Subject: Caterpillars and antiopa in DK

From: [email-masked] (Per)
Date: 8 May 96 18:34:30 GMT

Re. difference in male/female caterpillars.

>This raises some questions which I hope someone can answer:
>1. Is this a normal difference for this species?
>2. Is this perhaps a difference between male and female?
>3. Is there in general a difference between male and female 
caterpillars?
>4. Do male and female caterpillars in general differ externally?

Answer to Iman Heijboer, Soesterberg - The Netherlands:

Hello all,
I have been breeding many moths species ex ovo from the Danish and 
European fauna for more than 25 years and have quite some experience with 
caterpillars.
Here some answers to above questions.
1. Yes, the larvae of H. euphorbiae are very variable, especially if you 
compare larvae from different populations. They also change colour from 
one mould to the next.
2. No, there is no colour difference between male and female larvae. 
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 
Schmetterlingszucht.
  |____/\____| <- wings     
  \_________/ 1     
   \_______/  2
    \_____/   3
     \_|_/  Underside of female pupae of Sphingidae
      \|/ 
       Y
Vanessa antiopa etc. in Denmark this spring:
We also have had and have numerous observations of this splendid 
butterfly during april. The first were seen on april 10th and 11th, and 
especially april 19-23rd when we had very warm summerlike weather, 
antiopa was seen in large numbers in most the country. From two places, 
one on southern Zealand and the other on the island Bornholm, people 
reported 30-40 antiopa seen on a 1 hour walk in the forest. I have 
succeded in getting my hands on two females 20/4, and one have laid abt. 
300 eggs on may 3rd. So they seems to be fully fertile. To my opinion the 
great success of hibernation is due to the extremely dry and also cold 
winter here in DK. Also the other adult hibernating butterflies have been 
unusually abundant, f.i. rhamni, urticae and io. Also the moths have had 
a good winter, at Monima species and the Geometrid B. stratarius have 
been extremely abundant. To our pleasure also Endromis versicolora was 
flying in larger number than normal.
Notice that Russia now again have very warm weather. Imagine what happens 
if this continues the next 6 weeks! We may actually drown in antiopa, 
both native and immigrants.
By the way, we also have had sigtings of V. cardui and atalanta, as far 
as I know, in the days 20-22/4 and only in Jutland.

Best regards

P. Stadel Nielsen,
DK- 2840 Holte
Denmark
[email-masked]

PS. It would be nice if you all would indicate your name, city and 
country when writing a message. Sometimes it is very difficult to see, 
where people are living.

---

From: [email-masked] (Pierre Zagatti)
Date: 9 May 1996 13:15:28 GMT

In article <[email-masked]>, [email-masked] (Per) 
>Re. difference in male/female caterpillars.
(snip)
>>4. Do male and female caterpillars in general differ externally?

By rearing many species of microleps for years, it appeared that
testes were frequently visible dorsally through the cuticle 
in last instar larvae. This occurs in many endophytic larvae that
are poorly pigmented. In the case of the leek moth (Acrolepiopsis
assectella) it was the best method to separate sexes.

Pierre Zagatti

---

From: [email-masked]
Date: Fri, 10 May 1996 12:52:42 METDST

Hej Per.

I dit brev skriver du:
        Y
> antiopa was seen in large numbers in most the country.

De foerste eksemplarer, jeg har hoert om, er fra Skagen og Gilleleje
omkring 20/3, men allerede omkring 4-6/4 blev den ogsaa set flere steder i
Oestjylland.

> From two places,

Angaaende det sidste: Har du nogen kilder til observationerne af admiral
og tidselfugl? Jeg er ved at gaa i gang med et speciale om admiralens
traekforhold, og jeg er meget interesseret i at hoere naermere om foraars-
observationer - de er jo ikke saa almindelige.....

Med venlig hilsen

Morten D.D. Hansen
Skejby Vaenge 159
8200 Aarhus N