Featured Research

from universities, journals, and other organizations

Tiny Insect Develops Long-term Memory

Date:
January 13, 2009
Source:
Wageningen University and Research Centre
Summary:
If a specific butterfly anti-sex scent is coupled with a pleasant experience, then parasitic wasps are able to develop long-term memory and respond to this scent that they do not instinctively recognize. After successfully 'hitch-hiking' with a mated female cabbage white butterfly and parasitizing her eggs, the parasitic wasps are able to remember the route and navigate it again.

A hitch-hiking parasitic wasp (Trichogramma evanescens) near the eye of an impregnated cabbage butterfly (Pieris brassicae).
Credit: Image courtesy of Wageningen University and Research Centre

If a specific butterfly anti-sex scent is coupled with a pleasant experience, then parasitic wasps are able to develop long-term memory and respond to this scent that they do not instinctively recognize. After successfully ‘hitch-hiking’ with a mated female cabbage white butterfly and parasitizing her eggs, the parasitic wasps are able to remember the route and navigate it again. Researchers from Wageningen University, Netherlands, reported this finding in the Proceedings of the National Academy of Sciences.

Research in Wageningen has shown that a parasitic wasp can learn to recognize a scent secreted by mated (or inseminated) females of the large cabbage white butterfly Pieris brassicae. This takes place while they hitch-hike with the cabbage white butterfly to a host plant where they parasitize the freshly laid butterfly eggs. A day later, the parasitic wasp is able to travel the same route. Parasitic wasps that did not have this ‘pleasant’ experience do not distinguish between mated cabbage butterflies and ‘uninteresting’ virgin ones. The researchers demonstrated in experiments that long-term memory is developed to remember the scent.

During mating, male large cabbage white butterflies transmit a special scent, benzyl cyanide, to their partners. This scent repels male rivals. The Minute (barely 0.5 mm long) parasitic wasps of the species Trichogramma brassicae take advantage of the anti-sex scent of the cabbage butterfly. They essentially engage in chemical espionage. Inexperienced parasitic wasps detect the anti-sex scent and use it to recognize mated female butterflies. The parasitic wasps hitch-hike with these mated butterflies. When the butterflies lay their eggs on a cabbage plant, the parasitic wasp climbs off the butterfly to lay its own eggs in the freshly laid butterfly eggs. In this way it parasitizes and kills the offspring of the butterfly.

For Trichogramma brassicae wasps this is an instinctive, innate behaviour. But this does not hold true for the closely related parasitic wasp Trichogramma evanescens. This wasp parasitizes the eggs of many species of moths and butterflies, including the large cabbage white butterfly. Inexperienced wasps of this species climb onto cabbage white butterflies just like Trichogramma brassicae, but show no preference for female butterflies that have mated. The researchers therefore concluded that they do not respond instinctively to benzyl cyanide.

A research team led by Dr Ties Huigens of the Laboratory of Entomology at Wageningen University wondered if the parasitic wasps could learn this behaviour. That appeared to be the case: Trichogramma evanescens do react to the anti-sex scent benzyl cyanide if they have previously had a positive experience with mated butterflies. After hitch-hiking once with such females and parasitizing freshly laid butterfly eggs, they thereafter climb specifically onto mated butterflies and hitch-hike with them. Either only hitch-hiking or only parasitizing the eggs were not sufficient by themselves. The researchers therefore concluded that the parasitic wasps learn to associate the anti-sex scent of the female butterflies with the reward of parasitizing the butterfly eggs.

The parasitic wasps continued to exhibit this learned behaviour even a day after the initial experience. This is an indication of long-term memory. In order to demonstrate this, researchers provided inhibitors for long-term memory. The parasitic wasps that ate these inhibitors (protein synthesis inhibitors) did not respond to the anti-sex scent a day after they had hitch-hiked with mated butterflies and parasitized freshly laid butterfly eggs. Apparently, the proteins needed for the development of long-term memory could not be produced. Obviously, these insects, with their extremely small ‘brains’ (estimated to be less than 10 nanolitres in volume) are able to develop a long-term memory, even though the formation of such memory requires a great deal of energy. Scientists know this, for example, because insects are less resistant to stress situations such as dessication after they have formed long-term memory.

The possession of long-term memory is very important for these short-lived parasitic wasps because they will probably only have a few opportunities to hitch-hike with mated female butterflies. If they were to immediately forget a positive experience, they could miss these few opportunities. The entomologists from Wageningen expect that learning the espionage-and-ride strategy is a widespread phenomenon because it is adaptive for many species of parasitic wasps killing insect eggs.


Story Source:

The above story is based on materials provided by Wageningen University and Research Centre. Note: Materials may be edited for content and length.


Journal Reference:

  1. Huigens, M.E., Pashalidou, F.G., Qian, M.-H., Bukovinszky, T., Smid, H.M., Loon, J.J.A. van, Dicke, M. & Fatouros. Hitch-hiking parasitic wasp learns to exploit butterfly anti-aphrodisiac. Proceedings of the National Academy of Sciences USA, (in press)

Cite This Page:

Wageningen University and Research Centre. "Tiny Insect Develops Long-term Memory." ScienceDaily. ScienceDaily, 13 January 2009. <www.sciencedaily.com/releases/2009/01/090112201312.htm>.
Wageningen University and Research Centre. (2009, January 13). Tiny Insect Develops Long-term Memory. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2009/01/090112201312.htm
Wageningen University and Research Centre. "Tiny Insect Develops Long-term Memory." ScienceDaily. www.sciencedaily.com/releases/2009/01/090112201312.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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