Tuesday, August 30, 2011


The Entomologists at the University of Arizona are proud to present the first ever Arizona Insect Festival! Bring the whole family out to the UA Mall for an interactive learning experience about insects in our ecosystem. We promise a fantastic day of facts and fun!

There will be tents full of live insects and beautiful displays of insect specimens arranged to highlight and explain many different biological principles.
Knowledgeable people, scientists, teachers, students, and enthusiastic hobby entomologists.
Organizations that promote interest and understanding of insects and their natural world like SASI and Tucson Botanical Gardens.

We hare planning Insect Olympics and Rodeos, kids can make their own bugs, bugs can be tasted, photographed, held and admired...

As the program takes shape I will update this blog, and you can also find us on facebook.

Friday, August 26, 2011

Peppersauce Canyon, 4 weeks later

 I have been trying to collect some phenological data - see the column to the right of this blog - about the appearance of some key species that I observe every year around our house. Our own property is the only place where I can  hope to keep somewhat continuous records. Short visits to all other places will only allow a very limited snapshot of the insect life at that particular moment.

Alaus zunianus Eyed Click Beetle

 My second black lighting visit, exactly four weeks after the first, to Peppersauce Canyon on the north side of the Catalina Mts. made this very obvious: To me,  weather and temperature seemed similar, both visits fell within the monsoon season, and the moon was in the same phase. But in the world of short lived insects, changes occur quickly and are caused by rather small variations in temperature, humidity and simply the progressing season. So this time, the Phyllophagas and Anomalas  that 'rained' down on our lights a month ago were nearly absent, Chrysina gloriosa appeared, but only two specimens. There were only very few Lebias (Colorful Foliage Ground Beetles). I found a big big Alaus zunianus  but hardly any small click beetles which were so abundant last time..

The lone cerambycid was a very nice Neoptychodes trilineatus.

On a  dead log I found an assembly of fungus eaters that still await identification. I can only identify the tenibrionids as Platydema sp. Larger tenebrionids began walking at dusk just like last month.

Calosoma scrutator
A Calosoma scrutator  expected to prey on the insects at my light and was instead caught to be a star of our upcoming Arizona Insect Festival in September.

Diapheromera - Male

Bucrates species nova - Weissman's Conehead

Interesting walking sticks were marching up and down the oaks, and many species of grasshoppers and katydids, even a big Jerusalem Cricket came to the light.

Dynastes grantii

Being on my own with only some hunters camping somewhere down the road I was rather nervous and nearly jumped when a big object bumped into my back - a very nice male Hercules Beetle Dynastes grantii on his bumbling flight to the light.

Strategus sp.

 A big brown Ox Beetle followed, and I just cannot tell whether it is a female S. aloeus or a male S. cessus. Right after the big beetles, a human was drawn by my light, another entomologist who was collecting further up the canyon. I was delighted to meet John Spaulding and his friends and to scavenge beetles from their mercury vapor light as they were more interested in moths.

Arachnis picta - Painted tiger moth
 Moths were definitely the theme of the night, densely  covering our sheets and dancing in a cloud around every light.  The best one for me was the beautiful Arachnis picta - Painted tiger moth. We also found the impressive caterpillar of Syssphinx hubbardi  the dark moth with pink under-wings.

Syssphinx hubbardi caterpillar
Neuroptera were represented by Owl Flies, a very ornate antlion and at least three species of Mantispids, one of them a great mimic of the big aggressive and very common  Polistes comanchus.

Ululodes sp.,                                                     Glenurus luniger,                          and              Mantispid
 It seems that many species of insects time their emergence to coincide with the monsoon season, but every species uses different triggers for the fine tuning. Many species emerge  in masses at exactly the same time, ensuring that mates are available and find each other during the often very limited life time of adult insects. So repeated visits to the same location can always surprise the naturalist with completely new experiences.

Wednesday, August 24, 2011

Collecting trip to the Pinaleño Mountains

We were lucky, no major  storms hit, but the rain cover was a great idea
 I spent the last weekend with Wendy Moore's entomology lab group camping in the Pinaleño Mountains in eastern Arizona. The Pinaleños, often just called Mt Graham after the name of their most prominent peak, are the largest of our Sonoran Desert Sky-islands. Of all the sky islands, the Pinaleños have the greatest expanse of mixed conifer habitat. Smaller areas of this plant society are also found in the Catalinas (Mt Bigelow and Mt Lemmon, and in patches on other sky-islands). This habitat is home to several rather rare carabids, Wendy Moore's main research focus.

Scaphinotus petersi is a snail eater, and I found the two under the same piece of bark
 Other research  interests in our group ranged from general ecology of the sky islands, conifer botany, rare scorpion and pseudoscorpion species, flightless beetles (mostly tenebrionids and carabids), minute fungus eating beetles, to general insect photography, and later we were joined by a cerambycid geneticist from Cornell.
 Collection methods varied accordingly, from gleaning and substrate sifting to black lighting with a sheet for night flying insects, to searching with bright headlights for night active beetles and uv-flash lights for fluorescing scorpions,  to setting pit-fall traps, peeling lots of bark and rolling many logs.We also tried to cover  different elevations,  including the oak juniper region further down the mountain (Noon Creek Campground)

Leptomantispa sp., a mantisfly at the black light at Noon Creek
 I found it difficult to choose which of the many species we found would be the most interesting ones to introduce here.  So I will show only a few that fascinated  us most and in addition post links to my flickr sets that show all my photos from the trip.

Sesiidae,  Carmenta giliae, wasp mimicry clearwing moth

When you click on the links and flickr tells you that imbedding links is not permitted, just go to 'click here'. To see more than the initial thumbnails choose 'detail' or 'slideshow'.

Shannon Campground and trail

Columbine Corrals and high elevation meadows

Noon Creek black light

We are still working on the identifications of some species, so you may want to visit again later if you are curious. For completeness, I have augmented the actual Mt. Graham photos with a couple  of pictures from other sites. Those are of insects that I have frequently  found before and did not photograph again on this trip.

Several Nicrophorus marginatus turned up in the bathrooms of the campground
 We all came back tired and dirty and very satisfied with our finds. I added at least half a dozen new species to my virtual Arizona beetle collection that will hopefully result in an Arizona Beetle Atlas.  I posted some of my photos on bugguide and found out that one of the Elateridae is a new species currently being described, and that another researcher was hoping that I collected the pretty hairy caterpillar for his genetic research (I didn't).

Caterpillar of Lophocampa maculata, Spotted Tussock Moth

Thursday, August 18, 2011

Not for the squeamish

 Coleoptera (Beetles) are the largest and arguably most successful order in the animal kingdom. The extreme variety in physique and behavior found among beetles results from adaptations to nearly every conceivable ecological niche found in  terrestrial and aquatic habitats.  The eating habits of coleoptera species range from total abstinence in adult life  to absolute gluttony. Some beetles have a highly specialized diet while others are opportunistic omnivores. Beetles hunt animals, have their brood raised by foster parents, care for their larvae or abandon their eggs, destroy stored seeds and grain, prune plants and stimulate rejuvenating regrowth, feed on nectar while pollinating their hosts,  have wood boring Larvae, break down organic material and feces and further decomposition, and beetles also take care of dead bodies.

Steel engraving from Brehms Tierleben 1893
 Beetles in the genus Nicrophorus will bury small corpses of birds and rodents to give their larvae the exclusive rights to the food source. In Southern Arizona these species are much rarer than in moister climates, but I have found a couple at lights during cool humid nights at higher elevations.

Nicrophorus nigrita (from CA) and N. marginatus (AZ, Pima Co.)

Other beetles come to bigger dead bodies in different stages of decay. Forensic Entomologists use the strict sequence of species arrival as evidence for the timeline of a killing.

One of the workshops at our last SASI meeting studied for several days insects at the corpse of a dead pig that was (astonishingly) placed right outside the conference hotel.

Eric Eaton collecting beetles from a cow carcass in Madera Canyon
On our bug hunting trips into the Arizona grasslands we sometimes come across carcasses of cows that are nearly mummified by the dry heat. Entomologists like Eric Eaton know that those can be treasure troves for bug hunters, but I usually stand politely back behind the more enthusiastic colleges. A succession of Carrion and Carpet Beetles, Rove Beetles, a species of Checkered Beetles, Hide and Clown Beetles and a few Scarabs  can usually be found.

 The larvae of  Dermestes marmoratus  form at times a dense layer covering most of the carcass. Forensic labs make use of their voracious appetite to quickly and thoroughly clean bones.

Dermestes marmoratus
The adult beetles find carcasses through their acute sense of smell, congregate, mate, and the females lay their multitude of eggs.

