gall), and what is the role of the “host” plant?”
Charley can correct me if I’m wrong, but the host plant is both protection and food for the gall inhabitant. The insect somehow incites growth of the gall, sometimes by bringing along a pathogenic fungus or virus, other times by releasing hormones or even segments of genetic material. The insect then eats what is growing in the gall’s interior. Meanwhile, the plant’s bark or skin, already adapted to protect the interior tissues of the plant, protects the insect right along with. The timeline is tough to figure without knowing the species, but if there’s anything overwintering in there, I would bet on its emerging from the gall in April or May. That’s assuming that it did not already emerge in the autumn to overwinter as an adult somewhere, or else emerged even further back in time so it could mate and overwinter as eggs, waiting to form their own galls after they hatch in the spring. Source Credit: Joshua Stuart Rose, member of the BugGuide group on Facebook.
Charley Eiseman added the following comment:
That all sounds right to me. I don’t see exit holes so I’m guessing there is still something inside. Also, it seems to be the case that stem swelling type galls overwinter. Source Credit: Charley Eiseman, member of the BugGuide group on Facebook.
The following photographs show a Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted during a photowalk through Huntley Meadows Park on 17 September 2013. This individual is a male, as indicated by its coloration and terminal appendages.
The dragonfly is perching near ripe Swamp Rose (Rosa palustris) hips, shown below.
I am especially fond of shots in which the dragonfly strikes an unusual pose, such as the head-tilts shown in the preceding photo and Photo 3 in the following gallery.
The preceding photograph shows a female Handsome Meadow Katydid (Orchelimum pulchellum) perching on ripe Swamp Rose (Rosa palustris) hips. Blue eyes are a good field mark for identifying Handsome Meadow Katydids. Thanks to fellow photoblogger Mike Powell for confirming my tentative identification!
Did you notice the long, curved, reddish-colored structure extending from the posterior end of the abdomen? It’s an ovipositor that female katydids …
… use to insert eggs into hiding places (which can be in crevices on plants or even inside plant tissues). Can’t say if she’s actively laying — it’s quite an acrobatic process, involving curling up the abdomen, at least the times I’ve seen it in progress. But her abdomen appears pretty plump which may imply a full load of eggs. Source Credit: Matt Pelikan, BugGuide group on Facebook.
I discovered another malformedodonate as I was working my way through a backlog of hundreds of photos that need to be rated and post-processed. This individual is a female Blue-faced Meadowhawk dragonfly (Sympetrum ambiguum) spotted at Huntley Meadows Park on 17 September 2013. She is an andromorph that has a slightly malformed abdomen.
Photo 1.
Photo 2.
Photo 3.
Photo 1 shows the dragonfly perching near unripened Swamp Rose (Rosa palustris) hips. A small crimp in S5 of the abdomen is easier to see in Photo 2 than the other images. Remember that “S5″ refers to abdominal Segment 5 (of 10), numbered from front to back. Look closely at Photo 3: I think the image looks more like an artist’s animation than a photograph!
Tech Tip: Either mouse-over or tap photos to see captions.
The following photographs show an Autumn Meadowhawk dragonfly (Sympetrum vicinum), perching on the warm surface of the boardwalk at Huntley Meadows Park on 15 November 2013. This individual is an older female, as indicated by her muted coloration, tattered wings, and terminal appendages.
Photo 1. Autumn Meadowhawk dragonfly (female).
Photo 2. Autumn Meadowhawk dragonfly (female).
A partially eaten rose hip, the fruit of the Swamp Rose (Rosa palustris), appears in the lower-right corner of Photo 2. No silly, dragonflies don’t eat rose hips!
The following gallery features an Autumn Meadowhawk dragonfly (Sympetrum vicinum) spotted along the boardwalk at Huntley Meadows Park. This individual is a male, as indicated by its coloration and terminal appendages.
The dragonfly is shown perching on Swamp Rose (Rosa palustris) hips.
The rose hip, or rose haw, is the fruit of the rose plant, that typically is red-to-orange, but ranges from dark purple to black in some species. Rose hips begin to form in spring, and ripen in late summer through autumn. … Rose hips are particularly high in vitamin C content, one of the richest plant sources available. Source Credit: Wikipedia.
During a photowalk through Huntley Meadows Park I spotted a Yellowjacket Hoverfly (Milesia virginiensis), a member of the Syrphidae family of flies, feeding on Swamp Rose flowers (Rosa palustris). This is one of the coolest insects I’ve ever seen. Look closely — it looks like it’s wearing sunglasses!
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