avoiding infections in rearing programs

[Cris Guppy & Aud Fischer]

The most common reason for disease when rearing is high humidity. This is
tendancy is greatest for species that are adapted to low humidity habitats.
Since you were providing grass at 2-3 day intervals, presumably you were
rearing in sealed jars at high humidity to maintain the freshness of the
grass. Keeping your cultures disease free at high humidity will be
difficult, given that the grass is unlikely to be sterile unless grown in
sterile lab conditions. You will have to assess which is more feasible -
maintaining a sterile culture or providing a low humidity environment.
During my Masters thesis project I lost my entire 500 Parnassius larvae due
to high humidity rearing.

-----Original Message-----
From: Koen.Berwaerts <berwaert at uia.ua.ac.be>
To: leps-l at lists.yale.edu <leps-l at lists.yale.edu>
Date: January 26, 2000 1:32 AM
Subject: avoiding infections in rearing programs


>Hello,
>
>Last year I started a culture of Pararge aegeria (Lepidoptera: Satyrinae)
>for my PhD-project (University of Antwerp).
>We collected females in a forest (end of july-begin of august) and put
>them into small cages with full grown plants
>(Poa trivialis). When eggs hatched, we put them individually in plastic
>jars and supplied them (mostly every day, sometimes with 2 or 3 days
>interval) with blades of grass. The whole system was placed outside. The
>problems rose at the end of september.
>Several body parts of the green caterpillars became black. In a later
>stadium, they died (whole body was black and shrinked). At this moment
>more than 75% of my whole population is gone (750 individuals). The
>cterpillars were investigated by some specialists and they told me that it
>was Bacillus thuringiensis, that infected my culture.
>This year I'll start a new culture, but now in laboratory circumstances. I
>want to give all caterpillars a full grown plant (and not only
>blades)(=more optimal conditions).
>
>Can anybody tell me how to avoid these deadly infections? Is it a solution
>to put the whole system in the laboratory and rear the butterflies in more
>optimal conditions (and so less sensitive for infections) ?
>
>With kind regards,
>
>********************************************************************
>Berwaerts Koen
>Laboratory of Animal Ecology
>Department of Biology
>University of Antwerp (U.I.A.)
>Universiteitsplein 1
>B-2610 Wilrijk (Antwerp)
>Belgium
>tel.: +32 3 820 22 62 -- fax.: +32 3 820 22 71
>E-mail: berwaert at uia.ua.ac.be
>Http://bio-www.uia.ac.be/bio/deco
>*********************************************************************
>
>