Omorgus scutellaris
 After the dermestids are done with the softer parts, the tough hide still attracts the scarab related Hide Beetles, Trogidae. When disturbed they can withdraw legs and heads like tortoises.

Necrobia rufipes
Red Legged Ham Beetles (Cleridae) don't seem to make any difference between an Arizona cow or an Egyptian pharaoh, as they were also found in the wrappings of ancient mummies. They stay around when even the Hide Beetles are gone.

Tanatopilus truncatus and Dermestes caninus
 Not just the state of decomposition, but also the biological class of the dead animal seems to matter to some beetles. While mouse and small bird carcasses attract several Nicrophorus species, and the larvae on the dead cow were probably predominantly Dermestes marmoratus, I have found only Tanatopilus truncatus and Dermestes caninus on dead snakes in Arizona.

Dermestes caninus and Green Bottle Fly on a dead snake
 The smell of dead fish, often used as bait in pit falls, works for a number of carrion species but also attracts  dung beetles (scarabs).
I hope this detailed description of beetles on carrion did not gross you out too much. These beetles play a very important role in the ecological system, and the existence of at least one species is threatened in the US . It's endangered status inspired this imaginative campaign:

Tuesday, August 16, 2011

Finally: The other Stenaspis

During every good summer monsoon the Desert Broom bushes (Baccharis sarothroides) in Madera Canyon (Santa Rita Mts, AZ) start, whether spontaneously or caused by gnawing bug mandibles I do not know,  to ooze sweet phloem juices from their stems, attracting many paper, spider and  thread-waisted  wasps, leaf-footed and stink bugs, scarabs, and most impressive colorful big long-horned beetles.

I have documented this event every summer since 2007. I often found and photographed the 'big three' longhorns that are common in our area:

Tragidion densiventre was formerly T. annulatum but the genus recently underwent a revision. All the males that I saw had ochre colored lower elytra and enormously long banded antennae, while most of the females were red and black with a very fuzzy pronotum and shorter solid black antennae.

Trachyderes mandibularis seems to appear somewhat later than the Tragidions. The males have huge jaws that look more useful for interspecies fighting than bark-gnawing, but I have never seen them attack each other. Smaller males do seem wary of bigger ones. All individuals of the species are always prepared to quickly take flight which goes well with their wasp like black and yellow pattern. 

The big solid black Stenaspis solitaria is the most common of the longhorns. They can be seen flying  between desert broom bushes where they snack and meet their mates and the Velvet Mesquites trees  that are hosts for their larvae.

From other collectors I had heard about another,  metallic green Stenaspis, S. verticalis. Fred Skillman described how he found one last summer, recognizing it just from its antennae that protruded from the Baccharis branch that hid its body from view.

Stenaspis verticalis specimen in the UAIC
When I looked up the species in our University collection (UAIC) I found that the black S.solitaria specimens fill more than a drawer there, but all green S. verticalis specimens fit into just one unit tray.

Last Saturday evening a threatening thunderstorm drove me from Box Canyon into the safer Madera Canyon. I stopped at the little abandoned visitor center where only a few desert broom bushes survived last years attack by irresponsible collectors (Supposedly some interesting cerambycids develop in Baccharis branches and lay waiting in their pupal cradles, ready to 'pop' or to be excavated by some over-eager human.)
As usual, all the bug action was concentrated on just one old bush. Actually action is the wrong term. Chlorion wasp, Giant Agave Bug, Western Fig Beetle and a pair of Tragidions all perched peacefully sleeping close to the source of sweet juice.

I nearly disregarded a big dark Stenaspis on the same branch, until my flashlight beam fell on its red rimmed pronotum and legs. I still wasn't quite sure that it wasn't just a teneral S. solitaria because I had expected S. verticalis to be much more metallic and green.

During the day I would have been afraid to loose the beetle if I spend too much time taking pictures, but on that rather cool evening I even dared to wait for the Tragidion to crawl closer to the Stenaspis to have them both in one shot.
While taking those pictures I nearly lost my truck and had to be rescued by the famous bat and hummingbird photographer Bruce Taubert, but that is a different story....

Sunday, August 7, 2011

The Hanging Thiefs (or Murderers, rather) of Patagonia Lake

In the unlikely case that  you've ever tried to photograph the arrival of scores of dung beetles (Canthon imitator in this case) that rain down simultaneously on any fresh pile of cow dung, you will have noticed that the beetles literally dive out of sight right after they have landed. The one in the photo was only slow enough for a shot because the surface of  this cow pie was already getting dry.

