Monstrous!

I'm going to be out of the country for a short while without access to my blog, I expect. So this is an opportunity to publish a few short blogs that were planned but not executed before. For example, when I found those big Bot Flies in Sabino Canyon they exited me and a very select few of my entomologist friends to the point, that a much more popular monster was left by the wayside. Literally: just watch him walking along.

Our Gila Monsters were unusually visible this year, at least in Sabino Canyon. For several weeks the Group of the Friends of Sabino Canyon met on or two on each of their Wednesday hikes. No idea whether it was the same individual that took a liking to the group? I think the monsters are rather oblivious of people. Mostly they want food at this time. After all, they spend most of the year under ground, hiding from drought and food shortage between the rainy seasons.
When they are out, they gobble up whole clutches of quail eggs,  whole litters of rat pinkies...I once surprised one that was chewing down a whole rather grown-up pack rat. This venomous lizard  (the only  in the US) has to chew with their formidable jaws to release venom along a grove in their teeth.

On the lower jaw of my friend here you can see the big, bulging glands. Although I didn't get my nose too close to him, after all, Gila Monsters are said to suddenly lunge, bite, and then hold on for good, I noticed a peculiar chemical smell -  ok, all smells are chemical, but his perfume seemed nearly inorganic: a little like chlorine in a pool...   A pheromone? It is mating season.

 The smell of his poisonous droolings? But he wasn't drooling. He was only testing the air with his forked purple tongue. He was certainly not interested in me or my hiking boot standing between him and whatever he had to do before going into hiding once more.

The background is most important

Western Corsair, Rasahus biguttatus

The Western Corsair is an impressive Assassin Bug. He is fast, nicely marked, night-active, and a hunter of other insects. He runs them down, paralyzes them with his poisonous bite and sucks up their liquified tissues.

But there is something else in the picture that is at least as important as this predator for the ecosystem that we call desert: the cryptobiotic soil crust, those dark green specks he is walking on.

The spots are communities of cyanobacteria, green algae, lichens, mosses, liverworts, and other microorganisms that colonize the surface of bare soil.  "Cryptobiotic" means "hidden life."  This crusts in our backyard goes mostly unnoticed. and does not even look alive when it is very dry (as it usually is).  When it rains enough, though, the crust looks greener and more three-dimensional, like many little mounds of moss. There are more impressive and well studied examples in moister shaded areas in many national parks. But this unassuming variaty that covers the drier desert habitats may be of special importance and is probably the most fragile.

Haboob over Eloy AZ

 The crust is vital to the health of soils and ecosystems.
It holds the soil in place and protects underlying sediments from erosion. Lately we have seen our mountains disappear behind dust clouds that were blown in all the way from the Californian desert were agricultural use has laid the soil bare. Last year haboob clouds rose up horrifyingly from the Phoenix area. The thin living layer that covers undisturbed desert soil can prevent many of these events, but it is very fragile. Agriculture, development, motor vehicles, even grazing cattle will destroy it. Also, I am not sure how the current ongoing drought conditions will impact it. Once disturbed it may take decades for the fragile system to grow back to its former productivity, even under 'normal' weather conditions.

Where the layer is intact it can be the first start of organic soil development on bare inorganic sediments, absorbing water and, through photosynthesis and fixation of atmospheric nitrogen, enriching the surface with nutrients and organic matter. This in turn creates a favorable environment for seeds to germinate and for insects and other soil organisms to live. For more info and great photos go to this link.

Here in the arid Southwest we are learning the hard way that this fragile, living component  of our soil deserves diligent protection. As a kid in Germany I would not have thought that I would ever come to value this kind of ground cover so much. I remember that there was a particularly shady area in the yard behind my grandmother's house where we were not supposed to play because the ground was slimy and green and to our mothers 'full of germs' (these were the sixties). But I did see my first liverworts (probably Marchantia sp.) there and marveled at their shapeless not-quite-floral not-quite-fungal existence that sometimes did give hints of a higher organization. Even at four years old (the house was sold when I was five) it peaked my curiosity.   

