Episternus onthophagi, Gorz & Boron, 2018

Górz, Andrzej & Boroń, Piotr, 2018, Episternus onthophagi: a new monotypic genus of epizoic fungus found on Onthophagus beetles (Scarabaeoidea), Phytotaxa 376 (1), pp. 43-59 : 49-50

Episternus onthophagi . Górz & Boroń, sp. nov. Figs. 2–6 .

MycoBank No. MB 811949;

Etymology: From Greek “onthophagus” mean “excrement eating” in this case referring to the species of the genus Onthophagus .

Typus: Poland, Polish Carpathians: Beskid Niski, Magura National Park ; Ciechania 49° 27’ 042’’N, 021° 29’ 630’’E, 629 m elev. The thalli were dissected from Onthophagus verticicornis , 01 June 2013, leg. Górz A. The holotype have been deposited in the herbarium of Institute of Botany Polish Academy of Science in Cracow ( KRAM F 58 223) .

Additional material examined: Poland, Polish Carpathians: Beskid Niski, Magura National Park; Ciechania 49° 27’ 042’’N, 021° 29’ 630’’E, 629 m elev., and Żydowskie 49° 28’ 699’’N, 021° 27’ 947’’ E, 499 m elev., 19-May-2013, 01- June-2013, 12-June-2013, 24–30-June-2016. The thalli were dissected from Onthophagus fracticornis , Onthophagus verticicornis , Onthophagus ovatus and Onthophagus joannae , leg. Górz A.. Zachodniowołyńska Upland Ślipcze 50° 45’ 776’’N, 024° 00’ 616’’ E, 19-May-2011. The thalli were dissected from Onthophagus ovatus , leg. Górz A.

Diagnosis: Thallus 1 mm thick, composed of relatively large (12.5–17.5 × 6–6.5 μm), spongy-arranged, ovoid or bluntly-polygonal cells with darkening or transparent walls. The thallus-forming cells are not arranged unidirectionally. Thallus layers strongly adhering to the surface of sterna, mid- and hind-legs. No signs of exoskeleton penetrating structures of any kind neither on particular cells nor on whole thalli. Both the shape and size of particular thalli are strongly affected by their location on the insect body. Conidiogenous cells arise on the growing area which covers the entire surface of the thallus. In this layer blastoconidia are produced via multidirectional budding. Sexual morph unknown.

Habitat: dung beetle of genus Onthophagus .

Figures

FIGURE 2. Episternus onthophagi thalli visible on mesosternum and femur of the second pair of legs of Onthophagus verticicornis.Scale bare = 1 mm.

FIGURE 3. A cross section of the fragment of Episternus onthophagi thallus collected from Onthophagus verticicornis—braces indicate layers of the thallus: A—the blastoconidia producing, outer-most layer, B—the inner-most, carapace-adhered layer. Scale bars = 500 μm.

FIGURE 4. Fragment of Episternus onthophagi thallus collected from Onthophagus verticicornis.—arrows indicate one-septated cells. Scale bars = 10 μm.

FIGURE 5. Fragment of Episternus onthophagi thallus collected from Onthophagus verticicornis—arrows indicate round blastoconidia produced via multidirectional budding. Scale bars = 10 μm.

FIGURE 6. Fragment of Episternus onthophagi thallus collected from Onthophagus verticicornis—arrows indicate round blastoconidia produced via multidirectional budding (SEM).