Madam and I are staying in South Lake Tahoe this week, so today I took advantage of this rare opportunity to do some fall insect collecting in western North America. In many insect groups, most species have finished their business for the season by the time autumn arrives. This is especially true for my beloved longhorned beetles, whose spring/early summer flush is now but a distant memory. There are a few genera of longhorned beetles, however, that wait precisely until autumn before making their appearance—Megacyllene and Tragidion being the best-known examples in eastern North America, and Crossidius being the best known out west. I adore autumn collecting, both in the east and in the west—its cooler temperatures and lower humidity make conditions incredibly pleasant, and the longer shadows cast by a low-hanging sun make the landscape—gently morphing from monotonous tones of greens to dazzling shades of amber, tawny, and gold—even more stunning.
I figured my best shot for Crossidius was in the sagebrush habitat below the eastern slope of the Sierra Nevada, so I took the Kingsbury Grade over Dagget Pass and found some good looking habitat near Genoa with nice stands of Ericameria nauseosa (rubber rabbitbrush)—host of Crossidius coralinus—in peak bloom. It took quite a bit of work to find the beetles, and for the first half-hour the only insects I saw were non-native honey bees (eventually I did see a few native bees as well, which I collected for Mike Arduser). I also checked some Asclepias speciosa (showy milkweed) that I found hoping to find Tetraopes femoratus (red-femured milkweed borer) but saw only Polistes dominula (European paper wasp).
After quite a bit of seeching, I finally found a Crossidius adult, although it was not C. coralinus but rather the all-black C. ater.
Very quickly afterwards, however, I found the first C. coralinus, and over the next half-hour I collected about a dozen males and females of C. coralinus and one more C. ater.
Crossidius coralinus has been divided into several subspecies based on differences in markings and coloration across its geographical range—in this area, the species is assignable to subspecies C. coralinus temprans. I did a final check of the stands near where I parked and found one more adult C. coralinus, after which I decided I’d seen enough and went to another spot to look for different species of Crossidius.
After having such good luck with C. coralinus on E. nauseosa, I went a few miles further north to Jack’s Valley Habitat Management Area where I saw a different species of rabbitbrush (Chrysothamnus viscidiflorus, or yellow rabbitbrush) in bloom.
Yellow rabbitbrush is the host of a different species of Crossidius in this area—C. hirtipes, and I hoped I might be able to find this species as well. It didn’t take long, as I found a small female hiding in the inflorescence of one of the first rabbitbrush plants that I looked at. As sometimes happens, however, my early success was followed by an extended time without seeing another beetle.
The plants were sparse in the sagebrush habitat, and I zigzagged my way from plant to plant going west from the trailhead. Despite the lack of beetles, there were other insects active on the flowers, including assassin bugs and digger wasps.
Eventually, I came upon an area where the plants were more abundant, and I started encountering beetles more regularly, including several big males perched atop the flowers and another C. ater adult hiding inside the flowers on one of these same plants.
Bees—other than honey bees—were scarse, but I managed to pick up a few for Mike, and I also collected a few Eleodes sp. (desert stink beetles) that were, for some reason, crawling and perching on the rabbitbrush flowers. I’ve never thought of darkling beetles—at least those in the genus Eleodes—as anthophilous, and maybe this habit isn’t strict anthophily, per se, but it was remarkable to see so many of these beetles associated with the plants and hardly a single individual crawling about on the ground.
After a couple hours worth of effort, I’d secured about a dozen C. hirtipes, which, like C. coralinus, has been assigned to several subspecies (populations in this area being assignable to subspecies C. hirtipes immaculatus)—enough for my purposes, and I left to head back up into the mountains.
I’d hoped to find one more spot up in the mountains, but the sinking sun and rising elevation conspired to make conditions much too cool for all but the most persistent insects. I did stop at a powerline cut, where recently-cut Jeffrey pine (Pinus jeffreyi) trunks, stumps, and branches provided a perfect attractor for wood-boring beetles. Sadly, none were seen, even on the undersides of the logs and branches. Thus, my rare chance for fall insect collecting in western North America came to a close.
This is the eighth “Collecting Trip iReport”; this one covering a one-week trip to southern Arizona, New Mexico, and California from September 7–14, 2019 with meloid/cerambycid-enthusiast Jeff Huether. Jeff has been a frequent collecting trip partner during recent years, this being our sixth joint outing since 2012. Our initial objective on this trip was to collect cerambycid beetles of the genus Crossidius occurring across southern Arizona/California—part of a larger effort to sample as many of the named subspecific taxa as possible from multiple locations (including type locations when possible) for future molecular studies. We had good success, though we did not collect every taxon that we were after (we were a tad early in soCal). Also, the fact that we had Crossidius as our primary goal did not mean that we would not concurrently be on the lookout for buprestids (me), meloids (Jeff), or other cerambycids (both of us)—and in that regard we were also successful.
Day 1 – Dripping Springs Mountains, Arizona First stop of the trip, and we’re heading east to Safford. As soon as we got east of Superior up into the mountains we saw a place where Heterotheca subaxillaris was in bloom abundantly along the roadsides and pulled over. There were four species of Acmaeodera on the flowers, and I also found a fifth species on the flower of a small white aster. Nice first stop for the trip!
3.6 mi NW Bylas on US-70, Arizona Continuing our way to Safford, Jeff saw some patches of sunflower and wanted to look for Epicauta phoenix. I found the first two (but not in sunflower), and then Jeff found two more. As we were walking back to the car I noticed a Crossidius suturalis sitting on Isocoma tenuisecta that was not quite in bloom, and then another nearby on the same plant. We searched the area again, but the only plants were those few right around the car.
