Sexual dimorphism in insects

http://mosregbut.narod.ru/diacrisia-sanio.htm
I have the most striking example on my site - the meadow bear, her female not only looks different,but also half the size of the male. In general, the most pronounced dimorphism (well, at least from butterflies) is winter wingless or almost wingless females, and ornithopters. We also have a lot of pigeons, most of which differ in one way or another, sometimes very much.

Also tonkworms, many of the superfamily Bombycoidea, volnyanki.

Scolytidae, R. Xyleborus
example of Xyleborus dispar taken http://www.barkbeetles.org/index.cfm
male
female

This post was edited by Dzanat - 02.01.2008 22: 46

Sexual dimorphism is very pronounced in the well-known citrus pest Icerya purchasi. The female has one large egg sac, and the male is fully developed.

This post was edited by Eco[L]og - 02.01.2008 22: 56

Pictures:

male_2.gif — (19.89к)


male.jpg — (49.51к)


female.jpg — (38.94к)

I didn't deal with floaters at all.
In the Isaev determinant, it is said about the characteristics specific to females. Does anyone have photos of these traits, and other sexually dimorphic traits in swimmers?

I didn't deal with floaters at all.
In the Isaev determinant, it is said about the characteristics specific to females. Does anyone have photos of these traits, and other sexually dimorphic traits in swimmers?

Here's a look, on this page: http://www.entomo.pl/coleoptera/wodne/foto_wodne.php
for example, Dytiscus marginalis-samiec and Dytiscus marginalis - samica2, and for other species of this genus.

It seems to me that all the specific characteristics of female swimmers ( grooves and rough structure of the elytra ) are aimed at ensuring that the male does not slip off it during mating. This is also apparently facilitated by highly developed suckers and "claws" of males of many species.

Speaking of Gevorgyan , how is sex determined in insects? And if genotypically, do the larvae with the male and female genotype differ and to what extent? After all, they are also a significant life stage, usually a longer one.
And so, it seems to me that sexual dimorphism is really needed for successful mating and egg production.

Afterward, I remembered that bees have haploid males. (And sexual dimorphism is obvious.) Here Gevorgyan justifies himself. But to what extent does the adaptability of drones ensure the success of the bee family's survival?

It seems to me that all the specific characteristics of female swimmers ( grooves and rough structure of the elytra ) are aimed at ensuring that the male does not slip off it during mating. This is also apparently facilitated by highly developed suckers and "claws" of males of many species.

I don't know. It seems to me that the longitudinal grooves, on the contrary, reduce friction and contribute to slipping. By the way, the suckers of males are unlikely to stick on the ribbed areas.
However, the fins of female swimmers are in good agreement with Geodakian's hypothesis. Geodakian says that "non-progressive" signs first disappear in males, and then in females. In plavuntsy, not many species have ribbed females, but even there, along with ribbed ones, there are also smooth females (as I understand it).

The problem of sexual dimorphism in his hypothesis, in my opinion, is the most poorly developed. Geodakian says that there are reproductive and non-reproductive sexes. However, in explaining the occurrence of dimorphism (in general), it explains only non-reproductive. Thus, again, this suggests that the ribs of female swimmers are not reproductive dimorphism.
And if we go further, according to the Geodakian hypothesis, the ancient swimmers should have had these ribs in males, the vast majority of species.

This post was edited by Adamov - 17.01.2008 00: 40

Everything is very confusing, whether it's distinguishing features between different sexes or features in general... A banal example: why Calosoma sycophantha with green elytra, and inquisitor with bronze ones? And cyanescens is generally blue! The way of life is similar! And so don't throw it anywhere... You can only guess about the purpose of certain signs, but you may never reach the TRUTH. Why does a male Oryctes nasicornis need a horn? After all, there are plenty of males with rudimentary horns! These are even easier to find than the so-called f. major males. And it is hard to imagine that males would successfully use it in "battles" for females... In my opinion, there is some quirk of nature in this, some randomness of consistently appearing traits in populations of the same species. It can be said that the grooves on the female's elytra are needed for fixation during mating. But then why do they disappear? After all, such females, on the contrary, should be in the majority! And if not, why did they appear? One can only assume...

Yes, and has anyone ever seen the fights of our rhinos?

If you are interested, then, briefly but succinctly, sexual dimorphism for beetles is described on pages 27-28, Dened. DV, t3, part 1 (Krivolutskaya City)

Why does a male Oryctes nasicornis need a horn? After all, there are plenty of males with rudimentary horns! These are even easier to find than the so-called f. major males. And it is hard to imagine that males would successfully use it in "battles" for females...

Grebennikov observed that the horns of males act like a plow blade. But why don't females have them then...?

Then most likely the horn should have been in the females... They live longer and have to be buried more often. Moreover, rhinos bury themselves in a rather soft substrate-compost, hollow rot, rotted manure, etc.

Or it may also be that we are dealing with linked traits, i.e. some morphological feature is associated with a gene encoding a certain protein that is responsible for another (not at all morphological) trait. Think of the Central Asian Shepherd dogs - Alabai. They were selected not by "stat", but by liking - those who rushed at a person were shot back on the spot. And I read something similar about St. Bernards. And in the end - a "habitually clean" breed.