Navigation Links
Fewer aphids in organic crop fields
Date:7/13/2011

Farmers who spray insecticides against aphids as a preventative measure only achieve a short-term effect with this method. In the long term, their fields will end up with even more aphids than untreated fields. This has been reported by researchers at the Biocenter of the University of Wrzburg in the scientific journal PLoS One.

What's the status of the biodiversity in differently managed triticale fields? This is what the biologists at the Department of Animal Ecology & Tropical Biology wanted to find out. Triticale is a cross between wheat and rye. The cultivation of this crop is on the rise across the globe, because it delivers good yields even in poor soil conditions.

When comparing conventionally managed crop fields, which were either sprayed with insecticides or were left untreated, Jochen Krauss, Iris Gallenberger and Ingolf Steffan-Dewenter made a discovery, which should catch the attention of every farmer: "According to our results, the preventative application of insecticides against aphids does not produce any advantages even though it consumes a lot of time and money," Jochen Krauss sums up.

The scientists studied five triticale fields that were sprayed with insecticides against aphids, comparing them to ten other fields without any such treatment. "To be sure, the application of the insecticide led to a short-term decrease of the pest density," says Krauss. "After four week's time, however, significantly more aphids could be found in these fields than in insecticide-free fields. This also astonished the farmers who made their fields available for our study."

More aphids as a result of a decrease in natural enemies

The scientists offer two possible explanations for this phenomenon. One possibility is: The insecticides indiscriminately kill off beneficial animals that feed on the aphids, such as ladybugs or the larvae of lacewings and hoverflies. Because their enemies are missing, the aphids find it easier to return and proliferate than in insecticide-free fields.

Another possibility is an indirect effect: The insecticide just kills the aphids, after which their enemies leave the field for a lack of prey. Final result: In this scenario, the aphid population can also recover better after their return because the natural enemies are missing.

Greater biodiversity in organic crop fields

In conventional fields that have not been sprayed with insecticides, the pest control through natural enemies seems to work better thanks to the higher biodiversity in these fields. The biodiversity is far greater still in fields under organic management, as reported in PLoS ONE by the Wrzburg scientists.

The researchers found five times as many plant species and 20 times more types of pollinating insects in the 15 organic crop fields included in the study than they did in conventional fields. Furthermore, they detected three times as many natural enemies of aphids and five times fewer aphids in the organic fields than in the conventional fields.


'/>"/>

Contact: Dr. Jochen Krauss
j.krauss@uni-wuerzburg.de
49-093-131-82382
Pensoft Publishers
Source:Eurekalert  

Related biology news :

1. Fewer deaths with preventive antibiotic use
2. New MRI technique could mean fewer breast biopsies in high-risk women
3. The EU must allocate fewer emission allowances and stop making free allocations
4. Fewer honey bee colonies and beekeepers throughout Europe
5. Even small dietary reductions in salt could mean fewer heart attacks, strokes and deaths
6. Moa get fewer: Landmark study
7. Fragmented forests result in more snakes, fewer birds
8. Kids now see fewer television ads for sweets and beverages, but more for fast food
9. Rise in new terror groups globally, fewer coordinated attacks, report finds
10. Rapid growth in adolescence leads to fewer offspring, UC Riverside biologists find
11. Vet meds big shift to more women, fewer men driven by falling barriers, more female grads
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Fewer aphids in organic crop fields
(Date:3/30/2017)... 30, 2017 The research team of The ... (3D) fingerprint identification by adopting ground breaking 3D fingerprint minutiae recovery ... of speed and accuracy for use in identification, crime investigation, immigration ... ... A research team ...
(Date:3/29/2017)... 2017  higi, the health IT company that operates ... America , today announced a Series B investment ... EveryMove. The new investment and acquisition accelerates higi,s strategy ... transform population health activities through the collection and workflow ... higi collects and secures data today on behalf of ...
(Date:3/27/2017)... ROCKVILLE CENTRE, N.Y. , March 27, 2017 ... by Healthcare Information and Management Systems Society (HIMSS) ... Analytics Outpatient EMR Adoption Model sm . In ... top 12% of U.S. hospitals using an electronic ... recognized CHS for its high level of EMR ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... (PRWEB) , ... October 12, ... ... today announces publication of a United States multicenter, prospective clinical study that ... disposable, point-of-care diagnostic test capable of identifying clinically significant acute bacterial and ...
(Date:10/12/2017)... ... ... AMRI, a global contract research, development and manufacturing organization ... quality of life, will now be offering its impurity solutions as a stand-alone ... for all new drug products, including the finalization of ICH M7 earlier this ...
(Date:10/11/2017)... , ... October 11, 2017 , ... ... President Andi Purple announced Dr. Suneel I. Sheikh, the co-founder, CEO and ... Labs ), Inc. has been selected for membership in ARCS Alumni Hall ...
(Date:10/11/2017)... NJ (PRWEB) , ... October 11, 2017 , ... Personal eye wash is a basic ... one eye at a time. So which eye do you rinse first if a dangerous ... have Plum Duo Eye Wash with its unique dual eye piece. , “Whether ...
Breaking Biology Technology: