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:2/8/2016)... ... February 08, 2016 , ... Steve Helwig & Associates ... vital new community enrichment program, has teamed up with Citizens Opposed to Domestic Abuse ... from intimate abuse. To support all those victimized by the fear of violence in ...
(Date:2/8/2016)... , ... February 08, 2016 , ... Delta Dental of ... help combat pancreatic cancer. , Gary D. Radine, who recently retired as president and ... American Cancer Society’s 2015 CEO of the Year , helped lead the effort ...
(Date:2/8/2016)... ... February 08, 2016 , ... ... While a significant number of women and men with eating disorders report a ... that best predicts the development of an eating disorder. , At the ...
(Date:2/8/2016)... , ... February 08, 2016 , ... ... than 50% lower incidence rate of type 2 diabetes in the GrassrootsHealth cohort ... is time to make a change in public health,” states Carole Baggerly, Director ...
(Date:2/8/2016)... ... February 08, 2016 , ... ... speaking on how healthcare companies can use newly released government data on populations ... a population and intervene and capture the value they create to succeed in ...
Breaking Medicine News(10 mins):
(Date:2/8/2016)... EAST NORRITON, Pa. , Feb. 8, 2016 ... acquisition of November Research Group (NRG),s pharmacovigilance ... of pharmacovigilance system-related consulting services and an Oracle ... regulatory compliance services to Life Sciences companies. ... acquisition strengthens and expands HighPoint,s life sciences capabilities ...
(Date:2/8/2016)... Pa. , Feb. 8, 2016  As part of ... has announced today the appointment of Lori Chmura ... than 20 years in the industry, Chmura,s extensive experience in ... the advancement of Dune Medical Devices. ... will be responsible for leading all sales, marketing and operational ...
(Date:2/8/2016)... Velano Vascular, a medical technology company transforming ... their practitioners, announced today that the company has raised ... the proceeds from this financing, an extension of a ... to support the development and commercialization of the company,s ... Philadelphia , and a number ...
Breaking Medicine Technology: