A photo has been circulating this week that suggests that this is what our grocery stores will look like without bees:
Is that true? Is this our life without bees, come the future Beepocalypse?
A fruit is, essentially, a delicious plant ovary with embryos (seeds) inside. It’s how plants reproduce. Bees and other pollinators serve as plant sexual surrogates by spreading pollen (plant sperm!) around to flower ovaries. A fruit tree flower has to be pollinated to “set fruit” or begin to create the plant embryos that will become apples.
Some fruits are self-pollinating, and can fertilize themselves without any bees involved. The Navel Oranges seen in the photo above are a good example of a fruit that can self-pollinate. Most fruit trees–pears and apples in particular–are self-sterile for their own pollen. If you plant all Royal Delicious apples, for example, you won’t get fruit, with or without bees. Just as we don’t often marry our cousins, apple and pear trees require cross-pollination with “pollinizer varieties” that are not closely related to produce a full crop of fruit.
So it’s certainly true that loss of bees and other pollinating insects would limit our fruit choices. But what would happen if bees went away all together?
Actually, we already know what raising fruit without honey bees looks like. In a remote area in China, humans pollinate 100% of fruit trees by hand. Armed with pollen-loaded paintbrushes and cigarette filters, people swarm around pear and apple trees in spring, replacing bees as pollinators. The reason why they do that, though, is more complex than just “the bees died.”
There’s a fair amount of data about the history of human pollination, and the reason it happens in China has as much to do with economics and apple biology as it does with missing bees. In the early 1990s, farmers of marginal lands in the Hindu Kush Himalayan region–an area spanning parts of Nepal, China, Pakistan, and India–realized that apples could be a major cash crop. Their land was mountainous and hard to farm, so tree fruits were ideally suited to the region. A major shift occurred from subsistence farming to fruit crops. The payoffs were large–in some areas, farmers quadrupled their income. Now they had cash on hand to send kids to school and build roads. Quality of life improved.
With that early success, farmers found that certain varieties of apples and pears sold better than others. As new orchards went in, more and more of the same cultivars of apples were planted. And that is when things started to go wrong.
Clearing marginal forested lands for more agriculture destroyed nesting and food resources native pollinator species needed. The problem with insects as commercial pollinators is that they can’t just appear for 2 weeks, pollinate your plants, and disappear. They have to have something to eat the rest of the year, and a place to live. Clearing mountain forests got rid of habitat that pollinators needed.
Farmers planting new trees in their orchards made a logical economic choice: plant more trees that make marketable fruit. The consequences of that choice, though, were that fruit set was poor. Most of the trees they planted were the same variety, so were self-sterile.
So farmers added a few of what are called “pollinizer” trees–trees that serve as pollen donors. Pollinizer varieties usually don’t have pretty fruit, which means that farmers are giving up potential income if they plant them. The recommended mix of fruiting trees and pollinizer trees in orchards is 70:30. In most fruit orchards in this region, less than 10% of the trees were pollinizer varieties. Worse, you can’t just randomly pick two different kinds of apple or pear trees and have them be cross-fertile. (This compatibility matrix gives you a sense of just how complex choosing two pear cultivars to grow can be.) Your pollinizer variety also must bloom at the same time as your fruit variety–pollen needs to be used while it is fresh, and can’t be stored. So even with plenty of bees, fruit production was very low, and in some areas crops failed completely.
Another perfectly sensible economic decision made by farmers was to spray pesticides often to have better looking fruit, which commanded a better price. A perception that the problem with poor fruit production was caused by pest insects also encouraged more spraying. Just as in cultivar selection, this had unforeseen biological consequences. Poor pollination due to pollen incompatibility was made worse by killing off pollinating insects.
In 1999, the problem of poor fruit set was widespread throughout the Hindu Kush regions of Nepal, China, Pakistan, and India. Hand pollination was widely practiced through this region. However, by 2011, only apple growers in the Maoxian region of China were still hand pollinating. What was different about China that made hand pollination persist?
