Navigation Links
Insects that deter predators produce fewer offspring
Date:1/25/2011

Scientists studied the defences used by caterpillars that transform into large white butterflies, called Pieris brassicae. The insects regurgitate semi-digested cabbage leaves to make them smell and taste unpleasant to predators. The team found, however, that frequent use of this defence reduces the caterpillars' growth rate and the number of eggs they produce. It remains unclear why their defences affect them in this way, but the loss of nutrition from frequent regurgitation is thought to play a part.

Caterpillars are a target of pest control, as they destroy food crop by eating the leaves of cabbages and other vegetable crop. This new study, however, suggests that natural predators, such as farmland birds, do not necessarily have to consume large numbers of insects, to have a significant effect on the size of the population. Researchers found that 40% of caterpillars that defended themselves from predators by regurgitating food, died before transforming into a butterfly, despite successfully surviving the initial attack.

The study also showed that on average large caterpillars have 60 eggs, but those that used their defences against daily predator attacks produced approximately 30 eggs. It is thought that this effect could be widespread amongst herbivorous insects, suggesting that predators may have a larger impact on reducing the population of agricultural pests than previously thought.

Dr Mike Speed, from the University of Liverpool's Institute of Integrative Biology, explains: "Research has shown that large insects produce more eggs than smaller ones. This is commonly assumed to always be the case, but we have found that those that regurgitate food as a defence against predators, have fewer eggs, similar to the numbers of offspring smaller insects have. We also found that these insects grow at a slower rate and even those that successfully change into a butterfly, are smaller than normal."

Dr Andrew Higginson, from the University of Glasgow, said: "Interestingly, the caterpillars that grew at a slower rate were not forced, as a result of the attack, to metamorphose prematurely. They could have fed for longer, grown larger and produced more offspring, despite the daily use of their defences, but they appear to 'choose' to change into a smaller butterfly. More study is required to understand why they do this, but it could be that the threat of a fatal attack is too large for them to remain at the larval stage for too long and prompts them to transform into a butterfly early."

Dr Speed added: "This work demonstrates that it is important to maintain the diversity of predators such as wild birds, particularly in areas where large numbers of insects can destroy food crop. We now need to look at the defence mechanisms of a variety of insects to understand if other species react in similar ways."


'/>"/>

Contact: Samantha Martin
samantha.martin@liv.ac.uk
44-015-179-42248
University of Liverpool
Source:Eurekalert

Related medicine news :

1. Diet of contaminated insects harms endangered meat-eating plants
2. How pest insects might adapt to climate change, affecting agriculture and health
3. Anthem Blue Crosss Announcement That It Will Temporarily Suspend a 39% Health Insurance Rate Increase Should Not Deter Immediate Legislative Action
4. New Allergy Testing Available for Patients Allergic to Penicillin: Determining the Presence of Penicillin Allergy is Essential to Patient Care
5. The Power of Prayer Deterred Tsunami's Destruction Ministry Reports
6. EXCEL trial will determine safety and efficacy of drug-eluting stents vs. bypass surgery
7. Oransi Launches Robby Wash High Efficiency Laundry Detergent in U.S. – 10 Ounces Replaces 75 lbs. of Traditional Laundry Detergent
8. Inflammation Molecule May Determine Fat Levels
9. Regenstrief Institute to help improve disability determination through health information technology
10. Childrens sense of threat from parental fighting determines trauma symptoms
11. Robby Wash High Efficiency Laundry Detergent Offers 25% off Coupon – Replaces 75 lbs. of Traditional Laundry Detergent Saving $100 Annually
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand gesture animations, FCPX users ... - CEO of Pixel Film Studios. , ProHand Cartoon’s package transforms over 1,300 ... Pro X . Simply select a ProHand generator and drag it above media or ...
(Date:6/25/2016)... Montreal, Canada (PRWEB) , ... June 25, 2016 , ... ... the pursuit of success. In terms of the latter, setting the bar too high ... low, risk more than just slow progress toward their goal. , Research from ...
(Date:6/24/2016)... Texas (PRWEB) , ... June 24, 2016 , ... ... International Conference and Scientific Sessions in Dallas that it will receive two significant ... of the grants came as PHA marked its 25th anniversary by recognizing patients, ...
(Date:6/24/2016)... Plano, TX (PRWEB) , ... June 24, 2016 , ... ... taking part in Genome magazine’s Code Talker Award, an essay contest in which patients ... for an award to be presented at the 2016 National Society of Genetic Counselors ...
(Date:6/24/2016)... ... June 24, 2016 , ... National recruitment firm ... sciences executive with extensive sequencing and genomics experience, as Vice President of North American ... Hill will be responsible for leading the sales team in the commercialization of the ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... -- VMS Rehab Systems, Inc. ( www.vmsrehabsystemsinc.com ) reported today ... to build a strong and stable market for trading ... the OTC Markets-pink current trading platform. Explains ... seeing an anomaly in market trading activities that may ... Company, but shareholders and market players as well. I ...
(Date:6/24/2016)... Mass. , June 24, 2016   ... Spaulding Rehabilitation Network,s Dean Center for Tick ... Physical Medicine and Rehabilitation, MIT Hacking Medicine, University ... for Innovation, today announced the five finalists of ... for Lyme disease.  More than 100 scientists, clinicians, ...
(Date:6/24/2016)... SAN CLEMENTE, Calif. , June 24, 2016 /PRNewswire/ ... pulmonary function testing company, is now able to perform sophisticated lung ... ndd Medical Technologies , Inc. Patients are ... labs.  Thanks to ndd,s EasyOne PRO ® , ARL patients like ... any needed testing done in the comfort of her own home. ...
Breaking Medicine Technology: