Sometimes when counting aphids or preparing aphids to infest a set of plants for phenotypic resistance screening, the petri-dishes, brushes, microscope field become static and this makes it very difficult to work accurately. Has anyone had this experience and does anyone have tips for solving the problem without harming the aphids.
Dear Vicki
I haven't experienced this problem with aphids, but have when working with schools and a van der Graff generator. When the air was very dry e.g. with central heating on and windows closed, the charge generated was tremendous! So if you are working in an enclosed environment, you could try increasing the humidity by placing a dish of water near to where you are working. You can also buy a room humidifier.
When working with small insects I have had problems with static when using disposable plastic petri dishes. If possible I prefer to work with glass petri dishes, and also (very slightly) dampening the tip of paintbrushes helps when using them to pick up small beetles.
One of the main causes of static in buildings is the sythetic soles of footware which rub along the floor picking up charge as you walk. I believe you can get special antistatic shoes, but you could try having a pair of "lab shoes" that you only wear when handling insects and don't walk around in much.
Good luck!
Barbara
Thanks Francesc & Barbara,
The solution I have tried in the past has been to increase humidity (spray the surrounds with fine mist of water before working) and I do use glass pertri-dishes, it just doesn't always work. I will definitely look into dampening the brush first too and see if I can source some of the shoes :) . The aphids are so small the static can "move them around" and stick them to stuff - very frustrating indeed.
I work with head lice. Their size is 3-5 mm approximately and the static is a problem on dry days. Dampening the brush is the solution to that problem, as Barbara told you, and also using wet filter paper. Good luck!
Hi Vicki,
All answers useful.
You may have to hierarchisze the issue (is it more you than the dish, or air too ?). If you use glass dishes, it may be more you/the brush, etc etc...
The solution of discharging the brush on a metallic plate grounded somewhere may work (so kind of the same answer as Bubba's last one).
Luck
I have had this problem when counting and manipulating insect and mite eggs, immatures, adults, plus exuviae and frass. I take a piece of damp J-cloth and placing it on the base of the dissecting scope with the petri dish on top, Plastic disposable petri dishes are the worst, so I prefer to use glass; also dampening the brush helps. Periodical wiping the outside of glass petris with a damp cloth helps dissipate any static charges
In addition to wetting brushes, etc., you can try an anti-static gun. These can be used to discharge static charges of containers like glass or plastic petri dishes where you may be trying to manipulate aphids.
On dry days I found static problems with aphids, especially when I had dried them out for fresh weight/dry weight comparison. As I could not have damp brushes for this I earthed myself using an 'earthing wrist band', cheap and available from electronic retailers. Also having a nice desk mounted hood keeps your working space clutter free and helps reduce drafts.
I used to have this problem when working with mites. I used to do it near some piece or equipment with an earth or a plug and earth myself. Very simple to do and it just became routine.
Thank you so much to all who have answered this question. I appreciate the assistance - many very useful tips and nice to know I am not the only one with the problem :)
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