In Nepal, India, and Pakistan, the government and NGOs provided support to help promote using native pollinator species, as well as provided training and education about managing pollination. Planting of native host trees that provided nectar to support colonies through the harvest year was encouraged. Bees are now an important part of local economies, and hand pollination is now rare.
In China, officials promoted and offered training in hand pollination, rather than offering information about native pollinators. That’s not the only reason hand pollination persisted, though–100% of apple crops in the Maoxian region are pollinated by hand because it makes economic sense. By using humans as pollinators, the number of pollenizer trees that have to be planted can be minimized, and valuable land isn’t used up for non-productive trees. Fruit set is also much higher with human pollinators–every flower is fully pollinated and can become fruit. A person can pollinate 5–10 trees a day, depending on the size of the trees. Farmers pay their human pollinators US $12–19/person/day. The cost of renting a bee colony for pollination in 2010 was US $46.88/day.
Why are bees so expensive in Maoxian? Honey bees are still present–up to 50% of the fruit farmers surveyed in the Maoxian region in 2011 also kept honey bees! Bees are still viewed as primarily a honey-producing species in this region, so the connection between bees and pollination is not strong. Farmers in this region of China are uninformed about the effects of pesticides on bees–half of apple farmers surveyed did not know that pesticides would kill bees. The Maoxian region also sprays pesticides more often than other regions where pollinators have recovered. Most Maoxian beekeepers will not rent their hives to orchards, since the pesticide sprays continue during bloom season and they risk losing their entire hive.
One last additional factor is making things difficult for farmers: Global Climate Change. Frequent rains, low temperatures, and cloudy weather affect the number of days that plants flower and the times that pollinators can fly. Changes in flowering time also means that fruit trees and their local pollinators may not be in sync, which makes a mismatch between pollinator and plant timing more likely in an already strained system. Humans are more effective pollinators than insects under these adverse conditions.
What can North Americans learn from China’s pollination failure?
The story of hand pollination in China illustrates what a failure to understand natural ecosystem services looks like. Ecosystem services are things the earth does for us for free: Oxygen is produced; water is filtered; and plants are pollinated. When parts of an ecosystem are removed, it stops functioning the way it has in the past.
Problems with bees, agriculture, and pollination are deeply related to issues of habitat loss, global warming, and basic plant biology. Pesticides are a problem in bee deaths–for all bees, not just honey bees. But just getting rid of all pesticides will not solve our bee problems, and pesticides are only part of the story of human pollination.
In the most recent US honey bee reports from the winter of 2012-2013, 31% of hives failed in the United States. It wasn’t Colony Collapse Disorder or poisoning that was the problem, though–most of the bees starved. A summer of drought that reduced honey storage combined with odd winter weather stresses bee hives. It doesn’t help that corn, soybeans, and golf courses are not nutritious food sources for honey bees. We also know that incredible losses in native bee diversity are happening–in one study, 50% of Midwestern native bee species disappeared over a 100 year period.
Is China’s experience a picture of our future without bees? Probably not. But preserving our pollinators and pollinator habitat will be critical to keeping our food choices diverse. This Pollinator Week, consider planting some food for bees, or setting aside some nesting space for native bees. Check out this huge resource center for North American plant lists, nesting guides, and more.
This poster created by a pest control company claims to show dangerous American spiders. It is full of bad information. Half of the species on this chart don’t even occur in the USA. Please, don’t share it anymore!
Please don’t rely on this chart for meaningful information about American spiders. This chart is the result of a clever company re-purposing something they put together for Australia. Seriously; the Australian spider chart is exactly the same! And, frankly, the info isn’t all that accurate for Australians, either.
This post will address the parts of this poster that are wrong (pretty much all of it), and then suggest some resources for accurate information about American spiders.
Info that is completely wrong on the poster:
- Mouse spider: does not occur in the US. Mouse spiders are not aggressive, and often “dry bite” when disturbed. In other words, most of the time they don’t even inject venom!
- Black House Spider: does not occur in the US. Also, known to be timid and not dangerous.
- St. Andrew’s Cross Spider: Does not occur in the US. Harmless.
Info that is mostly wrong on the poster:
- Hobo spider: the species pictured does not occur in the US. We have some spiders called hobo spiders, but they are not the same species as the Australian one with a scary bite. Introduced hobo spiders in the US don’t seem to have venom as toxic as the rumors. In fact, a recent study of the introduced hobo species found they were fairly harmless.
- Brown Recluse: This is actually a complex of up to 6 different species of spider, and they do not occur in all areas of the US. There is a complex mythology about the bite of the brown recluse. Research suggests that the bite, while not pleasant, is not a pathway to nasty necrosis. A lot of other things cause necrosis of the skin, which is often blamed on a hapless spider.
- Wolf spiders: Lots of wolf spiders occur in the US, but they are of minimal medical importance. No serious medical consequences of a wolf spider bite has been reported, and their bite is not painful or toxic.
Information that is slightly right on the poster:
- Garden orb-weaving spiders do occur in the US, and are beneficial and harmless.
- Huntsman spiders: the species in the photo does not occur in the US. We have some huntsman spiders, but they are much more modestly sized than the Australian and tropical versions. Harmless unless provoked, and even then pretty harmless.
- Trap Door spiders do occur in the US, although not the species pictured. They are harmless and fascinating!
- Black Widow Spiders do have a toxic bite, and do occur in the US, but that’s about as far as the correctness goes. There are 5 different Widow species in the US, and Black Widow bites are not lethal to humans. In fact, as of 2011, there are no known reported deaths from black widow bites in the US. Black widow spider bites can cause muscle cramping and abdominal pain in some people; pregnant women and children are most at risk.
To sum up: This poster is unhelpful and mostly filled with bullshit with regards to US spiders. Don’t rely on it, and don’t share it.
How can you know what information online about spiders is good information?
Easy! Go to your local Extension website. In the United States, every single state has an Extension service (or did until state budget cuts a few years ago, anyway).
“Each U.S. state and territory has a state office at its land-grant university and a network of local or regional offices. These offices are staffed by one or more experts who provide useful, practical, and research-based information to agricultural producers, small business owners, youth, consumers, and others in communities of all sizes.”
The Extension Service is charged by the USDA and each state government with producing factual, well-researched information for consumer use. You can tell you are on an Extension website because it will be affiliated with a land-grant university, and have a .edu web address. So, for example, searching for “Nebraska fact sheet spiders” gives me this information specific to that state (and also some tips about keeping a wolf spider as a pet!).
There are amazing, free resources available to you. Use them! And look for that .edu web address. Don’t listen to stories of a friend who knows a friend who lost their Aunt Gertie to a giant toxic banana spider that was in a pack of underpants. Seek out reliable information.
Some actual helpful, authoritative resources about American spiders:
- Spiders do not bite. Some common sense about spiders from an expert. A Must Read!
- Real, peer-reviewed info about American Spiders
- Common spiders of the East Coast
- Seriously, you weren’t bitten by a brown recluse
- How to identify a Hobo spider (PDF)
- Sac spiders don’t really make webs in your scrotum.
A personal note:
I just finished a move across country. As part of this move, I had to clean out the space behind my washing machine. I was hunkered over shelves, trying to wipe things off, and when I stood up I’m fairly sure that my entire head was covered in cobwebs. I…may have let out a sound of a frequency last produced by Little Richard hitting one of his high notes.
I mention this to let you know that even bug people get the heebie jeebies around spiders sometimes. It’s ok to not like spiders as long as you remember the vast majority of spiders are your friends. You don’t have to kill them! They are valuable (and free!) pest control for your yard and garden. Unless there is something seriously wrong with your personal hygiene, spiders have no interest in living on you or in you. Try to live and let live.
There’s been a lot of reporting about new research about the insect repellent DEET this week. Unfortunately, some of the media didn’t quite get it right. Headlines like this one were common…and completely wrong.
The media coverage left a lot of people confused about DEET, and if it still worked. The results of the research were a lot more nuanced than “DEET suddenly stopped working so we are all screwed.”
Here is what the average person being bitten by mosquitoes needs to know, condensed:
DEET still works fine. It’s still one of the best insect repellents out there. We know a way it might become less effective now, as demonstrated in the laboratory.
