Naked Science Forum

General Science => Question of the Week => Topic started by: Sally Le Page on 02/08/2021 16:41:12

Title: QotW - 21.08.08 - Why do ladybirds have different numbers of spots?
Post by: Sally Le Page on 02/08/2021 16:41:12
We got this question from listener Ruomei:

"Why do ladybugs [ladybirds] have different numbers of spots on their backs?"

What do you think?
Title: Re: QotW - 21.08.08 - Why do ladybirds have different numbers of spots?
Post by: alancalverd on 02/08/2021 18:09:52
They are all different species. Apparently there are over 1000 recognised species, with between 0 and 13 spots and various "shell" colors.
Title: Re: QotW - 21.08.08 - Why do ladybirds have different numbers of spots?
Post by: Bored chemist on 02/08/2021 23:02:55
It's an interesting thought. A big part of the reason is so (or because) they recognise eachother for mating.
Which means they can "count"...
Title: Re: QotW - 21.08.08 - Why do ladybirds have different numbers of spots?
Post by: Sally Le Page on 10/08/2021 12:06:40
We asked ladybird expert Helen Roy to answer this on our show, which you can listen to here:

https://www.thenakedscientists.com/podcasts/question-week/why-do-ladybirds-have-varying-spot-numbers
Title: Re: QotW - 21.08.08 - Why do ladybirds have different numbers of spots?
Post by: alancalverd on 10/08/2021 18:10:02
It's an interesting thought. A big part of the reason is so (or because) they recognise eachother for mating.
Which means they can "count"...
This is of fundamental importance to those philosophers who want you to wonder whether other animals have consciousness or a sense of self. If you are a 4-spot gentlemanbird you only want to mate with 4-spot ladybirds so however your philosopher defines self or consciousness, you obviously demonstrate it in your mating behavior.
The fact that you only eat aphids and don't generally attack other ladybirds also implies that you have an acute sense of "other" and "same" which is a lot better developed than that of many humans.
Title: Re: QotW - 21.08.08 - Why do ladybirds have different numbers of spots?
Post by: evan_au on 10/08/2021 23:00:29
A lot of species also use pheromones to distinguish their own species.