Blastocrithidia papi sp. n. is a cyst-forming trypanosomatid parasitizing firebugs (Pyrrhocoris apterus). It is a member of the Blastocrithidia clade and a very close relative of B. largi, to which it is almost identical through its SSU rRNA gene sequence. However, considering the SL RNA gene these two species represent quite distinct, not even related typing units. Morphological analysis of the new species revealed peculiar or even unique features, which may be useful for future taxonomic revision of the genus Blastocrithidia. These include a breach in the microtubular corset of rostrum at the site of contact with the flagellum, absence of desmosomes between flagellum and rostrum, large transparent vacuole near the flagellar pocket, and multiple vacuoles with fibrous content in the posterior portion of the cell. The study of the flagellates' behavior in the host intestine revealed that they may attach both to microvilli of enterocytes using swollen flagellar tip and to extracellular membranes layers using hemidesmosomes of flagellum. Laboratory experiments on B. papi transmission in P. apterus demonstrated that the parasite may be transmitted vertically (via contaminated surface of eggs) and horizontally (via contaminated substrate and/or necrophagy). We argue that the parasite exploits transmission mechanisms intended for obligate bacterial symbionts of P. apterus.

Life Science Research Centre Faculty of Science University of Ostrava Chittussiho 10 710 00 Ostrava Czechia; Biology Centre Institute of Parasitology Czech Academy of Sciences Branišovská 31 370 05 České Budejovice Czechia; Institute of Environmental Technologies Faculty of Science University of Ostrava 710 00 Ostrava Czechia

Zoological Institute of the Russian Academy of Sciences Universitetskaya nab 1 St Petersburg 199034 Russia

Zoological Institute of the Russian Academy of Sciences Universitetskaya nab 1 St Petersburg 199034 Russia; Life Science Research Centre Faculty of Science University of Ostrava Chittussiho 10 710 00 Ostrava Czechia

References provided by Crossref.org

Multiple and frequent trypanosomatid co-infections of insects: the Cuban case study

Parasites of firebugs in Austria with focus on the "micro"-diversity of the cosmopolitan trypanosomatid Leptomonas pyrrhocoris

Diversity of RNA viruses in the cosmopolitan monoxenous trypanosomatid Leptomonas pyrrhocoris

Vickermania gen. nov., trypanosomatids that use two joined flagella to resist midgut peristaltic flow within the fly host

If host is refractory, insistent parasite goes berserk: Trypanosomatid Blastocrithidia raabei in the dock bug Coreus marginatus

Development of Phytomonas lipae sp. n. (Kinetoplastea: Trypanosomatidae) in the true bug Coreus marginatus (Heteroptera: Coreidae) and insights into the evolution of life cycles in the genus Phytomonas

RNA Viruses in Blechomonas (Trypanosomatidae) and Evolution of Leishmaniavirus

Obligate development of Blastocrithidia papi (Trypanosomatidae) in the Malpighian tubules of Pyrrhocoris apterus (Hemiptera) and coordination of host-parasite life cycles

Leptomonas pyrrhocoris: Genomic insight into Parasite's Physiology