Posts Tagged: praying mantis
Male praying mantids looking for "a little love" don't always fare well. Sometimes they lose their head. Female mantids can--and do--cannibalize them before, during or after copulation.
Now mantid researcher Katherine Barry of Macquarie University, Sydney, Australia, says that some hungry female mantids are deceptive liars. They emit chemical cues, or pheromones, as if seeking a mate, but what they want is not a mate, but a meal. Her research, "Sexual Deception in a Cannibalistic Mating System? Testing the Femme Fatale Hypothesis," appears in the Dec. 17 edition of the Proceedings of the Royal Society B.
The starving females in her study produced the same chemical cues that the well-fed females did. The deception clearly worked. “The consumption of one male improves body condition by approximately 33 percent and fecundity by approximately 40 percent," Barry pointed out.
In her abstract, Barry wrote: "The Femme Fatale hypothesis suggests that female mantids may be selected to exploit conspecific males as prey if they benefit nutritionally from cannibalism. Such a benefit exists in the false garden mantid Pseudomantis albofimbriata—females use the resources gained from male consumption to significantly increase their body condition and reproductive output. This study aimed to examine the potential for chemical deception among the subset of females most likely to benefit from cannibalism (poorly fed females). Females were placed into one of four feeding treatments (‘Very Poor', ‘Poor', ‘Medium' and ‘Good'), and males were given the opportunity to choose between visually obscured females in each of the treatments. Female body condition and fecundity varied linearly with food quantity; however, female attractiveness did not. That is, Very Poor females attracted significantly more males than any of the other female treatments, even though these females were in significantly poorer condition, less fecund (in this study) and more likely to cannibalise (in a previous study). In addition, there was a positive correlation between fecundity and attractiveness if Very Poor females were removed from the analysis, suggesting an inherently honest signalling system with a subset of dishonest individuals. This is the first empirical study to provide evidence of sexual deception via chemical cues, and the first to provide support for the Femme Fatale hypothesis."
We've seen scores of praying mantids lurking, snagging prey, and devouring their prey, but we've never seen any engaging in sexual cannibalism, which occurs when a female cannibilizes the male before, during or after copulation.
Professor Jay Rosenheim of the Department of Entomology and Nematology, University of California, Davis, has.
In fact, he captured an amazing photo of it and posted it on his website. His daughter, Leah, found the pair in their garden. "Note that the larger female has consumed the head of the smaller male (an example of the famous sexual cannibalism that can occur in this species," Rosenheim wrote. "Amazingly, the decapitated male continued to cling to the female and even attempt to re-initiate copulation several times."
With his permission, we're posting his photo below. We're adding two photos typically seen: a praying mantis waiting for prey--or a mate?--in a bed of cosmos, and another of a gravid praying mantis climbing a bamboo stake.
We don't know if a male lost its head during the male-female encounter, but we do know that we have an ootheca or egg case on our back porch.
Thank you, Mrs. Mantis!
This photo by Professor Jay Rosenheim of UC Davis shows sexual cannibalism. The female (larger one) has just chomped off the head of the male, during sexual reproduction.
A praying mantis perched on a cosmos waiting for prey--or maybe a mate? (Photo by Kathy Keatley Garvey)
Gravid praying mantis. (Photo by Kathy Keatley Garvey)
Today is Thanksgiving.
As we give thanks and reflect on a day set aside to be grateful, we realize that not all is great in the world of haves and have-nots, the generous and the greedy, and troublemakers and peacemakers.
Miscommunications turn into misunderstandings. Agreements turn into disagreements. Harmony turns into hostility. Like an open wound, tensions bulge, crack and fester. Life saddens, disappoints and crushes us.
But today is Thanksgiving, a day to be grateful. All around us, people are giving thanks, sharing memories, shoring up the holiday spirit, and feasting on turkey, mashed potatoes, cranberries, and pumpkin pie. Among the many things we are grateful for: we are grateful that we are not a turkey.
