Tandem mating

Looks like a fire bug Kat, normally eats lime tree seeds and mallow plants I think normally harmless I beleave.

Hi, Warwick, thank you very much for the English name. To be honest, these bugs I know from childhood, but we called them "trams" as they reminded trams to us. As children in socialistic countries we didn t have many toys, so the whole nature was toy for us :-)
I found them in my garden on the Hibiscus, and as it unusually started to bloom in September, I thought, they are the cause. Now I know more about them, as I googled it. Thank you. I found this interesting historical experience in Google:-)):
"P. apterus was the subject of an unexpected discovery in the 1960s when researchers who had for ten years been rearing the bugs in Prague, Czechoslovakia attempted to do the same at Harvard University in the United States. After the 5th larval instar, instead of developing into adults, the bugs either entered a 6th instar stage, or became adults with larval characteristics. All specimens died without reaching maturity.

The source of the problem was eventually proven to be the paper towels used in the rearing process. Furthermore, the researchers were able to replicate these results with American newspapers such as the New York Times, but not European ones like The Times. The specific cause was discovered to be hormones found in the native balsam fir tree (Abies balsamea) used to manufacture paper and related products in America. This hormone happened to have a profound effect on P. apterus, but not on other insect species, showing the diversification of hormone receptors in the insects."

Your welcome, wow I didn't know any of that Kat.

Nor me, lol. I have just found it today on Google.

Lol :-)

However, I do not know, how relevant is this information, because if it was trues, then it means that these bugs will be not developing around Abies balsamea (balsam fir). And it just came to my mind, that the bush, on which I observed this clustering, is just beside the young balsam fir.