The impaler

There are always outsiders in entomology, groups that don’t follow the norm. We’re taught, for example, that stink bugs are herbivorous (and often pests), that some feed on nitrogen-rich reproductive parts of plants while others feed on somatic tissue. So when you see a pentatomid on a light trap, you might think “How cute, look at this little bug! I wonder if there’s a plant around here it might feed on“. Then along comes the nasty little critter and impales a moth like it’s a scene from 300:

The poor moth never stood a chance

One might think it’s a fluke and not a regular occurrence, but then the next night you see the same thing, only this time it’s a poor ant that gets eaten:

As it turns out, there’s an entire subfamily of stink bugs (Pentatomidae: Asopinae) that is predatory, and it has been used as a pest control agent [1]. While its entomophagous habits are pretty well documented, I had never actually seen one. Finding out that some stink bugs make insect smoothies was one of the highlights of my recent jungle trip; I’ll leave the other ones for future blog posts!
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1.- Robert G. Foottit and Peter H. Adler, 2009. Insect Biodiversity: Science and Society. Blackwell Publishing Ltd. ISBN: 978-1-405-15142-9 Chapter 10: Biodiversity of Heteroptera – Thomas J. Henry

Pre-NMW 2013

We are currently in the middle of National Moth Week, and I am organizing a mothing event in a biological station (trying to, at least; I was supposed to leave yesterday but I had car trouble). I’ve been there several times and the moth diversity is astonishing: big/small, colorful/inconspicuous, with pointy or rounded wings, they’re all there.  I’d like to show you a few specimens that you can find there; I focused on macrolepidopterans when I took pictures, because they were less skittish than microleps.

A classic Automeris

Who said moths had dull colors?

Wasp mimics are a common sight at the light trap

Patterns and markings abound

Like I said, plenty of wasp mimics!

And finally, one of my personal favorites, the Dog-faced moth:

Looks like a dachshund or a basset hound

This is barely a small fraction of the astonishing moth diversity you can find there (not to mention other arthropods), and I hope to be able to photograph and collect a lot more that I have in past visits. If everything goes well and I manage to go, I’ll write a post-NMW 2013 post sometime next week after processing data and images.

 

 

Peculiar hitchhikers

Phoresis has been well studied interaction in biology, and it has been reported in both vertebrates and invertebrates. An example of vertebrate phoresis is the remora (Perciformes: Echeneidae), whose first dorsal fin is modified into an oval sucker that allows it to attach itself to larger marine animals, and one example I’ve seen often in invertebrates is pseudoscorpions on beetles, particularly longhorns (Cerambycidae). But I recently learned that phoresis in invertebrates is a world about which I know nothing.

We collected some beetles in the Andes a few weeks ago. Nothing too eye-catching, just some scarabaeids that landed on the light trap. We collected a few and didn’t think much about them after that, so they stayed in a jar at the lab. I reviewed the contents of the jar earlier this week and saw something interesting: about 30-40 mites were floating around in the alcohol, and two beetles had this:

Beetle is roughly 3 cm long

I didn’t recognize these structures, at least not on a beetle we captured alive. We had seen molds on dead beetles that had a similar overall shape, but there was one catch: molds don’t have legs!

Definitely not a mold!

I did what I usually do when I’m stumped and have no immediate access to my books/computer: I turned to Twitter for help. Sure enough, I soon received replies regarding these animals. Christopher Taylor (@CatOfOrg) identified them as phoretic Uropodina mite deutonymphs, and gave some insight as to what that stalk-like structure was. After that, Wayne Knee (@whknee) added that these mites use liquid glue, and form the pedicel by moving ahead, and that the mite later detaches, leaving the pedicel behind.

Sure enough, I found that different mites have different types of pedicels: they can be long, short, irregularly shaped, straight or helically coiled, and they can be homogenous or formed by packed bundles of fibers [1]. These are to assure successful phoresis on their hosts. I also found that host selection can be either very specific (one single species of centipede [2]) or non-specific (25 different species of beetles from several families [3]), but in both studies there appears to be a tendency for selecting specific body parts from which to attach the pedicel.

For the second time this week, I was stumped by arthropods (the first time was by some odd little things), which I really enjoy, for it means I’m always learning something new! And, again, it proves that Twitter can be an excellent tool for learning and sharing information.

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1.- Bajerlein, D., et al., Morphological diversity of pedicels in phoretic deutonymphs of Uropodina mites (Acari: Mesostigmata), Arthropod Structure & Development (2013), http://dx.doi.org/10.1016/j.asd.2013.02.002

2.- Bloszyk, J., Klimczak, J. & Lesniewska, M., Phoretic relationships between Uropodina (Acari: Mesostigmata) and centipedes (Chilopoda) as an example of evolutionary adaptation of mites to temporary microhabitats, Eur. J. Entomol. 103: 699–707, 2006

3.- Bajerlein, D. & Bloszyk, J., Phoresy of Uropoda orbicularis (Acari: Mesostigmata) by beetles (Coleoptera) associated with cattle dung in Poland, Eur. J. Entomol. 101: 185-188, 2004

Odd little things

When we learn about different animals, we are usually told about the big picture, the general characteristics that will help us identify a particular group. As we study specific classes/orders/families we come across some specimens that don’t quite match those broad guidelines, and it’s always a treat when we see them live and up close instead of reading about them in books and journals.

Today I went to my university’s campus to collect some insects. I was expecting to find some beetles, flies and grasshoppers, and maybe some aquatic insects, but not much else. While rolling over a log, we found this:

At first glance it looked like an arthropod egg of some sort, but then it started uncurling, revealing that it was actually an adult arthropod:

We’re usually told as kids that woodlice are the little bugs we find that can roll up into a little ball, but this particular specimen had too many segments to be an isopod, so I thought it might be a pill millipede and got excited. I had read about them, but I had never seen one in real life. When I got back home, I took a few pictures and noticed that some things didn’t quite match: My specimen had too many body segments (pill millipedes have 13 at the most, as far as I know), and the overall shape was different. It was much more stylized and “pointy”, whereas pill millipedes are rounder, at least the ones I had seen online.

When I reviewed pictures of the cephalic region, I noticed that the first and second body segments formed a particular shape, like a bicorne hat similar to the one Napoleon Bonaparte wore:

While odd, it makes perfect sense; the end of the body aligns with the union of the first and second segments when the millipede is curled up.

I still don’t know to which group this millipede belongs, and I welcome any input regarding an ID; I have three specimens at home in case more pictures need to be taken.

Now, finding one creature you’ve never seen before in a place you visit often is great, but seeing two in one day is remarkable. While glancing at some leaves, I saw what, from a distance, looked like a group of gregarious caterpillars:

Keep in mind that I was a few feet away, and my first thought was something I had seen before: gregarious Catasticta caterpillars, with their light colored bodies and dark heads, both covered in hairs. They tend to stay together, even different instars:

I asked a colleague to come take a look, and she poked it with tweezers. It was then that we realized that it was just one caterpillar, and not several. We were excited to see this for the first time: it was a hag moth caterpillar (family Limacodidae). We turned it over, and there it was, definitely a single caterpillar:

These caterpillars are quite interesting; they don’t have well developed prolegs, and they move in a worm-like fashion. Now, we were looking at it and discussing the advantages of the fleshy appendages, which lead us to ask ourselves how it would roll over. Cylindrical caterpillars usually just twist their bodies along their axis 180 degrees, and that is usually enough to allow the legs to grab on to something and roll over. But this caterpillar can’t do that, since its reduced legs and dorsal appendages don’t allow for such maneuvers. So how would it turn over?

Simple: It did an assisted backflip.

The caterpillar stretched its head and front of its body backwards, until its mandibles were able to bite the leaf it was on, and then it contracted all of its ventral longitudinal muscles so that the body rolled over its head and landed right side up.

I’ve said it once and I’ll say it again: the insect world is awesome!

The perils of being busy

We’ve all heard ourselves say “I’ll get to [X] as soon as I finish what I’m doing”, and realizing a while later (sometimes days) that we never got around to [X]. Sometimes it means that you simply have to do things on your personal time, like grade papers during the weekends or at home, but sometimes waiting to do something later can have terrible results, especially when it involves leaving moths in a relaxing chamber.

