To me, this would read as "(Walker & Fabricius, 1858)", which is obviously incorrect as Fabricius died in 1808.
Of course, the species was published by Francis Walker, so the F. is probably intended to identify the exact "Walker" as in "Walker, F.".
Francis Walker being one of the early authors I'm suspecting he might haver been the first to claim the name in zoological naming (and the F.
might not be needed), but I'm not too sure about that.
Anyway, the ampersand seems to be out of place, so it should be either (Walker, 1858) or something like (Walker F., 1858) or maybe (Walker, F., 1858).
Example
Purana guttularis (Walker, F., 1858)
This currently results in 2 authors: Walker & F.See for code here: https://github.com/gbif/name-parser/blob/master/name-parser/src/main/java/org/gbif/nameparser/ParsingJob.java#L1288
On this page the species is presented as : Purana guttularis (Walker & F., 1858) https://www.gbif.org/species/7953930
To me, this would read as "(Walker & Fabricius, 1858)", which is obviously incorrect as Fabricius died in 1808.
Of course, the species was published by Francis Walker, so the F. is probably intended to identify the exact "Walker" as in "Walker, F.". Francis Walker being one of the early authors I'm suspecting he might haver been the first to claim the name in zoological naming (and the F. might not be needed), but I'm not too sure about that.
Anyway, the ampersand seems to be out of place, so it should be either (Walker, 1858) or something like (Walker F., 1858) or maybe (Walker, F., 1858).