Super Crop Challenge #15

Can you identify the structure in the photo below (2 pts), what it is doing (2 pts), and the organism to which it belongs (order, family, genus, and species—2 pts each)? Comments will be held in moderation so everybody has a chance to participate, although there are early-bird bonus points on offer. Read the full rules for details on how (and how not) to earn points. Good luck!

Copyright © Ted C. MacRae 2013

Mr. Phidippus gets his loot

Synoptic collection of tiger beetles for Mr. Phidippus.

I’m sure by now Mr. Phidippus is wondering where his loot is. You see, some months ago Mr. Phidippus won BitB Challenge Session #5 with a solid string of 1st and 2nd place finishes in that session’s five ID and super crop challenges. The top three points earners at the end of each session are offered a variety of prizes, and among the choices offered Mr. Phidippus chose to receive a small collection of beetles from my collection. However, I’ve been remiss in my follow up, with only a heavy travel schedule and seemingly endless string of commitments when I am at home to offer as excuses for such.

At long last, however, I am making things right and have put together this small synoptic collection of tiger beetles that I hope Mr. Phidippus will find useful. Some of the species selected might be common in some areas, while others are certainly found very seldomly—and even then only by those who know what they are looking for. Nevertheless, one of the most fascinating features of tiger beetles is their extreme polytopism, so even commonly encountered species can look very different depending on what part of their range they come from. A perfect example of this is Cicindela scutellaris, represented in the box above by three individuals: one from Kansas (subspecies scutellaris), one from northeast Missouri (subspecies lecontei) and one from southeast Missouri (an unusual population representing an intergrade of subspecies lecontei and subspecies unicolor). Ranging from wine-red to blue-green to brilliant red and green, they are perhaps the best example of tiger beetle polytopism gone wild!

So, Mr. Phidippus this one is for you. Congratulations again on your win, and thank you for your patience!

Copyright © Ted C. MacRae 2013

Araneus marmoreus encore

Araneus marmoreus adult female—ventral view showing epigyne.

Here is the full-sized photo from which the crop shown in Super Crop Challenge #14 was taken. The small finger-like structure in the upper right of the photo—the object of the challenge—is the epigyne (or epigynum) of Araneus marmoreus (marbled orb weaver spider). Spiders have a rather unusual mating strategy—rather than possessing genitalia that couple for insemination, male spiders first form a packet of sperm (spermatophore) and transfer the packet to an enlarged segment (tarsus) at the end of their pedipalps. During mating, the male inserts the tarsus into the female genital opening, thereby effecting sperm transfer. The female genital opening and associated structures, located on the underside near the front of the abdomen, are called the epigyne and function to direct the male pedipalps during sperm transfer. The shape of the epigyne varies greatly and uniquely among species—probably serving as an isolating mechanism that prevents interspecific mating and also providing a good diagnostic character for species recognition among even very closely related species (similarly to the hardened male genitalia of many insect groups). An even closer view of the epigyne of A. marmoreus can be seen in this BugGuide photo.

Araneus marmoreus (marbled orb weaver) | Washington Co., Missouri

This is actually the second time I’ve featured A. marmoreus in a quiz—the intricate pattern of the dorsal abdomen being the subject of Super Crop Challenge #2. Folks had an easier time identifying the critter in that challenge than this one, which I guess is not surprising since people tend to know animals more by their color patterns than the structures of their genitalic openings. As in that first challenge, I encountered this adult female during a hike along the Ozark Trail, this time in Washington County in east-central Missouri. Unlike before, however, I found this spider crawling on a fallen log in the dark forest floor rather than resting in her web. The colors of this species are diverse and spectacular—a recipe that makes them almost irresistible to insect macrophotographers. That this is true is demonstrated by the 360! photos of this species posted to BugGuide.

Hot orange and yellows glow against the dark, moist wood of a fallen tree trunk.

While my previous photos of this species were colorful, these simply glow due to the more orange coloration of this individual and its contrast with the darkened color of the moist wood. It’s a November color scheme if there ever was one—appropriate since I took them exactly one year ago today on November 23, 2011. She was a lot more cooperative than the first subject, and because of this and the stable substrate on which she was sitting I was able to get my favorite shot of all—the face portrait! Not quite as endearing as a jumping spider face (with its large, anthropomorphic median eyes), but striking nevertheless.

