Researchers discover wasp larva disinfect their food before eating

Jan 08, 2013 by Bob Yirka report
Ampulex compressa, commonly called Emerald Cockroach Wasp. Pictured in Dar es salaam, Tanzania. Credit: Muhammad Mahdi Karim, Wikipedia

(Phys.org)—A team of German researchers has discovered that emerald cockroach wasp larva create a disinfecting clear liquid solution in their mouths that they spit out and use to disinfect their food before eating. This is especially important the team notes in their paper published in the Proceedings of the National Academy of Sciences, because the larva live inside the body of a cockroach.

Scientists have known for some time that the emerald wasp has special abilities that allow it to survive – it stings a cockroach twice, once to stun it, and then again to make it docile and then lays an egg on its leg that eventually hatches and bores its way into the hosts body. The larva then lives out its life inside the cockroach, using it as both cradle and . Now it appears, the wasp larva has a special ability of its own.

The researchers cut out a small section of the side of a parasitized cockroach and installed a small window. This allowed them to watch the larva inside as it went about its business. They were surprised to find that the larva spewed a liquid out of its mouth and then used it to cover the insides of its host before eating. Their curiosity piqued, the researchers examined the liquid more closely. They found that it contained micromolide and mellein – substances that are known to work as .

Cockroaches are obviously very dirty little bugs and they harbor all manner of viruses, bacteria and fungi. One bacterium commonly found on many species is Serratia marcescens – it's particularly lethal to wasps; for a larva to live inside a cockroach would require some degree of sanitizing. To address the problem, nature has provided the larva with the means of creating its own disinfectant, which also serves as a preservative – no bacteria, no rotting.

The team also tested the effectiveness of the antibiotic fluid, dousing with samples and found it killed off a wide variety of bacteria. They also collected cockroaches in the wild, comparing those that had been parasitized with a larva and those that had not. Those with larva in them showed evidence of the bacterial compound created by the larva, while those that were not parasitized, did not, proving that larva were in fact the source of the antibacterial agents.

Explore further: Rare new species of plant: Stachys caroliniana

More information: Larvae of the parasitoid wasp Ampulex compressa sanitize their host, the American cockroach, with a blend of antimicrobials, PNAS, Published online before print January 7, 2013, doi: 10.1073/pnas.1213384110 . http://www.pnas.org/content/early/2013/01/02/1213384110.abstract

Abstract
Food resources contaminated with spoilage or pathogenic microorganisms pose severe problems to all higher organisms. Here, we describe a food-hygienic strategy of the emerald cockroach wasp Ampulex compressa. The wasp larvae develop on and inside the American cockroach Periplaneta americana, a host that can harbor various putrefactive microbes, as well as human and insect pathogens. From P. americana, we isolated the Gram-negative bacterium Serratia marcescens, which is a potent entomopathogen that can rapidly kill insect larvae. It is also known as a food contaminant and as an opportunistic human pathogen. Using behavioral observations and chemical analyses, we demonstrated that A. compressa larvae impregnate their cockroach hosts from inside with large amounts of an oral secretion containing a blend of γ-lactones and isocoumarins with (R)-(-)-mellein [(R)-(-)-3,4-diydro-8-hydroxy-3-methylisocoumarin] and micromolide [(4R,9Z)-octadec-9-en-4-olide] as dominant components. We fractionated hexane extracts of the secretion and investigated the antimicrobial properties of the fraction containing the lactones and isocoumarins, as well as of synthetic (R)-(-)-mellein and micromolide, against S. marcescens and a Gram-positive bacterium, Staphylococcus hyicus, in broth microdilution assays. The test fraction inhibited growth of both tested bacteria. The activity of the fraction against S. marcescens was explained by (R)-(-)-mellein alone, and the activity against S. hyicus was explained by the combined action of (R)-(-)-mellein and micromolide. Our data suggest that the specific combination of antimicrobials in the larval secretion provides an effective frontline defense against the unpredictable spectrum of microbes that A. compressa larvae may encounter during their development inside their cockroach hosts.

Related Stories

A real-life zombie story in the life of bugs

Jun 24, 2011

(PhysOrg.com) -- In a recent study published in Biology Letters, a page of science fiction comes to life in a real-life zombie scenario between the ladybug and a parasitical wasp called Dinocampus coccinell ...

This beetle uses eggs as shields against wasps

Sep 14, 2011

(PhysOrg.com) -- New University of Arizona research has discovered that seed beetles from the desert Southwest shelter their broods from attacking parasitic wasps under a stack of dummy eggs.

Images of 300 million-year-old insects revealed

Sep 26, 2012

(Phys.org)—Writing in the journal PLoS One, the scientists have used a high resolution form of CT scanning to reconstruct two 305-million year old juvenile insects. Without the pioneering approach to ima ...

Recommended for you

Boy moms more social in chimpanzees

17 minutes ago

Nearly four decades of observations of Tanzanian chimpanzees has revealed that the mothers of sons are about 25 percent more social than the mothers of daughters. Boy moms were found to spend about two hours ...

Scanning robot helps put insect collection online

8 hours ago

A robot capable of scanning a tray of insect specimens in a few minutes will help make the virtual images and tagging information available to the public online, according to South Dakota State University ...

New mushroom discovered on campus is the first since 1985

9 hours ago

Two researchers who recently named the first new species of mushroom from the UC Berkeley campus in more than 30 years are emphasizing the need for continued green and open space on campus, as well as a full-fledged ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Telekinetic
1 / 5 (1) Jan 08, 2013
I'll try munching on a couple of parasitized cockroaches next time I get a cold.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.