Drosophila Stock Maintenance

Abstract

An insect culture maintenance system includes a sequence of open-ended cylindrical tubes [500, 502, 504, 506] joined pairwise alternately at their tops and bottoms using multiple dual-cap connectors. Each dual-capped connector has a channel from an inside of a first cap to an inside of a second cap. In use, connectors that cap the bottoms of the tubes [508, 512] are filled with insect food media [518, 520], while connectors that cap the tops of the tubes [510] are open. As a result of this design, adults pass from one tube to the next through the top dual-cap connectors, while larvae pass from one tube to the next through the bottom dual-cap connectors, resulting in propagation of subsequent generations of insects through the sequence of tubes.

Claims

1-3. (canceled)

4. An insect culture system comprising: a first cap having a top wall and a cylindrical side wall extending from the top wall, the top wall and the cylindrical side wall of the first cap defining a first cavity configured to receive an open end of a first tube, the cylindrical side wall of the first cap having a first side opening; a second cap having a top wall and a cylindrical side wall extending from the top wall, the cylindrical side wall of the second cap defining a second cavity configured to receive an open end of a second tube, the cylindrical side wall of the second cap having a second side opening; and a channel interconnecting the first side opening and the second side opening for propagating insects between a first tube coupled to the first cap and a second tube coupled to the second cap.

5. The insect culture system according to claim 4, wherein the cylindrical side wall of the first cap has a first inner diameter defining a first cylindrical region and a second inner diameter defining a first cylindrical space, wherein the second inner diameter is smaller than the first inner diameter such that the first tube is insertable only into the first cylindrical region.

6. The insect culture system according to claim 5, wherein the first cylindrical region is concentric with the first cylindrical space.

7. The insect culture system according to claim 4, wherein the cylindrical side wall of the second cap has a second inner diameter defining a second cylindrical region and a second inner diameter defining a second cylindrical space, the second inner diameter is smaller than the second inner diameter such that the second tube is insertable only into the second cylindrical region.

8. The insect culture system according to claim 7, wherein the second cylindrical region is concentric with the second cylindrical space.

9. The insect culture system according to claim 4, wherein the first cap, the second cap, and the channel are a unitary structure made of a single molded ductile material.

10. The insect culture system according to claim 4, wherein each of the first cap, the second cap, and the channel is made of at least one of plastic, silicone, or rubber.

11. An insect culture system comprising: a first tube having a first open end; a second tube having a second open end; and a dual-capped connector including: a first cap including a top wall and a cylindrical side wall extending from the top wall, the top wall and the cylindrical side wall of the first cap defining a first cavity configured to receive the first open end of the first tube, the cylindrical side wall of the first cap having a first side opening; a second cap including a top wall and a cylindrical side wall extending from the top wall, the cylindrical side wall of the second cap defining a second cavity configured to receive the second open end of the second tube, the cylindrical side wall of the second cap having a second side opening; and a channel interconnecting the first side opening and the second side opening for propagating insects between the first tube and the second tube.

12. The insect culture system according to claim 11, wherein the cylindrical side wall of the first cap has a first inner diameter defining a first cylindrical region and a second inner diameter defining a first cylindrical space, wherein the second inner diameter is smaller than the first inner diameter such that the first tube is insertable only into the first cylindrical region.

13. The insect culture system according to claim 12, wherein the first cylindrical region is concentric with the first cylindrical space.

14. The insect culture system according to claim 11, wherein the cylindrical side wall of the second cap has a second inner diameter defining a second cylindrical region and a second inner diameter defining a second cylindrical space, wherein the second inner diameter is smaller than the second inner diameter such that the second tube is only insertable only into the second cylindrical region.

15. The insect culture system according to claim 14, wherein the second cylindrical region is concentric with the second cylindrical space.

16. The insect culture system according to claim 11, wherein the dual-capped connector is made of a single molded ductile material.

17. The insect culture system according to claim 11, wherein the dual-capped connector is made of at least one of plastic, silicone, or rubber.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0010] FIG. 1 is a perspective view of a collection of tubes and dual-cap connectors that may be assembled to form an insect culture maintenance system, according to an embodiment of the invention.

[0011] FIG. 2A and FIG. 2B are a top view and perspective view, respectively, of a dual-cap connector, according to an embodiment of the invention.

[0012] FIG. 3 is a perspective view of a dual-cap connector, illustrating the movement of flies from the inside of one cap to the inside of another, according to an embodiment of the invention.

[0013] FIG. 4 is a perspective view of a dual-cap connector, illustrating the movement of larvae from the inside of one cap to the inside of another, according to an embodiment of the invention.

[0014] FIG. 5 is a perspective view of an assembled insect culture maintenance system, according to an embodiment of the invention.

[0015] FIG. 6 is a flowchart outlining the steps of a method for maintaining an insect culture, according to an embodiment of the invention.

[0016] FIG. 7 is a perspective view of an assembled insect culture maintenance system illustrating the movement of insects through the system, according to an embodiment of the invention.

[0017] FIG. 8 is a perspective view of components of an insect culture maintenance system, according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0018] In one embodiment of the present invention, an insect culture system may be assembled from a collection of components, which may be provided in the form of a kit. For example, FIG. 1 shows a collection of tubes 100a, 100b, 100c, 100d and dual-cap connectors 102a, 102b, 102c that may be assembled to form an insect culture maintenance system. The tubes and the dual-capped connectors are sized such that the caps of the dual-capped connectors fit on the ends of the tubes to close the ends. The tubes are open-ended cylindrical tubes preferably made of a durable, rigid, transparent material such as glass or hard plastic. Although the tubes are preferably open-ended cylinders, they could also have one or both ends be partially closed, or closed with a small hole, e.g., 3/16 inch (5 mm) or more in diameter.

[0019] Two detailed views of a dual-capped connector are shown in FIG. 2A and FIG. 2B. The dual-cap connector is preferably made of a single molded material, preferably a durable material such as plastic, silicone or rubber which may be partly ductile to facilitate placement of the caps on the ends of the tubes. Reinforcing portion 114 provides mechanical strength to help ensure that the two caps of the dual-capped connector do not break apart.

[0020] The connector has two caps, each designed to cover an end of one of the tubes. Specifically, the two cylindrical regions 116 and 118 are designed so that the ends of two tubes may be securely inserted into them. For example, the outer surface of one tube forms a fit with the cylindrical inner cap wall 104. The caps include cylindrical spaces 110 and 112 that remain above the lip of an inserted tube. For example, the cylindrical inner cap wall 106 has a diameter smaller than the outer diameter of the inserted tube, e.g., it may be equal to the inner diameter of the inserted tube. An essential feature of the dual-capped connector is the opening 108 connecting the cylindrical spaces 110 and 112 to form a single connected space. The channel 108 is preferably oriented horizontally and positioned within the inside of the caps at a vertical position such that it is not close to the rim of an inserted tube. This passageway or channel 108 from the inside of the first cap to the inside of the second cap preferably has a 3/16 inch (5 mm) diameter cylindrical shape. In some embodiments, there may be different channel diameters for different dual-cap connectors. For example, the dual-cap connectors may be of two different types, where first and second types have different opening sizes. The dual-cap connector shown in these figures is illustrative, and those skilled in the art will appreciate that various other designs can implement the same function. For example, in alternative embodiments, the dual-cap connector is formed of two separate caps with holes connected by a short tube. Yet another embodiment is discussed below in relation to FIG. 8.

[0021] FIG. 5 illustrates how the tubes and dual-cap connectors are assembled to form an insect culture maintenance system. Four cylindrical tubes 500, 502, 504, 506 are arranged with their longitudinal axes in parallel. The axes do not necessarily need to be in the same plane. First and second tubes 500 and 502 are connected at their bottoms with a dual-cap connector 508. Similarly, third and fourth tubes 504 and 506 are connected at their bottoms with a dual-cap connector 512. Second and third tubes 502 and 504 are connected at their tops with a dual cap connector 510, which may be of a different type than connectors 508 and 512. The tops of the first tube 500 and fourth tube 506 are capped or plugged, e.g., with terminal caps 514 and 516 (shown as cotton balls in FIG. 5).

[0022] Connectors 508 and 512 are half-filled with food media 518 and 520, respectively. As illustrated in FIG. 4, as larvae 406 eat the food media 408, they can move through channel 404 from the inside of cap 400 to the inside of cap 402, according to an embodiment of the invention. In contrast, the movement of adult insects from the inside of cap 400 to the inside of cap 402 is blocked by the food media 408. The food media fills only the deepest inside half of the cap (e.g., space 110 of FIG. 2B), leaving the other half (e.g., space 116 of FIG. 2B) clear for unobstructed insertion of the tube. In alternative embodiments, the food media can completely fill the entire cap. This can be achieved, for example, by filling the cap with food media after insertion of the tube into the cap.

[0023] Returning to FIG. 5, connector 510 is not filled with food media, so that its open passageway allows adult (flying or crawling) insects to freely pass from tube 502 to tube 504. The length of the tubes is such that the larva are unlikely to crawl to the top of the tube. The tube can be provided in any such length including at least 60 mm, at least 70 mm, at least 80 mm, at least 90 mm, at least 95 mm, at least 100 mm, at least 110 mm, at least 120 mm at least 150 mm, or more than 150 mm in length, or can be provided in any range of length such as between 60 mm and 150 mm, between 90 mm and 110 mm, or between 93 mm and 97 mm. As illustrated in FIG. 3, flies 306 can move freely through channel 304 from the inside of cap 300 to the inside of cap 302. In contrast, the eggs, larvae, and pupae are confined to the bottom of the tube where the food media is located. Thus, the tubes in FIG. 5 are arranged in a sequence with alternating passageways: the bottom dual caps are filled with food media so that only larvae can pass from one tube to the other, and the top dual caps have unfilled openings so that only flying adults can pass from one tube to the other.

[0024] The steps of a method for maintaining an insect culture using the system described above is shown in the flowchart of FIG. 6. These steps will be described with reference to the assembled insect culture maintenance system shown in FIG. 7. In step 600, a sequence of tubes are connected using dual-cap connectors, where the connectors at the bottoms of the tubes are filled with food media, while the connectors at the tops of the tubes are not filled with food media. F.sub.0 adult insects are inserted in the first tube, and the tube is capped to prevent their escape. The F.sub.0 adults lay F.sub.1 generation eggs in the food media. In step 602, these F.sub.1 eggs grow into F.sub.1 generation larvae 700 that eat the food media and propagate through the first dual cap from the first tube to the second tube. These F.sub.1 generation larvae then mature into F.sub.1 generation adults 702 in the second tube. In step 604, these F.sub.1 generation adults 702 propagate through the second dual cap from the top of the second tube to the top of the third tube where they lay F.sub.2 generation eggs in the food media at the bottom of the third tube. In step 606, these F.sub.2 eggs grow into F.sub.2 generation larvae 704 that propagate through the third dual cap from the third tube to the fourth tube where they mature into F.sub.2 generation adults 706 in the fourth tube. Steps analogous to steps 604 and 606 can be repeated for subsequent generations with additional tubes and connectors. As shown in the figure, F.sub.n-1 larvae 708 mature into F.sub.n-1 generation adults 710 which propagate via a top connector to the next tube. The F.sub.n-1 generation adults 710 then lay F.sub.n generation eggs that mature into F.sub.n generation larvae 712 which propagate via a bottom connector to the next tube. The process concludes as the F.sub.n generation larvae 712 mature into F.sub.n generation adults in the last tube.

[0025] As shown in FIG. 8, in an alternate embodiment of an insect culture maintenance system, the sequence of tubes 802, 804, 806, 808 has the form of a single slab 800 of material with parallel cylindrical passageways through it, and the sequence of caps has the form of a first multi-cap connector 810 to cover the tops of the cylindrical passageways 802, 804, 806, 808, and a second multi-cap connector 820 to cover the bottoms of the cylindrical passageways 802, 804, 806, 808. The multi-cap connectors have one or more dual-cap connectors built in to them to provide the same functionality as separate dual-cap connectors. The top multi-cap connector 810 has a space 812 cut out so that it fits over the top end of slab 800. Similarly, the bottom multi-cap connector 820 has a space 822 cut out so that it fits over the top end of slab 800. The top multi-cap connector 810 includes a single dual-cap connector with caps 814 and 816 joined by channel 818. The bottom multi-cap connector 820 includes two dual-cap connectors, one with caps 824 and 826 joined by channel 828, and another with caps 830 and 832 joined by channel 834.