The obligatory BitB face shot!

A word about the challenges—I’m not sure if the lack of response to this one is an indication of difficulty or further evidence of declining relevance of blogs as an interactive social medium. I can’t help but notice that blog commenting in general has dropped with the rise of more functionally interactive media such as Twitter and Google+. What do you think—was this challenge too hard, or has the concept of challenge posts lost its appeal?

Copyright © Ted C. MacRae 2012

Super Crop Challenge #14

Wow, has it really been five months since the last Super Crop Challenge?! Well, it’s time to start a new BitB Challenge Session (this will be #7), so what better way to start? Can you name the structure shown in the photo below (2 pts), the organism to which it belongs (order, family, genus, and species—2 pts each), and its significance (2 pts)?

Note: If you are not completely familiar with them, please read the full rules for details on how and how not to earn points. Good luck!

Copyright © Ted C. MacRae 2012

West Indian seagrape sawfly

I spent a few days in Puerto Rico last month. A quick in-and-out for work, there was little chance to do any real exploring. Nevertheless, I booked my return on the last possible flight out so that I would have at least part of a day to look around before needing to go to the airport. I’ve only been to Puerto Rico twice before—once in 1982 on a one-day visit during my honeymoon cruise (with a far-too-rushed guided tour to El Yunque), and again in 1999, also a quickie for work. Given my limited previous opportunities to explore San Juan, you might think I would choose La Forteleza and San Juan National Historic Site in Old San Juan for my day’s destination. After all, they were designated a World Heritage Site by UNESCO (United Nations Educational, Scientific, and Cultural Organization) in 1983. Tempting, but when I looked at the map of San Juan a nice, big, chunk of green immediately caught my eye—Bosque Estatal de Piñones (Pine State Forest). Call me single-minded, but not even a World Heritage Site can match the siren call of 1,500 acres of moist, subtropical forest!

Sericoceros krugii female guarding eggs on leaf underside of sea grape (Coccoloba uvifera) | Bosque Estatal de Piñones, San Juan, Puerto Rico

Mangrove forest covers much of the reserve, accessed by a wide (and annoyingly elevated) boardwalk—an interesting stroll but unsatisfying to me since I couldn’t root around at ground level. One can get only so much enjoyment from distinguishing red, black, and white mangrove before the sameness of the canopy and exclusion from the ground flora/fauna starts to become monotonous. I went back towards the parking lot (photographing a few lizards along the way—more on them in a future post) and had just begun walking the perimeter of a picnic area when I encountered some very large seagrape (Coccoloba uvifera) plants. I’ve seen a lot of seagrape in Florida and have never found any insects on it, so I initially didn’t make much effort to go over and have a closer look at them. However, even from afar I could see that these particular plants had been very heavily damaged by some type of defoliating insect. The first few branches I looked at showed no outward evidence of who the culprit was, but I reasoned it must have been some sort of lepidopteran caterpillar. As I was inspecting the branches, the insect in the above photo caught my eye—at first I thought it was some type of “homopteran” because of the apparent egg-guarding behavior it was showing, but a closer look revealed that it was actually a sawfly! An egg guarding sawfly; who would have thought?!

Female ovipositing her clutch of eggs, which are solid red when first laid.

Predictably, subsequent identification was quite easy as there is only a single species of sawfly in Puerto Rico—Sericoceros krugii in the family Argidae. About 20 species make up this Neotropical genus, occurring from southern Mexico south to Argentina; however, S. krugii is the only species occurring in the West Indies and in addition to Puerto Rico is found in the U.S. Virgin Islands and Dominican Republic (Smith 1992). The species in this genus seem to specialize on Coccoloba spp. (family Polygonaceae) as host plants; however, one species is reported from Triplaris caracasana—also in the Polygonaceae (Smith & Benitez Diaz 2001), and another from Lonchocarpus minimiflorus in the family Fabaceae (Smith & Janzen 2003).

Larvae consume all but the largest veins of the foliage.

