Photographs of Laboulbenia flagellata thalli

This is a set of Laboulbenia flagellata thalli, photographed using an Olympus BX40 light microscope with Olympus XC50 digital camera. Thalli were used to measure taxonomically important characters, employing MicroSuite Special Edition software 3.1 (Soft Imaging Solutions GmbH). Up to 15 morphometric parameters (measurements and ratios) were taken to characterize each thallus: TTL = Total Thallus Length, LOP = Length of Perithecium, LPT = LOP / TTL, WOP = Width of Perithecium, LWP = Length / Width Perithecium, HC1 = Height of Cell I, H1T = Height Cell I / TTL, WC1 = Width of Cell I, HW1 = Height / Width Ratio Cell I, HC2 = Height of Cell II, H2T = Height Cell II / TTL, WC2 = Width of Cell II, HW2 = Height / Width Ratio Cell II, LOR = Length of Receptable, LRT = Length Receptable / TTL. Further methods in:

Haelewaters D., De Kesel A., Gorczak M., Bao K., Gort G., Zhao S.Y., and Pfister D.H. Laboulbeniales (Ascomycota) of the Boston Harbor Islands II: Species Parasitizing Carabidae, and the Laboulbenia flagellata Species Complex. Northeastern Naturalist Special Issue 9.

Abstract: This paper presents thirteen new records of Laboulbenialean parasites on ground beetles (Coleoptera, Carabidae) from the Boston Harbor Islands National Recreation Area in Massachusetts. These are Laboulbenia anoplogenii Thaxt. L. casnoniae Thaxt., L. clivinalis Thaxt., L. egens Speg., L. filifera Thaxt., L. flagellata Peyr., L. inflata Thaxt., L. macrotheca Thaxt., L. pedicellata Thaxt., L. terminalis Thaxt., L. variabilis Thaxt., L. vulgaris Peyr., and Peyritschiella geminata Thaxt. Laboulbenia clivinalis and L. egens are new country records for the US. Moreover, we present additional localities for L. casnoniae, L. clivinalis, L. filifera, L. flagellata, L. inflata, L. pedicellata, L. variabilis, and L. vulgaris. The following new country records are presented: Laboulbenia clivinalis, L. filifera, and L. variabilis from Canada; L. flagellata from the Democratic Republic of the Congo; L. pedicellata from Ukraine; L. vulgaris from Croatia and Slovenia (and the first undoubtful record from Slovakia). Laboulbenia flagellata was found on eleven host species in the genera Agonum, Oxypselaphus, Patrobus, Platynus, and Pterostichus. Using this abundant material, we performed morphometrics to test the hypothesis that L. flagellata is a species complex. Specimens cannot be separated based on host genus (Agonum, Pterostichus). One parameter is significant between Pterostichus mutus and each of the four Agonum species after applying a strong Bonferroni P-value correction: H1T, the ratio of Height of Cell I (HC1) to Total Thallus Length (TTL). In addition, we collected fresh material to be able to add a molecular phylogenetic component to testing said hypothesis. We generated ITS and nrLSU ribosomal sequences of several species of Laboulbenia, including isolates of L. flagellata from multiple hosts. Phylogenetic inference of the concatenated dataset shows that L. flagellata isolates from three host species form two distinct clades, providing support for our hypothesis. We also show that L. coneglianensis is separate from L. flagellata, unequivocally ending a long-standing taxonomic debate.