The Orchid Mantis Might Not be so Orchid After All

Here we see a juvenile orchid mantis perched atop a man-made orchid cultivar that would not be found in the wild.

Here we see a juvenile orchid mantis perched atop a man-made orchid cultivar that would not be found in the wild.

The orchid mantis is a very popular critter these days, and rightly so. Native to southeast Asia, they are beautiful examples of how intricately the forces of natural selection can operate on a genome. The reasoning behind such mimicry is pretty apparent, right? The mantis mimics an orchid flower and thus, has easy access to unsuspecting prey.

Not so fast...

Despite its popularity as an orchid mimic, there is no evidence that this species is mimicking a specific flower. Most of the pictures you see on the internet are actually showing orchid mantids sitting atop cultivated Phalaenopsis or Dendrobium orchids that simply do not occur in the wild. Observations from the field have shown that the orchid mantis is frequently found on the flowers of Straits meadowbeauty (Melastoma polyanthum). A study done in 2013 looked at whether or not the mantids disguise offers an attractive stimulus to potential prey. Indeed, there is some evidence for UV absorption as well as convincing bilateral symmetry that is very flower-like. They also exhibit the ability to change their color to some degree depending on the background.

Orchid mantis nymphs are more brightly colored than adults.

Orchid mantis nymphs are more brightly colored than adults.

Despite our predilection for finding patterns (even when there are none) it is far more likely that this species has evolved to present a "generalized flower-like stimulus." In other words, they may simply succeed in tapping into pollinators' bias towards bright, colorful objects. We see similar strategies in non-rewarding flowering plants that simply offer a large enough stimulus that pollinators can't ignore them. The use of colored mantis models has provided some support for this idea. Manipulating the overall shape and color of these models had no effect on the number of pollinators attracted to them.

The most interesting aspect of all of this is that the most convincing (and most popular) mimicking the orchid mantis displays is during the juvenile phase. Indeed, most pictures circulating around the web of these insects are those of immature mantids. The adults tend to look rather drab, with long, brownish wing covers. However, they still maintain some aspects of the juvenile traits.

Adult orchid mantids take on a relatively drab appearance compared to their juvenile form.

Adult orchid mantids take on a relatively drab appearance compared to their juvenile form.


The fact of the matter is, we still don't know very much about this species. It is speculated that the mimicry is both for protection and for hunting. As O'Hanlon (2016) put it, "The orchid mantis' predatory strategy can be interpreted as a form of 'generalized food deception' rather than 'floral mimicry'." It just goes to show you how easily popular misconceptions can spread. Until more studies are performed, the orchid mantis will continue to remain a beautiful mystery.

Photo Credit: [1] [2] [3]

Further Reading: [1] [2] [3] [4]

Studying Mimicry in Orchids Using 3D Printing

Just when I thought I could stop acting surprised by the myriad applications of 3D printing, a recent study published in the journal New Phytologist has me pulling my jaw up off the floor. Using a 3D printer, researchers from the University of Oregon have unlocked the mystery surrounding one of the more peculiar forms of mimicry in the botanical world. 

The genus Dracula is probably most famous for containing the monkey face orchids (Dracula simia). Thanks to our predisposition for pareidolia, we look at these flowers and see a simian face staring back at us. Less obvious, however, is the intricate detail of the labellum, which superficially resembles the monkey's mouth. A close inspection of this highly modified petal would reveal a striking resemblance to some sort of gilled mushroom. 

Indeed, a mushroom is exactly what the Dracula orchids are actually trying to mimic. The main pollinators of this genus are tiny fruit flies that are mushroom specialists. They can be seen in the wild crawling all over Dracula flowers looking for a fungal meal and a place to mate. Some of the flies inevitably come away from the Dracula flower with a wad of pollen stuck to their backs. With any luck they will fall for the ruse of another Dracula flower and thus pollination is achieved. 

Despite being well aware of this mimicry, scientists didn't quite know what specifically attracted the flies to the flower. This is where the 3D printer came in. The research team made exact replicas of the flowers of Dracula lafleurii out of odorless silicone. They also printed individual flower parts. In doing so, the researchers were able to vary the color patterns as well as the scent of each flower. Using the parts, they were also able to construct chimeras, which allowed them disentangle which parts contribute most to the mimicry. 

What they discovered is that the key to Dracula's mushroom mimicry lies in its gilled labellum. This petal not only looks like a mushroom, it smells like one too. The result is a rather ingenious ruse that its tiny fly pollinators simply can't resist. What's more, this approach offers an ingenious way of investigating the evolution of mimicry throughout the botanical kingdom. 