 Competition, greed, and the urge to prepare food for their offspring are not the sole motivators for this rush. There is danger lurking at the dung buffet. At a pile of horse manure at Patagonia Lake we watched how the beetles had to pass a gauntlet of 12 huge robber flies to get to the feast. The only reason most beetles made it past the flies was that they all arrived pretty much simultaneously and the lurking robbers were distracted by the need to avoid ending up prey themselves and by courting the ladies among them.  A. Scarborough, our local Asilid specialist, tells me that Diogmites are known to congregate at places with high prey traffic density like bee hive entrances, and also for their high (10% of courting males) rate of cannibalism.

The robber flies seemed to ignore weak but quick prey like bottle flies and only lay in wait for the fat beetles. They were of the genus Diogmites, or Hanging Thieves. We soon got a demonstration of the reason for this name. A fly grabbed one of the landing beetles and carried it off to a mesquite tree.

At first the beetle seemed to have a fighting chance to get away. The effect of the paralyzing bite seemed slow, and as soon as the big beetle felt the tree branch  under his tarsi he started to scramble away, dragging the fly along. He probably would have stripped her off his back by crawling into some tight spot.

But  the fly was able to detach the beetle from his hold by using the enormous reach of her long legs. To keep him  from reaching the branch again,

the fly held the beetle with four legs and used just one pair, and later just one single leg to suspend the weight of the prey and herself. This trick earned the genus the popular name Hanging Thief. The beetle had now lost any chance of fighting back.

Other robber flies tend to crouch tightly above their prey holding it down with their superior body mass and strength. It seems that these slender flies need the suspension tactic to control their strong bulky prey while their paralyzing, tissue-dissolving poison is slowly taking effect.

Friday, August 5, 2011

Fighting Fig Beetles (Cotinis mutabilis)

In June and July, Fig beetles (Cotinis mutabilis) noisily careen all over Tucson's neighborhoods, and through the lower parts of foothills and canyons of the Sonoran Desert. They are day-active, compact, big, noisy strong fliers, and often described as black. Of course, they only appear black when seen against the bright sky. Sitting on the ground or on flowers, they probably impress you with the velvety green of their elytra and the shiny, metallic colors of their legs and underside. There is a questionable tradition of tying strings to the beetles and tossing them into the air to fly - performing tethered rounds and rounds around your head.

Life cycle: After mating, the females lay spherical gray eggs into soil with high organic content. Here in our sandy desert that usually means lawns or flower beds, old, decomposed cow dung or our compost pile.

The larvae feed for two years on organic material including the roots of grasses, alfalfa and shrubs, but they can also grow up on a diet of old cow manure.  In late spring of the second year they pupate close to the soil surface in earthen cells and eclose as adult beetles in June - July.

They adults feed on leaves, pollen, and everything sweet. On opuntia cacti in our backyard I often find a couple of beetle buts protruding from every hollowed out prickly pear.

Acacia or desert broom shrubs are often oozing sweet sap because of a sudden over-supply with water during the monsoon rains. This can  attract hundreds of Cotinis. When I watched these gatherings I was usually too distracted by the noisy coming and going  of the beetles (and also dodging tarantula hawks and paper wasps) to pay much attention to the behavior of individual beetles.When I noticed them shoving and pushing each other, I thought they were just haggeling for space at the sap bar.

Yesterday in Amado I watched a couple of them fighting over a spot of oozing sap on a Desert Broom branch that could have easily accommodated both of them. They very persistently faced each other, head-butting like little bulls. They indeed have a little horn-like structure on their forehead, but I couldn't tell whether that was used in the pushing and shoving match. The match actually went through several rounds, with one or the other fighter being pushed off the branch and immediately flying back to resume his stance.

In one of my pictures I captured one beetle flinging the other one over his back with a move that fighting stag beetles or the big dynastes would use.  The males of those species have special protrusions on their heads that are used to lever and grab the opponent off his perch. It looks as if the behavior is phyllogenetically older than the weapons of those species, as it seems to occur in this related but rather unarmed species.

Back in position again
 I am pretty sure that my two Cotinis were not just fighting over access to some sweet juice, but that I was watching a test of strength between males and a competition for a territory that would promise the winner access to females who would soon be drawn to the tempting food source.