Just in time for Halloween is a scary article about parasites that control their hosts’ behavior in the November 2014 issue of National Geographic, “Mindsuckers: Meet Nature’s Nightmare” by Carl Zimmer.
Let’s meet some ant relatives, the parasitic wasps, and learn how they turn their hapless arthropod hosts into “zombies.”
“It is as astonishing as it is sad to watch a ladybug turn into a zombie. Normally ladybugs are sophisticated and voracious predators. A single individual may devour several thousand aphids in a lifetime. To find a victim, it first waves its antennae to detect chemicals that plants release when they’re under attack by herbivorous insects. Once it has homed in on these signals, the ladybug switches its sensory scan to search for molecules released only by aphids. Then it creeps up and strikes, ripping the aphid apart with barbed mandibles.
Ladybugs are also well protected against most of their enemies. Their red-and-black dome, so adorable to the human eye, is actually a warning to would-be predators: You will regret this. When a bird or some other animal tries to attack, the ladybug bleeds poison from its leg joints. The attacker tastes the bitter blood and spits the ladybug out. Predators learn to read the red-and-black wing covers as a message to stay away.
A predator protected from other predators, the ladybug would seem to have the perfect insect life—were it not for wasps that lay their eggs inside its living body.”
The article goes on to talk about how a parasitic wasp feeds on the lady beetle, controlling it in a gruesome way.
As you would expect from National Geographic, the photographs in the November 2014 article are fantastic and chilling, all in one.
(Photograph © by Anand Varma/National Geographic; Jacques Brodeur Lab, University of Montreal, copyrighted image used with permission).
“Parasitic Wasp Dinocampus coccinellae
Spotted Lady Beetle Coleomegilla maculata
Ladybugs are said to bring good luck—but one infected by the wasp species Dinocampus coccinellae is decidedly unfortunate. When a female wasp stings a ladybug, it leaves behind a single egg. After the egg hatches, the larva begins to eat its host from the inside out. When ready, the parasite emerges and spins a cocoon between the ladybug’s legs. Though its body is now free of the tormentor, the bug remains enslaved, standing over the cocoon and protecting it from potential predators. Some lucky ladybugs actually survive this eerie ordeal.”
What is that glowing golden object on the spider’s back? It turns out that even spiders are not immune.
(Photograph © by Anand Varma/National Geographic. Copyrighted image used with permission.)
“The spider Leucauge argyra suffers a series of humiliations at the hands of the parasitic wasp Hymenoepimecis argyraphaga before it is put out of its misery. Paralyzed by the wasp’s sting, the spider stands helpless as its tormentor deposits an egg on its abdomen. Once the egg hatches, the larva holds tight to the spider like some malignant piggybacker, feeding on its internal fluids for a week. When ready to pupate, the larva coerces the spider into setting out on one last, misguided building project. Ripping down its own carefully constructed web, the spider spins a novel one consisting of just a few thick crossing strands. The larva rewards the spider for its efforts by sucking it dry. Then it spins its cocoon at the intersection of the two strands, where it can dangle safely out of reach of predators.”
(Images and text are from the November 2014 issue of National Geographic magazine.)
The article goes on to discuss several other examples and the evolutionary significance of these bizarre lifestyles. If you are a biologist, especially an entomologist, you are probably familiar with some of these examples, but perhaps not all of them.
Reading the article does give me some ideas for awesome Halloween costumes.
What do you think of the Mindsuckers article? Do you think the tie-ins to popular culture help foster science communication or do you think it confuses the lay audience?
Thank you to Lauren for bringing this article/opportunity to my attention.
Have you seen the new book The Bee: A Natural History by Dr. Noah Wilson-Rich with contributions from Kelly Allin, Norman Carreck, and Dr. Andrea Quigley?
Dr. Wilson-Rich is an urban beekeeper and although (as the cover suggests) honey bees are the main focus of the book, it includes information about all kinds of bees. After discussing the evolution and development of bees, as well as their biology and behavior, the authors review the history of bees and humans and also beekeeping. The authors follow up with “A Directory of Bees,” which is a pictorial field guide to solitary bees, bumble bees, stingless bees and honey bees. The directory is illustrated with large color photographs of preserved specimens from around the world.
The final chapter goes into the challenges currently faced by bees, including weather, climate, pests and diseases. Finally, the authors discuss some of the research initiatives aimed at helping bees and what individuals can do to help protect our bees, such as plant flowers and participate in citizen science projects. (My personal suggestion is to let your dandelions grow because they provide honey bees a meal late into fall and even early winter.)
The book is exceptionally appealing visually. Almost every page has a mix of color photographs and old-fashioned line drawings or wood cuts, with sidebars and other interesting features. Obviously, a lot of care was put into the design.
If you already know something about bees, you might be interested to find out that the book doesn’t just hash over old material. For example, as Dr. Wilson-Rich also mentions in his TED Talk (see below), beekeepers are finding honey bees in urban environments, such on the rooftops of city buildings, are doing better than those in rural and suburban areas. It might seem counter-intuitive, but two out of three overwintering hives survived in the city compared to two out of five in the country. The urban honey bees also produced more honey. They have some suggestions why this may be the case, such as the cities are warmer overall and probably the honey bees are exposed to less pesticides, but the bees are also likely having less interactions with other bees that might pass diseases or compete for resources.
Bees have been in the news and people are interested in learning more about them. The Bee is a quick and easy-to-read overview of a topic that would be equally useful for the layperson who knows little about bees and the beekeeper who wants to learn about bees from a more general perspective. Be prepared for a visual treat.
You can get a taste for how passionate Dr. Wilson-Rich is in his TED talk:
Hardcover: 224 pages
Publisher: Princeton University Press (August 24, 2014)
Disclosures: The book was provided by the publisher for review purposes. I am an affiliate for Amazon, and if you click through the linked titles or ads and make a purchase, I will receive a small commission at no extra charge to you. Proceeds will be used to maintain this self-hosted blog.
Ants have been known to have a positive impact on soils by mixing different layers and by adding nutrients, etc. Now a researcher from Arizona State University, Dr. Ronald Dorn, has found that ants are enhancing the breakdown of certain minerals and the movement of carbon dioxide into calcium carbonate (limestone). The bottom line: ants might be helping to remove greenhouse gases from the atmosphere.
Dr. Dorn did not start out to study ants. He actually began the study 25 years ago to look at weathering of olivine and plagioclase minerals from Hawaiian basalt. He placed samples in various sites in Arizona and Texas, and then went back every five years to see what was happening to them.
Other researchers have shown that weathering of calcium and magnesium silicates by living things is important in removing atmospheric carbon dioxide gases. A simplified reaction is shown here:
Over the 25 year period of this study, Dorn found the ant colonies of eight different ant species (Pogonomyrmex rugosus, Pogonomyrmex barbatus, Dorymyrmex bicolor, Forelius pruinosus, Liometopum luctuosum, Tapinoma sessile, Formica neogagates, and Camponotus vicinus), enhanced the weathering of the minerals some 50x-300x over that of the bare ground control. At the same time he found the percent carbonate increased substantially in the nests of all the different species.
Pogonomyrmex worker ant moving soil from its nest.
Of all the factors he studied, Dorn found that ants were by far the most important weathering agents. Given the amount of material a given ant colony moves around, that is not surprising.
What was a bit more surprising was that all the ant nests accumulated calcium carbonate over time, at levels well above what was happening in bare soil nearby. Perhaps it is time to investigate what exactly ants are doing in those underground galleries.
What do you think? Are ants an answer to removing excessive carbon dioxide from the atmosphere?
Dorn, R.I. (July 14, 2014) Ants as a powerful biotic agent of olivine and plagioclase dissolution. Geology.
Interested in learning more about the impact of ants on soils? Try this excerpt from the Encyclopedia of Soil Science Vol. 1
Remember that Pogonomyrmex nest with the shiny black spots around the nest entrances from a few weeks back?
Upon revisiting a few weeks later, the ants are looking better.
They seem to have cleaned up nicely.
Maybe there are a few spots left, but nothing like before.
What are they harvesting today? You probably recognize the beetle elytra, but what is the gray cylinder?
You might need to be from Arizona to recognize it. That is part of a seed pod from a tree with the common name “screwbean mesquite.”
Wonder what they will be up to next time I visit.
What kind of ants do you visit regularly?