Wednesday, September 25, 2013

Two rare Enoclerus species from Arizona

 Clerids in the genus Enoclerus are among my favorite beetles. They are fuzzy and colorful and they move around in fast little burst of high speed, resembling very much the Velvet Ants that they mimic.

Enoclerus quadrisignatus
 At our house we usually find the rather large Enoclerus quadrisignatus. I seem to remember seeing them nearly all year round, but my photos are all taken from May to July.

The drab Enoclerus moestus can be found on freshly dead pine in early summer at high elevations of the sky islands. It hunts for insects that come to lay their eggs in the wood. 

Enoclerus bimaculatus and E. luscus often appear at the black light in upper Madera Canyon. Dried specimens of E.bimaculatus have strikingly pink markings, but on  the living beetles they are ivory colored.

Both color morphs of Enoclerus laetus can be seen together on blooming Baccharis in autumn. While larvae and adult beetles of the genus Enoclerus usually feed on other insects, some of them also like protein rich pollen.

With 36 species north of Mexico, Enoclerus is the species richest genus of the family Cleridae in the US. While the genus ranges across the entire American continent, most species occur further south in Central and South America and it is assumed that their phylogenetic origin is located there.

Even though the beetles are small and quickly fly when disturbed, I have found and photographed several more species here in Arizona. Twice I have been extraordinary lucky: In 2009 I 'rediscovered' Enoclerus decussatus in Sycamore Canyon at my black light.

Enoclerus decussatus

 Clerid expert Jacques Rifkind said via email:
The bug you have there is very interesting--I've never seen anything like it in the U.S! I suspect it is a dark morph (with reduced markings) of the Mexican species Enoclerus decussatus. I have seen a similar color pattern in specimens from Mexico (there is one pictured on page 2 of my site). However, Enoclerus decussatus has not, as far as I know, been recorded from Sonora, which makes this a very unusual distributional record. In any case, it's hard to be sure of the identification without having the beetle in hand. I'd be very interested in examining this specimen if it is available. You possibly have a new species, but at the very least, you have the first U.S. record for a described Mexican species--a record that generates intriguing questions that only further collecting will be able to answer.
When I then sent him the specimen, he wrote: Your beetle arrived safely today. It is indeed Enoclerus decussatus (Klug). I looked into the literature, and it seems that Horn made a note in 1885 about a darkened specimen collected in Arizona. More recent checklists assumed this was an incorrect record, and the species hasn't been considered part of the US fauna since Corporaal's 1950s catalogue. So, you may have collected the first specimen of this in AZ since the late 19th century! And so it is now officially part of the US fauna. I will get a note out on the record soon." This record was then  published in the Pan-Pacific Entomologist. 
Enoclerus hoegei
 Last week in Madera Canyon I saw another little beauty running up and down on the branches of a Baccharis that was visited by a great number of different beetle and wasp species because it was oozing tree sap. 
Again, I couldn't find any record in BugGuide, so the photo was dispatched to Jaques. He answered: "That is Enoclerus hoegei -- a primarily Mexican sp. that has turned up (rarely) in Sabino Cyn, but never as far as I know in Madera Cyn. Barr considered it a new sp. but IMHO it's just variable-- as would be expected of something that ranges from AZ to Honduras. Tell Margarethe 'good job' again."

Wednesday, September 18, 2013

Insects of the Button Bush

Two weeks ago my friend Ned Harris alerted me that the Button Bushes in Sabino Canyon were blooming. That meant photo opportunities par excellence for all kinds of nectaring insects.

Button Bush, Cephalanthus occidentalis, in Sabino Canyon
Button Bush or Button Willow, Cephalanthus occidentalis, in the family Rubiaceae, can be found in all states east of the Rockies, but only in Arizona and California in the West. The perennial shrub has a high water use, so it grows along  Sabino Canyon Creek that is finally running again. I have yet to find it elsewhere.  Button Bush may like locations higher on the rocky bank than my other favorite insect bush the Seep Willow Baccharis salicifolia that is much more common and grows within sandy creek beds where it hangs on during floods and thrives on the nutrients that the water leaves behind.

Ned Harris in a field of Datura that's also in full bloom in Sabino Canyon
On Sept. 4, I joined Ned on one of his photo excursions and I was amazed how much the bushes had grown over the last three years.  So much so that a lot of insects were out of reach for my macro lens and I am relying on Ned who is taller and has a longer lens for most of this blog's images. Just kidding, Ned's photos are just way better than mine.

left: Carpenter bees: Xylocopa  tabaniformis, and californica Photo N. Harris. right: Sonoran Bumblebee Bombus sonorus
Even though we ignored the honey bees, we found plenty of native bees and bumblebees who shared the nectar with all kinds of big wasps. 

Top:  Pepsis grossa and another Tarantula Hawk
Below: Campsomeris tolteca, Prionyx sp, Polistes flavus
Very large Tarantula Hawks, Pepsis grossa, appeared in two color forms: Orange-winged (xanthic) and black-winged (melanic). The two color forms are not often seen in the same locality, but the black one was too large to be the similar P. mexicana. The scoliid Campsomeris tolteca and the sphecid Prionyx were also among the giants of their families.

Top: Gulf Fritillary, Queen, Monarch
Middle: Painted Lady, Bordered Patch, Arizona Metalmark
 Bottom: Black Swallowtail, Southern Dogface, Acacia Skipper
most photos Ned Harris 
Ned uses a long lens that isn't a dedicated macro, so he concentrates mostly on insects above 1 in body length, and so of course he loves all butterflies. We found everything from big Brush-foots (Nymphalidae) and Swallowtails (Papilionidae) to Sulfurs (Pieridae), Metalmarks (Riodinidae) and Skippers (Hesperiidae).

Pipevine Swallowtail by Ned Harris
My favorites are without doubt our very common Pipevine Swallowtail. These butterflies hardly ever sit still but keep flapping their wings because the slim buttonbush branches can hardly support their weight.  Much rarer is the similar Black Swallowtail but Ned got the nice shot in the group collage above.

White-lined Sphinx by Ned Harris
The White-lined Sphinx solves the weight problem by not landing at all but hovering over the flowers while nectaring. Because of this ability several moth species in the family Sphingidae have earned the common name 'Hummingbird Moth'.

Strigoderma pimalis and Cotinis mutabilis (Green June Bug or Fig Beetle)
Disappointingly few beetles showed up. I had expected a few sugar-loving cerambycids, but we found only two species of scarabs. But it was a blustery, overcast day and flying and cold starts in particular are much more costly for a beetle than for a butterfly with its much greater wing area.

Mexican Amberwing, Yellow-bellied Bee Assassin, Green Lynx spider
As usual in high traffic areas, there was a number of ambush predators. Dragonflies  kept an overview from an elevated perch, whereas spiders and assassin bugs were lurking in the foliage and even on the flowers.

The Buttonbushes of Sabino Canyon are definitely worth a yearly visit, even though they bloom in the hottest, muggiest time of the year. It's rare that I'm not envious of Ned's long lens and high performance camera, but this time I was quite happy to carry only my point-and-shoot and small binoculars, especially as I could count on Ned's generosity to share his photos!


Wednesday, September 11, 2013

Real time protocol of a scorpion sting

Today's not my day. Among the things that went wrong were the broken dog fence (Randy's problem but I feel for him), a Prairie Falcon that sent me racing for binoculars and then took off just as I got them, and then I got nailed by something.
I had let some black cloth dry over night on the wall along the driveway. When I picked it up I first thought it had given me and electric shock. It's often so dry here that static accumulates and one can get hit quite unpleasantly by those discharges. But this was way to strong a sensation and then also began to hurt a little like a bee sting. Since it was on my finger, my first reaction was to try and suck out whatever had been injected.

 Hoffmannius confusus (Stahnke 1940)
By then I knew that I hadn't felt anything quite like this before, so I began to carefully search the cloth. Sure enough, a scorpion was still hiding among the folds. Good that I brought my camera to shoot the falcon: now I took some booking portraits of my assailant.  He actually got away because I had no container. Next I posted the photos to the fb page of my friend and scorpion authority Warren Savary. If it turns out to be a scorpion sp. with a deadly poison - there aren't any described for Arizona, so it would be new to science - at least there will be proper documentation.
The pain is completely gone by now, but I can't quite decide whether my left hand is tingling or numb. Maybe both. All over I'm feeling a little shaky and like a migraine is coming on.
My lips and tongue are feeling like I'd be getting over local anesthesia from a dental appointment (good reminder - get a check-up before the art season starts and I get too busy!) And of course now I don't know whether this is a systemic reaction or if I brought that upon myself by sucking the stuff out.

But now, after half an hour, the tingling numbness has reached my right hand, so I'd say it is systemic. I'm slightly nauseated and beginning to sweat but my heart rate is a normal resting 78 per minute. The initial adrenalin boost has definitely worn off by now.
45 minutes after the sting I'm feeling quite normal again, only my lower lip is still numb. But then  Randy wants me to read some very garbled text that he has to edit. It's written by a not-English-speaking scientist (no me!) in English, and after reading I go right back to feeling confused, disoriented and nauseated. But I don't think the scorpion has anything to do with it. Poor Randy. He'll spend all day with those 30 pages.
I have to admit, 2 h after the sting I now have a slight headache an hot flashes. Hm. Need a control experiment volunteer (a group, actually) and better air conditioning.  
I took an aspirin and a half hour nap and woke up feeling completely normal.  
Warren identified the scorpion as one of our larger, most harmless species Hoffmannius confusus.

Tuesday, September 3, 2013

Hiding behind your Worst Enemy

Many species that are pursued by predators pretend to be what they are not to protect themselves. They may mimic toxic, dangerous or noxious tasting models or they may just become invisible sporting cryptic patterns that blend into the background.

