Navigation Links
Harlequin ladybirds escape enemies while native species succumb
Date:12/4/2013

The astonishing success of the alien invasive harlequin ladybird in Britain has given a team of scientists a unique opportunity to investigate a key ecological theory the Enemy Release Hypothesis.

The Enemy Release Hypothesis predicts that when a new alien species arrives into a country or region it is unlikely that the resident natural enemies will attack it.

Writing in the latest issue of the scientific journal Insect Conservation and Diversity the scientists conclude that, in the first ten years of the harlequin ladybird invasion the Harlequin arrived in the UK in 2004 it was much less likely to succumb to natural enemies (such as predators, parasites and pathogens) than the UK's native ladybird species such as the iconic 7-spot. Such natural enemies have evolved alongside native species and the research showed that they are less able to attack the new arrival.

The result may partly explain why the harlequin ladybird is such a successful invasive alien species supporting the notion that the harlequin is the "most invasive alien ladybird on Earth".

Ladybirds are generally not attacked by predators but there are a number of parasites - species that live in or on another species, so called hosts, deriving nutrients and usually resulting in death of the host - that exploit them. Ladybird parasites include wasps and flies (such as scuttles flies).

One of the most numerous ladybird parasites is a tiny wasp called Dinocampus coccinellae. It lays an egg inside a ladybird and subsequently hatches into a grub-like larva that devours the inside of the ladybird before emerging to pupate under the adult ladybird. It uses the adult ladybird as a bodyguard which twitches defensively above the small parasitic cocoon. The parasitic wasp emerges and the ladybird host dies.

The researchers monitored Harlequin ladybirds (Harmonia axyridis) and the native 7-spot ladybird (Coccinella septempunctata) for natural enemies over four years, from populations across southern England in areas first invaded by the harlequin ladybird between 2004 and 2009.

The study showed that about one in ten 7-spot ladybirds were parasitized by Dinocampus coccinellae whereas less than one in 100 harlequin ladybirds were parasitized The other common parasites that the team examined also favoured the native species of ladybird over the alien harlequin. The team found no evidence that the close proximity of harlequin ladybirds detracted the parasites from attacking the native species.

Paper lead author Richard Comont who carried out the research as a PhD student at the Centre for Ecology & Hydrology and is now Data Monitoring Officer at the BumbleBee Conservation Trust, said, "It's really exciting to find that native parasitoid species are attacking the harlequin, but they're only doing so in really small numbers the native 7-spot ladybird is almost 11 times more likely to be eaten than the harlequin. That really shows in part why the harlequin is increasing so quickly there's nothing holding it back."

Co-author Dr Helen Roy from the Centre for Ecology & Hydrology said, "The presence of the harlequin ladybird in Britain has given us the opportunity to test the enemy release hypothesis, a key ecological theory. Our work clearly demonstrates how some alien invasive species such as the harlequin ladybird can escape predators and parasites allowing them to successfully and rapidly spread across a country such as the UK."

Dr Roy added, "We need people to keep sending in records to the UK Ladybird Survey and we would be delighted to hear about any sightings of parasitized ladybirds. Every observation helps us to unravel the story of this alien invader and more broadly to our understanding of invasion biology."


'/>"/>

Contact: Barnaby Smith
bpgs@ceh.ac.uk
44-079-202-95384
Centre for Ecology & Hydrology
Source:Eurekalert  

Related biology news :

1. Study shows disease spread in ladybirds with sexually transmitted disease
2. Where can coral reefs relocate to escape the heat?
3. Novel combination therapy shuts down escape route, killing glioblastoma tumor cells
4. Why letting salmon escape could benefit bears and fishers
5. Declaring a truce with our microbiological frienemies
6. EU fishing fleets reap profits while taxpayers foot the bill
7. New technique controls dimensions of gold nanorods while manufacturing on a large scale
8. New evidence that cancer cells change while moving throughout body
9. Advance in regenerative medicine could make reprogrammed cells safer while improving their function
10. Study finds physicians need to better recognize use of herbal supplements while breastfeeding
11. Antiepileptic drug use while pregnant impacts early child development
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Harlequin ladybirds escape enemies while native species succumb
(Date:6/2/2016)... --  The Weather Company , an IBM Business (NYSE: ... in which consumers will be able to interact with IBM ... voice or text and receive relevant information about the product ... have long sought an advertising solution that can create a ... and valuable; and can scale across millions of interactions and ...
(Date:5/16/2016)... NEW YORK , May 16, 2016   ... authentication solutions, today announced the opening of an IoT ... to strengthen and expand the development of embedded ... provides an unprecedented level of convenience and security with ... to authenticate one,s identity aside from DNA. EyeLock,s platform ...
(Date:4/28/2016)... April 28, 2016 First quarter 2016:   ... 966% compared with the first quarter of 2015 The ... 589.1 M (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) ... guidance is unchanged, SEK 7,000-8,500 M. The operating margin ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016   Boston Biomedical ... novel compounds designed to target cancer stemness pathways, ... been granted Orphan Drug Designation from the U.S. ... of gastric cancer, including gastroesophageal junction (GEJ) cancer. ... designed to inhibit cancer stemness pathways by targeting ...
(Date:6/23/2016)... June 23, 2016  The Prostate Cancer Foundation (PCF) is pleased ... and faster cures for prostate cancer. Members of the Class of 2016 were ... Read More About the Class of 2016 PCF Young ... ... ...
(Date:6/23/2016)... NC (PRWEB) , ... June 23, 2016 , ... In ... University Hospital in Denmark detail how a patient who developed lymphedema after being treated ... tissue. The results could change the paradigm for dealing with this debilitating, frequent side ...
(Date:6/23/2016)... ... 23, 2016 , ... ClinCapture, the only free validated electronic ... showcase its product’s latest features from June 26 to June 30, 2016 for ... Disrupting Clinical Trials in The Cloud during the conference. DIA (Drug Information ...
Breaking Biology Technology: