I am seeking information on substances that may act as physical barriers to
movement of blackfly larvae across substrates.
I am planning a series of experiments with larval S. vittatum in which it
would be useful to restrict larvae to a small area of a larger substrate
(in a flume). I do not wish to prevent drifting, but to limit movement on
the substrate (i.e. looping) so that larvae remain within a small, defined
patch of the substrate (or leave via drift).
Substances such as "tangle-foot", petroleum jelly etc. do not seem to be
any barrier to looping blackflies.
I would be grateful to hear if anyone knows of any substances that larval
blackflies are reluctant to cross, or any suggestions of what may be worth
testing.
Thankyou
Jim Thomson
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