Question - what stimulates larva to pupate?

[Bill Cornelius]

I had an idea that a person could use this method to grow giant Lycaenid
caterpillars which we could release in theaters & sewers, see, & if it didn't
bring down the decadent capitalists, perhaps we could sell some to Hollywood for
$1000 a pop to cover R & D.
Bill

Mark Youles wrote:

> In article <20010701114443.3301.cpmta at c012.sfo.cp.net>,
> speedshark2000 at altavista.com wrote:
>
> > Hi this is Heliconius and i'm a grade 8 student.
> > i would just like to know when does a caterpillar know it's time to make a
> > chrysalis, or what stimulates it to do so.
> > i would greatly appreciate it if you could email me your answers before July
> > 4
>
> Without getting too compicated, the process is initiated in the insect
> brain, where neurosecretory cells release Prothoracicotropic hormone
> (PTTH) in responce to neural, hormonal or environmental stimuli.
>
> It is interesting to note that the injection of this hormone into the
> 'mature' larval stages of some hawks moths (just prior larval 'shrinkage'
> and pupation) have been shown to delay the pupation process and induce a
> further 'giant' larval stage.
>
> Hope this helps,
>
> Mark


 
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