BOOK NOTE: I interrupt this book review to note that Genius: The Life and Science of Richard Feynman is currently available, again, as a Kindle book, for two bucks. And now returning to our regularly scheduled review.

Garden Insects of North America: The Ultimate Guide to Backyard Bugs is not a pocket field guide. How could it be? There are over a million species of insects and probably a lot more (huge numbers certainly remain to be discovered) and of them, some 100,000 exist in North America. I’m actually not sure how many are represented in this book, but several thousand distributed among some 3,000 illustrations, mostly color photographs.

Note the use of the word “bug” in the title. This represents a recognition that words mean what people say they mean, and to North Americans with back yards, “bug” means a lot of things beyond the “true bugs” (which make up a subset of actual insects). Not also that this book does have info on creatures that are not insects, in order to help sort out the difference among the crawly buggy things you encounter in the actual back yard.

The insects in this book are divided up by specific microhabitat and behavior traits, such as “insects that eat leaves” or “insects assocaited with stems, twigs, shoots, and canes.” I’m not sure if I would have done it that way but I’m not an insect expert. The problem with insects, and one of the more interesting things about them, is their metamorphosis. Metamorphosis isn’t just about changing from a worm to a flying object, but also, changing diet and behavior considerably. So, today’s insect associated with a twig, as a small speck embedded in a foamy icky thing, is tomorrow’s insect associated with some other micro-habitat, and a winged creature that does not even eat.

This is a big giant and very pretty book, is as comprehensive as you are going to get for coverage of insects, and so far in the limited use I’ve given it prior to the arrival of snow and ice, is helpful and works as an identification guide.

There is almost no front or back matter, but what is there is helpful. Pages 42 through 682 is all beezness. (Though the bees actually start on page 672.)

Despite its stated focus on the garden, Garden Insects of North America seems to have more coverage than my other various insect books put together, except for beetles, for which you want to see Beetles of Eastern North America, if you are east of the Rockies.

The short version: This sort of fruit fly ruins fruit crops because it prefers to, and is able to, lay its eggs on harder, firmer, unrotten, and, essentially, ripe fruit, thus ruining it. Regular fruit flies focus on rotten fruit such as groundfall.

The Asian fruit fly manages this because of slightly different fruit detection mechanisms, though some of the details of this are not yet known. In the future, it is hoped that the exact chemical used by this fly to find its target ripe fruit can be reproduced and used in the manufacture of a bait, to reduce crop damage.

The paper is:
Evolution of multiple sensory systems drives novel egg-laying behavior in the fruit pest Drosophila suzukii, Marianthi Karageorgi, Lasse B. Bräcker, Sébastien Lebreton, Caroline Minervino, Matthieu Cavey, K.P. Siju, Ilona C. Grunwald Kadow, Nicolas Gompel & Benjamin Prud’homme. Current Biology, 9 March 2017.

From the press release:

The Asian fruit fly Drosophila suzukii reached Europe and the US about a decade ago. This invasive species ravages fruit crops, including strawberries and cherries, and there is currently no effective means of staving it off. Unlike other drosophilae, which lay eggs on rotting fruits, D. suzukii chooses ripe fruits, thereby accelerating their decomposition. Researchers from the Developmental Biology Institute of Marseille (CNRS / AMU) and LMU Munich recently discovered that D. suzukii has developed greater sensitivity to the smell and taste of ripe fruit, in comparison to fermented fruit, and the ability to lay eggs in relatively firm fruit. By selectively inactivating the fly’s neurons and olfactory receptors, they demonstrated that the smell of fresh fruit enhanced D. suzukii egg laying. The scientists are now trying to identify the molecule or molecules that elicit this response. This would then make it possible to develop bait or design molecules that could inhibit egg laying. The results of their work also offer insight into how instinctive behaviors like egg laying are altered in the course of evolution.

An international team including researchers at the university of Edinburgh and Antoine Wystrach of the Research Centre on Animal Cognition (CNRS/Université Toulouse III—Paul Sabatier) has shown that ants can get their bearings whatever the orientation of their body. Their brains may be smaller than the head of a pin, but ants are excellent navigators that use celestial and terrestrial cues to memorize their paths. To do so, they use several regions of the brain simultaneously, proving once again that the brain of insects is more complex than thought. The researchers’ findings were published in Current Biology on January 19, 2017.

