<p class="MsoNormal"><span style="font-family:Optima">My comma caterpillar is
sick!</span></p>
<p class="MsoNormal"><span style="font-family:Optima"> </span></p>
<p class="MsoNormal"><span style="font-family:Optima"><span> </span>It had shed its skin by mid-day today (ten
days old--3<sup>rd</sup> or 4<sup>th</sup> instar? I lose track). Around 4:30
or 5pm I noticed it had fallen from the leaf it had been resting on and was
lying on its side, unable to grasp with its legs. There was some green vomit on
the leaf and the paper towel where it had fallen. The thoracic region was
extended and the abdominal segments contracted, and it was heaving slightly and
excreting dry frass with effort. I coaxed the frass out with a paintbrush, and
it promptly began excreting another dry pellet without assistance but with
similar effort. Later it began writhing and contorting into a U. It emitted
several drops of green fluid, and a few orange-brown ones, but I don’t know
from which end. The skin has a greenish tinge where it should be white, but
otherwise it does not look unusual. I’ve attached a photo from today and one
from yesterday for comparison.</span></p>
<p class="MsoNormal"><span style="font-family:Optima"> </span></p>
<p class="MsoNormal"><span style="font-family:Optima">Poinar & Thomas, in their
1984 book <i>Laboratory Guide to Insect
Pathogens and Parasites</i>, state “loss of appetite, cessation of
feeding,diarrhea, gut paralysis, and regurgitation are characteristic initial
stages in many bacterial infections. Later the insect may appear sluggish
(rarely irritable), have convulsions, and become uncoordinated; a general
paralysis may set in, accompanied by septicemia and death.” This seems a fairly
apt description of my case, but are the symptoms similar in other disease
processes?</span></p>
<p class="MsoNormal"><span style="font-family:Optima"> </span></p>
<p class="MsoNormal"><span style="font-family:Optima">Its sibling died in the first
48 hours after barely feeding at all, which may or may not be related. It was
too small to observe much of the events leading to its demise, except that it
also lost grasp in its legs. Could the pathogen/disease be maternally
transmitted, or is ingestion the most likely route?</span></p>
<p class="MsoNormal"><span style="font-family:Optima"> </span></p>
<p class="MsoNormal"><span style="font-family:Optima">I quarantined the
caterpillar and removed the vomit, but perhaps not soon enough. Has anyone
tried disinfecting larvae and/or pupae? I have only a few individuals of common
species, but it is always a shame when there’s an epidemic (fortunately a rare
occurrence in my experience). Will the pupae be susceptible if not infected as
caterpillars? I’m probably more inclined to let nature take its course and hope
for the best, but it will be hard to watch if they all get sick!</span></p>
<p class="MsoNormal"><span style="font-family:Optima"> </span></p>
<p class="MsoNormal"><span style="font-family:Optima">Any thoughts or suggestions
for a curious observer?</span></p>
<p class="MsoNormal"><span style="font-family:Optima"> </span></p>
<p class="MsoNormal"><span style="font-family:Optima">Thanks,</span></p>
<p class="MsoNormal"><span style="font-family:Optima"> </span></p>
<p class="MsoNormal"><span style="font-family:Optima">Grace</span></p>