a bloom of ladybirds A large swarm of ladybugs. ConfidencehighAttestationwiktionary-attestedAlso used forjellyfish 2 sourcesWiktionary - bloomWiktionary - Appendix:English collective nouns
a loveliness of ladybirds Fanciful / unverified ConfidencelowAttestationwikipedia-uncited 1 sourceWikipedia - List of animal names