Exhibit A

After leaving about a dozen specimens from recent trips to the Andes and two other collecting sites in a relaxing chamber for over a week (because “I was just finishing cooking/grading/cleaning and I’d pin them right after”), I finally sat down and saw how they were, expecting them to be in a somewhat damaged, but recoverable state. Nothing was further from the truth. Mold had grown on every specimen, making them look like alien teddy bears.

There’s an Automeris moth in this pic, honest!

There was something cool about this, though. I would have thought that spending a week in the same humid, closed container would mean that I’d see the same molds on every specimen,  but no. I saw at least 5 different ones, and even moths collected at the same light trap on the same day grew different molds. I’d like to see if there are any papers regarding fungus specificity in Lepidoptera. The molds also appear to be body part-specific; some grow mainly on the abdomen, others mainly on the thorax. I’m aware that I only have 12 infected specimens in a single relaxing chamber, so it’s too early to draw conclusions, but it’s still interesting to see:

Localized mold

The bottom line is: Don’t pin tomorrow what you can pin today. Mold will attack if you let it, so always remember to pin specimens within 24 hours of leaving them in a relaxing chamber (unless you really want the alien teddy bears).

There’s no such thing as a dull beetle

When I ask people to name shiny, colorful insects, butterflies and the “regular” beetles (the common ones that people usually see, like ladybugs) are the ones that come up. There are many insects that people think as dull or drab, like wasps and the “ugly” beetles, like weevils. Since the most common scarabaeids here are brown or black, they too get thrown in the “ugly insects” pile. Yet nothing is further from the truth; earlier today, Bug Girl showed us some mind blowing cuckoo wasps, and I’d like to show you a few samples of the colorful beetles I’ve seen in the past few weeks.

When I showed this image to people, they thought it was some mineral deposit or a type of crystal in a rock formation.

Shiny mineral flakes in a rock of some sort?

But no, it’s not a rock! It’s a closeup of the elytra of a broad-nosed weevil (Curculionidae: Entiminae)

Ooh, shiny!

These colors are physical in nature; since they depend on the shape of tiny scales instead of chemicals, they don’t change when preserved in alcohol. The principle is similar to the one that the scales on a butterfly’s wing have, except butterfly scales vary greatly regarding shapes, and they tend to overlap; the scales in weevils tend to be rounded and either don’t overlap or do it in a disorderly fashion.

Myriad other beetle groups have very colorful members. One subfamily of scarabaeids, Cetoniinae, has some specimens that have elytra with a velvety surface. One fascinating aspect of these wings is that the colors vary with the ambient humidity; the higher the humidity, the darker the color of the beetle (This is very evident in another scarabaeid, the Hercules beetle). When wet, you can barely make out a pattern in the darkened forewings, but when they dry out a Rorschach-like pattern appears.

Or the start of a Pollock piece, if you prefer.

Yes, but this is all on the body/wings, you say. Bug faces are ugly, all black and boring. Again, the answer is no. Beetles have a vast array of colors, and in many cases this includes every part of the exoskeleton, including the head. Long-horned and tiger beetles have colors and patterns that rival those found in the masks of the Dancing Devils of Yare:

Hues of blue/green…

… or any color you like.

In short: beetles are awesome and they have some of the most amazing colors and textures in the insect world. I’ll do my best to keep showing you more examples of this!

Interrupted by a lady(bug)

Today in class, my teacher, a classmate (a plant physiologist and an immunology grad student, respectively) and I were discussing our journal reviews for this trimester. We’re focused on presenting our work and thinking how we could improve our manuscripts when we were interrupted by this:

 

I believe it is a Multicolored Asian Ladybug, Harmonia axyridis, although I’m not 100% sure. Regardless, it interrupted the discussion by flying across the room, and instead of ignoring it or removing it for being a distraction, we spent the next 15 minutes talking about how awesome ladybugs (and beetles in general) are. It was a good class!