First sightings for this year

Yes, I know. The first of May is a funny date to start this attempt to record some phenological data for our area in SE Arizona. I think there is still enough of my northern European upbringing in me to feel that this date is special. I will try to begin every month with a little summary of the season's best observations that haven't made it into a blog of their own.

So here goes:

Iron Cross Beetles, Tegrodera aloga, in Sabino Canyon, April 27 2013, Photo by Ned Harris

All week in Sabino Canyon we found big groups of mating and feeding Iron Cross Beetles. Most of them congregated around nearly dried up Whooly Star plants.

Gambel's Quail, Callipepla gambelii, with chicks

Yesterday, April 30, the first very tiny baby Gambel's Quail. The parents made such a ruckus that I actually went and checked whether it was a snake alarm. But eventually they coaxed some very young chicks out of the brush, so I knew what the excitement was about.

Centris pallida on Ironwood and Centris rhodopus on White Ratanay

The first Saguaros bloom and the first Ironwoods are covered in pink. The deep humm of Centris bees can be heard from a distance. Centri pallida visits the leguminous trees, the flowers of the White Ratany and Creosote are attracting the darker Centris rhodopus.

Mesquite flowers in Saguaro National Park West are covered in mating Netwing Beetles of the genus Lucaina, and the first Lycus sanguinea showed up, too. No group leks for this species.

Creosote Bush Katydid, Insara covilleae, nymph

I also found a very camouflaged last instar nymph of the Creosote Bush Katydid, Insara covilleae, feeding, as it should, on creosote leaves.

Enallagma civile (Familiar Bluet)

At a pond at the Desert Museum, another nymph had just left its old skin and its former element behind to spread its wings as a Damsel Fly. But first it had to patiently wait until its teneral paleness transformed itself into the beautiful color of an adult Bluet.

Today: May 1, the first Lesser Nighthawk swooped out of his hiding spot in a Palo Verde in the State Land. In the evening they were courting, a pair gracefully dancing over our backyard while continuously making a sound like a melodious purr.

White-throated Swifts Aeronautes saxatalis) adapted from a photo by Alexander Viduetski

 In the morning four White-throated Swifts were also very active over our yard, but their shrill, twittering calls drove the dogs crazy and their ballet soon deteriorated into a wing-on-wing battle, with two of them (a couple, two males??) tumbling repeatedly all the way to the ground. I had never before seen them do anything but catch bugs so high above that they seemed to belong to another reality...not earthbound as they suddenly seemed. The things we do for sex...

Prickly Pear Cacti and Chollas are in full bloom. The flowers are full of Diadasia bees, the digger bees that are specialised on cactus flowers.

Little swarm of feral, Africanized Honey Bees. The wandering swarm (left) is very peaceful and approachable. The one that found a cavity in the saguaro will build a hive there and then may get aggressively territorial

This year we seem to have fewer feral Honey Bees than usual. Our Africanized version is not as freeze tolerant as the European stock (that's why they never became a problem in Europe and further north in the US, just here in the Southwest where the winters are usually warm). The species is otherwise very robust and there are enough bees left to increasetheir population again to compete with our native bees.

Male Black-tailed Gnatcatcher

From my studio window I'm watching the antics of four or five fledgling Black-tailed Gnatcatchers. They are probably learning to glean the Palo Verde tree for small caterpillars of the Palo Verde Looper.

Palo Verde Looper, Faculta inequalis

The adult moths are coming to my black-light at night where they are eagerly awaited by several small Red-spotted Toads who were joined last night by the first huge Sonoran Desert Toad.

Western Banded Gecko, Coleonyx variegatus

I have never seen a Banded Gecko this big and colorful. I think he must be in his mating-season best!

The other Spider Wasp

When I think of spider wasps, usually the big Tarantula Hawk (Pepsis or Hemipepsis) comes to mind first. They are the most impressive members of the family Pompilidae or Spider Wasps. Huge, colorful, rating three out  of four on Justin O. Schmitd's pain index scale ...and we have many more species of the same family here in Arizona. I am finally learning to recognize them by their sturdy shape and the spurs on their hind tibiae, even when they are not dragging their name-giving prey around.

When caught and stung, the spider is paralyzed by the wasp's venom. The adult wasp will not feed from its prey but store it in a hole, dug by the wasp or often even by the spider itself if she was ground-dwelling. The solitary wasp will lay one egg on the spider and over time the wasp larva will develop, slowly eating the paralyzed spider alive. The wasp larva will then pupate and later emerge from the burrow as an adult.

Most primitive Hymenoptera follow this pattern. Provisioning the larvae with a nectar/pollen mix as practised by bees and some wasps is considered a phylogenetically higher development, as is the cooperative raising of the brood by several or many related females in the social wasp, bee and ant species.
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Isodontia elegans with a katidid

 Like the Pompilidae, wasp in the family Sphecidae (Thread-wasted Wasps) also provision their brood with paralyzed prey. Every species in this family targets its own very narrow range of  prey species. In an earlier blog I have described the two closely related Chlorion spp., the Steel-blue Cricket Hunter and the Cyaneus Roach Hunter that are easier to identify by their prey preferences than by their looks. 

Ammophila sp., I imagine that the long abdomen serves as a counter-weight for the long-bodied caterpillars that the members of this genus have to transport

 As a family Sphecides (Thread-waisted Wasps) can be easily recognized by the extremely elongate and thin waste, or petiolate abdomen, that all member-species have in common. It provides the wasp with the flexibilty to bring the stinger at the end of the abdomen forward to sting the prey insect that she is holding with her long legs.

While some Sphecids like Ammophila build rather simple ground nests that they close by pushing sand over the opening with their foreheads, others, like Isodontia (Gass Carrier Wasps)  close the entrance with a plug of specially collected grass cuttings. 

Other family members build far more elaborate structures. Last winter, Randy and our friend Frank watched a wasp flying repeatedly into the water heater cabinet on the side of Frank's house. When they finally told me, the wasp was gone but a cluster of mud cylinders, one of them still open,  was attached to a waterline. To my relief it was the line that feeds the swamp cooler, so the young wasps were in no danger of being cooked alive when Lyn and Frank were taking a hot shower.
I kept visiting the nest ever now and then, planning to eventually wrap it in gauze to catch at least one of the inhabitants.
From December to March nothing happened. 

 In mid April (yesterday), there was suddenly a second hole in the clump of hardened mud, and something seemed to be going on in the cylinder that was always open. When a slender black and yellow wasps suddenly emerged I wasn't prepared and only got a very blurry photo before he disappeared. By now I sensed that things would quickly begin to happen in the other chambers, too, so I removed the whole nest carefully and brought it home (to our bedroom where the light is best).

Black and Yellow Mud Dauber, Sceliphron caementarium, emerging

 I heard buzzing from at least two chambers. I now see that I positioned the nest up-side down, that may have aggravated the kids. The noise made me wonder: to buzz like that, they must be already clad in a well-hardened exoskeleton. No wonder Number One had made such a fast exit. But now I was ready.
Soon moist spots appeared where two cylinders were plugged with concrete-hard mud. Next a pair of mandibles pushed through and cut out a circular area which then fell outward. The head showed, the front legs, and seconds later the whole wasp emerged: A  Black and Yellow Mud Dauber,
Sceliphron caementarium.This one took off right away, too.

The next one allowed me to get my little camera ready for a short birthday video with sound:

Here is a link to the flickr version of the same video. I think the quality there is somewhat better than the blogger-direct-upload and not as cluttered as u-tube

Empty cocoon left in the chamber, spider leg top left side

 Removing the sidewall from the now empty chambers I found the empty, parchment like pupal cocoon and a single spider leg. A female Black and Yellow Mud Dauber catches spiders of many different species to stock the nursery before she lays one egg in each cylinder.  There is another, related Mud Dauber that preys mainly on Black Widow Spiders. Our healthy young wasps had finished all their provisions before they pupated. So I am very grateful to Gary R. McClellan for allowing me to use his images of a Black and Yellow Mud Dauber nest that he opened before the wasp larvae had eaten the spiders. The photos clearly show the variaty of spider species in the wasp nest.

Prey assembled in the nest of Sceliphron caementarium (Black and Yellow Mud Dauber) Photos by Gary R McClellan

Sceliphron caementarium

 

Atkins versus High Glucose diet:
While the growing larvae needed to build up their bodies and hence lived on a high protein diet, adult Mud Daubers need fast burning calories for their high energy flight muscles. Their live now centers on finding a partner, building a mud house, and hunting. To support this lifestyle they are nectaring on flowers, especially on those easily accessable ones of the parsley and carrot type (Umbelifera). For lack of any wildflowers I offered Lantana to our kids, but they didn't like it at all and buzzed off. There are always our hummingbird feeders...


P.S. The first time I saw a Mud Dauber actually collecting mud I was watching dragonflies at a pond on Fort Huachuca. That was when it was still open to aliens like me. Here at home in the very dry bajada of the Tucson Mountains, I had never seen any wasps of that genus. But some years ago, Frank put in a bird bath that is always overflowing and creates a little mud puddle while also feeding one of his huge mesquite trees. The wasp found this mud source and began building her nest not far from a porch light that attracts hundreds of moths and consequently spiders at night. In the morning I often still find spiders hanging around. They need to watch out! 7 new Daubers are on the prowl and they tend to establish nests in the same place where they hatched.

Sceliphron caementarium

Classification: Hymenoptera (Ants, Bees, Wasps and Sawflies) » Aculeata - Bees, Ants, and Stinging Wasps » Apoid Wasps (Apoidea)- traditional Sphecidae » Sphecidae (Thread-waisted Wasps) » Sceliphrinae » Sceliphrini » Sceliphron » Sceliphron caementarium (Black and Yellow Mud Dauber)

Insects at Sabino Canyon

Bush Katydid, Scudderia sp., nymph,

Leaf Beetle, Griburius montezuma

Metallic Wood Boring Beetle, Acmaeodera griffithi

Broad-nose Weevil, Ophryastes sordidus

Mesquite Longhorn Beetle, Aethecerinus latecinctus

Ironcross Beetle Tegrodera aloga



 Blister Beetle, Nemognath sp.

Mating Treehoppers, Vanduzea laeta

It always pays to watch the competition

Yesterday, when I arrived for the weekly nature walk of the Friends of Sabino Canyon the temperature was in the fifties. Much too cold for mid-April morning in Tucson and too cold for most insects and lizards that I wanted to see. In addition, a fierce wind was howling down into the canyon from the Catalinas. The other naturalists decided to look mostly at plants, I guess because those can't hide from the elements. Two saguaros, one with an imposing crest, looked indeed positively defiant.

Eastern Collared Lizard, who stayed hidden yesterday (Photo Ned Harris, April 2012)

But I don't get to Sabino often enough, so I was going to give Esperero Trail a try because that's where I had seen the beautiful Eastern Collared Lizards last year. The trail leaves the main canyon and winds up the mountain side with full exposure to the western wind gusts. It seemed like a dumb idea but I am stubborn and in Arizona the sun usually breaks through eventually.

View into Sabino Canyon from Esperero Trail

 Well, it didn't and there seemed to be very few living things willing to share the exposed mountain side with me. Until I came to some part of the trail that rose somewhat over its surroundings resulting in a low but pronounced hill top.

Ash-throated Flycatcher, who was out and about

 There was a big Ash-throated Flycatcher busily swooping from his perch as if catching - flies? Sure enough, even in this abysmal weather some Bee Flies, Tachinids, Robber Flies  and even some butterflies (Tiny Checker Spots, Marine Blues) were hill-topping, a behavior that is typical for many flying day active insects.

Some of the hill-topping flies and butterflies

 Males had staked out little territories, patrolling back and forth, chasing everything that flew by, driving off other males and trying to mate with passing females. I think I understand why the big collared lizards and the flycatcher seem to prefer this exact area. It's the place where they can be sure to find enough prey. Of course the ectotherm lizards had the luxury to take the cold day off while the endotherm bird had to keep working, especially as he was feeding nestlings that I could hear keening in a Saguaro hole. I followed the bird to an especially exposed area with some bare boulders where he seemed to concentrate his efforts.

 At first I payed little attention to a big black fly that landed as if to bask in one of the sparse sunny spots because I mistook it for a Mexican Cactus Fly, a common syrphid. But then I heard a very deep basso buzz when the fly changed to another boulder, only about 5 m from the first. That sound is one of the loudest and deepest flight noises I've ever heard here in Arizona - not easy to forget. Through my new little Papillon binoculars I could also verify that the fly was not all black but had silvery grey flanks - a bot fly in the genus Cuterebra. (Later identified by Jeff Boettner as C. austeni)

Rodent Bot Fly, Cuterebra austeni, Esperero Trail, Sabino Canyon, Pima County Arizona, April 2013 

This is only the third time that I encountered these big, fascinating insects. Some people may feel that the live history of bot flies seems like an episode from the X Files or the movie Aliens. I think, however, that the film makers borrowed their ideas from the biology of these flies whose larvae are mammalian parasites.

Deer Bot Fly, Cephenemyia jellisoni infects the alimentary tract of ungulates like white-tailed deer, mule deer, moose or elk. Photo by Philip Kline Pusch Peak,  Catalina Mountains, Pima County, Arizona, March 2009

 While some bot fly larvae develop in the alimentary tract of mammals, the big black and grey Cuterebra that I was watching yesterday belonged to the group that develops subcutaneously in mammals. Luckily they are quite species specific in their host choices so I knew that I wasn't the target - the host would most likely be a rabbit or a pack rat. The female fly will lay hundreds of eggs in rat runways. Only a few of the larvae will actually find their way into a passing rodent.

Rodent Bot Fly, Cuterebra sp., Pima Canyon, Catalina Mts. Pima County, Arizona, September 2009

 The only bot flies likely to infest humans do not occur north of Southern Mexico. As I mentioned, the deep characteristic buzz of the big flies is rather recognizable and would probably warn the victim of an intended egg drop. To give their larva a chance to find their way into the body of a wary primate, female bot flies in the genus  Dermatobia  have an amazing strategy. They capture another insect like a mosquito, horsefly or tick that is drawn to warm blooded mammals for its own reasons and attach a load of their eggs to this carrier. When the released  mosquito later lands on a primate for a blood meal, the bot fly eggs hatch and the young larvae bore into the warm skin of the doubly victimized monkey or human.

Cuterebra sp. larva ready to pupate found crossing Sabino Canyon Rd. on Feb. 22, 2011. Photo by Fred Heath

 While feeding from the host subcutaneously for several weeks the larvae have to behave reasonably well. They seem to prevent inflammation even though they need to keep a hole in the host's skin open to be able to breath periodically. They probably have anti inflammatory and antibiotic capacities. I have two good friends who both got parasitized in Central America, are now in their eighties, and live and love to tell about it. If not removed prematurely, the larvae will eventually leave the host, drop to the ground and pupate. In time a new generation of mature adults will hatch. These big flies are born without mouth parts. From their time as maggots in the flesh, they are provisioned with enough energy reserves to survive for about 10 days, time enough to start the cycle again.

Catching the redeye to Amhesrt, MA 

Yesterday's bot fly, however, is not going to propagate his genes this way. Instead he is contributing them to conservation biologist Jeff Boettner's research project at UMASS - Amherst. There are many open questions concerning host relationships and phylogeny of the group. As specimens are difficult to obtain, Jeff would be grateful for specimens and info about lek sites. Here is a link to his info pamphlet.

Classification:
Arthropoda (Arthropods) » Insecta (Insects) » Diptera (Flies) » Calyptratae » Oestroidea » Oestridae (Bot Flies) » Cuterebrinae (New World Skin Bot Flies) » Cuterebra (Rodent and Lagomorph Bot Flies)

Velvet Mites, Trombidioidea and Chiggers

With this post I am going out on a limb. I got an e mail request to identify a small red bug. I am using bug here as a general term for arthropod, because:

Question:
'Hello Dr. Brummermann,

My co-worker and I were on Mt Lemmon today, in the Marshall Gulch area and we came across thousands of tiny red insects. Our first thought was chiggers, but after looking into it, these insects were too big to be chiggers.

They were bright red, had 6 legs, and large antennae. About 25% of the ones I looked at appeared to be dead (curled in on themselves and dry), but this could have just been the case for the one location that I was seriously investigating them in.
While I don't have any pictures, I can guess they were approximately the size of this "o" (San Serif, 12pt font). They were found in areas with large amounts of dead leaves, and when we dug under the leaves, they appeared to be moving through the soil.
Do you have any ideas as to what we saw?'

Answer:
Without a photo there is not too much to go on. What seemed to be dead ones could be exuviae - in that case I would guess that they were some early instar true bugs or other hemipterans. But since they seemed to be soil related and bright red, how about mites instead of insects? Their front legs could be mistaken for antennae. Here is a photo of a giant velvet mite: http://bugguide.net/node/view/200679
They are usually bigger than your 'o' but.... There are often outbreaks with thousands of them. They are predators as adults.
Let me know what you think and consider carrying a camera for documentation!

Trombidiidae (Velvet Mites) from my backyard. These live in sandy soils, are huge, around 5 mm in length and show up only after rains

Question:
Thank you very much for the speedy reply!

They could have been mites; we didn't have any magnifying lenses on us at the time, so I could have mistaken the front legs for large antennae. Will they bite humans (or other large mammals) or do they only go after other insects? If I'm up in the area again within the next few weeks, I'll take a picture!

Thank you again,

Answer:
At first, I was going to say
Your observation that the bugs were in the leaf litter makes me think that they are really in the family Velvet Mites (Trombidiidae) and not the so called 'Red Spiders", also mites, that live and feed on plants and can become pests.
Velvet Mites (Trombidiidae) may be parasitic on insects as young instars. As adults they will become predators of insects. This is the info in BugGuide, Wikipedia and other web locations.

But I am now looking at John Henry Comstock's 1948 Spider Book, revised in 1965 by W.J. Gertsch. I know that is ancient for a science book, but while a good part of the older taxonomy had to be  revised according to more recent phylogenetic research, the life history of the described organisms has not changed and the old biologists were famously thorough observers.

This last paragraph sounds suspiciously like chiggers, doesn't it?

I moved on to the 1998 Review: Biology and Ecology of trombiid mites (Acari: Trombidioidea) by Zhi-Qiang Zhang, Experimental and Applied Acarology, 22 (1998). The paper first states that the systematics of the group are in flux, and many of the old subfamilies that Comstock still included have since been accorded family status.

Euryopis sp. Spider with a trombidioid larvae (red) and trombidioid adult on the left

 These mites are of economic importance and may be used for biological pest control. But identification even to the genus can be difficult and in many cases either the larval stages and hosts are not known or the larvae are described but not the adults. Trombidiid larvae have been found as parasites on many different arthropds. Some seem very host specific, others can use a variaty of hosts.

If you can read this table that I copied out of the Zhang paper, you'll find that two of the families do use vertebrates as their larval hosts: Leeuvenhokiidae and Trombiculidae They are Chiggers!
So the chiggers that chew into the vertebrate skin (not burrow under the skin) are larvae of Velvet Mites, but not all Velvet Mites are chiggers. Here is a link to the blog of Dragonfly Woman where she explains how the young chiggers actually feed on vertebrate skin.
The mites I was asked about are probably not chiggers, for two reasons: First, It is far too early and cold for chiggers on Mt Lemmon right now. We still had snow a couple of weeks ago.  Second, chiggers (the parasitic larvae) are very tiny, much smaller than the observed mites. But I cannot tell whether these mites could be the adults of what we call chiggers.

 Classification:
Arthropoda (Arthropods) » Arachnida (Arachnids) » Acari (Mites and Ticks) » Acariformes » Trombidiformes » Prostigmata » Anystina » Parasitengona » Trombidiina » Trombidioidea » Trombidiidae (Velvet Mites)