OVITRAP AND METHOD OF CONTROLLING VECTOR BORN DISEASE

Abstract

The present invention relates to an ovitrap (10) and novel method of controlling mosquito populations comprising the use of light (20) to create a photo stimulus, causing mosquito larvae (102) to move from a location (Va), where gravid mosquitoes have deposited their eggs, in a direction away from the light, to a location (Vb). where they are trapped and killed. The ovitrap utilises this behaviour to more effectively capture and kill larvae. The ovitrap comprises a container (12), a cover (14), and a means (16) for dividing the container (12) into two regions (101; 102), which in use are filled with water, and which communicate via an opening (26) such that a volume (Vb) below the means (16) defines a larvae (102) trapping region, and a volume (Va) above the means (16) defines an egg (101) receiving region. A light source (20) is mounted above the container (12) and is positioned to direct light downwards at a water surface (92), such that when the light is turned on, it creates a photo stimulus, and the larvae (102) respond by moving in a direction away from the light, from the volume above (Va) into the volume below (Vb) via opening (26). A gating mechanism (18) opens and closes the opening (26) when the light is respectively turned on and off, such that the larvae are trapped in the volume below

Claims

1.-32. (canceled)

33. An ovitrap comprising a container, which in use is filled with water and a water conditioning agent, characterised in that the container is connected to a water tank with a mechanism ensuring an appropriate water level in the ovitrap is maintained.

34. An ovitrap as claimed in claim 33, wherein the water tank comprises a receptacle with an outlet, lid, and hose.

35. An ovitrap as claimed in claim 33, wherein the water tank further comprises one or more of adjustable legs, a water conditioning cage, and a water inlet valve.

36. An ovitrap as claimed in claim 34, wherein the water tank further comprises one or more of adjustable legs, a water conditioning cage, and a water inlet valve.

37. An ovitrap as claimed in claim 33, wherein flow is controlled by a valve mechanism, comprising a valve body, float arm and float.

38. An ovitrap as claimed in claim 34, wherein flow is controlled by a valve mechanism, comprising a valve body, float arm and float.

39. An ovitrap as claimed in claim 35, wherein flow is controlled by a valve mechanism, comprising a valve body, float arm and float.

40. An ovitrap as claimed in claim 33, wherein the container comprises a mechanism for locating a cover, and the cover has a lower portion, which is shaped to facilitate location and retention.

41. An ovitrap as claimed in claim 34, wherein the container comprises a mechanism for locating a cover, and the cover has a lower portion, which is shaped to facilitate location and retention.

42. An ovitrap as claimed in claim 35, wherein the container comprises a mechanism for locating a cover, and the cover has a lower portion, which is shaped to facilitate location and retention.

43. An ovitrap as claimed in claim 37, wherein the container comprises a mechanism for locating a cover, and the cover has a lower portion, which is shaped to facilitate location and retention.

44. An ovitrap as claimed in claim 33, wherein the cover comprises a surface, which is adapted to assist a female mosquito to position herself for optimal egg laying.

45. An ovitrap as claimed in claim 34, wherein the cover comprises a surface, which is adapted to assist a female mosquito to position herself for optimal egg laying.

46. An ovitrap as claimed in in claim 35, wherein the cover comprises a surface, which is adapted to assist a female mosquito to position herself for optimal egg laying.

47. An ovitrap as claimed in in claim 37, wherein the cover comprises a surface, which is adapted to assist a female mosquito to position herself for optimal egg laying.

48. An ovitrap as claimed in claim 40, wherein the cover comprises a surface, which is adapted to assist a female mosquito to position herself for optimal egg laying.

49. An ovitrap as claimed in claim 44, wherein the surface of the cover is roughened.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:

[0070] FIG. 1 is a cross sectional view of an assembled ovitrap, showing the different parts of the trap;

[0071] FIG. 2 is a cross sectional view of a funnel component;

[0072] FIG. 3 is a cross sectional view of a container component;

[0073] FIG. 4 is a cross sectional view of a cover component;

[0074] FIG. 5 is a cross sectional view of a light array;

[0075] FIG. 6 is a cross sectional view of a gating mechanism;

[0076] FIG. 7 is a cross sectional view of the ovitrap with the gating mechanism in an “open”-“lights on” position;

[0077] FIG. 8 is a cross sectional view of the ovitrap with the closure component in an “closed”-“lights off” position;

[0078] FIGS. 9A, 9B and 9C illustrate the assembled ovitrap of the invention in use;

[0079] FIG. 9A shows recently hatched larvae in a water filled ovitrap—“lights off”;

[0080] FIG. 9B shows larvae moving in response to the light stimulus—“lights on”;

[0081] FIG. 9C shows larvae in a water filled trap—“lights off”;

[0082] FIG. 10 shows a second embodiment of ovitrap with a solar cell;

[0083] FIG. 11 is a block diagram showing the electronics for the ovitrap of FIG. 10;

[0084] FIG. 12 is a diagram illustrating light with a colour temperature in the range 5000K-10000K;

[0085] FIG. 13 is a diagram illustrating a cool white spectrum, with two peaks, a first peak at about 450 nm-470 nm and a second peak at about 500 nm-700 nm contrasted to a warm white light;

[0086] FIG. 14 is an ancillary water tank, for use with an ovitrap of the invention, with its lid removed;

[0087] FIG. 15 is an illustration of the water tank of FIG. 14 connected to an ovitrap; and

[0088] FIG. 16 is a cross section view of the embodiment illustrated in FIG. 15.

DETAILED DESCRIPTION

[0089] The Figs illustrate an ovitrap (10) according to a first aspect of the invention.

[0090] In the FIG. 1 embodiment illustrated, the ovitrap comprises five primary structural components, (illustrated separately in FIGS. 2-6) a container (12), a cover (14), a funnel (16), a gating mechanism (18) and a light source (20).

[0091] The funnel (16) comprising a wide mouth (22) and a narrow stem (24) with an opening (26) at the bottom of the stem, which funnel is seated in the container (12), which in use is filled with water, such that its' stem (24) is positioned such that its' opening (26) is located towards the base (28) of the container (12). The funnel (16) has a rim (30) with locating apertures (not shown) allowing the funnel to be retained by lugs (32), on stops (34) which project inwardly from the inner wall (36) of the container (12).

[0092] Cover (14) (See FIG. 4) comprises a lower portion (38) which is shaped and sized to sit on the rim (30) of the funnel (16) snugly within the upper confines (40) of the container (12). The cover comprises side walls (42), with openings (44), which project upwardly away from the lower portion (38), a cross member (46) which supports the light source (20), and a top portion (48) which contains a void (50) and is shaped to house the gating mechanism (18), and electronics (52) as broadly illustrated in FIGS. 6 and 11. The top portion is also shaped to allow water to run off its outer surface (54) and has a portion (56) which extends peripherally beyond the container (12) boundaries. This provides an attractive environment for the gravid female mosquitoes and helps limit evaporation of water from the trap.

[0093] Mounted in the void (50) within the top portion (48) is the gating mechanism (18) which comprises a shaped plug member (58) which engages the funnel (16) where it narrows to the stem (24). The plug member sits at the end of a rod (60) which can be moved up and down from its normal closed position (62) (FIG. 8), where it is in a downward position closing the opening (26) in the stem (24), to an open position (64) (FIG. 7), where it is in a raised upward position, opening the opening (26) in the stem (24).The rod is operated by the action of a solenoid (66) which is controlled by a solenoid driver (68) operated by a microprocessor (70) powered by a battery (72) or other power source. The solenoid driver (68) is synchronised with a light (LED) driver (74) so that the mechanism is “open” when the lights (20) are turned on and “closed” when the lights (20) are turned off.

[0094] The turning on and off is controlled by a clock (76) and/or light sensor (78). The ovitrap also has a temperature sensor (80) and humidity sensor (82) for data gathering facilitating effective “remote” management.

[0095] In the FIG. 10 embodiment the trap is provided with a solar panel (84) which links with a charger (86) to the battery (72) and a power convertor (88) although the trap can also be mains operated via a mains adaptor (90) if desired.

[0096] Turning to FIG. 9a-c the following describes the devices method of operation. An ovitrap is first assembled, filled with water, preferably distilled or conditioned water (aged). To this may be added organic attractants (including mosquito eggs), insect growth regulators, pheromones or the like and the gating mechanism checked to ensure it will operate as desired.

[0097] FIG. 9a shows an ovitrap after eggs have hatched. Before this however, a gravid mosquito will have been attracted to the trap, which is filled with water (shaded) and which may contain additional attractants to just below the container surface (92). Gravid mosquitoes enter the ovitrap via openings (44), land on the surface (39) of the lower cover (38) and deposit their eggs on the meniscus of a volume of water (darker hatching) above (Va), and above the funnel (16) which volume defines an egg (101) receiving region. In this state the lights (20), which are directed downwardly towards the water surface (92), are turned off, and the plug (58) of the mechanism (18) closes the funnel opening (26) separating, and preventing communication between, the volume of water above (Va) and a volume of water below (Vb) (lighter hatching).

[0098] In order to kill the larvae (102), they are “herded” from the volume above to the volume below, where they are trapped. To facilitate this movement and trapping the light (20) and gating mechanism (18) operate such that the gating mechanism is opened when the lights (20) are turned on (FIG. 9b). In response to the light stimulus, preferably a light stimulus which emits an intense light, the larvae of, particularly, Aedes aegypti or Aedes albopictus, swim away from the light, through the opening (26) into the volume below (Vb). The light need only be triggered for a short period, programmed anywhere up to 300 seconds, which is a sufficient duration for the larvae to move from Va to Vb, whereupon the light is switched off and the plug closed (as FIG. 9c). The trapped larvae (102) swim upwards, are trapped in the volume below (Vb), and eventually die from oxygen starvation (suffocation). Their brief presence however, stimulates other gravid females to deposit eggs, and the process of turning the lights and gating mechanism on and off ensures substantially that all future larvae are trapped and suffocated, thus providing effective mosquito and disease control.

[0099] Lights may be triggered daily, every few days or weekly depending on the requirement.

[0100] As the trap allows larvae to survive for some period within the trap, but not emerge as an adult, it has the added effect of making the trap more effective over time since larvae that survive in the trap release pheromones that are detected by gravid females looking for suitable locations for egg laying. The more larvae present in the trap, the more likely nearby flying gravid females will detect it and lay eggs, as it shows that the water source is viable for its offspring.

[0101] The intense light preferably generates at least 5 lux, more preferably at least 100 lux, and more preferably still at least 200 lux. Most preferred is a light that generates between 270 and 310 lux, typically about 290 lux.

[0102] Most preferred is a lighting which emits light with a colour temperature of greater than 5000K, more preferably still, a colour temperature in the range 5000K-10000K as illustrated in FIG. 12.

[0103] Preferably the light has a cool white spectrum, with two peaks, a first peak at about 450 nm-470 nm and a second peak at about 500 nm-700 nm as illustrated in FIG. 13.

[0104] The preferred lighting comprises a LED light source.

[0105] The funnel (16) or container (12) may be impregnated with an Insect Growth Regulator (IGR), e.g. periproxifen or methoprene and/or pheromones or other attractants that will leech out into the water body at a controlled rate over time. The leeching of such additives will be internal to the trap.

[0106] FIG. 14 illustrates a water tank (200), with it's lid removed. It comprises a receptacle (202) with a plurality of height adjustable legs (204). The receptacle has a cage structure (206) for retaining a conditioning agent, such as hay, an outlet (208) and baffles (210) in the surrounding vicinity to reduce debris accumulating about the outlet.

[0107] As is more clearly seen in FIG. 15 the water tank (200) is fitted with a lid (212), and a hose (214) feeds the ovitrap (10). In detail, and as shown in cross section, FIG. 16, the receptacle (202) may be filled or connected to a water supply via an inlet (216) which, as illustrated, comprises a multi diameter hose attachment. The supply may be a mains supply or e.g. a separate feed, such as a water butt. A hose (214) takes a volume of water (Vc) from the water tank to the ovitrap (10), and flow is controlled by a valve mechanism (218), comprising e.g. a valve body (220), float arm (222) and float (224). The hose may comprise multiple sections (214a; 214b) connected about a connector (226) provided on the ovitrap.