Thread subject: :: Request for paper about melanistic Syrphidae

Posted by Rui Andrade on 24-05-2019 22:18

Recently I reared a female Scaeva pyrastri from the egg that I saw being laid. The female turned out to be melanistic. So I was curious to know more about this phenomenon in Syrphidae and I'm here asking if someone can send me a pdf file of the following paper:

Knutson, L.V. 1971. Melanism, Ring-segments and Associated Abnormalities in Female Hover Flies (Diptera: Syrphidae). Journal of the New York Entomological Society 79 (4): 201‒209.

Thank you!

Posted by Rui Andrade on 24-05-2019 22:19


Posted by Rui Andrade on 24-05-2019 22:19


Posted by Rui Andrade on 24-05-2019 22:20


Posted by johnes81 on 24-05-2019 23:15

unrelated to the document: since you state that you had reared this specimen, what did you feed it? food source could be a factor in color, size and other things. Just curious.

Posted by Rui Andrade on 25-05-2019 00:16

I gave aphids to the larva, but in this case I don't think the food source is the reason for the colour of the abdomen.
See here the interesting comments by Menno Reemer about melanism in S. pyrastri and other syrphids:

Posted by johnes81 on 25-05-2019 01:47

to be honest, the text that stands out most to me in that post is "unclear, but might have, seems to occur", which is really conjecture or speculation.

i tried to link to the page for you:

Posted by Rui Andrade on 26-05-2019 02:01

Yes, it's true, the causes are unknown but perhaps there is some evidence to suggest parasitism. I'll have to read the literature, so thank you for the link!

Posted by johnes81 on 26-05-2019 14:34

I'm happy that i could find it for you. I hope that it is useful to you.

I don't think that the causes are unknown so much as noone wants to use science to deduce the cause. Remember when science required the path of hypothesis, theory, then law? today we seem to be publishing theories. I think that biochemistry could tell us the cause but noone is investigating this. missing ovaries indicates missing chemical or hormone (if this is appropriate for diptera.) I think that the world is lacking biochemists or noone is interested in this particular study. I suppose that if it isn't related to agriculture, weaponry or technology, then funding is not available?

anyway, i'm sure that a scientific answer can be found but we need more scientific people to participate. I wish i were better at math and chemistry. I wish i were a millionaire, then i could spend some time studying alot of things.

Posted by Rui Andrade on 28-05-2019 00:03

The lottery is never won by the right people! :o