Subject: Re: Caterpillars and antiopa in DK

From: Matti Ahola <[email-masked]>
Date: Thu, 9 May 1996 23:07:35 +0300

Hi Per!

>>4. Do male and female caterpillars in general differ externally?
>
>Answer to Iman Heijboer, Soesterberg - The Netherlands:

>3/4. Yes and no. Sometimes you can find a difference especially in
>Arctiidae and Lymantriidae, where female larve often feed some days or a
>week longer than male larvae, and they are also somewhat bigger/heavier.
>You see this very clearly in the Orgyia species like O. antiqua.
>If you want to distinguish male and female immature stages, it can be
>done on pupae. Generally female pupae are heavier and larger, but a safe
>difference is that female pupae have 3 unmarked abdominal segments and
>males 4 i.e. count the number of segments from the wingsheets until you
>meet a segment with a longitudinal "slit". See drawings in books on
>breeding butterflies and moths f.i. Friedrich: Handbuch der...

Hinks & Byers (1973) have also found external differences of both sexes of
larvae. There are little pits on the skin. Female larva has one pair of pits
ventrally on the 8. and 9. segments, male larva has only one pit on the
ventral part of 9. segment in the middle close to the anterior edge of the
segment. I can see these pits, too, but not on every species. E.g. some
green larvae are very difficult in this field.

Kind regards

Matti Ahola
[email-masked]