On Sun, 6 Apr 2003, Kay Easton wrote:

In article .hx,
Kostas Kavoussanakis writes

I was wondering why the new leaves of my giant hollyhocks were full of
holes. I just noticed large (5cm) gray, green and brown caterpillars
on them. Any idea what they are?

I knew I was careless in my description: I have two (one: green; two:
gray), possibly three (brown?) types of caterpillars.

Mallow skipper Carcharodus alceae '..up to 23mm, fairly stout ... body
greyish green, tinged with blue;

Not sure I have this (and I am off sick, so I won't go out looking for
them today). The gray ones looked to be a dull colour (I went close
with a macro lens).

Larentia clavaria '.. up to 32 mm; green, sometimes yellowish betwen
segments, with whitish dots and black spiracles; a brown or pinkish line
extends down the middle of the back and a dark line along each side;
head whitish with grey-green markings' 'When the caterpillars are
disturbed, they drop to the ground, curled up to resemble mallow seeds'

Probably have these: they look lime-green, matching the hollyhock
leaves. Could see no other colours yesterday.

Possibly. Caterpillars have big appetites. Can you find some mallow
plants nearby to transfer them to?

Not to my knowledge (not that I would be able to recognise them).

(1)carter and Hargeaves: A Field Guide to caterpillars of Butterflies
and Moths in britain and Europe, pub Collins.

Excellent posting, thank you very much.

Kostas (thanks to the other contributors to the thread too).