A caterpillar question

[Wild-Woman]

Is it possible to tell the sex of a caterpillar before it pupates and emerges as an adult? Do they only carry this information at DNA level-no obvious genetalia clues?

Don't know much about caterpillars!

[wildlifesnapper]

Hi

not as far as I know.You can tell from some pupae is they are male or female.
neil

[Dogghound]

No you carnt sex a caterpillar. A caterpillar or any other larva for that matter has no reason to breed so sexual dimorphism isnt found. Infact i dont think they even have any sort of genitalia, as they are basically just an eating machine.

[Wild-Woman]

Originally Posted by Dogghound

No you carnt sex a caterpillar. A caterpillar or any other larva for that matter has no reason to breed so sexual dimorphism isnt found. Infact i dont think they even have any sort of genitalia, as they are basically just an eating machine.

So like I thought, just carried as DNA. But even then, I wonder if the sex is predetermined or whether this is decided when the metamorphosis takes place in the pupa, or whether sometime like temperature affects gender...bit like some reptiles.
Questions, questions!

[wildlifesnapper]

Hi

the sex must be determined before pupation as like I said you can tell male and female pupae , some female pupae are twice the size of males. I doubt that temperature has an effect as the tropical lepidoptera have a constant temp.

neil

[Dogghound]

Yes im sure it must be pre-determined but there is no use to show it until pupation/imago when it is needed or closer to being needed. Its likely when reaching the stage for pupation the body triggers a chemical respose that causes sexual development.

[Wild-Woman]

Originally Posted by wildlifesnapper

Hi

some female pupae are twice the size of males

Hmm. Didn't realise that! Would that be mainly moths then? With butterflies, the sexes are about the same size when they've emerged. Can only think of Wall browns that are noticably different.

There's so much to learn and understand,so many puzzlements.

[Dogghound]

Originally Posted by Wild-Woman

There's so much to learn and understand,so many puzzlements.

There is alot of things to find out too, alot of insect behaviour is unknown so the more people observe the better, birds and mammals have always had more interest taken in them but insects have quite fascinating behaviour.

[wildlifesnapper]

Originally Posted by Wild-Woman

Hmm. Didn't realise that! Would that be mainly moths then?

yes it's mostly the moths that have such differences in body size.
This is the best example I've got , Vapourer moths female (left) and male;



neil

[Wild-Woman]

Originally Posted by wildlifesnapper

yes it's mostly the moths that have such differences in body size.
This is the best example I've got , Vapourer moths female (left) and male;



neil

Wow-they are different! Thanks for that. Are you,or did you rear them?