Lepidoptera, mycobiota, herbivorous insects, MOTU diversity, similarity

Mycobiota of phylloplane are considered as one of the most diverse microbial assemblages. Conversely, the microbiota of the caterpillar gut are assessed as a poor due to strongly alkaline gut conditions. So far, in herbivorous insects, more attention has been paid to bacterial microbiota, whereas fungal ones were neglected. We aimed to 1) Compare richness and betadiversity of the gut and phylloplane fungal microbiotas; 2) Quantify their overlap (similarity); 3) Identify MOTUs significantly associated with them. Fungal microbiota was identified by DNA metabarcoding (gene ITS) and data were analysed using rarefactions, GLMs, Multi-level pattern analysis and partial RDA. Fungal assemblages were richer than bacterial in majority of samples for phylloplanes and in half of samples for caterpillar gut. Betadiversity of fungal assemblages was higher in caterpillar gut than in phylloplane and their similarity was quite low (38.12%), suggesting that caterpillar gut harbour separate fungal microbiota, as was confirmed also by RDA. Fungal MOTUs most significantly associated with the caterpillar gut were Ophiostoma, Mucor or Cyberlindnera, whereas MOTUs associated with phylloplane were Holtermanniella, Gibberella, Seimatosporium or Mycoleptodiscus. The results suggest that the fungal microbiota of the caterpillar gut is not entirely derived from phylloplane and, therefore, it represents an attractive environment for further research taking into account its specific diversity. Research was funded by the Ministry of Education of the Czech Republic (LO1208), Inst. of Env. Technologies (CZ.1.05/2.1.00/03.0100, (CZ.1.05/2.1.00/19.0388), NextGenProject (CZ.1.07/2.3./20.0303), University of Ostrava (SGS23/PřF/2016, SGS15/PřF/2017 & amp; SGS14/PřF/2018) and Czech Science Foundation (GA18-08803S).