chemical ecology for sustainable sorghum production in ethiopia
DESCRIPTION
This study was presented during the conference “Production and Carbon Dynamics in Sustainable Agricultural and Forest Systems in Africa” held in September, 2010.TRANSCRIPT
![Page 1: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/1.jpg)
Chemical Ecology for Sustainable Production of Sorghum in EthiopiaYlva Hillbur, Department of Plant Protection Biology, SLU
ABSTRACT: The sorghum chafer can cause devastating damage in ripening sorghum. The chafer is arelatively large (2.5 cm) scarab beetle and twenty or more of them can be found on each sorghumhead sucking out kernels in the milky stage. In dry-land parts of Ethiopia, where sorghum is animportant staple, crop losses of up to 70% due to sorghum chafer attack have been reported.Conventional management methods have proven unsuccessful in controlling the beetle. The famershave instead developed an alternative method using rotting fruit to attract beetles to a point source ofinsecticide. The method is built on the fact that the beetles, like most insects, use odors to find food.Although the method is promising fruit is scarce in some regions and the odor bait is thus variable. Asynthetic, standardized attractant would allow for constant use as well as for monitoring of beetlepopulations between regions and seasons. In a joint project between SLU and Addis Ababa Universitywe have studied the biology and chemical ecology of the sorghum chafer and identified two highlyactive odor attractants. One is a host plant component discovered by electrophysiological screening ofthe antennal response to a wide range of known fruit and flower volatiles. The other is a pheromonecomponent identified from extracts of the sorghum chafer females. Both compounds catch largenumbers of sorghum chafers when used as odor baits in traps in the field.
DISCUSSION AFTER PRESENTATION: There was a lot of interest in the project and questionsconcerned how many insect traps a farmer would need in order to catch enough beetle pests to beeffective, and what would the cost be. The project is starting to study this element now and next yearbut the effectiveness depends partly on the life cycle of the pest and the timing of the trapping. It thetraps can be produced cheaply enough it is anticipated that it could prove cost-effective.
![Page 2: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/2.jpg)
Chemical ecology for sustainable production of sorghum in Ethiopia
Ylva Hillbur, Department of Plant Protection Biology, SLU
![Page 3: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/3.jpg)
70% crop loss, difficult to control
![Page 4: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/4.jpg)
Sorghum chafer, Pachnoda interrupta
![Page 5: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/5.jpg)
![Page 6: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/6.jpg)
Fruit can be scarceVariable bait quality
![Page 7: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/7.jpg)
Objectives:
1.Standardize the traps with synthetic plant odor lure as bait
2. Increase efficiency by adding pheromones
![Page 8: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/8.jpg)
Different food sources – which odor signals?
Sorghum bicolor Abutilon figarianum
![Page 9: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/9.jpg)
Odor collection
![Page 10: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/10.jpg)
Which odor molecules do the samples contain?
Gas chromatography (GC)
![Page 11: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/11.jpg)
GC-EAD (GC-coupled Electro Antennographic Detection)
Which odor molecules can the insect smell?
![Page 12: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/12.jpg)
GC-EAD using beetle antennae
![Page 13: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/13.jpg)
Antennal response to sorghum odor
1.Tridecane 2.(Z)-3-Hexenol 3.1-Octen-3-ol 4.1-Octanol
![Page 14: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/14.jpg)
Antennal response to abutilon odor
1.(Z)-3-Hexenol 2.Tetradecane 3.Methyl salicylate 4.Methyl anthranilate
![Page 15: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/15.jpg)
Field testing
![Page 16: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/16.jpg)
Rasa
Embuay Bad
Field Sites
![Page 17: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/17.jpg)
Field trapping
![Page 18: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/18.jpg)
![Page 19: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/19.jpg)
![Page 20: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/20.jpg)
Wire mesh cage with bait placed here
Beetles
Wire meshcage
Sex pheromone
The trap
Odor bait
![Page 21: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/21.jpg)
The sorghum blend: as good as its’ best component
![Page 22: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/22.jpg)
The abutilon blend: as good as its’ best component
![Page 23: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/23.jpg)
• Single compounds good attractants
• Screening of several compounds by single sensillum recordings
![Page 24: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/24.jpg)
Locationof sensilla=Odor detectingsensory hairs
![Page 25: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/25.jpg)
Single sensillum recordingwith odor stimuli
![Page 26: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/26.jpg)
Stimulus: substance that activates neuron
1 sec 2 3 4
Single sensillum recording
![Page 27: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/27.jpg)
Field trapping – plant odors
• Strong attraction to 2,3-butanediol
![Page 28: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/28.jpg)
Do sorghum chafers use pheromones?
![Page 29: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/29.jpg)
![Page 30: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/30.jpg)
![Page 31: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/31.jpg)
![Page 32: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/32.jpg)
Wire mesh cage with bait placed here
Beetles
Wire meshcage
Sex pheromone
![Page 33: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/33.jpg)
Wire mesh cage with bait placed here
Beetles
Wire meshcage
Banana
Aggregation pheromone
![Page 34: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/34.jpg)
Field trapping – live insectsMean trap catch over four days
0
10
20
30
40
50
60
Unm.F Mated F M M+F Unm.F+Food
M +Food M+F +Food Food Control
malesfemales
Unmated females attract males
![Page 35: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/35.jpg)
Field trapping – live insectsMean trap catch over four days
0
10
20
30
40
50
60
Unm.F Mated F M M+F Unm.F+Food
M +Food M+F +Food Food Control
malesfemales
Mated females or malesare not attractive
![Page 36: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/36.jpg)
Field trapping – live insectsMean trap catch over four days
0
10
20
30
40
50
60
Unm.F Mated F M M+F Unm.F+Food
M +Food M+F +Food Food Control
malesfemales
Combining unmated females with
food increasesattraction
![Page 37: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/37.jpg)
Pheromone identification
• Multiple extractions of males and females
• Comparison of odor profiles
![Page 38: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/38.jpg)
Pheromone identification
• Multiple extractions of males and females
• Comparison of odor profiles
19 female-unique compounds
![Page 39: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/39.jpg)
Field trapping -female compounds
![Page 40: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/40.jpg)
Field trapping -female compounds
• Phenylacetaldehyde very attractive to both sexes
![Page 41: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/41.jpg)
Future plans
• Field testing of blends SUPERLURE!• Lures with high longevity• Cheap & efficient traps
![Page 42: Chemical Ecology for Sustainable Sorghum Production in Ethiopia](https://reader037.vdocument.in/reader037/viewer/2022102815/554bfe9ab4c9053f078b4bb8/html5/thumbnails/42.jpg)
Jonas Yitbarek Bekele Emiru Stefan Satya Gitachew Merid
Gashebesaw & the field team
Collaboration: Ministry of Agriculture, Addis AbabaFunding: Sida / SAREC