I have a few thoughts and some new information to share with you regarding bees and other insects, and I figured I'd gather them into this one post. None of them are connected and yet all of them are connected; I'm feeling a little scattered this morning but I'm hoping it will all evolve into a cohesive whole.
Firstly I've been wanting to share with you some new facts about honeybees and pesticides. As you know, I belong to my local beekeeping association (MDBA) and they have monthly meetings with guest speakers covering all sorts of topics. In May, we heard from a research scientist about the recent study he participated in; namely the amount of pesticides making their way into urban beehives. The effects of persistent, continuous use of pesticides in agricultural fields is well studied and known, but until now, no one had studied the effects on urban and suburban hives.
Perhaps it may surprise you to know that the amount of pesticides used by homeowners is quite high. According to the USGS, the amount of pesticide runoff in urban streams is higher than in agricultural streams. This tends to be due to user error. In agricultural settings, everyone is trained in the proper use of poisons; it is required by law. No such law is required for homeowners, and we tend to think "if a little works, a lot will work even better!" (This is true for herbicides and fertilizers too by the way.) So homeowners tend to go overboard on the amount of chemicals they use.
Anyway, this particular study was performed over two years in urban areas all over the country: Sacramento, the Bay Area, and San Diego in CA; many also in Texas, Michigan, and Florida. (Side note: This researcher worked for Bayer. You might remember that Bayer and Monsanto merged last year. Bayer/Monsanto, along with Syngenta, are the largest producers of pesticides. You may wonder why a large producer of pesticides underwrote this particular study. I did. But I also trusted that this scientist was on the up and up and reported the findings fairly, despite who paid for it. This didn't stop a general backlash by many in the MDBA community, which I witnessed when I went up to talk to him afterward; he got pretty lambasted for taking money from Bayer to perform this study. A valid concern. But one I don't want to talk about here.)
There were several guidelines regarding the location of the hives, how far apart they were from each other, how many hives each beekeeper had, etc (although all were Langstroth hives). The scientists took fresh nectar from all the hives every month, along with fresh pollen. This was done in an interesting way: The scientists requested the beekeepers to add a new frame to the hive two days before they arrived, and so whatever nectar was in those frames was fresh; and they installed a sort of brush thingy at the entrance of each hive at the same time to collect fresh pollen. Then these two products were tested for about 200 common pesticides, including neonicotinoids (systemic pesticides). Plus, they had one graduate student who, for two years, identified all the different pollens that were coming in and determined what the bees were feeding on depending on the season, which was very interesting (more tree pollens than I would have thought - don't discount trees when you're planting for bees!).
The results were encouraging, I thought. Michigan had the worst amounts, but they still weren't terrible. California was definitely on the 'low' side. Fresh nectar had almost negligible amounts of pesticides, but the ones that showed up the most were the systemic ones (still negligible though). Pollen had a greater amount, but still in levels well below anything that would harm humans. So of course the next question is, would that amount harm the bees? And the answer is, yes, but in an amount the researchers felt was acceptable. It's a standard ratio used for most testing of these kinds of things, and it's not perfect. They assume a certain amount of loss is okay. As beekeepers, we might assume any amount of loss is not okay. Still, the results were much better than I feared, and we don't have to worry about eating our local honey. At least here, that is.
Agricultural fields are a different story. Remember the post I wrote last week about Iowa and the lack of bees in the gardens on campus? Think about what Iowa mostly consists of - huge amounts of land are given over to agriculture, just like a large portion of the midwest. Those enormous areas (we're talking hundreds of miles) are mostly GMO corn and soy. Those areas don't have any insects at all. So it's no surprise that the local areas that do welcome insects don't have any.
Which brings me to my next little tidbit. I've been reading a great book called Bringing Nature Home by Doug Tallamy. I'm learning all sorts of things that are really no-brainers, I don't know why I never thought of them before. Or maybe I did, but I didn't truly absorb it. Like, native insects have evolved to eat and feed from native plants. Many things we plant in our gardens come from completely different countries; our native insects cannot utilize those plants. Some have adapted to eat from those 'aliens' as long as they are in the same family as their native food. But many of our plants don't have any native cousin, so when bugs encounter them, they don't know what to do with them. For instance, crepe myrtle trees (Lagerstroemia indica), which are all over the Bay Area, hail from Asia, and don't have any closely related species that are native to our area. So our native creatures cannot feed from their beautiful leaves or bark, and cannot eat any nectar or pollen it produces. Now, European honeybees can be found on these trees, but they don't love it, and it's not a first-choice food. You will not find a native bumble bee or caterpillars on crepe myrtle.
What this tells me is that a large percentage of our suburban plants should be native. As a beekeeper of European bees, I have to provide both native and alien species, so that I'm feeding everyone. I've always tried to plant 50/50, grouping things mainly by community rather than by country of origin, and now I'm glad I've done it this way. It's important to plant native species for native wildlife. Habitat loss is one of the biggest factors contributing to insect loss, and make no mistake - insect loss is HUGE right now.
Which brings me to my third 'musing.' A couple of weeks ago a friend of mine came by and we were talking about her plantings of passionflower vine for the Gulf Fritillary butterflies. She mentioned that the foliage is a little sparse on the passionflower vine, and the caterpillars decimate it, leaving none for the next batch. We both decided it's important to plant a lot of one thing if you're planting for a particular insect, because if you want the insect to eat the plant, they might eventually eat themselves out of a habitat. So don't just plant one of something, particularly if you're doing it for insects. Plant a few.
Bringing it back to the my last point, what about an interplanting of a native species in the same place? Like why not have a native clematis, say, twining up the same area as the passionflower? You'll get two kinds of blooms at two different times, and attract two (or more!) different pollinators to those flowers. Diversity is really, I think, the key. We need more species diversity in our suburban gardens, not less.
Which brings me to my last thought, which is trophic levels. This is something I have learned about recently, but maybe you learned this in junior high. Plants are autotrophs, because they can produce their own food. The rest of us are heterotrophs, which means we all rely on plants in one way or another for our food. It all begins with plants. From insects up to apex predators, if we didn't have plants to produce food for us, we wouldn't have food. Every layer is of vital importance, and insects are part of this. Think about how many creatures eat insects for food, and on and on up the trophic levels, creating what we eat every day.
I think a lot of people don't particularly like insects, and that's ok. You don't have to like them to appreciate them, and the role they play in our ecosystems. I still get a little shivery when I come across some bug I've never seen before in my garden. And even now, I have to shake myself a little and give myself a little talking to, and remember to just wait. Go look it up, figure out what it is, what it does, where its place is in the larger ecological picture. I've gotten to the point though where I welcome prey insects like aphids, because they bring in the higher levels, the predators. Remember your predator/prey ratios: There's always a lot more prey. But predators do come. And largely, my garden ecosystem takes care of itself.
Now, squirrels, that's another matter all together. I'm not sure I can ever appreciate squirrels.
So, food for thought. While you're out enjoying your garden today, spare a little time to truly think out your garden's ecosystem. Where are you helping nature? And where could you do a little more to bring nature in?