Insect catching device

An insect catching device having (a) a radiation source which emits a wavelength that is suitable for attracting insects, (b) a quantity of an adhesive material provided on a surface of the device on which insects impinge when attracted to the device by the radiation source, and (c) a shield for restricting direct exposure of the adhesive material to radiation from the radiation source.

This invention relates to an insect catching device. The invention is
 concerned in particular with a device of the kind which comprises a source
 of radiation having a wavelength suitable for attracting insects to the
 device, and a quantity of an adhesive material provided on the surface of
 the device of which insects attracted to the device by the radiation
 source impinge.
 Insect catching devices which use a radiation source to attract insects are
 known. The radiation will often have a wavelength in the ultraviolet
 region: suitable radiation sources will often emit radiation having a blue
 appearance. Radiation sources emitting radiation with a blue-green
 appearance are also known to be suitable for certain applications.
 Insects attracted to such a device by a radiation source can be retained in
 the device by means of an adhesive material provided as a coating on a
 surface of the device, generally behind the radiation source. Such a
 device will therefore often comprise one or more tube elements from which
 ultra violet radiation is emitted, and an adhesive coated back plate.
 Many adhesive materials which are suitable for use in such insect catching
 devices can be degraded when exposed to ultraviolet radiation. This leads
 to a reduction in the capability of such devices to retain insects within
 them. Frequent replacement of the adhesive material, generally on a
 pre-coated backplate, is required.
 The present invention provides an insect catching device which includes a
 shield to restrict direct exposure of adhesive material in an insect
 catching device to insect attracting radiation.
 Accordingly, in one aspect the invention provides an insect catching device
 which comprises:
 (a) a source of radiation having a wavelength that is suitable for
 attracting insects,
 (b) a quantity of an adhesive material provided on a surface of the device
 on which insects attracted to the device by the radiation source impinge,
 and
 (c) a shield for restricting direct exposure of the adhesive material on
 the said surface to radiation from the radiation source.
 The device of the present invention has been found to be capable of
 attracting insects to it as efficiently as devices which do not include a
 shield. Moreover, the presence of a shield has been found to prolong the
 period in which the adhesive material provided to collect insects is
 effective. This therefore results in greater convenience in operation of
 the device of the invention, and reduced operating cost.
 Moreover, a shield can be used to enhance the lifetime of an adhesive
 insect collection material while also allowing the radiation source (such
 as a fluorescent tube) to be positioned close to the adhesive material to
 maximise insect attraction.
 The radiation source used in the device of the invention will generally be
 provided by a fluorescent tube element. Such elements can emit radiation
 on a suitable wavelength for attracting insects. Such radiation would
 generally be ultraviolet radiation. Suitable ultraviolet radiation might
 have, for example, a purple appearance or a blue-green appearance. The
 radiation source can be provided as an elongate tubular body. The tubular
 body can be straight, for example to extend between connecting terminals
 at opposite ends thereof. The radiation source can alternatively have its
 connection terminals provided adjacent to one another at one end thereof,
 the radiation source having a generally curved configuration.
 The shield will preferably extend along substantially the entire length of
 the body of the radiation source. For example, when the radiation source
 provides an elongate, generally straight, tubular body, the shield will
 extend along substantially the entire length of the tubular body.
 The shield can be provided as a coating on the radiation source. For
 example, when the radiation source comprises a generally tubular body,
 that body can be provided with a coating, over at least a substantial part
 of the portion of the body which faces the adhesive coated surface of the
 device when in use.
 A shield that is separate from the radiation source can also be used. The
 shield will then comprise an element that is located between the radiation
 source and the adhesive coated surface of the device. The element can be
 self supporting, so that it is sufficiently rigid to be able to retain a
 suitable configuration to act as a shield even when supported at only one,
 two or more points along its length. A suitable shield can be provided by
 an appropriately formed sheet of metal or other material (for example
 polymeric or ceramic material) having suitable shield properties.
 Preferably, the shield will be constructed so that the intensity of
 radiation that impinges on the adhesive coated surface of the device is
 not more than about 80% of the level in the absence of the shield.
 Preferably, the intensity is not more than about 65%, especially not more
 than about 45%, for example, not more than about 25% of that figure.
 The shield can restrict direct exposure of the adhesive material to
 radiation from a radiation source by, for example, absorption of the
 radiation or reflection. Reflection of the radiation will be particularly
 appropriate for many applications (although non-reflective shields can
 perform satisfactorily). This can be achieved by use of a reflective
 material for the surface of the shield which faces the radiation source.
 For example, when the shield is provided by a coating on the radiation
 source, the coating can be a metallised coating. When the shield is
 provided as an element located between the radiation source and the
 adhesive coated surface, a reflecting surface can be provided by
 polishing, or by an appropriate surface coating.
 The adhesive material can be provided on a surface of the housing of the
 device. Preferably, however, the adhesive coating is provided on a sheet
 element which can be loaded into the device for use, and removed when its
 fly collecting properties have deteriorated, for example due to
 deterioration of the adhesive properties of the adhesive material, or due
 to collection of a large number of insects. The element can be received in
 appropriate formations such as grooves or slots in the device housing.
 Suitable adhesive materials for use in the device of the invention are
 known, and are available widely on pre-coated sheets for insect
 collection.

Referring to the drawings, an insect catching device 2 comprises a housing
 4. The housing is open over a front face, which is covered by a grill,
 which is not shown in the drawings for the sake of clarity.
 A plurality of radiation emitting fluorescent tubes 8 are located in the
 housing. The tubes are straight, extending from one side of the housing to
 the other.
 The rear internal surface 10 of the housing is covered by a removable sheet
 element 12, having an adhesive material over its exposed surface facing
 towards the radiation source tubes and the grill. The adhesive coated
 sheet can be slid into the housing through a slot in the top face of the
 housing, received in appropriate vertical grooves 14 at each end of the
 housing.
 Separate shields 16 are provided between each of the fluorescent tubes and
 the adhesive coated surface. The shields are formed from aluminum. The
 surface of the shields which faces towards the tubes can be polished so
 that radiation from the tubes is reflected by the shield away from the
 adhesive coated surface. The shields are concave when viewed along the
 axis of the radiation source tubes. The shields restrict exposure of the
 adhesive coated surface to radiation from the radiation source tubes.
 In use, insects are attracted to the device by radiation from the radiation
 source tubes. Such insects pass the tubes and impinge on the adhesive
 coated surface. They are retained on the surface by the adhesive.
 The shields provided between the radiation source tubes and the adhesive
 coated surface restrict exposure of the surface to radiation. This
 restricts degradation of the adhesive material which would otherwise
 result from its exposure to ultraviolet radiation.