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LITERATURE REVIEW
Work has been carried out on a broad range of different insect species. A review by Rees (1985) covers work on
the spectral and behavioural responses of 22 stored product insects to lights of different wavelengths with specific
reference to fly killer designs.
There have been many other studies on non-stored product insects. Crescitelli and Jahn (1938) showed the
electrical response of the grasshopper eye was maximally stimulated with light in the green spectrum. Mote and
Goldsmith (1970) discovered that there are separate UV (in the UVA spectrum) and green receptors in the eye of
the cockroach, Periplaneta americana. McCann and Arnett (1972) and more recently Bellingham and Anderson
(1993) studied Dipteran species and found spectral sensitivity peaks in the UVA, the green and another peak in
the red region at 630nm. They also discovered a difference in light sensitivity between the sexes and in different
regions of the eye.
Markze et.al.(1973) showed that the electrical response of the eye of a variety of stored product insects was
particularly sensitive to light between 520nm and 560nm. This was backed up in behavioural experiments from
Kirkpatrick et.al (1970) (1972) who found in general that stored product moths were more attracted to green light
and stored product beetles to UVA light. However, the picture is not as clear cut as that. Roppel and Butler (1970)
and Stermer (1958,1959,1966) tested a number of stored product beetles; Attagenus megatoma, Rhyzopertha
dominica and Tribolium castaneum and found them to be more attracted to green light with Plodia interpunctella
(a stored product moth) more attracted to UVA light.
COMMISSIONED STUDIES
The literature clearly demonstrates that insects are attracted to both UVA and green spectral peaks. Insect-OMatic
then decided to test what would happen if both peaks were emitted from the same light source. A lamp was
created by Sylvania (the Synergetic lamp, patented by Insect-O-Matic) that contains both UVA and green
phosphors and was tested in-house in 1993 by Insect-O-Matic scientists. The results showed that the Synergetic lamps were significantly more attractive to house flies than the UVA lamps.
However, in order to prove the validity of this research it was decided to commission independent testing of the
hypothesis. The work was carried out in 1995 by the Medical Entomology Centre at Cambridge. Veal et.al. showed
that lamps containing UVA + green phosphors (the Synergetic lamp) caught on average 30% more houseflies in a
2 hour period than lamps containing UVA phosphors only.
Given the previously referred to research on light sensitivities in Dipteran eyes that showed spectral peaks in both
UVA and green wavelengths, this result is perhaps not surprising.
In 1994, Insect-O-Matic commissioned further studies on the effects of Synergetic lamps on mosquitoes. The
work was carried out by Hill (1994) at the London School of Hygiene and Tropical Medicine. Whilst it is well
documented that mosquitoes are attracted to a range of stimuli of which light in just one, Synergetic lamps were
more effective in attracting mosquitoes than other lamps.
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