5.7 mi NE Safford, Arizona After getting a hotel in Safford, we had time to come back to a spot where Jeff had collected Epicauta phoenix back in July. We found quite a few (see photo) on plants nearby the original collection spot. Looking around more I found an Acmaeodera convicta perched on the tip of a shrub—first time I’ve collected this species! There were several species of tenebrionids crawling on the ground, perhaps prompted to activity by cooling temps as rain whipped up in the distance. I kept one eye on the skies and the other on the plants and eventually found two more A. convicta perched together on the same type of shrub just as rain began pelting my back. We made a quick dash back to the car and called an end to Day 1 in Arizona.
Day 2 –1.9 mi S Artesia, Arizona We started seeing Isocoma tenuisecta just coming into bloom as we headed south of town so stopped to see if we could find any Crossidius. I looked at a lot of plants before finding a single C. suturalis sitting on one of the non-blooming plants and in the meantime found one Trichodes peninsularis and a fair number of Zonitis dunniana on the flowers. Looking around on other plants, I found one large Chrysobothris sp. (not C. octocola, but longer and narrower) on the branch of a living Acacia constricta [Edit: this is C. knulli—a new one for me!] and one Acmaeodera disjuncta, several more Z. dunniana and T. peninsularis on flowers of Hymenothrix wislizeni. Finally, I did some sweeping of the bunch grasses in the area and got a nice series of what I presume to be Agrilus rubrovittatus—first time I’ve collected that species!
17.7 mi S Artesia, Arizona Another stop with both Isocoma tenuisecta and also Gutierrezia microcephala coming into bloom. We immediately began finding Crossidius pulchellus on the latter and eventually collected a good series of them and also Trichodes peninsularis off the plants When I returned to the first plant we had checked (in fullest flower), a Lampetis webbii landed on it right in front of me! I eventually found C. suturalis on Isocoma tenuisecta, as well as Trichodes sp. and a few C. pulchellus. There was a tall-stemmed malvaceous shrub off which I got a male/female pair of Tylosis maculata, and sweeping produced a couple more Agrilus rubronotata, a few more T. peninsularis, and one Acmaeodera scalaris. I saw a couple of Acmaeodera disjuncta on Baileya multiradiata flowers but missed them both!
1.1 mi N Rodeo, New Mexico We slipped just inside the New Mexico border to visit the area around the type locality of Crossidius hurdi. We found a spot where there were good stands of Isocoma tenuisecta along the roadsides and checked them out. Like the other spots today they were just starting to come into bloom, and rain had just moved through the area. We found perhaps 20 Crossidius individuals total, and honestly they were so variable that I don’t know whether they represent C. suturalis, C. hurdi, or both! [Edit: they are all C. suturalis] I also collected one Sphaenothecus bivittatus and several individuals each of three species of clerids on the flowers of these plants. A male Oncideres rhodosticta was found on the twig of Prosopis glandulosa, and I also found a cool meloid that I’ve never seen before—Megetra punctata!
Willcox Playa, Arizona We plan to visit Willcox Playa tomorrow (my inaugural visit!), but we had some time at the end of the day and decided to come take a look. There were some stands of Isocoma tenuisecta at the north end of the playa, and I found just a couple of Crossidius individuals on them, presumably C. suturalis, but it looks like they are bedding down for the evening. Also got a couple of Enoclerus sp. on the flowers.
Day 3 –8.4 mi SE Willcox, Arizona On our way towards the Chiricahua Mountains to see if we can find any Crossidius host plant stands. We found patches of Isocoma tenuisecta and Gutierrezia microcephala along Hwy 186 southeast of town—the former was just coming into bloom, but there were plenty of Acmaeodera (scalaris, disjuncta, and amplicollis) on the flowers, including on the unopened heads. We found perhaps a dozen Crossidius suturalis on them as well, and Jeff found one small female that looks like C, hurdi [Edit: it is C. suturalis]. I looked at a lot of Gutierrezia before finding a single C. pulchellus sitting on one of the plants. The same diversity of Acmaeodera as well as a few A. gibbula and T. peninsularis was also found on flowers of Hymenothrix wislizeni, and I took a series of about 10 specimens of what I looks like A. parkeri on flowers of what appears to be Stephanomeria pauciflora. There were also some tiny membracine treehoppers on a thorny shrub (maybe Condalia?) being tended by ants—both adults and young, and I collected a few of the adults.
Jct AZ-186 & AZ-181, Arizona After passing over a small range towards the Chiricahuas we didn’t see any Isocoma tenuisecta until we got to Hwy 181. There were some Baccharis sarothroides at the junction also, so we stopped and looked around. The Isocoma was just barely coming into bloom, but I found two Crossidius on them—one male C. suturalis and one small female that may be C. hurdi [Edit: nope, it is C. sururalis]. Heterotheca subaxillaris was in bloom abundantly, but there were no Acmaeodera on them and the area in general looked quite dry. I did find two A. decipiens on Sphaeralcea sp., and in the way back to the car I spotted a huge Lampetis webbii hanging on Ericameria nauseosa (which we’re not even close to blooming)—surely an incidental record.
4.1 mi SE Willcox, Arizona We came back towards town where things seemed to be further along and found stands of Isocoma tenuisecta in full bloom at the junction of Blue Sky Rd (a classic Arizona collecting locality). Crossidius suturalis were out in numbers on the flowers! Every now and then I got one that seemed too heavily maculated, making me think it could be C hurdi, but in the end I decided that all represented C. suturalis.
