Subject: Re: Dwarves - Diet

From: Andrew Stagg <[email-masked]>
Date: Mon, 25 Mar 1996 10:41:58 -0000

I find that with last instar A.urticae, small adults can be achieved by 'underfeeding' the larva and forcing early pupation. Not however that about 50-60% losses of pupae can occur.

Andrew Stagg

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From: "A.P.K.Torry" <[email-masked]>
Date: Mon, 25 Mar 1996 09:01:38 GMT

>I am definitely no expert, but I wonder if dwarves are caused by a
>hormonal imbalance during development.  This could be induced by their
>diet, if they ingested a plant such as Ageratum.  Ageratum produces a
>chemical which destroys juvenile hormone.  Insects eating it can become
>premature adults.  Could this be a possibility?

Would cultivars of Ageratum (ie garden annuals) have the same chemical?

If so I will have a go at rearing a sequence of 'dwarfves' from my captive
stock of Garden Tigers (Arctia caja), after all they will eat anything (even
damp newspaper).

Andrew

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From: "A.P.K.Torry" <[email-masked]>
Date: Mon, 25 Mar 1996 08:53:10 GMT

>I too have managed to (unintentionally) breed dwarf Saturnia pavonia
>females.  I found this occurs if you feed the larvae on bramble twigs stuck
>into a milk bottle in a bigish cage (45cm x 45cm x 60cm).

Hmmm interesting theory, you may be right, as bramble is the exact FP I used
for the Brown-tails (E. Chrysorrhea) and they produced quite a high
proportion of 'dwarf' males.

I have got an 'oversized' female Pavonia which I fed on Dog-Wood (Cornus
alba) and I found that this FP is particularly useful for a lot of
polyphagous species. The Arctiidae love it, and it is very easy to force
into leaf indoors early in the year.

Andrew