Until now, ethological research suggested that ants memorized the scenery perceived along their route as it is projected on their multifaceted retinas—thus using a body-centered, or egocentric, frame of reference. By this hypothesis, to recognize memorized surroundings and follow a path formerly traveled, ants would need to orient their bodies in the same way each time. But they sometimes need to walk backwards as well, and this doesn’t prevent them from finding their way back to their nest. Could it be that ants can recognize a route when facing the opposite direction? Are they able to create a visual model of their environment that is independent of their body orientation?

To answer these questions, the researchers studied Cataglyphis velox, an Andalusian desert ant known for its solo navigation ability. First they let the insects familiarize themselves with a route that included a 90° turn. After a day of training, ants that received a cookie crumb light enough to carry while walking forward handled the turn without the slightest difficulty. However, those given large cookie crumbs had to move backward, and unlike the others, they maintained their bearing instead of turning.

They also exhibited unexpected behavior: After walking backward a bit, they would occasionally drop their crumb, turn around, observe the scenery while pointing their bodies in the right direction, return to the crumb, and resume towing it backward – but this time in the correct direction. For these ants, body alignment thus seems necessary for recognition of scenery perceived by their retinas, but they are then able to memorize the new bearing and follow it backward. This behavior also shows that they can recall the existence of the dropped cookie crumb, and its location, in order to return to it after updating their bearing. These observations imply that at least 3 kinds of memory are working in unison: the visual memory of the route, the memory of the new direction to follow, and the memory of the crumb to retrieve.

Through another experiment using a mirror to reflect the sun1, the team demonstrated that the ants used celestial cues to maintain their bearing while walking backwards. Furthermore, ants were able to move in straight paths, whether walking forward, backward, or sideways. Once a bearing is memorized, they stay on it no matter how their bodies are oriented. Together these observations suggest that ants register direction using an external – or allocentric – frame of reference.

These new findings show that the ants’ spatial orientation relies on multiple mental representations and memories woven together through a flow of information between several areas of their brain. This offers a whole new perspective on the world of insects, which is much more complex than previously believed.

And now, a press note from the American Chemical Society:

Water striders’ ability to walk and jump on the surfaces of ponds and lakes has long amazed curious observers — and inspired robot designers who want to mimic the bugs’ talent. Now, scientists have measured for the first time key parameters that allow them to walk on water — by studying their leg shadows. The findings, reported in the ACS journal Langmuir, could contribute to designs for water-skimming robots.

More than 2,000 years ago, Greek scientist Archimedes explained flotation, stating that the upward, floating force on an object in water equals the weight (or downward force) of the water displaced. The principle has informed the building of ships, submarines and other aquatic vehicles. But for tiny water striders, water isn’t displaced. It is expelled by the insect’s hairy legs. The updated Archimedes principle predicts that the weight of the expelled water should equal the floating force. But confirming this prediction experimentally is a challenge. Because water striders are so light, they are almost impossible to weigh using conventional techniques. So Yu Tian and colleagues used an unconventional method — analyzing the shadows cast by the insects’ legs.

The researchers placed a white sheet of paper at the bottom of a lab aquarium housing water striders and installed a light source above the water. The insects’ stick-straight legs cast shadows that were rounded, representing the curvature of the water and the expelled water volume from which the floating force and weight can be calculated, the researchers say. Also, from these measurements, the striders’ slightest shifts in weight and body angle could be detected for the first time.

The authors acknowledge funding from the National Natural Science Foundation of China.

The abstract from the original publication:

Forces acted on legs of water-walking arthropods with weights in dynes are of great interest for entomologist, physicists, and engineers. While their floating mechanism has been recognized, the in vivo leg forces stationary have not yet been simultaneously achieved. In this study, their elegant bright-edged leg shadows are used to make the tiny forces visible and measurable based on the updated Archimedes’ principle. The force was approximately proportional to the shadow area with a resolution from nanonewton to piconewton/pixel. The sum of leg forces agreed well with the body weight measured with an accurate electronic balance, which verified updated Archimedes’ principle at the arthropod level. The slight changes of vertical body weight focus position and the body pitch angle have also been revealed for the first time. The visualization of tiny force by shadow is cost-effective and very sensitive and could be used in many other applications.

Citation: Yelong Zheng, Hongyu Lu, Wei Yin, Dashuai Tao, Lichun Shi, and Yu Tian. 2016. Elegant Shadow Making Tiny Force Visible for Water-Walking Arthropods and Updated Archimedes’ Principle. Langmuir 2016 32 (41), 10522-10528. DOI: 10.1021/acs.langmuir.6b02922

Europe has 13.4 million too few honeybee colonies to properly pollinate its crops, according to new research from the University of Reading.

The discovery, made by scientists at the University’s Centre for Agri-Environmental Research (CAER), shows that demand for insect pollination is growing five times as fast as the number of honeybee colonies across Europe as farmers grow more insect-pollinated oil crops, such as oilseed rape and sunflowers, and fruit.

Click here to read all about it.

Here’s a video:

Published on Jan 8, 2014

Europe has 13.4M too few honeybee colonies to properly pollinate its crops, according to new research from the University of Reading.

The discovery, co-funded by BBSRC and made by scientists at the university’s Centre for Agri-Environmental Research (CAER), shows that demand for insect pollination is growing five times as fast as the number of honeybee colonies across Europe as farmers grow more insect-pollinated oil crops, such as oilseed rape and sunflowers, and fruit.

More on honey bees and related topics.

Bug Girl writes a lot about this topic.

Carl Zimmer on honey bee colony collapse

Part I:

Part II:

Photo Credit: wildxplorer via Compfight cc

Navigation over long distances, communicating with other bees about newly found hard to get and far away sources of food, mechanisms of controlling reproduction within the colony, thermoregulation of the hive, building and maintaining architecture, species recognition, a mechanism of changing behavior among a number of different tasks (thermoregulation, foraging, building the hive, attacking selected invaders, swarming) … Yeah, being a honey bee is hard.

Colony Collapse Disorder (CCD) is a thing where the colonies of bees in a given area are affected by something that causes the number of bees to reduce in population over time … the worker bees seem to disappear … so the colony dies. Think about all the things I mentioned above. Any small subset of these things could be disrupted to cause something like CCD. The transfer of information about where to go to find food, and the process of foraging and navigating to food sources and back involves a lot of different mechanisms; the disruption of any one or two of those mechanisms might cause worker bees to fly off and not come back. The process of foraging at distance and carrying back food requires a great deal of energy. Any part of the process of maintenance and distribution of food to worker bees could cause them to starve or reduce in energy level, causing them to not return to the hive. Leaving most of these tasks and mechanisms untouched and operational but adding a pathogen that demands more energy from individual bees could have a similar effect. In other words, in the absence of any good information about what causes CCD, it would be very hard to come up with a simple explanation for that phenomenon on the basis of what bees do normally. The phenomenon can also be caused by any two or three of a dozen things, such that the cause in any given case could be very different from the cause in a different case.

To this we can add another feature of honey bees. For the most part, we are talking about bees that are not living in their native habitats. Our honey comes from a subset of honey bees that have been to varying degrees domesticated, and that are living in a climate that is not where they originally evolved. Imagine going to a region where chickens are grown but that is environmentally very different from the region where a chicken like bird lives normally, and deleting one or two of the key things we do to keep those chickens alive. I.e, leave all the chickens out for the winter in Montana. Not feed them. Etc. There would be “Coop collapse disorder” in no time. The fact that honey bees exist in a sort of liminal state of wildness (they forage in the wild, although the “wild” may be human maintained farm fields and orchards) and domestication (their hives are generally built and maintained by humans who may also provide heat and protection from predators) together with the fact that honey bees have undergone some degree of selection (to make them a bit less fierce, for instance) may mean that the complex web of physiological and behavioral adaptations that make bees “work” properly is somewhat more delicate than it might be for wild bees living in their native tropics.

I don’t mean to give the impression that bee experts have no idea what causes CCD. They do have ideas, evidence, and there has been a fair amount of research done (below are links to a few key blog posts that summarize much of this). The point I’m making here is that the complexity of CCD and the difficulty in understanding this phenomenon should not be a surprise.

Just now, the European Union has decided to implement a regulation that bans a certain kind of insecticide, neonicotinoid, from use in their purview, because it is possible that this insecticide has a negative impact (perhaps multiple negative impacts) on bees, contributing to CCD. This may be a good idea, even if the insecticide in question is not “the” primary cause of CCD, if the chemical simply makes CCD a much more likely thing to happen. Banning it may be like giving a patient with some horrid infection an IV of fluids. The IV is not directly treating the infection, but the patient may require the support provided by the IV (and other things they do for you in a hospital, like the great food and a TV strapped to the ceiling) may be what it takes to allow other treatments, or the patient’s own immune system, to bring the individual to a state of better health.

The ban was not universally supported. Voting against the bad were the United Kingdom, the Czech Republic, Italy, Hungary, Romania, Slovakia, Austria and Portugal; voting for the bad were Belgium, Bulgaria, Denmark, Estonia, Spain, France, Cyprus, Germany, Latvia, Luxembourg, Malta, the Netherlands, Poland, Slovenia and Sweden. Ireland, Lithuania, Finland and Greece abstained. This resulted in a vote that would not automatically institute the ban, but a decision by the controlling commission to move forward with the ban was made possible, and that is what has happened. The ban will run for two years and apply to flowering crops that normally attract bees. In a way, this is more of a giant experiment than an actual ban.

The Guardian reports:

Europe will enforce the world’s first continent-wide ban on widely used insecticides linked to serious harm in bees, after a European commission vote on Monday.

The landmark suspension is a victory for millions of environment campaigners concerned about dramatic declines in bees who were backed by experts at the European Food Safety Authority (EFSA). But it is a serious defeat for the chemical companies who make billions a year from the products and also UK ministers – who voted against the ban. Both had argued the ban will harm food production.

…

Tonio Borg, health and consumer commissioner, said: “Our proposal is based on a number of risks to bee health identified by the EFSA, [so] the European commission will go ahead with its plan in coming weeks. I pledge to do my utmost to ensure that our bees, which are so vital to our ecosystem and contribute over €22bn annually to European agriculture, are protected.”

It is almost certainly not the case that bee researchers unanimously agree that neonicotinoid is the most important cause of CCD or that banning it will work. Neonicotinoid is actually a good kind of insecticide because it works by being taken up by plants, and thus, targets invading insects selectively, and also, affects insects that are not bothered much by other insecticides because the insects bore into the plant. So, there may be some serious consequences to agriculture in Europe caused by this ban.

It will be interesting to see what happens over time. I’m not sure how long it will take for the ban to fully take effect. Since it is added to soil, neonicotinoid will remain “in use” for a while after it is no longer applied. And, even if neonicotinoid was a key cause of problems in bees, it is quite possible that other causes were exacerbated by neonicotinoid use, and the effects of those causes may take longer to go away or become less important.

One interesting aspect of this ban is the way in which environmental groups and the chemical companies that make the insecticide have bifurcated into two distinct ways of thinking. Again, from the Guardian:

Greenpeace’s chief scientist, Doug Parr, said [of a dissenting vote by the UK]: “By not supporting the ban, environment secretary, Owen Paterson, has exposed the UK government as being in the pocket of big chemical companies and the industrial farming lobby.”…

But a spokesman for Syngenta, which makes one of the three neonicotinoids that have been suspended, said: “The proposal is based on poor science and ignores a wealth of evidence from the field that these pesticides do not damage the health of bees. The EC should [instead] address the real reasons for bee health decline: disease, viruses and loss of habitat.”

and…

Prof Simon Potts, a bee expert at the University of Reading, said: “The ban is excellent news for pollinators. The weight of evidence from researchers clearly points to the need to have a phased ban of neonicotinoids….

vs.

“Bayer remains convinced neonicotinoids are safe for bees, when used responsibly and properly,” said a spokesman for Bayer Cropscience. “As a science-based company, Bayer is disappointed that clear scientific evidence has taken a back-seat in the decision making process.”

Both Bug Girl and Carl Zimmer have written a fair amount on this topic, and their posts include links to a great deal of additional information.

