A stingless bee worker, preparing to fly. (Tetragonula carbonaria)
While at the IUSSI conference in Australia this summer, I got the chance to tour some stingless beehives. It was a really lovely experience, and the thing I was most struck by was how small these little bees are! When we approached the hives, the air was busy with an active cloud of small, black insects that looked more like small houseflies than the bees I was expecting. These stingless bees, sometimes called “sugarbag bees” or meliponines, are cousins to the familiar European honeybee. Both species belong to the family Apidae and the subfamily Apinae, but the sugarbag bees are members of the tribe Meliponini, whereas honeybees are in Apini.
Inside the hive of Tetragonula carbonaria, a stingless bee. The brood mass is visible in the center, the honey-storing resin pots to the left, and the yellow pollen baskets to the right.
Sugarbag bees are native to Australia, and generally dwell in small cavities, such as hollow logs, rock crevices, or even underground. As such, many species can be kept rather easily by humans, in small hive boxes not much bigger than a shoebox. The bees have reduced stingers, which are incapable of stinging. Although they can bite, with their mandibles, they are fairly unaggressive. The beekeepers opened several hives for us and allowed us to look at the comb structure, and the swarming bees seemed utterly uninterested in their human invaders. The comb of these bees is particularly interesting, as eggs are provisioned in closed pods rather than larvae being fed and cared for by workers as is the case in honeybees. The pattern by which the bees advance the “brood mass”, or comb, varies from species to species, from the spiral seen above to more organic, serpentine patterns. (I have pictures. I have so many pictures. A topic for another post.)
A newly eclosed stingless bee worker, with sisters visible still in their cells. (Tetragonula carbonaria)
The sugarbag bees make a honey that is lower viscosity and more liquid than that of European honeybees. It’s quite delicious, and varies a lot between species and depending on what the bees have been feeding on. The bees make The beekeepers told us that stingless bees are apparently becoming a popular “pet” in Australia, with most people keeping them more out of interest than for their honey. In fact, our tour guides had recently made the switch to primarily rearing hives for sale, and such hives sell at about $400AUD.
I sat in on a introductory entomology lecture about cockroaches this week, so this seemed like a good topic. Above you see my least favorite insect and also my frequent friend and visitor for night time assays in the greenhouse this past summer, the American cockroach.
I like this picture because it shows off a lot of great cockroach adaptations: the flattened body for fitting through tight spaces, the head tucked defensively under the pronotum, with the eyes wrapped around the top of the head for good vision in this postion, the long delicate antennae for sense perception in the dark, and the cursorial legs for running at high speeds.
My feelings about cockroaches have evolved since I entered entomology, and while I still don’t welcome them in my house, I now consider them fairly interesting to observe in other places and I even keep a small colony of hissers. I think I crossed a hurdle while I was desperately collecting insects for my class collection during my own introductory grad student course. After months I had somehow managed not to encounter a single cockroach of any species, which left me down an entire order. When I finally saw one of these large ladies scurrying across a pavilion floor I jumped on it with my bare hands. (In terms of weird cockroach collecting methods this still does not top the dinner doggy bag incident.)
Pyrophorus sp. click beetle collected in Argentina. (aka Deilelater sp.)
Here’s a cool beetle I found a while back, all the way down in Argentina. This is a member of the family Elateridae, the click beetles, so named for their snapping/jumping defense mechanism. Click beetles are cool enough that I really ought to give them their own post, but for now I’ll just direct you to Ted McRae’s recent excellent post on the subject. There are tons of species of click beetles, all pretty easily identifiable by their elongate shape, back pointed pronotum, and the mesosternal spine they use to go click.
This particular click beetle has an extra trick up its sleeve.
Pyrophorus sp. click beetle with glowing eye spots on pronotum.
The glowing click beetles are a genus (recently revised into several genera) notable for the two glow-in-the-dark spots on their pronotum. Several species are native to the Southern US. In researching these beetles I find a mixed bag of explanations for why they glow. The adult beetles bioluminesce at night, and this light, which can vary in color from species to species, is involved in species-specific recognition cues in mating, much like fireflies (Feder & Valez 2009).
The eyespots also brighten when the beetles are startled, suggesting a warning, anti-predator function. Facultative aposematism (warning colorations that are only sometimes used) can be especially useful when an organism has different categories of predators, some of which will find it distasteful and learn to respond to warning coloration and some of which will not (Sivinski 1981).
Finally, both the larvae and the adult beetles bioluminesce and the light may also function as an attractant for small insect prey, particularly for the larvae. (My source for this last bit is Wikipedia. Make of that what you will.)
I posted a while back on maggot art as an outreach activity, and in that post I made the claim that adult hairy maggot blowflies are quite lovely. My friend (and forensic entomologist) Meaghan Pimsler has come to the rescue, providing a gorgeous set of photos in defense of this claim. She was also kind enough to give me some additional information on the biology of these interesting flies.
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Chrysomya rufifacies, the hairy maggot blowfly is invasive in the US, and native to the pan-Asian region. They are of interest to forensic entomologists partly because the young maggots are predators and cannibals. The adult flies often lay their eggs on carcasses with fly eggs of other species so that their offspring can feed on the other maggots. Not only does this set up some interesting ecological interactions between the invasive species and native flies, but the patterns of colonization of various flies help forensic entomologists to determine time of death for corpses.
Iridescent green-blue-gold coloration of the adult hairy maggot blow fly.
Interestingly, these flies have monogenic sex determination, meaning that each female will lay only male or only female offspring. Also, hairy maggot blowflies are not very cold tolerant, and so each year they start out confined to the southern US states, and then successive waves colonize farther north. They can reach as far as Canada before it gets too cold for them.
Who could say no to this cute face?
On a less attractive note, in Australia and Thailand, where these flies are considered native, they have been recorded to cause myiasis in both humans and animals. Myiasis is a really lovely (I’m just kidding; it’s gross) parasitic infection wherein fly larvae develop in the tissue of a living mammal. In the case of humans and flies, this is most likely to mean maggots infesting a open wound, although a few types of flies (most famously the botfly) can burrow into unbroken skin and develop under the surface.
A group of hairy maggot blow flies viewed under a scope.
Google search activity for “fire ant” and “wedding gift” show a strong correlation. (via Google Correlate)
While playing with Google Correlate recently, I discovered that lots of people tend to search for the term “fire ant” at the same times when lots of people search for the term “wedding gift.” In fact, with regards to being the search term most strongly correlated with “fire ant,” searches for a “wedding gift” rank second only to searches for “fly traps.” (I am uncertain if this latter represents an urgent need for pest control solutions or carnivorous plants, but I wish people luck in their quest.)
What does this mean? Do fire ant stings somehow induce people with a desire to form government-recognized pair bonds, or at least acquire gifts for such events? Does the proliferation of wedding cake cause outbreaks of ravenous stinging ant populations? Could the fire ants themselves be the ones searching for the perfect, tiny wedding gift?
Or, more likely, does this correlation highlight the strongly seasonal nature of both these phenomena? I’ll let you judge that for yourself and also tell you that the answer is that last one. In fact, fluctuations in fire ant and wedding gift searches are more likely affected by fluctuations in temperatures, weather, and times that are convenient to fly in-laws across the country. These similar direct causes (with the exception of vacation time and airfare, which fire ants tend not to worry about) probably lead to the indirect correlations. This is a fun reminder that establishing causality can be challenging, and statistics must be interpreted with care.
Judging by the graph of search activity, the need to deal with both weddings and pesky fire ants peaks in summer months and tapers off sharply in the cold of winter, when presumably both ants and prospective happy couples go dormant for the winter.
Other notable seasonal search terms that correlate with “fire ants”:
0.8307 – kentucky bluegrass (I assume the lawn sod and not the music genre)
0.7859 – snake identification (snakes form a large subset of the list, which I take as evidence that life’s unpleasant venomous biting things come in clusters)
“Wedding gift” on the other hand tends to correlate extremely strongly with terms involving golf, for reasons I will leave to some other scientist to explore.
A wingless phorid fly from an army ant raiding column under magnification.
Here’s a pretty cool little critter. This strange-looking bug is actually a wingless phorid fly that we captured running in a column of army ants in Arizona. Army ants are somewhat famous for hosting a wide variety of myrmecophiles.
Carpenter ant pupa cocoon and first instar larvae.
Ants, like butterflies, are holometabolous and go through complete metamorphosis with an egg, a larva (~caterpillar), a pupa (~chrysalis/cocoon), and adult ant (~butterfly). In ants, the larvae resemble small white grubs and cannot move by themselves–they are fed and tended by the worker ants.
Carpenter ant first instar larvae viewed under magnification.
The larvae are covered in fine hairs which help them stick together in clumps, making it easier for adult workers to move and tend them. In fire ants, these hairs also help with rafting behavior, because they can trap a layer of oxygen around the larvae, helping them breathe and making them extra buoyant. Rafting fire ant colonies use their babies as tiny floatation devices. Please take a moment to consider the wonder of nature.
As they grow, the larvae molt several times, and each growth stage is referred to as an instar. The larvae pictured above are extremely tiny because they are first instar larvae, having only recently hatched.
A pupating carpenter ant larva after spinning her cocoon.
When the larvae are old enough they prepare to metamorphose into adults. Some ants, like these carpenter ants, spin themselves into cocoons to pupate, while others, like fire ants, leave their pupae exposed. Above, you can see an opened cocoon that contains a larvae that has not yet molted into its pupal form.
Additional fun fact: ant larvae have a closed digestive tract (I assume to prevent them from making a mess all over the colony. It’s like the ant equivalent of diapers.). They poop for the first time when they molt into pupae. Best line from a paper ever: “…the larva defecates for the first time…. Workers help out.” (Taber, 2000). This is also the least appealing job description.
A carpenter ant pupa in her opened cocoon.
While the job of the larva is eating and growing, the job of the pupa is developing–reorganizing its system into an adult ant. Ant pupa look basically like unmoving, pale adult ants, darkening up right before their final molt to adulthood. The newly molted ants are still fairly pale and soft-bodied. They are referred to as “callows.” Their exoskeleton darkens as it hardens, until they are prepared to go about the daily business of an adult worker ant.
Adult carpenter ant worker.
PS: Here is a cool video of a queen ant helping a pupa shed its old larval skin.
Harvester ants fight while a freeloader fly awaits the spoils of war.
I snapped this picture of fighting harvester ants in Arizona, and it wasn’t until I could see the images under the camera’s magnification that I was able to notice a few cool details. First, please note that this is not in fact, two harvester ants fighting, but rather two and a half ants fighting. These ladies are tenacious in battle. Second, as I glanced through the series of pictures of this encounter I realized that one of the ants had a passenger. (Or, perhaps, was showing off her lovely living hat.) Paul Lenhart clued me in to the really interesting bit of biology playing out here.
Harvester ant tug-of-war, with freeloader fly looking on.
The fly riding out the fight atop one of the ants’ heads belongs to the family Milichiidae, the freeloader flies. These very small flies are best known for the members of the family which make their living as commensals or kleptoparasites of predatory insects. The adult flies hang out near predators, such as spiders or assassin bugs, and sometimes even ride along with them (attendance) awaiting the opportunity to sip up fluids exuded by wounded prey.
Freeloader fly rides out a fierce ant tussle.
Much like mosquitoes and blood-feeding, in many species only the female exhibits this parasitic behavior, presumably because she needs a high protein diet to lay her eggs. Some myrmecophilous species (ant-loving) have developed such a specialized relationship they even directly solicit ants for food via regurgitation or have larvae tended by worker ants in the nest. In some cases this interaction takes the form of a “mugging.” The flies pursue an ant, and, if they can successfully grab hold of the head by gripping the end of the antennae, the ant will then freeze and the fly can extend its proboscis into the ant’s mouth and trigger the regurgitation reflex (Wild & Brake, 2009). As always, Alex’s pictures are impressive, so if you can’t access the paper figures definitely check the subset in his gallery.
Fire ants are the little devils that we here in the south love to hate. As such, there’s a sort of popular mythology that has risen up around them and the methods for getting them to go away. Browsing forums around the net you can collect these bits of entomological folklore by the dozens. Some of them are useful and some… not so much.
Blow ’em up
For example, there’s the ever-popular “grits will make things explode” theory as applied to ants:
“i heard that corn meal (ya know the stuff you can use to make corn bread) is something i heard kills them, they bring it to their nest … and they eat it, but they cant digest it so they explode (not literally, i wish they did though) so they just bloat till they die.”
Leaving aside the likelihood of grits causing anyone to explode there is one gaping flaw to this “common sense” theory. While corn grit is used as a foundation for several commercial baits (such as Amdro), the key ingredient is the poison-laced oil the ants lick from the surface of the grits. In fact, due to a sieve plate in their mouths and a constriction in their gut, most adult ants cannot chew or swallow solid food. Instead, this job falls to the older larvae, who chew and partially digest solid food brought to them by the workers before sharing it via regurgitation.
Sorry, Amdro artist, that’s not quite how it works.
Death by explosion seems to be a popular predicted outcome of various home remedies… possibly a case of vengeful sadism in response to one too many painful bites. Still, artificial sweetener?
“The local news put a story about using Equal sugar substitute (I think it is in the blue packages?) on ants – it makes some ants explode. So, it’s bad for people and for ants.. go figure!”
I, personally, have never managed to make ants explode (and believe me, I’ve tried*). According to Snopes this misconception arose around the same time as a satirical article which claimed that aspartame was first developed as a pesticide before companies “realized they could make a lot more money on it as a sweetener.” That is to say, it’s a hilarious suggestion, but not true.
Doesn’t mean there aren’t videos about it, though.
…a few explosions would improve this immensely.
Spice things up
“When I lived in Florida, I used powdered cinnamon on the the mounds that were near plants I wanted to work with. This would keep them from crawling out of that mound until a good rain washed it away, then they would come out of there again.”
I can’t speak from any personal experience of fire ants interacting with cinnamon (although one researcher found the cinnamon treatment actually increased ant activity compared to untreated colonies). There’s another flaw in this methodology, however.
If you watch a fire ant mound you will observe very little activity of ants coming and going from the body of the mound. In fact, few people realize that fire ants use complex networks of underground tunnels for much of their foraging activity. A single large colony may have more than a hundred meters of underground tunnels criss-crossing its territory like a subterranean highway system, the entirety of which it can construct (or reconstruct) in under two days (See Tschinkel’s The Fire Ants). You may have noticed lines of excavated dirt from these tunnels running along the ground after a rain. Such tunnels allow the workers to shelter from enemies and the heat of the day as they fan out in search of food. Workers will even sometimes partially bury or cover over food resources they find. (This is inconvenient for the researcher attempting to count foragers visiting sugar vials in the field.)
Kill them with kindness
Speaking of sugar vials.
“Fire ants hate sugar. If you have ever tried putting out a sugar bait for fire ants, you know what I mean. They will walk a mile to avoid some sugar.”
This is my personal favorite because it is pretty much the complete opposite of true. Fire ants LOVE sugar. Yes, they are opportunistic omnivores, and yes, they will scavenge on almost anything made available to them, and yes, proteins and lipids are pretty essential to the development of their young, but simple sugars are tops in terms of maintaining an energetic, active workforce which promotes colony growth. (Also applies to humans.)
“Your fire ants are different from ours. Ours will absolutely NOT go anywhere near anything sweet. They only eat protein here.” (San Antonio)
Unless your type of fire ant is, say, a completely different species of ant, it’s unlikely the underlying biology and metabolism could accommodate such a radical shift in dietary preferences. I’ve personally sampled fire ants across Texas, Mississippi, and even Argentina with both sugar and cricket baits, and let me tell you the sugar baits are hella popular.
Fire ants even seek out natural sugar resources, such as visiting extra-floral nectaries on plants (essentially sugar glands) or milking honeydew from aphids and other hemipterans.
Fire ant drinking at cotton extrafloral nectary.
Poison their fields and sabotage their supplies
A few of these sugar-based fire ant prevention tips recommend spraying sugar water, or watered-down molasses across your entire property, positing that this will promote microbial growth in the soil and drive off fire ants.
“The use of molasses actually stimulates the micro organisms in the soil, and this activity will drive away fire ants, actually, any type of ant.”
“If you spray or soak their mounds with anything sugary, the decomposition process speeds up on their food supply. The fire ants know this and will abandon a mound contaminated with sugar.”