Photo Credit: Luis Baquero (http://bit.ly/21GhYGJ)

Further Reading:
http://onlinelibrary.wiley.com/doi/10.1111/nph.13855/abstract

Dung Seeds

There are a lot of interesting seed dispersal mechanisms out there. It makes sense too because effective seed dispersal is one of the most important factors in a plant's life cycle. It is no wonder then that plants have evolved myriad ways to achieve this. Everything from wind to birds to mammals and even ants have been recruited for this task. Now, thanks to a group of researchers in South Africa, we can add dung beetles to this list.

That's right, dung beetles. These little insects are famous the world over for their dung rolling lifestyle. These industrious beetles are quite numerous and play an important role in the decomposition of feces on the landscape. Without them, the world would be a gross place. They don't do this for us, of course. Instead, dung beetles both consume the dung and lay their eggs on the balls. They are often seen rolling these balls across the landscape until they find the perfect spot to bury it where other dung-feeding animals won't find it. It is this habit that a plant known scientifically as Ceratocaryum argenteum has honed in on.

The seeds of this grass relative are hard and pungent. Researchers questioned why the plant would produce such smelly seeds. After all, the scent would hypothetically make it easier for seed predators to find them. However, the typical seed predators of this region such as birds and rodents show no real interest in them. What's more, when offered seeds directly, rodents only ate seeds in which the tough, smelly coat had been removed. Using cameras, the researchers studied the behavior of these animals time and time again. It was only after viewing hours of video that they made their discovery.

Although they weren't big enough to trip the cameras themselves, incidental footage caught dung beetles checking out the seeds and rolling them away. As it turns out, the scent and appearance (which closely mimics that of antelope dung) tricks the dung beetles into thinking they found the perfect meal. As such, the dung beetles do exactly what the plant needs - they bury the seeds. This is a dead end for the dung beetle. Only after a seed has been buried do they realize that it is both inedible and an unsuitable nursery. Nonetheless, the drive for reproduction is so strong that the plant is able to successfully trick the dung beetles into dispersing their seeds.

Photo Credit: Nicky vB (bit.ly/1WVgs0G) and Nature Plants

Further Reading:
http://www.nature.com/articles/nplants2015141

The Accidental Grain - How Rye Evolved Its Way Into Our Diet

Humans have been altering the genomes of plants for a very long time. Nowhere is this more apparent than in the crops we grow. These botanical mutants are pampered beasts compared to their wild congeners. It is easy to see why some traits have been selected over others, whether it be larger leaves or fruit to munch on, smaller seeds to keep them out of our way, or tough rinds to make shipping easier. However, not all of our crops have been consciously bred for our consumption. Just as many weed species are adapting to herbicides today, some species of plant were able to adapt to the more archaic methods of early farming, which allowed them to avoid the ever watchful eye of the farmer.

This concept is known as Vavilovian mimicry (sometimes referred to as crop mimicry) and it is named after the Soviet botanist and geneticist Nikolai Vavilov (who was later imprisoned and starved to death by Stalin because of his firm stance on basic genetic principles). The idea is rather simple. At its core it involves artificial selection, albeit unintentional. A wild plant species finds certain forms of agriculture appealing. It becomes an apparent weed and the farmer begins to deal with it. Perhaps this plant is a close relative and thus looks quite similar to the crop in question. As the farmer weeds out plants that look different from the crop, they may be unintentionally selecting for individual weeds that more closely resemble the crop species. Over enough seasons, only those weeds that look enough like the crop survive and reproduce, sometimes to the point in which the two are almost indistinguishable.

Rye is an interesting example of this idea. Wild rye (Secale montanum) was not intentionally grown for food. It was a weed in the fields of other crops like wheat and barley. Both wheat and barley are annual plants, producing their edible seeds at the end of their first growing season. Wild rye, however, is a perennial and does not produce seed until at least its second season. Therefore, most wild rye plants growing in wheat or barely fields are killed at the end of the season when the field gets tilled. However, there are some mutant rye plants that occasionally pop up and produce seeds in their first year.

It is believed that these mutant annual rye were harvested unintentionally and reseeded season after season. Over time, other traits likely developed to help push rye into the spotlight for these early farmers. Like many wild grasses, wild rye has weak spindles (the part that holds the seed to the plant). In the wild, this allows for efficient seed dispersal. On the farm, this is not a desirable trait as you end up quickly losing the seeds you want to harvest. Again, by accidentally selecting for mutants that also had thicker spindles and thus held on to their seeds, farmers were unintentionally domesticating rye to parallel other cereal crops. It is believed that oats (Avena sterilis) also originated in this manner.

Photo Credit: Lotte Grønkjær (http://bit.ly/1xMEfVw)

Further Reading: [1] [2]