Featured Research

from universities, journals, and other organizations

Cunning super-parasitic wasps sniff out protected aphids and overwhelm their defenses

Date:
February 24, 2012
Source:
BioMed Central Limited
Summary:
In the war between parasite and host, the parasitic wasp and the pea aphid are locked in a battle for survival. New research shows that this cunning parasite sniffs out differences between protected and unprotected aphids, and alters its egg-laying strategy, in order to overwhelm aphid defenses and ensure survival of wasp offspring. The wasp lays an egg inside the pea aphid, where the egg hatches and converts the aphid's insides into a wasp nursery. The wasp larva uses the still-living aphid as a food source, eventually pupating inside the aphid and emerging as a fully-formed mature wasp. However the pea aphid is not defenseless. It is protected by a bacterial symbiont.

The super-parasitic wasp, Aphidius ervi, attacks the pea aphid, Acyrthosiphon pisum.
Credit: Alex Wild

In the war between parasite and host, the parasitic wasp, Aphidius ervi, and the pea aphid, Acyrthosiphon pisum, are locked in a battle for survival. New research published in BioMed Central's open access journal BMC Biology shows that this cunning parasite sniffs out differences between protected and unprotected aphids, and alters its egg-laying strategy, in order to overwhelm aphid defenses and ensure survival of wasp offspring.

The wasp, A. ervi, lays an egg inside the pea aphid, where the egg hatches and converts the aphid's insides into a wasp nursery. The wasp larva uses the still-living aphid as a food source, eventually pupating inside the aphid and emerging as a fully-formed mature wasp. However the pea aphid is not defenseless. It is protected by a bacterial symbiont Hamiltonella defensa (and its associated bacteriophage APSE).

Although the wasps still lay their eggs, wasp larvae are unable to develop normally. Researchers from the Universities of Georgia and Arizona collaborated with researchers from Akita Prefectural University, Japan, to investigate what tactics the wasps might use to overcome the aphids' symbiont defense strategy. The researchers found that wasps which laid two eggs (superparasitism) in aphids infected with H. defensa and APSE were much more successful at producing live offspring.

However laying two eggs in uninfected hosts had little effect on the number of surviving wasps as only one wasp can complete development in each aphid. This suggests that having twice the amount of factors secreted by the developing wasp overpowers the protection due to bacterial infection, and is an adaption to ensure the survival of one wasp at the cost of two.

In a twist it seems that the wasps are able to work out which aphids are harboring the symbionts and which are not. Dr Kerry Oliver, who led this study, explained, "We discovered that A. ervi would preferentially lay two eggs in infected hosts, and a single egg if the aphids were unprotected. We don't for sure how wasps discriminate, but, when we looked for differences between the aphids, we found that infected aphids produced less of the compound trans-b-farnesene. This compound is a major component of aphid alarm pheromone and wasps are known to use this cue to find hosts."

Whatever the trick that they are using to work out which aphids are infected, wasps appear to be able to lay just enough eggs to stay ahead in the arms race.


Story Source:

The above story is based on materials provided by BioMed Central Limited. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kerry M Oliver, Koji Noge, Emma M Huang, Jamie M Campos, Judith X Becerra and Martha S Hunter. Parasitic wasp responses to symbiont-based defense in aphids. BMC Biology, 2012 DOI: 10.1186/PREACCEPT-4284799146146604

Cite This Page:

BioMed Central Limited. "Cunning super-parasitic wasps sniff out protected aphids and overwhelm their defenses." ScienceDaily. ScienceDaily, 24 February 2012. <www.sciencedaily.com/releases/2012/02/120224110739.htm>.
BioMed Central Limited. (2012, February 24). Cunning super-parasitic wasps sniff out protected aphids and overwhelm their defenses. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2012/02/120224110739.htm
BioMed Central Limited. "Cunning super-parasitic wasps sniff out protected aphids and overwhelm their defenses." ScienceDaily. www.sciencedaily.com/releases/2012/02/120224110739.htm (accessed April 16, 2014).

Share This



More Plants & Animals News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
In Washington, a Push to Sterilize Stray Cats

In Washington, a Push to Sterilize Stray Cats

AFP (Apr. 14, 2014) To curb the growing numbers of feral cats in the US capital, the Washington Humane Society is encouraging residents to set traps and bring the animals to a sterilization clinic, after which they are released.. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins