My most dear, most kind, most precious, wish-fulfilling one,
Thank you for your kind email and news. I will check later about your life practices, but regarding your questions about stupas and dead insects:

If you recite mantras and blow over the dead insects, then it purifies their negative karma, because negative karma is not with the body but with the consciousness. Wherever the consciousness is, you can purify the negative karma, so the consciousness can transfer from the lower realms and get a higher rebirth. This can happen because the body has a connection with the consciousness before [the insect is] dead.

After death I think no need to take the insect around the stupa. I am not sure but I never heard, so I’m not sure.

For sure, recite mantras such as Chenrezig mantra (OM MANI PADME HUM), Medicine Buddha mantra, Lotus Pinnacle of Amoghapasha (OM PÄDMO USHNISHA VIMALE HUM PHAT), the Stainless Pinnacle Mantra, also Milarepa mantra and Namgyalma mantra.^*

Think that the sentient being, wherever it is born, may it be liberated from the lower realms and receive a higher rebirth and may it meet Dharma and achieve enlightenment as quickly as possible.

Recite one mala or half a mala or even ten or fifteen times, then blow on the insect and think that you have purified that being’s negative karma and defilements. Then you can think they become Chenrezig or the deity whose mantra you have been reciting.

With much love and prayers...

[^* These mantras and other resources are freely available online at FPMT.]