Subject: Re: Collecting tips

From: Gaden Robinson <[email-masked]>
Date: Thu, 6 Apr 1995 15:05:18 GMT

>Could anyone out there give me some very general tips on ensuring
butterflies collected in the tropics do not get destroyed by ants and
mould before you've even made it back to the airport!!! Is a sprinkle of
naphthalene in the collecting tub, with all the specimens in envelopes,
enough?

Yes. No.
OK - you have three distinct problems. Problem one: humidity/moisture
which facilitates mould growth and also "tropical rot" - rare but
spectacular because your specimen disarticulates as a result of bacterial
action which takes out the intersegmental membrane. I am assuming
you are talking papered butterflies here. You can dehydrate in a warm air-
stream in a makeshift oven with a bulb assuming you have electricity, but
if you're generating your own power specifically for this it's a real
bind and very expensive in terms of weight and fuel. A blackened metal oil-
drum with vents cut-out and stood in the sun works well, too. The slick way
is to interleave the papers in a Tupperware container with cooked silica
gel (blue); remove and re-cook the silica gel when it absorbs as much
moisture as it's going to (indicated by its turning pink). Add more blue
silica gel until your specimens are dry (s.g. stays blue). If you have
recourse to airconditioning back at base, specimens will keep for a few
days (say five) with fungicide (below) until you get them out then they
will dry quickly in a/c conditions.

Problem two. Pests. Naphthalene is not an insecticide nor a fungicide. At
best it is a repellent. Store specimens in airtight boxes when not drying.
Pests are: ants, wasps, cockroaches, crickets, psocids and small rodents.
Fruit flies will oviposit and their larvae will eat fermenting insects.
Place drying ovens/devices on makeshift tables with legs in cans of water
to dodge the ants. Screen out wasps with netting. Put a small Vapona strip
(or fragment of same) in the storage box when not drying to zap things like
Psocoptera (and beware, Vapona is oily and "creeps" - don't allow it to
contact specimens directly).

Problem three: fungus attack. Chlorocresol is the only surefire fungicide -
a generous pinch (not literally - it's a phenolic skin irritant) sprinkled
in a 100-cubic-inch box should be enough to stop mould. Chlorocresol will
keep mould at bay indefinitely, but specimens will rot after ten days.
Thymol is also a good fungicide but there are some fungi which are immune
to it. I suspect from experience in Indonesia that there is also one rare
fungus which is resistant to chlorocresol but its incidence and viablity is
so low as to make it almost irrelevant.

This all sounds great. In practice, in a rain forest with 99% humidity and
four hours' rain a day it all goes to hell. Everything is soaked and the
silica gel that didn't get washed away is permanently pink and you put all
the chlorocresol in your boots long ago. Under these circumstances, you
work like a beaver for four days then call in the chopper, get the pilot to
drop you straight into the Hilton carpark and run like hell for the
airconditioning... Only kidding! Good luck!
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Dr Gaden S. Robinson, Biodiversity Division, Department of Entomology,
The Natural History Museum, Cromwell Road, LONDON SW7 5BD, UK.
Tel.: +44-(0)171-938-9494. Fax: +44-(0)171-938-8937.
INTERNET: [email-masked] [or] [email-masked]
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