Bioassay is an important means used by our team which named Insecticide Pro Max to detect the double-stranded RNA-producing Pseudomonas chlororaphisB3-3G,we obtained with high insecticidal activity against Plagiodera versicolora, and it is also the crucial step in our experiment. However, in the process of bioassay, we found that the action of cleaning and gripping the insect must be taken and will take a long time in both the early stage of feeding Plagiodera versicolora and the later stage of detecting the obtained P. chlororaphisB3-3G.
We believe that making a convenient, lightweight, low-cost and reusable insect gripping device will greatly simplify the bioassay process. Therefore, we have a lot of discussion on the design of the insect gripping device, and have carried out iteration updates on the hardware design in the actual use stage.
We soon had an idea for the design of the first-generation insect gripping device. According to the basic requirements of convenience, support points and handheld function, we made reference to the brushes commonly used in art rooms. The brush bristles were removed from the brushes, fixed on small sticks with double-sided tape and eye-catching red tape was pasted on the joints. The purpose of removing adults or larvae was achieved by holding it and direct scraping, as shown in Figure 1. However, in later experiments, it was found that when larvae and adults were removed in this way, the insects sometimes could not be transferred well from the brush to the new leaves and they would adhere to the brush. If the action was too large, they would be disable. We realized that such a design could injure Plagiodera versicoloras, if they were contacted with brush bristles too hard or accidentally touched by the wooden stick. This was an unexpected result, and then we brainstormed again and updated it to the second generation.
Figure 1A: Stick-shaped insect brush (design drawing)
Figure 1B: picture of real product
As shown in Figure 2, inspired by the laboratory's disposable dropper, we wondered if we could blow down the adult insect through gas. So while retaining the brush bristles of the first generation, we replaced the wooden stick that held the bristles with this kind of dropper, using local materials, combining the two. The device did not harm the insects, but also had brush bristles to help.
Figure 2A: insect brush with suction capsule (design drawing)
Figure 2B: picture of real product (design drawing)
In the follow-up experiment, new problems followed. We found that in different periods, different shapes and sizes of Plagiodera versicolora had different ability to withstand the wind effect from this kind of dropper. The development of Plagiodera versicolora is beyond our control, but whether we can intervene in the effect of wind power by certain devices. Under this assumption, we design and put forward a variety of ideas. Under the inspiration that the pipette gun will match different gun heads according to different situations, we can also match different sizes of “gun heads” for insect gripping device. Therefore, without changing the part of the dropper, the brush bristles are glued to the gun heads of different sizes of the pipette gun, and then gun heads and droppers are assembled. In this way, the desired design will be achieved, as shown in Figure 3.
Figure 3: replaceable brush heads of different sizes
During the next experiment, we also found that some larvae are difficult to find in the dark environment in the box would make during the cleaning process, so that some larvae would be discarded together with the replaced leaves. If a floodlight is added to the front end of the insect brush, the morphological changes and characteristics of the insects may be more intuitively observed during the picking process, which is clearer and more convenient than observing directly under the fluorescent lamps.
So how to realize this idea? The small, luminous tool we first thought of was the Light-Emitting Diode (LED). But how to install the diode on the original insect brush became a serious problem. If it is directly installed on the nozzle of the second-generation brush, the previous equipped air outlet will be blocked and ineffective. If the diode is wrapped around the upper end of the brush, it goes against our original intention of requiring convenience for the device. On balance, we decided to make an extension of the application scenario for the second-generation device, and no longer require the coexistence of lighting and air outlet. We changed the upper end of the third-generation dropper into a push-action pen tube, assembled the button battery and LED in the pen tube to make a small flashlight, and added bristles at the front end. As shown in Figure 4.
At this point, the design and production of the three generations insect gripping devices for Plagiodera versicolora has been completed. As shown in Figure 5. After a series of the mentioned schemes' design and verification, our core device design is finally determined. Under the investigation of the actual situation, the second-generation and third-generation insect brush are retained for the different tasks of insect gripping, which are already in use. Constant iterations have resulted in a convenient, lightweight, low-cost and reusable insect gripping device. The production of this insect brushes is only a small step forward for our bioassay process, but when our design is accepted by other research teams that need insect gripping, it will represent a big step for us. Therefore, our research on insect gripping devices will not stop at this bioassay, but continue to be people-oriented and polish products, in order to let really useful insect gripping devices walk up to the world.
Figure 4A: illuminated insect gripping device
Figure 4B: picture of real product
In the follow-up experiment, new problems followed. We found that in different periods, different shapes and sizes of Plagiodera versicolora had different ability to withstand the wind effect from this kind of dropper. The development of Plagiodera versicolora is beyond our control, but whether we can intervene in the effect of wind power by certain devices. Under this assumption, we design and put forward a variety of ideas. Under the inspiration that the pipette gun will match different gun heads according to different situations, we can also match different sizes of “gun heads” for insect gripping device. Therefore, without changing the part of the dropper, the brush bristles are glued to the gun heads of different sizes of the pipette gun, and then gun heads and droppers are assembled. In this way, the desired design will be achieved, as shown in Figure 3.
Figure 4C: picture of actual operation