The un-condensed version:
DEET is one of our oldest and best insect repellents. It’s universally acknowledged as the best repellent around, and has broad activity against several types of biting flies and ticks. This is why a problem with DEET is big news–it’s invaluable in preventing transmission of several different diseases.
Amazingly, scientists are just beginning to understand how DEET works, even though it’s been in widespread use for 50 years. We know it stops ticks and mosquitoes from biting, but the exact mechanism of how that happens is still not clear. Does it make us ‘invisible‘ by blocking mosquitoes from smelling? Does it smell horrible to biters? It’s still not settled science yet.
That’s important to know, since if we know how something works, we can copy it and try to make new and better controls. There is always a concern with evolution of resistance in insects–they are commonly used to study genetics and mutations for a reason. Insects breed fast, and they breed often–which means that small genetic changes, if they are helpful at keeping a bug alive and having sex, can spread quickly through a population.
Resistance to DEET, our most powerful and broad spectrum insect repellent, would be a very bad thing. And so it makes sense that entomologists interested in human health would be studying how DEET works.
Evidence of genetic resistance to DEET in mosquitoes has actually been around since 1994. In 2010, researchers found that they could increase the frequency of a gene that made mosquitoes ignore DEET to 50% in a couple of generations. That’s alarming, but that was in a laboratory-bred colony.
‘Laboratory-Bred’ is an important distinction for both that study and the recent one. Mosquitoes in a cage have only one source of food (often the hapless graduate student that is rearing them). They can’t fly off and look for other people or animals to bite. It also means that their sexual choices are limited to other mozzies in the cage, so resistance can evolve more quickly that it would out in the wild where they have a wider choice of hookups.
Scientists use work in the lab to model the real world. It helps us understand how organisms grow, change, and respond to their environment. That doesn’t mean that it’s a firm prediction of what will happen out in the larger world, especially with a group as diverse and wily as mosquitoes. That’s why I think headlines like the one at the top are irresponsible, and mangling the message of the research.
You can see an interview with one of the researchers here; note she is careful to repeat that we should not discard DEET wholesale on the results of this research!
“What this work indicates is that there may potentially at some point in the future be some problems with the repellents that we have, that we need to be aware of in advance. Possibly we can use this information to alter the repellent DEET to make it more effective, it may also help us in finding new repellents because we will know if [mosquitoes] are able to overcome certain things……Even though repellents are working fantastically at the moment, what this tells us is maybe how to prevent problems cropping up, and how to alter things for the future to make them more effective.” [emphasis mine]
- CDC list of recommended insect repellents
- Mosquito repellent clothing (uses a different chemical than DEET)
Articles referenced in this post:
- Stanczyk N.M., Brookfield J.F.Y., Field L.M., Logan J.G. & Vontas J. (2013). Aedes aegypti Mosquitoes Exhibit Decreased Repellency by DEET following Previous Exposure, PLoS ONE, 8 (2) e54438. DOI: 10.1371/journal.pone.0054438.t001
- Ditzen M., Pellegrino M. & Vosshall L.B. (2008). Insect Odorant Receptors Are Molecular Targets of the Insect Repellent DEET, Science, 319 (5871) 1838-1842. DOI: 10.1126/science.1153121
- Jaramillo Ramirez G.I., Logan J.G., Loza-Reyes E., Stashenko E., Moores G.D. & Vontas J. (2012). Repellents Inhibit P450 Enzymes in Stegomyia (Aedes) aegypti, PLoS ONE, 7 (11) e48698. DOI: 10.1371/journal.pone.0048698.t003
- Rutledge L.C., Gupta R.K., Piper G.N. & Lowe C.A. Studies on the inheritance of repellent tolerances in Aedes aegypti., Journal of the American Mosquito Control Association, PMID: 8014634
- Stanczyk N.M., Brookfield J.F.Y., Ignell R., Logan J.G. & Field L.M. (2010). Behavioral insensitivity to DEET in Aedes aegypti is a genetically determined trait residing in changes in sensillum function, Proceedings of the National Academy of Sciences, 107 (19) 8575-8580. DOI: 10.1073/pnas.1001313107
I saw this tweet a while back, and it made me awfully curious:
Is that true? Because that seems like not a very smart thing to do, if you are a large and tasty insect. Or, in this case, two large leaf-eating insects belonging to a group that specializes in being invisible to predators by looking like a stick. Two sticks having sex is the sort of thing I’d notice, anyway.
The risk of predation while you are making out–or more literally “hooking up” in the case of insects–is a major issue. You can see from this photo that a fair amount of Kama Sutra-ish contortion is needed to successfully maneuver into place. This does tend to inhibit one’s ability to run away!
Several different papers I read repeated that stick insects have remained paired for up to 79 days, but I was not able to see an actual reference with the original details. Some of the references cited date back to 1910, so not surprising that I can’t get my hands on a digital copy.
From one paper describing mating behavior:
“The Indian stick insect Necroscia sparaxes may remain coupled for up to 79 days (a record for insects)”…Intromission may occur only initially or intermittently. In either case, a substantial proportion of male time-investment is not spent in ejaculate transfer.
In captivity, Diapheromera veliei and D. covilleae pair for 3 to 136 hours and the penis may be inserted and removed up to 9 times. The genitalia are not in contact for ca. 40% of this period, and attachment is maintained by a male clasping organ.
It’s generally thought that the male hangs around in order to have repeated matings, but also to drive off other males that want to get lucky. I found several reports of stick insect menage a trois (or sept) in the literature, including this etching of kinky stick insect activity. The male is–literally–cock-blocking a competitor.
So, it’s probably correct to say that stick insects can remain paired for up to 79 days, even though I can’t verify that directly. It is less correct to say that they “have sex” for 79 days, just as it would not be technically correct to say you mated for 8 hours if you had sex at 10pm and again at 6am. Well, unless you are into that tantric stuff, anyway.
Snce 1400 hours = 58 days, the numbers don’t match up, and it is not correct that stick insects mate for 1400 hours. It’s more like 1,896 hours!
Sivinski, J. (1978). Intrasexual Aggression in the Stick Insects Diapheromera Veliei and D. Covilleae and Sexual Dimorphism in the Phasmatodea, Psyche: A Journal of Entomology, 85 (4) 405. DOI: 10.1155/1978/35784
Once again, It’s time to celebrate the little animals that…facilitate plant sex by moving plant sperm around.
I’ve discovered over time that a lot of people don’t actually know what pollination is, other than it’s something that’s needed to get fruit. That’s certainly true; apples, bananas, blueberries, melons, peaches, pumpkins, almonds, and a whole bunch of other plants need to be pollinated for us to get the food we like.
That’s the what of pollination. But the WHY seems to be left out. Plants need lovin’ too, and the options for them to get their freak on are somewhat limited. It’s tough to “throw a leg over” when you don’t actually have any legs.
Pollination = sex for plants. There. I’ve said it.
Sure, you can toss your pollen out on the wind and hope it lands in the right place. And for a lot of plants, evergreens in particular, this works just fine. Most spring days my car looks like there was a pine tree bukakke fest.
That methodology results in a lot of wasted gametes (plant sperm) though, so for nearly all flowering plants, insects or other pollinators are needed for plant nookie. Think of bees and other pollinators as little flying plant wangs.
Most flowers contain both male and female sexual parts, and while plants can self-pollinate, it’s a lot more
enjoyable productive to have a second (or third…or fourth…) party involved. Cross-pollination also reduces inbreeding.
Plants attract insect pollinators with lovely colorful displays, special smells, and gifts of nectar or extra pollen that makes a nice snack. And in return plants receive a sort of sexual courier service. This partnership has been going on for over 100 million years, and has resulted in amazing modifications in both plants and animals.
Without pollinators, some of the finest things in life would not exist:
All brought to you by a bug-facilitated bonk.
The Xerces Society has many free and wonderful publications on how to plant habitat for pollinators. Why not check those out and establish a horizontal hula zone in your backyard? And don’t forget to give your sweetheart a bouquet of plant genitalia.
(yes, this is a repost of last year’s Pollinator Week essay, mostly because I didn’t have time to look up new euphemisms.)