(Investigator 16, 1991 January)
Certain herbs, legumes and trees are supposed to repel insects. I put one plant to the test by planting it around my door.
Plants that supposedly make flies take flight include Basil, Tansy, Pyrethrums and Rough Halgania.
Mosquitoes are said to give a miss to Basil, Rosemary (Rosemarinus officialis), Pyrethrum, Beans, Peas and also Walnut trees.
Aphids and weevils allegedly stay away from Garlic plants, Pyrethrum and Mint.
The plant I tried around my front door was the Pyrethrum.
When the white flowers bloomed haphazard observation soon revealed that flies strolled over the leaves, and mosquitoes landed on the flowers, as much as on neighbouring plants such as Fuchias and Azaleas.
In the hope that science would succeed where nature failed I parted with $12.50 and bought an "Electronic Insect Repeller" which, according to the label, "drives mosquitoes off with a high frequency sound".
The packaging of this cigarette-lighter-sized, Hongkong-made, object said:
"American scientists…found that the only mosquito that bites humans is the pregnant female. One thing she can't bear is the sound of the male mosquito. Sentinel Insect Repeller emits a sound identical to his."
After two minutes in the garden while protected by the Insect Repeller I noticed two itchy lumps on my chin.
Certainly that was a discouraging start. "Perhaps insects need more time to adjust to the idea of being repelled" I reasoned. I haven't tested this yet because the high-pitched, whining "Repeller" gave me a headache and soon began to repel me.
There was one redeeming feature. Mosquitoes that had landed remained comparatively immobile when the "Repeller" was on and could be easily squashed with a finger.