This past summer, you and I probably shared a similar bee experience: outside on a hot day, little metallic bees stuck to your bare arm, lapping up sweat from your skin.
These bees, called sweat bees, are from the Halictidae family and are very common. Between the US and Canada, there are approximately 520 known species of these shiny, and often colorful (like this Agapostemon texanus), insects. But why do they drink sweat?
Salt is necessary for egg production in insects (a female butterfly can lose more than 50% of the salt she’s born with in just one egg complement) and human sweat is absolutely loaded with it. Many insects have a hard time meeting their salt requirements, since nectar and pollen are not high in salts. This leads insects to drink our sweat, or even tears (a behavior exhibited by some bees from the Apidae family, though they may be after proteins too). Bees, moths, and butterflies will alight on the eyes of crocodiles and drink from mud puddles, feces, and urine to meet their salt needs.
In butterflies, this ‘puddling’ behavior (named for the plethora of butterflies found at mud puddles) is mostly seen in males, who transfer huge amounts of salt to females in their sperm. However female bees are commonly found drinking human sweat (which is why you may have experienced an unpleasant pinch when you try to brush one off your skin). This behavior is not believed to be harmful, so next time you see a sweat bee tell her: ‘Drink up!’
Family: Halicitinae (with: other sweat bees, alkali bees)
States: Most likely all except Hawaii and Alaska
Agapostemon texanus belongs to one of North America’s most striking genera – all Agapostemon males and females have beautiful, metallic blue/green coloration. Males and females of Agapostemon species look very different (a phenomena called sexual dimorphism). Male abdomens are yellow-and-black/brown striped while female abdomens are consistently metallic and blue-green.
Of all the Agapostemon, A. texanus is the most widespread, appearing from Costa Rica to Southern Canada. In the US, it is most common west of the Mississippi River. A. texanus has two generations a year, with mostly males active in the early fall and mostly females hibernating through the winter and active in spring and early summer (this split is due to a unique system called haplodiploidy).
Female A. texanus are strictly solitary, though females of closely-related species (like A. radiatus)have been found to make all their nests together in one area (called an aggregation) or potentially even use singular nests communally (A. nastus).
A. texanusnest in the soil, creating long tunnels by digging. Females search for dark spots under pebbles or leaves to construct the entrance to the nests, making nests hard to spot by parasites. Females leave their nest open during the day as they forage on a variety of flowers (A. texanus are generalists) before closing the nest entrance in the late afternoon/early evening by pushing soil up from inside the main tunnel to close the door for the night. High security area!
Nests tunnels have been found up to 150 cms deep (nearly five feet!).
Sources and Further Reading (first is freely available and has a great drawing of an A. texanus nest!):
For most of us, a highly social hive of buzzing honey bees come to mind. But this is actually only a tiny sliver of the social structural pie. Here are some (but not all) other types of organization:
Solitary: Most bees are solitary, where a single female makes her nest alone. Solitary bees lay their eggs in small cells on top of a bed of food – the egg later hatches and feeds itself. Adults typically emerge from their cells around the same time, forage, lay their eggs, and then die while larvae/pupae wait underground for the next appropriate ’emergence’ season. This means adult generations do not overlap.
Gregarious nesters: These bees often appear social, as many solitary females will nest individually, but nearby one another, in ‘aggregations’.
Communal nesters: This is when multiple solitary females all share one nest, but lay their own eggs in individual cells within that nest.
Facultatively social: These species can be solitary or social, depending on environmental cues. In one species, Ceratina australensis, two sisters will sometimes form a colony together instead of nesting alone, with one foraging and reproducing and the other acting solely as a guard.
Primitively eusocial: Here, there are reproducing ‘queens’ and nonreproducing (but not sterile) ‘workers’. Queens and workers generally look similar, and workers can sometimes replace queens.
Advanced eusocial: The honey bee colony: reproducing queens, nonreproducing, functionally sterile workers. Workers and queens do not look similar. The workers care for the queen’s young, and there are overlapping generations of adults.
Wikipedia has a great chart (bottom of page) showing the differences between terms used to describe sociality, including: Eusocial, Semisocial, Subsocial,and Quasisocial.
Grant writing is a new thing for me, so you should take all my advice with a grain of salt – but this is one piece I think might be worth considering. Grant writing isn’t really a big, scary exercise in writing and self-promotion (well, I mean, it is that too) but more importantly it’s an exercise in listening.
But who are we listening to? To answer this, we must think about who are we in conversation with as we write our grants. There can be several answers to this question – and several audiences for you to consider.
The Grant Reviewers – Imagine you have to sit down and look over hundreds of applications from, mostly, similarly qualified candidates. What would make some stand out? It isn’t likely to be that one extra paper you published – it’s more likely to be that your application was enjoyable and easy to read. When the pages fly by and your story is interesting, you’ll leave the reviewers with a far more positive impression of you, and your science. So spend lots of time perfecting the readability of your writing – the reviewers will thank you.
The Grant-granting Agency – I work as an assistant poetry editor for a literary magazine – in some ways we are a ‘granting agency’ in that we grant author’s work publication in our journal. Nothing is more irritating than reading work that doesn’t fit the stated goals of our magazine! Granting agencies likely feel the same way – if your work doesn’t fit the criteria, or address the points in the application instructions clearly, it doesn’t matter how amazing you are, you simply haven’t demonstrated you deserve this grant. Pay close attention to the wording used in the application for who they are looking to give this money to – and then use that same language to describe yourself and your work, so it’s easy to spot how you fit the bill.
Your Critics – Another creative writing tidbit is the idea of workshops; you bring in a piece of writing and distribute it to your peers, who read it and comment on it – telling you what worked and what didn’t. You usually end up with 15 copies of your work that all say slightly different things… but have some common underlying thread. Apply the same principles to your grant – send it to lots of people, those with and without experience in your field or with you/your projects, etc. The suggestions they send back will vary and you absolutely should not take every suggestion, but look for the underlying themes. Are certain sections unclear? Do you need to reorganize so your question is broader and has more impact on your field? Is the tone bogging the piece down? Listen to what your critics are saying underneath their suggestions to get to some of the real issues with the piece.
Your Cheerleader – Grant writing, maybe because it’s new or maybe because I have some serious impostor syndrome, is some hard stuff. I have to catch myself from making all kinds of qualifying, humbling statements like ‘this was a pretty big paper’ (since grant writing is all about acknowledging your accomplishments). So make sure you have a cheerleader – preferably somebody in your field but not your adviser who can tell you that you are GRRRRRREAT. It could be your mom, but would you really believe her? Find that one professional who can make you feel like others in your field recognize how awesome you are – and then read their email while listening to that ‘New Avengers’ song from ‘Avengers: Age of Ultron’. I promise, you’ll feel ten feet tall after and swagger like you’re Iron Man.
Yourself – If you can’t represent yourself in the grant application, you don’t deserve to get it – whoever you represented does. No matter everyone else’s suggestions, edits, comments, and concerns, make sure before you submit that the grant still sounds like you. No one knows your smarts, skills, achievements, creativity, humor, etc like you do – so always read that last draft with yourself in mind.
Listening is hard and takes practice – pulling out the ‘underlying concerns’ in a critic’s piece or identifying what to do to make your narrative read more easily can be difficult. Not receiving a grant isn’t actually always about you and your qualifications – there are so many nuanced reasons, especially when there’s so little money to give out and such competitive pools of applicants (that you’re a part of!). Put your best application forward, then back away from the result – and be prepared to try again.
A huge thank you to, first, Palaver Magazine for publishing this piece here on page 79, and then for Poetry in Data for also publishing this piece here (you can listen to the poem here). I must also acknowledge Dr. Wulfila Gronenberg, as this is a found poem sourced from his 1999 paper: Modality-Specific Segregation of Input to Ant Mushroom Bodies. All of the words in this poem were found in the various sections of Dr. Gronenberg’s paper and – as is the case with all found poetry – it is the essence of the source that provides the true poetic inspiration.
This paper is the foundation for my work in ant neuroanatomy (paper forthcoming, stay tuned!). There is a section of the ant brain called the mushroom bodies, which is known to be involved in learning and memory (among other complex behaviors). There are two regions (the lip and collar) which receive input from different peripheral processing lobes: the optic lobe (which processes visual information and inputs to the collar) and the antennal lobe (which processes chemo-sensory information and inputs to the lip). This study by Gronenberg compared the size and structure of the mushroom bodies across several species of ants, wasps, and different genders of ants (which have vastly different behaviors over their lives).
Based on the differences in mushroom body size between the species, Gronenberg was able to tie individual variation to species-specific behaviors and living conditions. One example would be variation in the role of vision in the ants’ lives. Ant species with reduced eyes had reduced optic lobes and mushroom body ‘collar’ regions (a region we know to be associated with the input of visual information). If you don’t have large eyes, you likely aren’t processing much visual information – so you won’t need large brain regions to deal with vision.
The collar regions of males were found, across many species, to be much larger than that of female workers; male ants fly through the air to find females and mate, giving vision a critical role in their behaviors as compared to grounded, sometimes subterranean female workers of the same species.
Gronenberg showed there was a common design among Hymenopteran (ants, bees, and wasps) mushroom bodies, as well – making this one of the earliest studies to look into mushroom bodies outside of honey bees and Drosophila flies.
On Twitter, nature-lovers will send scientists photos of an animal asking for a #WildID – or species identification. But can you #WildID a bee?
The answer: sometimes yes (but usually no).
Often bees of the same genera will look very similar (for example these two different species of male Agapostemon):
And sometimes, two bees of the same species will look very different (like the abdominal coloration of these two female Augochloropsis metallica):
This makes telling a bee’s species from a photo very difficult; sometimes the features an entomologist must look at to ID a species are hidden under hairs, or even involve dissecting the bee.
However, sometimes a photo with location data can tell us everything we need to know to #WildID – some species have very distinctive features (especially when we know where the photo was taken, and thus what species are in that range). For example the triangle of black on the thorax of Bombusfranklini (featured here),combined with information about the bee’s range, can be used to ID B. franklini with relative certainty. Sometimes even the time or flower a bee was spotted on can help #IDthatBee – if it is an early dawn forager, or a pollen-specialist that only visits a specific species.
Don’t be afraid to #WildID your next bee photo – even if the experts can’t get the species, often the next best thing (genera) can be ascertained with a glance. Check out Bees in Your Backyardto try your hand at IDing to genera, yourself!
Status: Critically Endangered, last recorded in 2006 by Dr. Robbin Thorp
Name: Franklin Bumble bee
Family: Apidae (with: honey bees, carpenter bees)
States: Oregon and California
B. franklini has experienced a sharp decline since 1998, and has not been spotted in the wild for over a decade, earning itself a spot on the critically endangered species list and a spot as the Bee Bytes mascot. It also has one of the most narrow distributions for a bumble bee in the world.
The yellow half of the thorax (closer to the head) with an inverse U shape in black can be used to differentiate it from the similar looking B. occidentalis.
Like other bumble bees, B. franklini are social; they live in colonies with a queen, who reproduces, and her daughters, who gather nectar and pollen. The colony does not overwinter.
B. franklini are generalists, meaning they can use a variety of flowers for food; like all bumble bees, they are buzz pollinators, vibrating at a high frequency to dislodge pollen from the flowers’ anthers.
A potential cause of B. franklini decline is the fungal pathogen Nosema bombi, which has been found with increasing prevalence on museum specimen from declining populations. It is possible exotic strains were introduced from Europe, due to the American agricultural industry’s use of bumble bees reared in Europe to pollinate crops.
These bees are ground-nesters, thought to live in abandoned rodent burrows in grassy meadows. A paucity of research on B. franklini means little is known about the species, making conservation efforts more difficult.
My first co-author published paper came out this summer in Behavioral Ecology and Sociobiology, and I’m (no surprise) very excited. The paper, the foundation for the kind of work I want to do in my PhD, is titled: Caste Differences in the Mushroom Bodies of Swarm-Founding Paper Wasps: Implications for Brain Plasticity and Brain Evolution (Vespidae, Epiponini), authored by Sean O’Donnell, Susan J Bulova, Sara De Leon, Meghan Barrett, and Katherine Fiocca. If you haven’t left me after the long title, that’s a good sign – let’s take a quick jog back to our eusocial basics!
A eusocial colony has several different types of individuals (called castes) which perform different tasks in the colony. In the most advanced colonies, reproducing Queens complete few tasks besides laying eggs; they rarely leave their nests, have extensive social contact with workers, and do not gather food. In contrast, female Workers don’t reproduce, complete a variety of tasks inside and outside of the nest (gathering food, feeding larvae, maintaining the nest, defense), and often act alone. It would be hard for these two groups to act more differently!
In theory, we could see how some of these tasks could differ in the demands they place on the animal’s brain. For example, flying outside and searching for food while avoiding predators might require larger regions of the brain in charge of processing visual information (called optic lobes) when compared to sitting in a dark nest all day, laying eggs.
And this is where a key ecological theory comes in – called Neuroecology Theory. This theory predicts that, because brain tissue (like all tissue) is costly to produce and maintain, evolutionarily successful organisms won’t invest willy-nilly in brain tissue they don’t need since those resources can be spent elsewhere. Instead they will invest more in regions of the brain that help them deal with the cognitive demands their environment presents – for the flying wasp, this is the optic lobes.
Imagine we are building a two story house in a flood plain. Sure, we could invest in fire-resistant materials, nuclear-grade shutters, and the kinds of steel they use to make sky-scrapers sway just right in the wind. But if we have a limited amount of money, or resources, we know we will be most successful if we address the most pressing demand of our environment and build a house on stilts, to withstand floods.
