One hundred and thirty avocados were infested
with late Medfly eggs (approximately 48 h old at
the time of the cold treatment) according to the
previously published methods (Jang, 1996). Each
avocado was ‘cored’ through the fruit just above
the seed using a 7-mm cork borer. The resulting
transectional ‘plug’ was removed and a 1-cm section
was removed from the center. One endocarp
end of the halved plug was placed back into the
avocado. Approximately 900 eggs in 10–20 ml of
water were inserted (1–2 cm) into the center of
the fruit through the open end. The second portion
of the plug was then replaced into the fruit
and both ends of the fruit plug were secured with
masking tape. Ten infested avocados were held at
room temperature (22–23°C) for the duration of
the longest treatment time as a control sample for
the cold-treated avocados. In addition, a second
non-treated control consisting of either an artifi-
cially infested peach fruit or C. capitata eggs
placed on a standard artificial diet (wheat, torula
yeast, sugar and preservatives) was included as a
‘positive control’ due to the poor host suitability
of avocado fruit (Jang, 1996).