Eye spots of moths and butterflies that are revealed with a sudden flick of the wings are widely accepted as a signal to scare or confuse predators. If you have ever seen the up-side down stance of an Eyed Silkmoth that feels threatened you can easily imagine that a hungry bird might be scared away from this fat clumsy morsel that suddenly resembles a cat or an owl. And maybe the scare even works as a defense against the attack of a lizard?

Antheraea oculea (Western Polyphemus Moth)
Most reptiles are predators of insects - the diet of many lizards consists entirely of arthropods and even baby alligators often grow on the proteins of grasshoppers and moths until they are big enough to hunt other prey.

But this isn't where the relationship ends. Evolution has linked insects and reptiles through more than just the food chain.

Papilio rutulus (Western Tiger Swallowtail) caterpillar

Observe the spots on the bloated body of the Western Swallowtail caterpillar: to my eye they not only distract from the real head that remains tucked down and hidden, they also seems to suggest the face of a snake.

Elephant Hawkmoth, Deilephila elpenor by Amy MacDonald
The resemblance to a snake seems even more impressive in the caterpillar of the Elephant Hawkmoth because it is longer, bigger and adds a cobra-like threatening posture to the mere looks of a serpent.
When my friend Alex Pelzer was working on his Ph.D. using these moths as his model, we tried to test whether birds are indeed afraid of the snake mimic. At the time, I had a young tame Jackdaw (small corvid). When offered the big writhing worm the bird seemed confused, but then attacked the caterpillar and tried to eat it.

My trusting friend Jakob the Jackdaw

So instinctive aversion? Not really.
But: the jackdaw was young, hand-raised and inexperienced. Like young wolves, chimpanzees, and humans, the highly social and intelligent corvids are born with very little instinct. Instead, they have a great capacity for learning. In fact, this young bird looked to me for approval of any new food it found, and it would try to eat everything I offered. So he wasn't a good test animal at all, we should have tried something more precocious, like a young chicken. We just all had a lot to learn.

Macacha (Fulgora laternaria) by Leonel Baldoni
In the rainforests of central and South America lives an insect in the family of the Fulgorid Planthoppers that looks even more like a reptile than our caterpillars, at least in photos where you have no size comparison.
My friend Lois O'Brien is an expert of the group Fulgoromorpha. She writes:

"Fulgora, the lantern fly or peanut bug, has a head that looks like a peanut from above. But from the side, the head looks like an alligator head, complete with false eyes and false nostrils ...and a big mouth full of false teeth." 
To humans this planthopper looks so dangerous that there is a widespread legend that its bite kills within 24 h - the only antidote being to have sex before that time runs out. O'Brien speculates whether the 'alligator mimicry' targets birds, reptiles or monkeys, even humans, and wonders about the size difference between model and imitator. As baby alligators are quite small and quite ferocious hunters (and often under the fierce protection of their really terrifying mother), the size difference bothers me less than the difference in habitat between presumed model and mimic. But birds and monkeys get around ... and maybe they are wary enough of alligators to carry the image in their memory wherever they go.
Fulgora laternaria from Cuvier's La Regne Animal
Or maybe the mimicry model isn't an alligator but just another reptile like a lizard. In any event, the similarity seems just too suggestive to be without any function at all.
But if all else fails, Fulgora can still flash two big eye-spots at the attacker as well.

Chrysalis of Dynastor darius stygianus (photo V. Izerskyy)
 Here is another striking tropical example posted by Vladimir Izerskyy on facebook. It's the pupa of Dynastor darius stygianus which seems to be mimicking  the head of a Boa constrictor peruvianus. Dynastor darius stygianus is found in Peru, for example in Coviriali, Satipo, Peru. Clearly, the  pupa needs protection even more than any mobile form of insect, but we are more used to camouflage as the means of survival of pupas.

We found another unexpected reptile imitator closer to home:
After the black-lighting session of the last 'Infestation Party' at Pat Sullivan's house in Ramsey Canyon, Arizona, there were a lot of entomologists as well as left-over moths still hanging around in the early morning hours. The humans were congregating outside with cups of strong coffee and plates of Schwarzwaelder Kirschtorte (great way to wake up!).

Do you see the snake lurking?
At one point I bent down to take a photo of something low in the vegetation at our feet, when I heard Charlie O'Brien's warning 'Careful, there's a snake under those leaves'. And indeed, there was the eye, the shiny nose, the bigger ventral scales and the curved body of a snake - cartoonishly overdrawn but very convincing from the right angle.

But - overemphasized detail aside - I had had my morning coffee already! - so to me it was just a sleepy moth, a beautiful Glover's Silkmoth.

Glover's Silkmoth (Hyalophora columbia gloveri)

Literature: The Wild Wonderful World of Fulgoromorpha, L. O'Brien, Denisia 04, zugleich Kataloge des OOe. Landesmuseums, Neue folge Nr. 176 (2002) pp 83-102