• 2012-03-29 Carl Zimmer in the New York Times: 2 Studies Point to Common Pesticide as a Culprit in Declining Bee Colonies
• 2012-03-31 Bug Girl’s Blog: Are Neonicotinoid Pesticides Killing Bees?
• 2012-05-23 Bug Girl’s Blog: Bees and Pesticides (again)

Photo Credit: Chalkie_CC via Compfight cc

Where to the fish get them? Well, at the base of aquatic ecosystems are algae that produce these molecules. So, stuff that eats stuff that eats stuff in aquatic systems eventually eats these algae directly or indirectly. And here’s where Dragonflies come in. They hatch and mature through non-adult stages in the aquatic ecosystem. There, the Dragonfly larvae are little tiny super predators, eating other invertebrates and even tiny fish. In this manner they concentrate long chain polyunsaturated fatty acids. Then, they emerge as adult insects and fly around where terrestrial animals munch on them. In this way, these rare and important complex molecules become a bit more abundant in terrestrial systems than they otherwise might. This applies broadly to “emerging” insects that start out in an aquatic form, but in some environments the Dragonflies are a major factor. More generally, dragon flies move piles of biomass across the landscape, away from ponds and lakes where bio-molecules naturally accumulate because stuff goes down hill.

Citations for two recent research papers that discuss this are below.

And now for the book. There are over 300 species of Dragonfly and Damselfly in North America east of the Rocky mountains. Dragonflies and Damselflies of the East (Princeton Field Guides) by Dennis Paulson covers them all. We’ve been dragging this book up to the cabin (it is a bit large) for several weeks now and we’ve been able to identify everything. Beyond that, Dragonflies and Damselflies of the East has a lot of good information in it about the morphology and anatomy…essential if you want to do identification…and taxonomic relationship among these critters. There are a lot of photos and they are spectacularly good and very useful. There are also plenty of other illustrations and line drawings, and range maps that look great and are easy to use. The introductory sections are rich in detail about Dragonfly and Damselfly ecology and biology.

Paulson also has a Dragonflies and Damselflies of the West, which I’ve not seen but looks similar based on the descriptions. To be clear: The East book is mainly “East of the Mississippi” but also covers a range pretty far west, as obviously the Mississippi is not a Dragonfly boundary. If you are anywhere in or west of the Dakotas or Texas, you may want the Western book.

Images provided by Princeton Press.

M. I. Gladyshev, A. Yu. Kharitonov, O. N. Popova, N. N. Sushchik, O. N. Makhutova, & G. S. Kalacheva (2011). Quantitative estimation of dragonfly role in transfer of essential polyunsaturated fatty acids from aquatic to terrestrial ecosystems DOKLADY BIOCHEMISTRY AND BIOPHYSICS, 438 (1), 708-710 DOI: 10.1134/S1607672911030094

O. N. Popova, & A. Yu. Kharitonov (1). Estimation of the carry-over of substances by dragonflies from water bodies to land in the forest-steppe of West Siberia CONTEMPORARY PROBLEMS OF ECOLOGY, 5 (2012), 49-56 DOI: 10.1134/S1995425512010043

Abstract: The results of many years’ monitoring of the number and distribution of dragonflies in the Chany area of the Baraba forest-steppe are presented. An estimation of the biomass carry-over by dragonflies from water bodies to land ecosystems is given. The data presented provide evidence of the important role of dragonflies in the migration of substances from water bodies to land.

Nonlethal exposure of honey bees to thiamethoxam (neonicotinoid systemic pesticide) causes high mortality due to homing failure at levels that could put a colony at risk of collapse. Simulated exposure events on free-ranging foragers labeled with an RFID tag suggest that homing is impaired by thiamethoxam intoxication. These experiments offer new insights into the consequences of common neonicotinoid pesticides used worldwide.

CCD (Colony Collapse Disorder) was identified as a phenomenon in which colonies of honey bees (Apis mellifera) would suddenly disappear from their own hive. Suggested causes have included pathogens, parasites, habitat loss, and even pesticides. So far studies have failed to make any clear links.

Pesticides have always been on the table as a possible cause because these days so many bees forage on industrial grown grasses (corn, sunflower, etc. etc.) which are periodically dusted with insect killers. In particular, Neonicotinoid pesticides, which are used to protect crops against sap-sucking insects (such as aphids) are associated with loss of functional behaviors such as navigational skills. Bees that are exposed to non-lethal doses of Neonicotinoid pesticides forage abnormally, have “olfactory memory” problems, are easily disoriented and become poor learners. Essentially, a dose of this sort of pesticide may make it impossible for a bee to return to the nest. If an entire colony of bees is infected by this chemical, by direct exposure as well as indirect exposure (among bees back in the hive after foraging bouts) the entire colony cold just fly off and not come back over a fairly short period of time.

In the present study, the research team “tested the hypothesis that a sublethal exposure to a neonicotinoid indirectly increases hive death rate through homing failure in foraging honey bees,” focusing on the recently marketed form “thiamethoxam.” They exposed bees to this chemical then measured their ability to find their way home, using tagged bees. Then, they modeled the effects of the combination this problem of getting lost with other problems bees have while foraging, like getting eaten and such on colony viability. For the later, they simply modeled honey bee population dynamics with the “I got lost because I ate thiamethoxam” factor added in.

The bees were tracked with a very tiny device called a RFID device, as in this photograph from the Science paper:

The researchers tagged 653 individual bees over four separate treatments, in an area of France.

To simulate intoxication events, foragers received a field-realistic, sublethal dose of thiamtethoxam… and were released away from their colony with a microchip glued on their thorax. RFID readers placed at the hive entrance were set to detect on a continual basis tagged honey bees going through the entrance. Mortality due to post-exposure homing failure, mhf, was then derived from the proportion of non-returning foragers.

Other bees, not dosed with the poison, were also monitored for comparison.

The bees dosed with the poison were less likely to return to the hive if released a kilometer away, than those not treated. In the case of bees released at a place they had been to before, from which they could use their internal bee-ish mapping abilities to fly home, the treated bees were very slightly less likely to return to the colony. Bees that were released at random locations that they were not likely to be familiar with were more discobobulated, and while both treated and untreated bees had a hard time making it back to the colony, the difference between the two was more dramatic.

A: Bees released at a location known to them a kilometer away from the hive; B: Bees released at a random location a kilometer away from the hive. The gap in the graph is overnight.

One thing that strikes me as especailly interesting here is that many bees don’t make it back over a fairly long period of time even under normal conditions, and that some bees stay out overnight!

Once these numbers were obtained from empirical fieldwork, they were plugged into models for bee population dynamics. The result is the following graph (see caption for explanation):

Comparison of honey bee population dynamics between simulated colonies exposed to thiamethoxam (red lines) or not exposed (blue lines), following six demographic scenarios. L: queens daily laying rate (nb. of eggs per day). Exp: proportion of foragers exposed to treated crops during the day. The non-exposed colony follows either (A and D) a normal development trajectory (at L=2000), (B and E) an equilibrium dynamic (L=1800), or (C and F) a slightly declining trajectory (L=1600). Shaded areas delineate the exposure period (e.g., oilseed rape). Pairs of trajectories in exposed colonies were obtains with the lower and upper bounds of homing failure mortality (0.102 and 0.316), in order to delineate the best and worse estimates for population dynamics, respectively. Dotted lines extend the declining trajectory expected for a sustained exposure.

As you can see, colonies with bees exposed to a disorienting chemical are more likely to reach a critical level of population size. In fact, the difference between non-affected and affected colonies can be quite dramatic, and for sustained exposure, heading towards the point of no return is well within the range of possibility over a period of just a few months.

The researchers conclude:

Our study clearly demonstrates that exposure of foragers to non-lethal but commonly encountered concentrations of thiamethoxam can impact forager survival, with potential contributions to collapse risk. Furthermore, the extent to which exposures affect forager survival appears dependant on the landscape context and the prior knowledge of foragers about this landscape. Higher risks are observed when the homing task is more challenging. As a consequence, impact studies are likely to severely underestimate sublethal pesticide effects when they are conducted on honey bee colonies placed in the immediate proximity of treated crops. Finally, this study raises important issues concerning exposed solitary bee species, whose population dynamics are probably less resilient to forager disappearance than honey bee colonies.

Henry, M., Beguin, M., Requier, F., Rollin, O., Odoux, J., Aupinel, P., Aptel, J., Tchamitchian, S., & Decourtye, A. (2012). A Common Pesticide Decreases Foraging Success and Survival in Honey Bees Science DOI: 10.1126/science.1215039