- 1. Importance of Color in InsectControl: Sweetpotato
WeevilNirupa Gadi Conrad High School Conrad, MT 59425
2. Introduction Sweetpotatoes are the sixth mostimportant crop
in the world They are nutritious, high incarbohydrates, proteins,
Vitamin A,riboflavin, and calcium Leaves can also be used as
avegetable Sweetpotatoes can also play a vitalHealthy
Sweetpotatoesrole in future energy supply fromorganic production 3.
Problems The Sweetpotato Weevil (Cylasformicarius) is one of the
mostserious insects that causes damageto the sweetpotato crop Even
a small grub population cancause severe damage to the roots ofa
plantGrub of the Sweetpotato Weevil Because of the high incidence,
manyfarmers are frustrated and are givingup cultivation. Without
proper and effective control,they may cause complete loss
ofsweetpotato productionDamaged Sweetpotatoes 4. Problems (contd)
Control methods such as usingtoxic pesticides are somewhateffective
but are not desirable tothe environment There is an urgent need
fordevelopment of an eco-friendlycontrol methods Pheromone traps
are currentlyStandard Trap Currently Being Usedbeing used for
monitoring, but noeffective control has been reached 5. Hypothesis
While reading some literature, I realized theimportance of color to
insects Each species of insect is attracted to a differentcolor
What color trap would attract the highest numberof weevils? Color
preference would help in mass trappingthese weevils from various
fields 6. Materials Nine standard unitraps Colored tapes of brown,
black, gray, yellow, red, white,green, and blue to cover eight of
the traps Stopwatch Datasheets Pencils and meter stick Pheromones
Sweetpotato Weevils 7. Methods Tests were conducted at the Chemical
Ecologyand Entomology Laboratory at the University ofGuam
Experiments were run in a dimly lighted laboratorywith the standard
unitrap of different colors Tested colors werebrown, black, gray,
yellow, red, white, green, andblue One standard trap was also added
as the control 8. Methods (contd) Different colored traps were
placedone meter from the center and hadan equal distance apart Ten
weevils were released in thecenter of the trap circle and givenfive
minutes to go to a trap The number of adults attracted bythe
different colored traps wereColor Choice Experiments Conducted in
arecorded for the duration of the time Laboratory 9. Methods
(contd) Two sets of test were carried out in the laboratory One set
was tested with a pheromone which is achemical that attracts
insects The other was conducted without a pheromone Each set was
repeated 70 times for validity 10. Analysis The total number of
weevils that responded percolor were combined and set as a
percentage thatwas attracted to each trap color 11.
ResultsPercentage ( SE) of sweetpotato weevils attracted to traps
(without pheromonelures) of different colors. Different letters
indicate significant differences between treatments (one-way
ANOVA)45 A40 20% increasePercentage of weevils
attracted3530B25BB2015 C10CC C CC 5C 0 Green StandardYellow Black
Brown Gray Blue RedWhite 12. Results (contd)Percentage ( SE) of
sweetpotato weevils attracted to traps (with pheromone lures of
different colors. Different letters indicate significant
differences between treatments (one-way ANOVA)70 A60Percentage of
weevils attracted 42.5% increase504030B20 C10C CCCCC 0 Green
Standard YellowBlack Brown Gray Blue RedWhite 13. Results (contd)
Green colored traps were most attractive to theweevil compared to
the standard (a combinationof white, yellow, and green) traps
Without pheromone, they drew 20% more than thestandard traps that
were currently used With the pheromone, the green traps lured
42.5%more weevils than the standard traps 14. Discussion The green
colored traps attracted nearly 50%more weevils than the currently
used standardtrap My results are agreed with the results
ofFrederiksen et al. (2008), Kelber et al.(2003), Reddy and Raman
(2011) They indicated the color importance for insects I recommend
my results for the sweetpotatoweevil control 15. Conclusions My
study showed that green coloredtraps with a pheromone
highlyattracted sweetpotato weevils If used by farmers, we can trap
mostof the weevils by this attract and killmethod and save the
sweetpotatocrops You can kill the weevils with thesetraps by
filling them halfway withsoap water When the weevils enter thetrap,
they will drown Effective Green Colored Trap 16. References Kelber,
A., A. Balkenius, and E.J. Warrant. 2003.Color vision in diurnal
and nocturnal hawkmoths.Integrat. Comp. Biol. 43: 571-579.
Fredericksen, R., W.T. Wcislo, and E.J. Warrant.2008 Visual
reliability and information rate in theretina of a nocturnal bee.
Curr. Biol. 18: 349-353. Reddy, G.V.P., and A. Raman. 2011. Visual
cuesare relevant in behavioral control measures forCosmopolites
sordidus (Coleoptera:Curculionidae). J. Econ. Entomol. 104:
436-442. 17. Acknowledgements I would like to thank G.V.P. Reddy
for providing labfacilities and for guidance I acknowledge the help
I received from the staff ofthe Chemical Ecology Laboratory at the
Universityof Guam I would also like to thank Sigma Xi for giving
methe opportunity to present my results
