This study compared the efficacy of CDC light traps fitted with different light sources (incandescent, UV tube light, UV LED) for collecting outdoor-biting malaria mosquitoes. In semi-field dual choice tests, traps with UV tube light caught over 4 times as many An. gambiae and over 2 times as many An. arabiensis compared to traps with incandescent light. In field tests in western Kenya, traps with UV tube light caught over twice as many wild female Anopheles mosquitoes than traps with incandescent light. The UV tube light traps were most effective for collecting major malaria vectors and other mosquito species outdoors, highlighting their utility for malaria vector surveillance given high indoor insecticide use.

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P. O. Box 30772-00100 Nairobi, Kenya
icipe@icipe.org | www.icipe.org
INTRODUCTION
OBJECTIVE
RESULTS
IMPACT AND CONCLUSION
REFERENCES/FOOTNOTES
To compare different UV sources (tube light and LED) with
incandescent light for collecting An. gambiae s.s. and An. arabiensis
in both semi-field and field systems
1. Cohnstaedt, L. W., Gillen, J. I. Munstermann, L. E. 2008. Light-emitting diode technology
improves insect trapping. J Am Mosq Control Assoc, 24, 331-4.
2. Kline, D. L. 2007. Semiochemicals, traps/targets and mass trapping technology for mosquito
management. J Am Mosq Control Assoc, 23, 241-51.
3. Allan, S. A., Day, J. F. Edman, J. D. 1987. Visual ecology of biting flies. Annu Rev Entomol, 32,
297-316
This research is funded through a National Institute of Health (NIH) Grant
Claudia Wyer1, Margaret M. Njoroge2, Manuela Herrera-Varela2, Ulrike Fillinger1,2
1London School of Hygiene and Tropical Medicine, Malaria Centre, UK;
2icipe-Thomas Odhiambo Campus, Malaria Research Programme, Mbita, Kenya
Comparative light trap sampling of outdoor malaria vectors
Use Of Ultra Violet (UV) Light In CDC Light Traps Improves The Outdoor
Trapping Of Mosquitoes
Light trapping is a commonly used method for the collection of malaria
vectors. Standard Center of Disease Control (CDC) incandescent light
traps have long been used, however research suggests that ultraviolet
(UV) light may provide a more powerful visual cue than light in the
infrared spectrum. This study aimed to deduce the catch efficacy of UV
light traps versus incandescent light traps for insectary-reared
Anopheles gambiae s.s. and Anopheles arabiensis in a semi-field
setting, and for the major malaria vectors in the wild in western Kenya.
When both choice of traps in the semi-field were fitted with
incandescent light bulbs an approximately equal proportion of the
released mosquitoes were trapped (in test trap: An. gambiae s.s. 0.45,
95% CI 0.40-0.52; An. arabiensis: 0.48, 95% CI 0.42-0.55).
CDC light traps fitted with UV tube lights proved to be the most effective of the three light sources at trapping female host-seeking An, gambiae
s.s. and An. arabiensis mosquitoes in a semi-field system, and at trapping wild Anopheles mosquitoes in the field outdoors. Given the need for
monitoring malaria vector populations outdoors due to high insecticide coverage indoors, UV light traps can provide a useful tool for the
entomological surveillance of Anopheles mosquitoes.
• CDC light traps with
incandescent light, UV
tube light and UV light-
emitting diodes (LED).
• Dual-choice tests with
different combinations
of traps were set in an
80 m2 screened semi-
field system.
• Catch efficiency of the
traps compared in
recollecting 200 host-
seeking An. gambiae
s.s. and 200 An.
arabiensis released
each night for 8 nights.
• The three trap types
were tested in the field
in cattle-keeping
homesteads. The cattle
served as an odour
source.
• Experiments followed
randomised block
designs. Generalised
linear models were
used to generate odds
ratios (OR) or rate ratios
(RR) and associated
confidence intervals
(CI).
FemaleAnophelesmosquitoes
trapped
0
2
4
6
8
10
12
14
16
18
20
An. rivulorum An. coustani Mansonia spp.
Meanno.ofmosquitoestrapped
per
Species
INCAN LED UV UV TUBE
In the dual-choice tests host-seeking An. gambiae s.s. were 4 times
more likely to be trapped in the test trap with UV light than in the trap
with incandescent light, and An. arabiensis were 2 times more likely to
be trapped with the UV light trap than the incandescent light trap.
METHODS
An. gambiae s.s An. arabiensis
Under field conditions,
wild female Anopheles
were over twice as likely
to be trapped with UV
tube light than
incandescent light,
however, the LED
generated UV light did
not increase trapping
efficacy.
Dual choice semi-field test
Field trapping of mosquitoes
Major species of field collection
Diversity of mosquito
species were trapped in
the field.
Secondary malaria
vectors, An. coustani
and An. rivulorum, were
pre-dominant in
outdoor catches.
An. rivulorum
responded strongly to
UV tube light.
Mansonia, an important
vector of zoonotic
diseases, was
collected in large
number with UV light.