Willcox Playa, Arizona We went to the Playa to see if there were any tiger beetles to be had. I hiked to the edge of the Playa, and within a few minutes I saw a Cicindela pimeriana—just the second one I’ve encountered (the first was last night at gas station lights)! With that promise of more, I hiked the entire playa edge and never saw another one! I only saw one other tiger beetle—Cylindera lemniscata—seems I’m a bit late in the season for the Willcox Playa tiger beetles. Nevertheless, it’s a cool place and was fun to see. I’ll definitely be back during the summer, not just for here but for nearby Blue Sky Rd. Arriving back at the car, I did find one Moneilema sp. (I think M. appressum) on cholla. There were Crossidius suturalis abundant on the Isocoma tenuisecta, which, like the last spot, was in full bloom, but I’d gotten my fill of them at the previous spot and didn’t collect any.
Willcox, Arizona (epilogue) Collecting the insects from the field is only the beginning. Each night they must be processed for storage until they can be mounted once back in the lab.
Day 4 – Santa Rita Mountains, Box Canyon, Arizona We passed through Box Canyon on our way to Madera Canyon, so we decided to stop near the dry falls where last year I’d collected such a nice diversity of Acmaeodera spp. on flowers of Allionia incarnata. There was evidence of recent rain, and we found the patch nicely in bloom with four species (scalaris, decipiens, cazieri, and parkeri) on the flowers. Nearby in the wash before it crossed the road was a yellow composite (Xanthisma gracile), from which I collected the first three as well as gibbula, rubronotata, and disjuncta. Euphoria verticalis scarabs we’re flying plentifully around the flowers also—first time I’ve seen the species.
Flats below Madera Canyon, Arizona There are records of Deltaspis tumacacorii from Madera Canton at Proctor Rd collected on Croton, so we stopped by on our way south to give it a try. This seems to be a rather hard-to-find bug, so I didn’t have high expectations, and that’s a good thing because I didn’t see the beetle nor anything that even remotely resembled Croton. I ended up checking out the desert broom (Baccharis sarothroides) in the area on which I’d collected Stenaspis verticalisarizonensis and Tragidion spp. (also without high expectations). There were some interesting congregations of Euphoria leucographa feeding at sap flows on the stems and a few Stenaspis solitaria but otherwise litttle of note. I did find one Hippomelas planicauda hanger-on on a low fabaceous shrub (not Mimosa biuncifera), and inspecting the Gutierrezia microcephala plants revealed nothing but a single Acmaeodera rubronotata.
Madera Canyon Rd, Arizona We stopped real quick down the road on the way out of Madera Canyon because we saw stands of Isocoma tenuisecta, although they were still just shy of blooming. We looked at quite a few and found a single Crossidius suturalis—probably we are a tad early, and the area looks like it could use a good rain to pop things out and bring the Isocoma into bloom. We also saw low plants that could be the Croton that Deltaspis tumacacorii has been found on [Edit: I do not believe these are the plants, as they are too low]. Would be good to revisit this spot after a good rain!
Tumacacori Mountains, Walker Canyon, Arizona Our second shot at Deltaspis tumacacorii, which has also been taken in Walker Canyon. We found thick stands of knee-high flowers that we immediately took to be the Croton—just as described by our contact—on which the beetles have been taken. However, we quickly began doubting that ID and decided the plant must be some type of composite. That would make more sense from a host plant standpoint, as all known host plants for Crossidius spp. are composites (subsequently determined to be Pseudognaphalium leucocephalum, family Asteraceae). We looked at the dense stands for quite some time but didn’t see any beetles (or much of anything else) before deciding that we were probably too early—had the beetles already emerged we would have at least found some stragglers. I did take a few Acmaeodera on the flowers (scalaris and rubronotata), as well as a large cantharid (Chauliognathus profundus). I also took single A. amplicollis and A. rubronotata individuals off of a large helianthoid composite (Viguiera cordifolia) and one A. rubronotata on a small yellow composite (Xanthisma gracile). There were a multitude of darkling beetles crawling in the ground—in one spot I saw five individuals of several species all within a one-square foot area. We’ll have one more shot at D. tumacacorii tomorrow at Kitt Peak.
Day 5 –Pan Tak, Arizona (road to Kitt Peak) Today’s destination is Kitt Peak to look for Deltaspis tumacacorii and Acmaeodera resplendens, but at the entrance we saw some Isocoma tenuisecta just coming into bloom and decided to check it out. We found a half-dozen Crossidius suturalis but had to really work for them. Alliona incarnata was also nicely in bloom, but I got only one Acmaeodera parkeri? and one A. alicia off of the flowers. There was some Gutierrezia microcephala present, also not quite in bloom, off of which Jeff got a pair of C. suturalis and gave me one. Kinda dry but lots of flowers—wish there would have been more beetles coming to them.
Kitt Peak National Observatory, Arizona Our last chance to find Deltaspis tumacacorii, and I also got a tip that Acmaeodera resplendens has also been taken up here. We immediately found several species of Acmaeodera (amabilis, amplicollis, decipiens, and rubronotata) abundantly on several composite flowers—Heliomeris longifolia, Heterotheca fulcrata, Hymenothrix wrightii, Solidago velutina, and Gutierrezia microcephala, and I found a single A. solitaria on a pink malvaceous flower, but no A. resplendens. We also searched thoroughly for any Croton-like plant for D. tumacacorii but found nothing. The Kitt Peak records of that species are older than the Walker Canyon, Peña Blanca, and Madera Canyon records, and most of the records seem to be in August rather than September, so I suspect we are a bit late for both the species and its host plant. My plan at this point is to return sometime during the middle of August and enlist the help of the source of one of the recent records to accompany me.