Last summer as a praying mantis "prayed" for dinner in our bee garden, we were thankful we were not a bee.
On Thanksgiving, we're grateful we're not a bee, this bee. (Photo by Kathy Keatley Garvey)
Here's a good reason why you should not clean the fixtures around your porch lights--if you need a reason.
The lights attract all kinds of nocturnal flying insects. It's like the proverbial draw of a moth to a flame.
Spiders weave their webs on the light fixtures to trap their prey. If you remove the webs, you'll remove the insect smorgasbord.
Recently we saw an insect we'd never seen before on the light fixture: a praying mantis lying in wait, maybe to snare a moth or share the spider's bounty.
The porch light screams '"science project!" We remember our son's science projects in elementary school, including "Can a Plant Grow Upside Down?" and "How Fast Can a Yo-Yo Spin?" Somewhere the curious mind of a science student will look at the light on his or her front porch and ask: What insects are flying toward the night light and how many? How many predators are lying in wait? What do they eat? And, what roles do these lights and predators play in luring the insects to their death?
Meanwhile, the praying mantis has vanished. It's end of the season. Next year there will be many more praying mantids. One deposited an egg case beneath a table on the back porch. After they emerge and eat their brothers and sisters (no sibling love there!), one or more may hang out on the light fixture next year.
Porch lights attract predators and prey, including this predator, a praying mantis. (Photo by Kathy Keatley Garvey)
Praying mantids are, oh, so patient.
They perch on a flower, their spiked forelegs seemingly locked in a praying position, and wait to ambush unsuspecting prey.
A green praying mantis recently did just that on our cosmos.
Usually we have to hunt for the mantids because they are so camouflaged or concealed.
Not this one.
This one was as visible as a green elephant in a field of snow.
Despite its conspicuous visibility, the attempts of this lean green machine proved fruitful. First, a honey bee. Then a fiery skipper.
His prayers were answered.
A praying mantis perches on a cosmos. (Photo by Kathy Keatley Garvey)
A strike! First prey is a honey bee. (Photo by Kathy Keatley Garvey)
Second strike! A fiery skipper butterfly. (Photo by Kathy Keatley Garvey)
A freeloader. A moocher. A sponger.
That's the freeloader fly.
A praying mantis is polishing off the remains of a honey bee. Suddenly a black dot with wings edges closer and closer and grabs a bit of the prey.
So tiny. So persistent. So relentless. That's the freeloader fly.
Don't look at the mangled honey bee. Don't look at the hungry praying mantis.
Look at the freeloader fly. Wait a few seconds and you'll see another.
The scene: a camouflaged praying mantis is tucked beneath some African blue basil leaves and the light is fading fast. (You could say I took this image "on the fly.")
Senior Insect Biosystematist Martin Hauser of the Plant Pest Diagnostic Branch, California Department of Food and Agriculture (CDFA) identified these "freeloader flies" as family Milichiidae and "likely the genus Desmometopa." See Wikipedia.
They are so tiny, Hauser says, that the mantids, spiders and Reduviidae (think assassin bugs) "don't bother chasing them away or even trying to eat them."
Hauser pointed out images of freeloader flies from BugGuide.net: http://bugguide.net/node/view/23319/bgimage
And look at all the freeloaders on this prey: http://bugguide.net/node/view/512989/bgimage
Back in March of 2012, agricultural entomologist Ted C. MacRae who writes a popular blog, Beetles in the Bush, posted an image of an assassin bug eating a stink bug. Check out all the flies engaging in what he calls kleptoparasitism--stealing food.
Everybody gets fed. Nobody leaves hungry.
Praying mantis eats a honey bee while a freeloader fly, family Milichilidae, does, too. Another freeloader edges closer. (Photo by Kathy Keatley Garvey)
The freeloader fly is quite persistent. (Photo by Kathy Keatley Garvey)