Wolcott (1948) describes how this species often defoliates long stretches of seagrape on the beaches of Puerto Rico, leaving “windrows of excrement on the sand underneath the naked branches and leaf midribs…” He also describes its apparent lack of natural enemies (although it has since been recorded as a host for a tachinid fly—Bennett 1999) and the fact that birds do not seem to eat them as possible reasons for its abundance and frequent outbreaks. To me, the screaming red/black coloration of the adult and apparent unpalatability to birds suggest the presence of chemical defenses, and although I couldn’t find any information on this specific to Sericoceros spp., many social species of sawflies are typically well-defended chemically and, thus, aposematic. Despite this apparent defensive capability, the remarkable maternal guarding behavior exhibited by the adult females suggests the eggs still need additional protection from predators and parasitoids. Sericoceros spp. are not the only sawflies to exhibit this behavior, which apparently has evolved across numerous sawfly lineages (see Social Sawflies, by James T. Costa).

This mature larva will soon spin a coccoon on the bark for pupation.

There were only a few, apparently mature larvae still around on the trees that I could find. Wolcott (1948) describes most outbreaks as occurring during the fall and winter months, after which the insects might completely disappear for many months or even a year. I must have caught the tail end of one such outbreak, although the number of females that I saw guarding eggs suggests another wave of defoliation would soon be occurring.

Congratulations to itsybitsybeetle, who showed up late to the party but still managed to pull out the win for Super Crop Challenge #13. Brady Richards came in a close 2nd, while Sam Heads and Mr. Phidippus share the final podium spot. The overall standings remain the same, with Sam leading Brady by a single, slim point and Mr. Phidippus only six points further back. There will be two more challenges in BitB Challenge Session #6, so it’s still possible for somebody to make a late run, especially if one or more of the leaders falters down the stretch. Remember—the top three points earners at the end of the session will get a choice of some loot, so don’t hesitate when the next challenge rolls around.

REFERENCES:

Bennett, F. D. 1999. Vibrissina sp. (Diptera: Tachinidae) a parasite of the seagrape sawfly Sericoceros krugii (Hymenoptera: Argidae) in Puerto Rico: a new record. Journal of Agriculture of the University of Puerto Rico 83(1–2):75–78.

Smith, D. R. 1992. A synopsis of the sawflies (Hymenoptera: Symphyta) of America south of the United States: Argidae. Memoirs of the American Entomological Society 39:1–201.

Smith, D. R. & Benitez-Diaz. 1991. A new species of Sericoceros Konow (Hymenoptera : Argidae) damaging villetana trees, Triplaris caracasana Cham. (Polygonaceae) in Paraguay. Proceedings of the Entomological Society of Washington 103(1):217–221.

Smith, D. R. & D. H. Janzen. 2003. Food plants and life histories of sawflies of the family Argidae (Hymenoptera) in Costa Rica, with descriptions of two new species. Journal of Hymenoptera Research 12:193–208.

Wolcott, G. N. 1948. Insects of Puerto Rico. Journal of Agriculture of the University of Puerto Rico 32(4):749–975.

Copyright © Ted C. MacRae 2012

Super Crop Challenge #13

What are these? Where did I find them? Who do they belong to? Full rules are here, and don’t forget to look for hints. Good luck!

Copyright © Ted C. MacRae 2012

Super Crop Challenge #12

It’s time for a new BitB Challenge Session, and to begin the 6th edition we start off with a Super Crop Challenge. This is a combination challenge, with points on tap for naming the organism (order, family, genus) and visible structures. As always, standard challenge rules apply, including moderated comments, tie-breaker points for first correct answers, and possible bonus pts for additional relevant information at my discretion. Mr. Phidippus ran away with BitB Challenge Session #5, but Tim Eisele and Dennis Haines fought to the end for podium honors. Will one of them de-throne Mr. Phidippus, or will somebody else make a surprise run? Or, perhaps, 3-time champ Ben Coulter will return to stake his claim as the true BitB Challenge Session champion. Let’s get started!

Copyright © Ted C. MacRae 2012

Two more winners

When I announced the winner of BitB Challenge Session #5, I had forgotten about a comment I made in a previous challenge that I was considering awarding prizes to the session’s 2nd and 3rd place finalists as well as the winner. After thinking about it some more I have decided it would be a good idea—2nd and 3rd places in the final standings may lack the prestige of a BitB Challenge Session Championship (snort!), but they are certainly no small accomplishment. With that, I offer my congratulations to Dennis Haines and Tim Eisele, 2nd and 3rd place finalists (respectively) in BitB Challenge Session #5.

Gentlemen, contact me for your loot.

Copyright © Ted C. MacRae 2012