Field trip etiquette

Field trips are an integral and vital part of an entomologist’s work. It’s where we collect specimens, make in situ observations regarding behavior and a vast array of other important data. Typically, planning a field trip requires time, money and close coordination with all the participants, along with permits (for collection in protected areas and/or of endangered species) and special equipment in some cases. This means that even a short trip can be a logistical headache. In order to make the most out of it, everyone must be prepared to do their job from day one.

Here’s the catch: “Their job” is not only to do science. Living with other people for a specified period of time (days/weeks) requires much more effort than simply seeing them from 9 to 5 at the lab. It means cooking, cleaning, organizing and everything you’d do with housemates. If this doesn’t work out, then the research will also suffer. What’s worse, the longer the trip is, the more these things will annoy and upset everyone. So how do we avoid this?

There are simple guidelines one can follow to ensure that the trip goes as smoothly as possible. These are aimed at staying at a biological station instead of camping, but most are common to both.

• Establish pet peeves before the trip starts: Some people hate being pranked, others can’t stand overcooked pasta and still others cringe at the thought of listening to classic rock instead of drum & bass during the road trip. Some of these are understandable, so there’s almost always a way to accommodate them, but others are a bit tougher. Discussing them beforehand saves bitter moments in the field.
• Make sure everyone has chores to do: Everyone must do something during the trip. Leaving all chores to a select few (or in extreme cases, one person) creates tension and resentment. One of my most strictly enforced rules is “Whoever cooks does not do the dishes“. I also encourage everyone to do each chore at least once: cook, do the dishes, clean the bathrooms and the like, but sometimes people admit that they’re lousy at cooking, or that they simply don’t enjoy doing one chore, and different group members negotiate. In the end, whether everyone does everything or if they specialize in a single chore is not too important, as long as they contribute equally to getting the chores done.
• Be polite, but firm, when correcting/enforcing: If someone didn’t clean the bathrooms (or their workspace) well, you can’t rage at them, as it accomplishes nothing productive. Instead, politely ask them to do it again. The same applies to enforcing schedules; if the group has to leave at 6:00 am and it looks like they won’t make it in time, then wake them up or pressure them, but politely. Don’t wait until it’s 5:55 and snap at them!
• Realize that people need their space: Yes, you’ll be spending 24 hours a day in the same place, which can be great for socializing, but everyone needs some uninterrupted time alone to read, listen to music, write, take a nap or simply sit and stare at the wall. As long as it doesn’t interfere with field activities and chores, this alone time is key to a good mood from everyone.
• No hogging collecting sites: Notoriously common in light traps or relatively small field locations, this is one of the biggest quarrel starters. People looking for a specific specimen will often call “The next [insert specific insect here] that falls in the light trap is mine!”, or will get territorial on a specific portion of the area where the group is collecting. I’ve found that helping others get the specimens they want/need is much better for morale and bonding. It’s tricky to balance collecting your own specimens and being altruistic, though.

I’m sure other people follow different rules; some groups prefer to individualize everything (everyone does their own cooking and cleaning, for example), while others have specific ways of dealing with problems (leaving tardy people instead of waiting 10 minutes). Which are your particular rules? Are there any important ones I missed? Let us know in the comments!

An entomologist’s (and a photographer’s) bucket list

As a kid, I grew up reading about fantastic animals, creatures that were more incredible than anything my imagination could assemble: bats with leaf-like noses, hoatzins, axolotls, elephants, platypus, dinosaurs and countless arthropods and sea dwellers. As I grew up, I had the oportunity to learn more about these and other creatures, and in some cases, meet them up close.

While studying Zoology in college, I started a “bucket list”: animals, places or events I had to see (and photograph, if  possible) before I turned 30. In the past decade, I’ve crossed many off my list: I went to Angel Falls, fed an elephant, held a male Long-Tailed Sylph (Aglaiocercus kingi) and saw a tail-less whip scorpion in its natural habitat, among others.

