It took only 2 days following my initial post about this “mystery pest” on Black Huckleberry in the Osprey Trail area (McIntosh Run barrens) to document, courtesy of Joshua Barss Donham & Rosa Barss Donham & iNaturalist, occurrences of the infestations well beyond the area I examined on July 2. Here’s the new iNaturalist Map:
Occurrences of Exobasidium in the Backlands as reported on iNaturalist 9 am on June 5, 2023
All occurrences noted by JBD & RBD were on Black Huckleberry. From the iNaturalist Halifax NS Backlands Project Page:
So it’s clear the infestation extends well beyond Osprey Trail area, i.e. it’s not associated with any conditions peculiar to the Osprey Trail area. ‘Seems likely it will be found throughout the larger, misty and for quite a while now, very wet Chebucto Peninsula area.
Thx JBD & RBD, also KM for an iNaturalist report on June 18, 2023
More Observations July 6, 2023:
I conducted a ‘walking survey’ in the area of Connaught Battery Park, outside of the Backlands proper but nearby. Over a distance of approx. 200 m, 9 discrete Huckleberry stands were observed, Exobasidum was present in 3 of them, not heavy infestations. At one (Hb9Exo3), the deformed berries were blackened and decaying, at the other 2 stands the deformations & galls were pinkish. See Map below for locations. Related iNat entries:
https://www.inaturalist.org/observations/171472173. Hb1Exo1.
https://www.inaturalist.org/observations/171472651. Hb3 (not infected)
https://www.inaturalist.org/observations/171473072. Hb4 (not infected)
https://www.inaturalist.org/observations/171473426 Hb5Exo2
https://www.inaturalist.org/observations/171473813. HB6 (not infected)
https://www.inaturalist.org/observations/171474386. Hb9Exo3
More Observations July 7, 2023:
I conducted a semi-formal, opportunistic survey for presence of Exobasidium on Black Huckleberry on the walking trail at Shaw Wilderness Park in Halifax NS on July 7, 2023. Stands were a few meters in diameter and larger; about 3 sq meters close to the walking trail were examined closely. In all cases where Exobasidium was observed, it’s occurrence was ‘occasional’, typically not more than about 1 specimen per sq meter. This contrasts with its ‘prevalence’ on Black Huckleberry in the area of the Osprey Trail circa 2 km distant ) observed on July 2.
related iNat Entries *=with Exobasidium; ~=No Exobasidium observed):
X1*, X2*, X3*, X4*, X5*, X6*, X7*, X8~, X9*, X10*, X11*, X12~, X13~, B1*, B2~, B3~
Summary map of all observations to date:
Circled points are the recent surveys. *=Exobasidium prevalent, ~=Exobasidium occasional