The ‘mushroom bodies’ are one area of a wasp brain, involved in learning, memory, and integrating information from the various senses. Previous to our study, scientists have shown that the relative size of the mushroom bodies (mushroom body volume as compared to total brain volume) increases with foraging behavior, the job of the workers. But scientists had also shown that maintaining social dominance via aggressive social interactions can have positive relative mushroom body size effects. This leaves us in a bit of a pickle:
Do queens, with their limited task repertoire but high social dominance, or workers, with their many tasks but decreased social demand, have larger relative mushroom bodies?
To answer this, we sliced wasp brains at a thickness of 14 microns – or 1/7 the thickness of a sheet of paper (seeleft). After setting the slices on glass slides, we stained the brain tissue a deep blue and photographed each slice – allowing us to measure the area of each region of the brain every 14 microns. By stacking all the slices on top of one another, we get a complete 3D image of the brain – and thus the volume of each of the pieces, since we know the thickness of our slices! Then, we could compare the relative volumes of our mushroom bodies in queens and workers of several different eusocial wasp species. You can see a 3D brain below.
So what did we find? In a nutshell:
for 13/16 species, Queens had greater relative mushroom body sizes than their workers
species with larger colony sizes saw larger differences in the relative mushroom body sizes of their queens and workers
These results are consistent with the idea that maintaining social dominance increases relative mushroom body investment – and adds the additional caveat that it seems to increase investment more than foraging.
The fact that larger colonies saw larger queen-worker differences in mushroom body investment may be a result of increasing ‘caste specialization’ – this is the idea that, as colonies get larger, the gap in work performed by the queen and the workers gets larger as well.
This is just one kind of question we can answer using histological techniques – we can also look at the effects of light, sociality and other behaviors, disease, body size, etc. on animal brains. All of this gives us a better understanding of how evolution works, and how different brain region sizes are selected for – or against – in different conditions.
Welcome to Bee Bytes, a #scicomm project to introduce bees to the public!
What is Bee Bytes?
Bee Bytes will be a weekly to biweekly series on my blog, where I write “bite-sized” posts about an invasive or native bee species in the United States, describing its distribution, taxonomic relationship, and a few fun facts in brief! Each post will be 256 words or less – the number of unique characters you can represent with just one ‘byte’ (and exactly as long as this post). The end will have extra resources, in case you want to look for more about your favorite bees.
I don’t get it, why bytes?
A byte is used to encode a single text-character in a computer; my ‘bee bytes’ will be used to encode a single bee in your memory!
Where can I find these bytes?
For now, get your Bee Bytes fix here on my blog; in the future, I’m hoping to make a ‘trading card style’ website where you can search the deck for your favorite bees. That can be an after-quals project.
How long will you be doing Bee Bytes?
With 4000+ species in the United States, I can write for the next 77 years or so before I cover every species we’ve got! By that time, we’ll have so much new information I might even have to start over!
4000 species? Aren’t you byte-ing off more than you can chew?
Listen, bugger – you can buzz right off with that negativity.
Check out this link for the impetus behind ‘Bee Bytes’.
Year one of my PhD program is officially over and, with the advent of the fall semester, I would like to celebrate the things that I’ve achieved in just one year. In some ways, this blog has functioned as my ‘praise journal’ – the technique I wrote about in this blog post about overcoming impostor syndrome. This past year has been very hard – a PhD is about growing as a scientist, which (it turns out) means more than just learning science; it means learning to think and work differently. This growing process is hard – my perfectionism, anxiety, and workaholism have been dangerous company to keep as my PhD has progressed. But each graduate student has their own areas of personal growth where they will be challenged during their graduate career.
This past year I’ve accomplished the following scientific things:
Taken six classes, and many online workshops
Taught two classes
Gathered brain data on over 160 specimen and counting, including spiders, ants, termites, and wasps – and helped finish three full projects for my lab, one of which is already published
Gathered microbial community data for another lab that will result in an eventual publication for them
Started working on an additional four projects for my lab, with exciting results incoming!
Made a poster on ant pesticides with my STAR mentee!
Began developing a pretty fantastic thesis proposal, if I do say so myself #justbeethings
Co-author on my first published paper (this one was big enough that it deserved to be mentioned twice)
Presented at two scientific conferences
Received two travel awards
Attended the Bee Course, 2017!
Mentored over 400 student hours between six different undergraduate students
Was the only Biology student to win the College of the Arts and Sciences TA Excellence Award
Elected to several biology leadership roles and accepted for science outreach positions
Had my #scicomm accepted for publication at Buzz Hoot Roar, The Female Scientist, and more
All in all, it was a scientifically successful first year, all while I dealt with a lot of personal adjustments and challenges. What started out slow and scary, has built to something incredible – it’s easy to see, when it’s all in one list, how much there is to be proud of from this first twelve months of my journey. Here’s to many, but not too many, more!