temperature sensitive?

[Roger C. KENDRICK]

Hi Rebecca,

Yes, it would seem moths are temperature dependent.

>From what I can remember in the UK, threshold temperatures for activity
varied according to the season, for example a minimum temp. of around +4
or +5°C in January or February would see some activity, four degrees
higher would result in a lot of activity. Minimum temperatures in July or
August for similar levels of activity would be +13°C for some activity
and about +17°C for a lot of moths to be on the wing. Those who recall
the extremely warm nights of August 1996, when minimum temperatures were
sometimes over 20°C may also recall that the amount of activity was
considerably reduced, possibly indicating an upper threshold of activity.

In Hong Kong there would appear to be a similar trend, with the really
warm summer minima being too high for many species. Consequently there
are two peaks of activity in the year, in April/May and again in
September/October. Winter minimum temperature for reasonable activity
appears to be around 14 or 15°C. Optimum minimum temperature range seems
to be 19 to 25°C throughout the year. Nights where the minimum is above
27°C (as is happening at the moment) result in markedly lower numbers of
active moths.

Hope this helps.

Roger.

Rebecca Jolly wrote:

>      A colleague (without internet access) was chatting to me and
>      wanted to know the answer to the following:
>
>      Assuming that butterflies need warmth to fly, presumably moths
>      require less warmth (as generally they are night-flying).  Are
>      moths temperature sensitive?  At what temperature do they cease
>      to fly?  What is the minimum temperature?
>      He has just reared some death's-head hawkmoths (Acherontia
>      atropos) and I think this has sparked his interest!
>
>      If anyone can comment I would be very grateful as I am unable to
>      answer his questions myself!
>      Thanks
>      Rebecca

 ________________________________________________
Roger C. KENDRICK   B.Sc.(Hons.)
PhD student & Demonstrator, Dept of Ecology & Biodiversity
The University of Hong Kong
mailto:kendrick at hkusua.hku.hk
http://web.hku.hk/~kendrick/hkmoth.htm   « Hong Kong Moths »
http://www.geocities.com/RainForest/Canopy/1085/   « H.K. Lepidoptera
Group »
=================================================