During a field trip last weekend I saw one of the creatures I had longed to see for almost a decade: a scorpionfly. Yes, for many entomologists this isn’t a big deal, but they’re not that common down here. I was alone at the light trap at the time, since the two other researchers were ornithologists and had fallen asleep by 9:30 pm. I was doing a routine check when I looked down and there it was, stumbling on the floor; at first I thought it was a big crane fly, but when I looked closer I saw two pairs of wings and a face akin to the Egyptian god Set, and I knew that I was finally able to strike it off my list. It was a hangingfly (family Bittacidae) rather than a true scorpionfly (family Panorpidae), but still a fantastic find for me.

One of the worst things about finding it, though, was the inability to share my excitement with anyone; my friends at the station were asleep, no internet service and my friends back home would replace every song on my computer with the sound of a thousand vuvuzelas if I sent them an SMS at 2:30 am. I had to wait to return to civilization to share my excitement with fellow arthropod enthusiasts, since the ornithologists just said it resembled a mosquito on steroids.

Managing to finally strike that off my list has made me review it. Here are a few of the items:

– See a monarch butterfly migration completely covering a tree
– Swim with great whites (no playing heroes here, I’m perfectly happy to see them from inside a cage)
– Visit and photograph every one of my country’s national parks
– See a salamander
– Photograph a tiger beetle

Some are easier than others, but I hope to be able to cross them all off in the next couple of years.

Which items are on your list, and which have you managed to see/do?

The overlooked research paradise

The Australian outback, jungles, tundras, deserts, highlands, savannas and marshes. They’re the remote regions most field scientists love to explore and research, due to both the little we know about them and for the spectacularly diverse wildlife. Plants, animals and fungi in these remote environments have incredible adaptations to their specific habitats, and that will always spark our curiosity. Yet there is one place I enjoy as much as (or even more than) these biomes, and it’s right in the middle of my city. It’s the Caracas Botanical Garden.

This little corner of green immersed in the metropolis is packed with spectacular flora and fauna. One would expect that in 70 hectares (173 acres for those of you who still refuse to adopt the metric system) you’d find low diversity; this is far from the truth. With over 1700 plant species, the associated wildlife diversity/density is quite high. Yet I’m interested in one specific, albeit very broad, group: the arthropods. Since my first visit to the CBG in 2005 I’ve photographed over a thousand different species of them, and each time I go I see something new; this never ceases to amaze me.

I started my Masters just a few months ago, and for my dissertation I want to make a catalog of the arthropod taxa living there and in which area they can be found, among other things like pest/medically important species present and their control, and teaching the general public about the importance (and awesomeness) of arthropods. There’s also an idea for a field guide to the most common arthropods (with pictures, given that I dabble in photography), but that’s still a long way off.

I’m aware of the herculean challenge that I plan on undertaking. I know that I probably won’t get much further than subfamily for the tens of thousands of specimens I collect, save the few emblematic species like Morpho menelaus. I’m also aware that I will need loads of time and an exorbitant amount of coffee to compile, organize, crunch, double-check and then present the data I collect. I’m also quite realistic and know that I will only manage to collect a fraction of the arthropod fauna in such a diverse environment. Having my field work so close to home/work might bring up other problems, eloquently explained by Terry McGlynn over at Small Pond Science. Yet I still want to do this.

My goal is not to have the Definitive Guide to the Arthropods of the Caracas Botanical Garden, but merely a stepping stone for future studies; I want there to be a reference for insect-plant interactions studies; I’d like for people who wish to study population fluctuation, mating patterns, ethology, ecology, biology, taxonomy and anything even tangentially related to arthropods or urban wildlife to have some idea of what one can expect to find in this little biodiversity hotspot. I also wish to emphasize the importance and value of having such a vast array of species right there, in the city. There’s no need to travel hundreds of kilometers or hike El Ávila (the mountain/national park that borders Caracas) for hours to see cellphone-sized spiders, impressive beetles and stunning butterflies. There is little to no information on the wildlife here, which makes this place an excellent research site.

Yes, visitors will be more interested in the colorful tanagers or the occasional sloth than in arthropods. To most people, they’re the crawling things that when stepped on, they go “crunch”. And that’s precisely the group I want them to learn about and appreciate.

Cycloneda sanguinea