Faya (Myrica faya) is an introduced weedy tree threatening native ecos
ystems in Hawaii. Classical biological control has been investigated f
or several years but has yielded few insect pests or pathogens, none o
f which currently offers control in the field. As an alternative, atte
ntion was recently given to identify locally established insect pests
and pathogens. Botrytis cinerea causes widespread fruit rot and is the
first pathogen reported from faya in its nonnative habitat. Infection
of flowers and foliage is rarely observed. Fruit rot occurs on trees
of all sizes in a variety of habitats throughout the Hawaiian range of
faya. In 1992, over 49 and 51% of mature fruit at two sites were infe
cted. Similar percentages of immature fruit were infected or infested
with B. cinerea. Adults and fruit-feeding larvae of Amorbia emigratell
a and Cryptoblabes gnidiella collected from infected fruit clusters in
the field were heavily infested with viable conidia and may serve as
vectors. Selection of more aggressive or ecologically fit strains or i
ntroduction of large numbers of Botrytis-infested insect vectors early
in the fruiting season may enhance faya biocontrol.