Road to Kitt Peak, Arizona We had noticed Gutierrezia microcephala and some other yellow composites in bloom about halfway up the mountain on our way to Kitt Peak and decided then to stop and take a look around on the way down. I took “down” the mountain, Jeff took “up.” I hadn’t walked very far when I saw what I at first thought was the cantharid Chauliognathus profundus (which I had seen yesterday at Walker Canyon preying on another cantharid) on G. microcephala flowers, but something about it gave me pause—it was too cylindrical and robust. I leaned closer to get a better look and realized it was a cerambycid—one that I did not recognize, a beautiful orange color with black elytral apices and pronotal spots! I quickly grabbed it with my right hand, immediately saw another elsewhere on the bush and grabbed it with my left hand, and as I stood there trying to fumble a vial out of my pack to put them in I saw a third individual taking flight from the bush and spiraling into the air and out of reach! I shouted out to Jeff, who came down to where I was, and showed him what I’d found, and together we decided that it must be Mannophorus forreri—a very uncommonly encountered species and more than adequate consolation for not finding Deltaspis tumacacorii earlier in the day. We spent the next hour searching up and down the roadsides, and I ended up with two more individuals from Gutierrezia flowers and two from Heterotheca fulcrata. Jeff found an additional individual on flowers of Thelesperma sp. I also picked up a few black and white Enoclerus sp., one on flowers of G. microcephala and a mating pair on flowers of Acacia berlandieri. We have a long drive to California in front of us now, and it sure is good going into the drive with such a great find under our belts.
Day 6 – Cajon Pass, California Finally made it into California! Once we turned off the interstate, we made a quick stop to look at the roadside habitat where we spotted a good stand of Isocoma sp. in full bloom. We looked at quite a few plants but didn’t find any beetles on them. There were also good numbers of Ericameria nauseosa plants as well (host for Crossidius coralinus), but they weren’t quite yet in bloom yet and the only thing I found on them was a mating pair of Agrilus walsinghami. Moved on quickly to the next spot!
Lancaster, California We met up with Ron Alten and traveled to a classic “Crossidius” collecting site (up to four species have been taken there). We’d stopped at a couple of places on the way there but not found anything—either the host plants were not yet blooming or no beetles were found, so we had the feeling that we might be a week or two early. We had to drive into the habitat a ways before we started seeing host plants—in this case Ericameria nauseosa—but eventually we found a nice large area with the plants in full bloom. It didn’t take long before we found Crossidius coralinus (populations in this area are assigned to subspecies ascendens) on the blossoms. We worked the area for a couple of hours in the heat (97°F) and got a sufficient series for study with some individuals in ethanol for DNA analysis. Males exhibit quite a bit of variability in the degree of development of the elytral markings (thin to moderately expanded sutural marking), while females were quite consistently fully expanded. Males also outnumbered females by 3:1, and all of the individuals I collected were perfect and not damaged—both suggesting that the species is just beginning to emerge. Perhaps that is why we did not find individuals of the other species (mojavensis, suturalis, and testaceus). What I did find, however, was a small trachyderine cerambycid that none of us recognized! It was on the flowers of E. nauseosa—just like C. coralinus—and at first I thought it might be a small, aberrant C. coralinus, but the elytra are completely blue-black and the size was significantly smaller than the smallest C. coralinus male that we saw. I scanned BugGuide and didn’t find anything that matched, so this will have to remain a mystery for now. [Edit: I later determined this to be a heavily marked C. discoideus blandus. In the field I couldn’t see the orange laterals on the elytra.]
Day 7 –Santa Catalina Mountains, Mt. Lemmon, Arizona We decided we were just a bit to early for things in California and decided to come back to Arizona where we’d been having better success. I wanted to take another shot at Acmaeodera resplendens and had been told that Oracle Ridge Trail was a good locality for them, though maybe a bit late. We began seeing them soon after getting out of the car—unmistakable by their brilliant metallic green to copper color. They were not numerous, so I had to work for them and walked the trail about 2 miles out collecting them off a variety of flowers. The majority were on Bahia dissecta, and I also found occasional individuals of them and other species of Acmaeodera (amabilis, amplicollis, decipiens, and rubronotata) on flowers of Heliomeris longifolia, Heterotheca fulcrata, Hymenothrix wrightii, Ageratina herbarea, Achillea millefolium, sweeping, Cirsium sp., and prob. Viguiera dentata. One other beetle I found was a Megacyllene sp. sitting on a plant under a stand of Robinia neomexicana [Edit: this is M. snowi snowi—another new one for my collection!].
Scenic Overlook, Santa Catalina Mountains, Arizona A quick stop on the way back down the mountain at a spot where we’d seen Gutierrezia microcephala and Heterotheca subaxillaris blooming along the sides of the road. There wasn’t much going on—a couple of Acmaeodera amplicollis and one A. rubronotata on the flowers of H. subaxillaris, one Enoclerus sp. on Solidago velutina, one A. solitaria on Baccharis sarothroides, and another swept from grasses. I did see Peucetia viridans (green lynx spider) feeding on a very bristly tachinid fly.
Day 8 –Santa Rita Mountains, Montosa Canyon, Arizona (halfway up) We decided to visit Montosa Canyon to take another shot at Deltaspis tumacacorii and also see if maybe we could find more Acmaeodera resplendens. We didn’t see many flowers along the way up the canyon until about the halfway point. When we did start seeing them we made a quick stop to see what might be on them. I collected some of the more common Acmaeodera (rubronotata, decipiens, and amplicollis) off a few different yellow composite flowers, but we quickly decided to take a look at the higher elevations.