I honestly can’t answer if there might be some kind of multi-tier effect whereby increased microbes or mold could in some way affect fire ant populations. I dug through the literature but couldn’t find any study supporting this at all. Color me skeptical. If you’d like to draw your own conclusions, here are the few factoids I did dig up:
Activity for ant mounds treated with molasses was not significantly different than control mounds at any time (Vogt et al 2002).
Sinzogan et al recommends spraying mixes of water and sugar or molasses over fields to attract ants and enhance their foraging activity (2006).
Molasses has been used to control soil nematodes (Schenck 2001).
Molasses treatments may be good for your plant roots (Welbaum et al 2010).
I’d say that sounds like molasses treatments are a win for everybody! Except maybe soil nematodes and the person trying to get rid of fire ants.
Wrath of the gods
But what about more direct (and dramatic) concoctions? Vinegar and baking soda, that old paper-maché volcano stand-by is popular as a nest drench, apparently going for the “ant Pompeii” effect:
[whoops, the previous video got taken down. here’s a different one:]
Meanwhile, a slightly less bubbly version employs club soda:
“I read where a liter of club soda will kill three mounds of Ants pour directly on ant (fire ants) and the Co2 will displace the oxeygen and sufficate them.”
Do these fizzy products actually work? Elizabeth “Wizzie” Brown at Texas A&M has actually studied the effectiveness of this suggested fire ant cure, along with many other home remedies. Unfortunately, things that sound too good to be true generally are. Of the club soda remedy Brown says, “It also claimed that the club soda would leave no toxic residue, would not contaminate ground water and would not indiscriminately kill other insects or harm pets. Pretty much all that part was true, but what wasn’t true was that it would be effective in killing fire ants, unless of course you happen to drown a few in the process.”
Set them on fire
Some people use a gasoline drench, with or without a match. I’m not even going to link or quote any examples because this is really, really ILLEGAL. And it’s hella bad for the ground water, which is even more vital of a natural resource then, say, fossil fuel. Seriously, shame on you.
Other people employ less toxic things like fire crackers and while it’s probably not a very effective tactic, it’s certainly dramatic.
Unfortunately, fizzy, flaming, or not, just dousing the mound probably isn’t going to succeed in drowning, suffocating, or exploding the colony. Fire ants are well adapted to flood conditions. Meanwhile, the mounds themselves are only a small part of a much bigger picture. Fire ants use their mounds seasonally to moderate the temperature of the brood and adult ants. It’s a great way to warm up after a long chilly night. Beneath the nest, fire ants dig long, vertical tunnels with occasional flat, round chambers for living quarters. (Dr. Walter Tschinkel compares them to “shish kebabs on a stick.”)
Seriously, though
“I have been fighting them for 20 years now. Spent tons of money and tricks that did not work. My father even tried to Pee on them. Nothing works.”
What does work? Commercial baits and toxic drenches can poison the ants, while applications of boiling water provide a non-toxic alternative. Less fatal drenches may still have some effect. (For example, orange oil was found to reduce ant activity in one of the papers above.) Fire ants move around naturally in response to environmental pressures, so sufficient disturbance may induce fire ant colonies to put up a satellite nest or relocate, hopefully to your neighbor’s yard.
Don’t feel too bad. They’ll be back.
*My mom has a particular anecdote on this topic she loves to tell. While she was at the door talking to a neighbor, 8-year-old me wandered up and asked “What do we have in this house that can make an explosion?” I then wandered back into the house. My mother decided to cut her conversation short. Early adventures in SCIENCE.
Lots! One cool example is they can form living rafts of ants to survive floods.
do katydid nymphs sting?
Nope.
carpet beetles bite
Not people. They will wreck natural fibers and insect collections, though.
do carpenter ants live alone or with family?
With family.
a bug with six legs and looks like a lady bug
Sounds like a ladybug. 😀
…or it could be a mimic, taking advantage of the ladybug’s warning coloration. There are a number of beetles (and even spiders) that do this.
small bugs in bathroom
insects that live around the toilet
bug that eat toilet paper
silver bugs in bathroom
bathroom bugs tiny
little silver bugs in my bathroom
little bugs in bathroom
silver insect, bathroom
tiny little bugs in the bathroom
bugs in bathroom
6legs2many 
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