Oviposition preference
Exclusion netting (a mesh bag approximately100 x150 mm) was placed
around single infructescences after petal fall in both years on wild and
cultivated blackberry bushes. Netting bags were secured at the base of
the cluster with a foam strip encircled by a plastic zip tie to ensure a
tight seal to prevent insect entry but not damage the plant. Fruit were
monitored, and when ripe fruit were observed in both cultivation types,
all netted, ripe berries were collected at a single wooded and
cultivated site on the same day and brought back to the lab. The
following day, fruit were examined under a microscope to verify a lack
of insect or mechanical damage. A two-choice bioassay was set up using
equal weights of cultivated and wild blackberries placed in 35 x10 mm
petri dishes in the bottom of a 473-ml plastic container. Two 5–7-day
old females from the laboratory colony (see Hardin et al. 2015) were
added to the container and removed after 90 minutes and the number of
eggs per berry was counted. A separate two-choice assay compared
oviposition preference between a single cultivated and single wild
blackberry fruit using the same protocol.