The first is marginally better, but only because the second has a very obvious grammatical mistake in its word order. In English questions, the verb (are) has to come before the noun (the females), so you can never begin a question by saying "Why the females...". In Italian, you can make a question simply by changing the intonation or adding a question mark. In English, this isn't possible - you have to use a grammatically correct question form. The other mistake is the article 'the'. The genitive 'Russia's' makes this noun phrase definite, so there is no article. We can say either 'Russia's beetle population' or 'the beetle population of Russia'. And remember to use a capital letter at the beginning of all your sentences.

Neither of them sounds good at all but the second one sounds worse. Why are all the females black among the beetle population in Russia? Do not use "the" in front of the name of a country unless it is followed by "Republic" or "Kingdom" or something similar.

Hi Cristina, I would choose the second one, but for me "Why all the females in Russia's beetle population are black?" sounds better.

#1 is better. Better still would be: -why are all the females in the Russian beetle population black?

I guess second one. Construction as I remember is *Asking word* *subject* *verb*