Santa Rita Mountains, Montosa Canyon, Arizona (entrance to Whipple Observatory) The road was gated past the km-13 point—Jeff took the roadsides, and I took a ridgetop trail off to the south for a little over a mile. The panoramic views were spectacular, and at the southern terminus I stood at the edge amidst gale-force winds admiring the landscape! Acmaeodera were diverse and abundant, though not quite as abundant as yesterday on Mt. Lemmon or a few days ago on Kitt Peak. However, I did get another nice series of A. resplendens, along with decipiens, rubronotata, amplicollis, and amabilis. Host flowers were collected for most of these: Hymenothrix wrightii, Erigeron neomexicanus, Linum neomexicanum, Heliomeris multiflora, Verbesina enselioides, Heliopsis parvifolia, Heterotheca subaxillaris, and Machaeranthera tanacetifolia. I also collected a small series of A. decipiens perching on grass stems and a very cool-looking wasp—black with a bright orange thorax and whitish abdominal apex [edit: I believe this is the scoliid Psorthaspis portiae].
Santa Rita Mountains, lower Montosa Canyon, Arizona We stopped at a spot near the bottom of the canyon on the way out to see what was going on at the lower elevations. The answer—not much! There were a variety of woody shrubs and other plants in bloom, but the area seemed rather “wilty”. I think this area has a lot of potential, we just didn’t hit it at the right time. I did take an impressively huge tarantula hawk, just because.
Flats below Montosa Canyon, Arizona I was a bit disappointed at not finding any beetles at what seemed would be the last collecting stop of the trip. But on our way out we saw a patch of Isocoma tenuisecta in bloom in the lowlands some distance west of the entrance to the canyon—just what we were looking for! Jeff and I each quickly found Crossidius suturalis individuals on flowers of the plants and continued searching up and down along the roadway. We didn’t find any more for awhile but when I got back to the area where I started I spotted another one sitting on a plant on the other side of the barbed-wire fence. I extended my net handle to the max, maneuvered it in position, took an assertive swipe, and got it. Just as I was putting it into the bottle, I saw another one take flight from a plant right beside me. I hadn’t closed the bottle yet but didn’t want the other one to get away, so I capped my thumb over the opening, awkwardly wielded my net into position one-handed, chased after it and took a swing and got it, too! (More often than not these situations end up with me losing both specimens!). There was also a good amount of Hymenothrix wislizeni along the roadside, off the flowers of which I collected several Acmaeodera gibbula, A. disjuncta, and A. rubronotata. This is probably the last collecting locality of the trip, so I’m happy to end up having success with this subspecies of Crossidius (C. suturalis intermedius), which we havn’t found in large numbers on this trip. Just after leaving the site, we saw a bobcat on the side of the road—my first one! Unusual to see one in the middle of the day—it was a small one, must’ve been quite hungry!
Phoenix, Arizona (epilogue) Bill Warner was kind enough to host Jeff and I for our last night in Arizona prior to returning home tomorrow. What an amazing collection he has built, and his use of flight-intercept traps in recent years has turned up even more amazing beetles. I was happy to also meet Andrew Johnston and Evan Waite, who joined us for dinner.
Polistes carolina/perplexus with Magicicada prey | Shaw Nature Reserve, Missouri
I’ve probably used the term predator satiation more often during the past couple of weeks than I have during the entire rest of my life. Students of ecology know this as an antipredator adaptation in which prey occur at such high population densities that they overwhelm predator populations.¹ This ‘safety in numbers’ strategy reduces the probability that any given individual will be consumed, thereby ensuring that enough individuals survive to reproduce. With St. Louis currently experiencing the appearance of Brood XIX of periodical cicadas, I’ve gotten lots of questions recently from many coworkers and friends wanting to know more about these cicadas. Often the first question is “What is their purpose?” My standard reply begins with a statement that they, like all living organisms, are the products of natural selection, which then presents an opportunity to explain how natural selection might result in such massive, temporally synchronized, multiple-species populations. A few eyes have glazed over, but I think most have found my answer interesting, often even leading to further questions about where they lay their eggs, what is their life cycle, why are they so loud, how do they “do it” and select mates, etc. Of course, as an entomologist with a strong natural history orientation, I’m always anxious to introduce people to ecological concepts, and right now the periodical cicada is providing a conspicuous, real-life example of such.
¹ Also called “predator saturation,” although this term might be misconstrued to mean that it is the predators that are over-abundant.
First the eyes...
A few weeks ago, right at the beginning of their emergence in the St. Louis area, my friend Rich Thoma and I observed predator satiation in action. While hiking one of the trails at Shaw Nature Reserve, we heard the unmistakable shriek and cellophane-sounding wing flapping of a just-captured male cicada. Tussling on the ground ahead of us was the cicada in the grasp of a Polistes carolina/perplexus wasp, which was repeatedly stinging the hapless cicada on the underside of the abdomen. The shrieking and wing-flapping grew less frequent as the stinging continued, until at last the cicada lay quiet. As we approached, the wasp spooked and flew off, but we knew it would be back—we parked ourselves in place while I setup the camera, and before long the wasp returned. It took several minutes of searching from the air and on the ground before the wasp finally relocated her prey, but once she did she began voraciously devouring it. As the wasp was searching, we hypothesized that our presence had altered the visual cues she had memorized when flying off, resulting in some confusion when she returned, and thus the long period of time required to relocate her prey.
...then the legs!
We watched for awhile—first the eyes were consumed, then the legs. As it consumed its prey, Rich remarked that he bet he could pick up the wasp and not get stung—likely the entirety of its venom load had been pumped into the cicada. Both of us declined to test his hypothesis. We also wondered if the wasp would butcher the cicada after consuming part of it and bring the remaining pieces back to the nest. We had seen a European hornet do this once with a band-winged grasshopper, consuming the head, then cutting off the legs from the thorax and flying away with it before returning to collect the abdomen as well. No butchering took place this time, however, the wasp seemed content to continue eating as much of the cicada as possible—a satiated predator if there ever was one!
Leg after leg is consumed.
One eye and all six legs down, time to start on the abdomen.
A few more photographs from this past week in Campinas, Brazil. It rained during the afternoon but stopped by the time I arrived back at the hotel, allowing me to stroll the lavishly landscaped grounds during the mild evening hours. There is a pink-flowered shrub forming a hedge row in back of the hotel that is highly attractive to many types of insects. The identity of the shrub remains a mystery to me, and most of the insects I’m finding on it I can recognize only to family – I’m hoping the hotel staff will be able to name the former and that the readers of this blog might be able to provide IDs for the latter.
Calycopis sp. poss. origo (Lepidoptera: Lycaenidae). ID by Dave Hubble and Chris Grinter.
It took a bit of effort to find an unobstructed view of this hairstreak butterfly (family Lycaenidae) as it visited the flowers within the shrub. Every time I tried to move foliage out of the way to get a good view, the butterfly became alarmed and flew to another part of the hedge row. My antics drew the attention of a hotel worker, who was apparently interested enough in what I was doing to act as a spotter whenever the butterfly flew to help me relocate it. Eventually I got a few shots that I was happy with, including the above.
A flesh fly (Diptera: Sarcophagidae).
I presume this to be a type of flesh fly (family Sarcophagidae) based on the stout bristles and color pattern that seems typical for the family. I like the striking contrast in coloration between the fly and the flower. There are a few flybloggers who I’m hoping might be able to give a better identification.
A potter/mason wasp? (Hymenoptera: Vespidae).
This appears to me to be some kind of potter or mason wasp (family Vespidae, subfamily Eumeninae) – it was a bit smallish at only about 12mm in length. I hope one of the knowledgeable wasp bloggers out there (ahem… Eric?) can at least confirm this level of identification and perhaps the tribe or genus as well.
Azya orbigera (Coleoptera: Coccinellidae). ID by Tucker Lancaster.
Every ladybird beetle (family Coccinellidae) I’ve ever seen is some variation of black and red/orange/yellow and has a smooth, glabrous appearance. This beetle is cobalt blue with a dense pubescence over the dorsal surface, but it still seems to me to be some type of ladybird beetle. It was a tiny little thing, so I suppose it could be one of the multitude of small beetle families with which I am unfamiliar.
Quedas sp.? (Hemiptera: Cicadidae).
This cast cicada exuvium was not on the shrub, but on a nearby tree at about eye level. I really wish I could have seen the cicada that emerged from it, because this is certainly the biggest cicada exuvium I have ever seen. I was about to simply label it “family Cicadidae” but seem to recall that cicada higher classification is in a bit of flux these days. At any rate, given its great size I wonder if it might represent one of the giant cicadas in the genus Quesada.
I still have many more insect photographs from the past week and will certainly increase that number over the next week as well. Stay tuned!
Our guest blogger for today is Anne McCormack. I have known Anne (or known of her) for more than 25 years now, first as a long-time editor of Nature Notes, the journal of the Webster Groves Nature Study Society, and more recently on a personal basis as I, myself, have followed in her editorial footsteps. Anne is an astute naturalist whose breadth of knowledge spans not only botany but also entomology and ornithology, all of which she write about in her own blog at Gardening with Binoculars.
I planted Common Dogbane (Apocynum cannibinum) because some of my butterfly-watching friends reported numbers of juniper hairstreak butterflies on the patch of dogbane at Powder Valley Nature Center in Kirkwood. I assumed incorrectly that dogbane was a host plant for hairstreaks, and believing it to be little more than caterpillar food, I placed it in a hot, dry, narrow strip along the driveway. Ragged, caterpillar-chewed leaves wouldn’t be noticed there, and I forgot about it. After a few seasons, it was still a modest-sized clump, but the leaves were in great shape. In fact, it had grown into an attractive bush of airy, elegant lime-green foliage, wine-red stems, and tiny white flowers. It’s quite a contrast to its relative, Common Milkweed, growing next to it, which looks as if it were designed by Dr. Seuss—even before it gets chewed to bits. At this point I decided it was time to look it up and see why it had failed to support hordes of munching caterpillars. As you have already guessed, gentle reader, the Juniper Hairstreak’s host plant is juniper, not dogbane, but good old Common Dogbane is a great nectar plant. Now that Dogbane and I understand each other better, I can appreciate the amount of traffic its tiny white blooms bring in, like this Peck’s Skipper butterfly. Ants, butterflies, tiny native bees, honeybees, and this mason wasp are busy there all day long.
Along with several species of moth, it is the host plant for the Dogbane Beetle, which spends its larval stage devouring the roots and its adulthood dining on the leaves of Dogbane, and nothing but Dogbane. Dogbane Beetle can be confused with Japanese Beetle by beginners like myself, but unlike its fellow Coleopteran, Dogbane Beetle is harmless. That makes its iridescence all the more gorgeous, as shown in this wonderful photo by Courtnay Janiak. It’s a native insect that has shared a long evolutionary history with this under-appreciated native plant. American Indians valued it for its bark, which is tough but peels off in long strips. They plaited it for bowstrings and anything that called for twine; hence, its other common name, Indian Hemp. Don and Lillian Stokes, in their 2002 PBS show about bird watching, demonstrated how birds seek out the dry stems of this perennial, pulling off strips for nests in early spring. Nesting material can be hard to come by for birds in the tidy suburbs, so I don’t clean up the stems after frost. “Bane” in the name refers to the toxin cymarin in the plant’s leaves, though the plant would have to be covered in braunschweiger before my dog would be interested. Edgar Denison, in Missouri Wildflowers, translates the genus name Apocynum as “away dog.” The species name cannibinum refers to hemp. Its seedpods remind me of French green beans. These split at the end of the season, and the seeds fly away on fibers similar to milkweed seeds. Collect some and try this plant in your butterfly or native plant garden. Give it a spot where it’s easy to watch the colorful visitors.
When I started participating in blog carnivals last year, Circus of the Spineless was – for me – the pinnacle of blog carnivals. I wanted to take my shot at hosting this venerable celebration of creepy crawlies, and even though the waiting list for hosting was almost a year long, I offered my services and settled in for the long wait until February 2010. Ten months have passed and the time has come. In the meantime, I did my blog carnival host début with Berry Go Round #21 and snatched the sophomore slot for nature blogging’s newest carnival with House of Herps #2. Through those efforts, I learned that blog carnival hosting is an incredible amount of work/fun, and while plants and herps are fascinating, inverts are my true love. It is, thus, with great pride that I join the ranks of previous hosts in presenting this, the 47th edition of CotS. Featured below are 16 submissions by 14 contributors that cover representatives from 5 classes in 3 invertebrate phyla. A humorous look at some of the personalities behind invertebrate study is presented as a bonus for those who make it to the end.
Coral Reefs Jeremy at The Voltage Gate reports on peer-reviewed research on the impact of herbivorous fish on the recovery of coral reefs in his post, Protecting herbivorous fishes significantly increases rate of coral recovery. Coral reefs have been hard hit by the challenges of bleaching and disease, pressures likely linked to climate change, and macroalgae, when given the opportunity to dominate, provide even further challenges. This can happen when populations of herbivorous fish, major grazers of macroalgae, are reduced through commercial harvest. The study authors evaluated ten sites over a two-and-a-half year period in and around the Exuma Cays Land and Sea Park (ECLSP), which was established as a no-take marine reserve in 1986, finding an increase of coral cover during the study period from 7 percent to 19 percent. However, ECLSP reefs were responsible for all of this increase, with no net recovery occurring outside the ECLSP. These results illustrate the importance of reserves as a refuge for biodiversity and the service they provide in keeping marine systems intact.
Sea slug (Glaucus atlanticus) This gorgeous nudibranch species got a foul slandering when they started washing up on Gold Coast beaches in Australia. Miriam Goldstein debunks this unfair treatment in her post, Sea slugs have self esteem too, at Deep-Sea News, noting its absolutely stunning iridescent blue and silver color with gorgeous feathery tentacles. Further exception is taken with such descriptors as “slimy”, “venomous”, “blue-bottle eating”, and “cannibals” – with the truth behind each of these terms far more fascinating than the visceral reaction their use was intended to elicit. Good news as well – you don’t have to travel to Australia to see these things – they live throughout the world’s open oceans (but you will have to get far from shore, where the pelagic jellys upon which they feed can be found).
—-“Informal Group” PULMONATA
Iron-clad snail (Cyrsomallon squamiferum) I’ve known about iron-clad beetles, species of Zopheridae whose exoskeleton is so hard and thick it is almost impossible to impale them with an insect pin. I’d never heard of an iron-clad snail, however, until I read Dr. M’s post, The Evolution of Iron-Clad Samurai Snails With Gold Feet, at Deep-Sea News. Unlike the seemingly iron-impregnated beetles, these snails actually utilize iron sulfide in a series of armor plates covering the “foot.” Just described in 2003 from a hydrothermal vent in the Indian Ocean, it is the only known animal known to use iron sulfide as skeletal material. Only time will tell if these snails achieve the same popularity as living jewelry as the beetles.
¹ The taxonomy of the Gastropoda is under constant revision, as the results of DNA studies increasingly reveal as possibly polyphyletic many of the former orders (including the Opisthobranchia and Pulmonata, now known as “informal groups”).
Samurai crab (Heikea japonica) Mike Bok at Arthopoda shares two stories about this crab – one an ancient Japanese legend, the other a modern piece of scientific folklore – in his post, Samurai Crabs: Transmogrified Japanese warriors, the product of artificial selection, or pareidolia? In the first, popular legend alleges that these crabs were transformed from drowned samurai warriors, each one identifiable by the face of the fallen samurai that it bears on its backs and for whom the crab searches in the depths of the oceans around Japan. This ancient legend has led to a modern scientific quibble about whether the stylized face that can be seen on the crab’s carapace is the result of artificial selection by generations of superstitious Japanese fishermen, who have selectively released crabs bearing any resemblance to a human face. This may make for compelling scientific debate, but Mike counters even the considerable eloquence of Carl Sagan in providing his own thoughts on why this likely is not true.
Amphipod (Phronima spp.) In another example of the intermixture of science and culture, Mike Bok (Arthopoda) asks, Did Phronima inspire the design of the Alien Queen? Mike agrees with the claim that the original “soldier” alien morph seen in “Alien” (1979) was based on a painting by artist H. R. Giger, but he thinks that Phronima more likely influenced the design of the queen alien morph in “Aliens” (1986). The truth may remain hidden at Stan Winston Studios, but the broad crest atop the head of Phronima, bearing tubular, upward-pointing eyes, its “necro-parasitic” tendencies, and a chillingly suggestive photograph of the beast from a 1981 paper lend an air of plausibility to Mike’s hypothesis.
Harvestmen, daddy-long-legs John at Kind of Curious follows up on David Attenborough’s Life in the Undergrowth Episode 1 with his post, Daddy Long Legs Daddies (aka Harvestman). Looking like spiders but lacking their venomous and silk-spinning abilities, it seems that nobody can agree on the proper name for these spider relatives. Brits call them “harvestmen”, but Americans call them “daddy-long-legs”, a term that in the UK refers rather to crane flies (which less informed Americans simply call “giant mosquitoes”). Let’s not even mention the daddy-long-legs spider (Pholcus phalangioides), which actually is a spider.
Neoscona crucifera (barn spider) Anyone who hikes along woodland trails in the eastern U.S. during autumn knows what a “spider stick” is – i.e., any handy stick that can be waved probingly in front of one as they hike, lest they run smack into the web of any number of orb weavers that are fond of stretching their large webs across such natural insect flyways. Jason, at Xenogere, has some biggun’s in his neck of the woods, which he describes in intriguing detail in his post, Walking with spiders – Part 3. Barn spiders are some of the biggest, allowing one to fully appreciate their polychroism and polymorphism. I challenge even the most arachnophic of readers to look at Jason’s photographs and not be mesmerized by their beauty.
Horned passalus (Odontotaenius disjunctus) Joan Knapp at Anybody Seen My Focus? shows photographs of this beetle in her post, Bess Beetle: Horned Passalus (Odontotaenius disjunctus), as it lumbered slowly and gracefully over a fallen tree branch. Perhaps the cool temperatures were the reason for its sloth. Or perhaps the missing antenna indicated a feeble, old individual on its last (six) legs. A brief interruption for photographs seemed not to deter the beetle from its destination, somewhere in the leaf litter beyond the log…
Skipper butterflies (family Hesperiidae) Randomtruth at Nature of a Man loves skippers (are they butterflies, or aren’t they?), and you’ll love his photographs of these delightful little half-butterflies in his post, Day Skippers. While there is some slight doubt about the identity of individuals he sees in his backyard (skippers are notoriously difficult to identify in the field), there is no doubt that these little guys are loaded with personality. You won’t believe the “natural history” moment he caught on film (er… pixels?) and presented in the final photo sequence.
Monarch butterfly (Danaus plexippus) Grrlscientist summarizes a recent peer-reviewed paper in her post, Migratory Monarch Butterflies ‘See’ Earth’s GeoMagnetic Field. The paper reports on photoreceptor proteins in monarch butterflies known as “cryptochromes” that not only allow the butterflies to see ultraviolet light, but also allows them to sense the Earth’s geomagnetic field. These highly conserved proteins evolved from the light-activated bacterial enzyme phytolase, which functions in DNA damage repair. Most animals have one of two types of cryptochromes, but monarchs have both – providing the first genetic evidence that the vertebrate-version of cryptochrome is responsible for the magnetoreception capabilities in migratory birds. Further research may provide insight on the workings of the circadian clock, which could lead to better understanding of sleep disorders and mental illnesses such as depression and seasonal affective disorder, as well as development of new treatments for jet lag and shift-work ailments.
Ants (family Formicidae) Katydids, grasshoppers, cicadas – what do ants have on these singers of the insect world? Plenty, as Roberta at Wild About Ants points out in her post, Ants: No Longer the Strong Silent Types. It turns out that ants have patches of ridge-like structures on their gaster, which they rub against a curved ridge (called a “scraper”) on the petiole to communicate with each other via stridulation. While lacking the decibel level of a cicada, these sounds are nevertheless in the audible range for human ears and are thought to have alarm, mating, and recruitment functions. Even more fascinating, stridulation is not the only tool in the ant music chest – drumming and rattling have also been documented. Curiously, however, ants do not possess ears, rather likely sensing sounds through their legs or by specialized hairs on their antennae. Check out the provided links to SEM photographs and a sound recording.
Bald-faced hornet (Dolichovespula maculata) Diane Tucker, Estate Naturalist at the Hill-Stead Museum in Farmington, Connecticut, writes at Hill-Stead’s Nature Blog. In her post, Be it ever so humble, she takes a look at some of the different animal nests that become revealed during autumn’s leaf drop – particularly those made by the bald-faced hornet (and also birds such as oriole’s). From its start as simple cluster of chambers, to its growth over the course of the summer – growing fatter until the summer’s apex of warmth and light, then tapering off with the approach of fall, these insect homes are a marvel of nature – intricately constructed homes made entirely of paper.
Common green bottle fly (Lucilia sericata) Bug Girl discusses the resurging use of bottle fly larvae in her post, Maggot therapy. The academic among us will appreciate her discussion of the mechanisms that allow these seemingly disgusting vermin to function as incredibly delicate microsurge0ns in cleaning and disinfecting open wounds. The morbid among us will appreciate the links to the most entertainingly disgusting medical photos one can imagine. Check it out – but not over your lunch hour!
BUGS IN FIR
Wanderin’ Weeta (With Waterfowl and Weeds) was going to make an owl out of Douglas fir cones, but instead she found globular springtails, a crab spider, and a ladybug in a sprig of fir. We’re glad she has an interest in little hitchhikers such as these, even if the kids at school when she was growing up didn’t.
Bug Girl shows that entomologists have a sense of humor with her post, Monday Morning bug jokes – a video compilation of jokesters from the recent Entomological Society of America Annual Meeting in Indianapolis. My favorites were the best dung beetle pickup line (“Is this stool taken?”) and Marvin Harris’ rendition of the minimum number of insects needed to elicit control (1 pubic louse, or 1/2 codling moth larva :)). J. McPherson was equally, if unwittingly, hilarious due to his Christopher Lloyd-esque mannerisms. My favorite entomological joke of all, however, was not featured, so I offer the following addendum to Bug Girl’s post: