NEWS
Use bats in your stables to fight AHS midges
By now, if you want a fighting chance of preventing your horses from contracting, and very possibly dying of, African Horse Sickness( AHS), your inoculation programme should be complete. But there ' s something else that you can do in your stable yard that might lower the number of carrier midges of the virus and improve the odds against infection, and that is to install a bat box and encourage bats into your environment. The AHS virus is spread by a tiny midge named Culicoides imicola that is active in the early morning from around dawn and late afternoon towards sunset. Bats, on the other hand, feed from early evening to early morning. Insect-eating bats consume vast number of
... and fight bluetongue in sheep, too
insects nightly, mostly locating them by their powerful sonar, which operates in the same way that an underwater sonar is used in a fish-finder, for example. In a process called echolocating, the device( or bat) issues a sonar pulse. When this pulse encounters an object in its path, for
MAILBAG
From page 7 plastic lining are leaking, but on the other hand the rate of water loss seems very great. Is there a formula one can use to calculate evaporation and what are the factors involved, eg temperature, relative humidity? The formulae I have found on the internet are unduly complicated for my unmathematical brain. AllIwantisa example a school of fish or, in the case of a bat an insect, it reverberates back to the transmitter which, sensing the direction it came from and the time it took from transmission to return, can determine both the position of and the distance of the school or insect.
thumbsuck figure to confirm my conviction of undue evaporation, rather than the dam has sprung a leak. In another part of the garden I have a koi pond and, while it also drops in level in hot weather, it doesn ' t seem to drop anything like as fast as my grey water holding dam. I have discussed this issue with friends who have pools in Johannesburg and Pretoria
In this way, fishermen are able to target where to fish and at what depth, and bats, by making instantaneous calculations, can alter their flight paths to intercept their prey. Larger species of bats have been measured to have lower-frequency sonars which are only capable of locating
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and anecdotally it would seem that the evaporation of water this spring was very great indeed. Parched East Rand Any reader have an answer to this question? Meanwhile, Parched, have a look at our article on grey water in this editon. ~ Editor
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