RxPG News Feed for RxPG News

Medical Research Health Special Topics World
  Home
 
   Health
 Aging
 Asian Health
 Events
 Fitness
 Food & Nutrition
 Happiness
 Men's Health
 Mental Health
 Occupational Health
 Parenting
 Public Health
 Sleep Hygiene
 Women's Health
 
   Healthcare
 Africa
 Australia
 Canada Healthcare
 China Healthcare
 India Healthcare
 New Zealand
 South Africa
 UK
 USA
 World Healthcare
 
 Latest Research
 Aging
 Alternative Medicine
 Anaethesia
 Biochemistry
 Biotechnology
 Cancer
 Cardiology
 Clinical Trials
 Cytology
 Dental
 Dermatology
 Embryology
 Endocrinology
 ENT
 Environment
 Epidemiology
 Gastroenterology
 Genetics
 Gynaecology
 Haematology
 Immunology
 Infectious Diseases
 Medicine
 Metabolism
 Microbiology
 Musculoskeletal
 Nephrology
 Neurosciences
 Obstetrics
 Ophthalmology
 Orthopedics
 Paediatrics
 Pathology
 Pharmacology
 Physiology
 Physiotherapy
 Psychiatry
 Radiology
 Rheumatology
 Sports Medicine
 Surgery
 Toxicology
 Urology
 
   Medical News
 Awards & Prizes
 Epidemics
 Launch
 Opinion
 Professionals
 
   Special Topics
 Ethics
 Euthanasia
 Evolution
 Feature
 Odd Medical News
 Climate

Last Updated: Oct 11, 2012 - 10:22:56 PM
Research Article
Latest Research Channel

subscribe to Latest Research newsletter
Latest Research

   EMAIL   |   PRINT
Insects that deter predators produce fewer offspring

Jan 25, 2011 - 5:00:00 AM
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.

 
[RxPG] 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.




Advertise in this space for $10 per month. Contact us today.


Related Latest Research News
Bone loss associated with increased production of ROS
Sound preconditioning prevents ototoxic drug-induced hearing loss in mice
Crystal methamphetamine use by street youth increases risk of injecting drugs
Johns Hopkins-led study shows increased life expectancy among family caregivers
Moderate to severe psoriasis linked to chronic kidney disease, say experts
Licensing deal marks coming of age for University of Washington, University of Alabama-Birmingham
Simple blood or urine test to identify blinding disease
Physician job satisfaction driven by quality of patient care
Book explores undiscovered economics of everyday life
Gene and stem cell therapy combination could aid wound healing

Subscribe to Latest Research Newsletter

Enter your email address:


 Feedback
For any corrections of factual information, to contact the editors or to send any medical news or health news press releases, use feedback form

Top of Page

 
Contact us

RxPG Online

Nerve

 

    Full Text RSS

© All rights reserved by RxPG Medical Solutions Private Limited (India)