PINEAPPLE - Tropical Fruits - page 357

Pests
Insects can cause direct damage to various plant parts or vector diseases
(Table 12.5). Prior to 1953, pineapple fruit were fumigated with methyl
bromide before importation into continental USA. Pineapple fruits that are
more than 50% 'Smooth Cayenne' are not now regarded as a host for tephritid
fl ies: Mediterranean fruit fl y, C. capitata (Wiedermann); the Melon fl y, D.
cucurbitae (Coquillet); and the Oriental fruit fl y, D. dorsalis Hendel; hence, insect
disinfestation is no longer required (Armstrong and Vargas, 1982).
The pineapple scale, Diaspis bromeliae (Kerner), occurs wherever pineapple
is grown. In Hawaii, pineapple scale is not normally a major problem in
fi elds, probably because of scale parasites and predators. However, because
of the US quarantine requirement, fruit have to be insect-free, and even low
levels of pineapple scale at harvest present quarantine problems. Scale can
be controlled relatively easily by preharvest insecticide applications, taking
into consideration label requirements relating to last application prior to
harvest time.
The pineapple fruit mite, Steneotarsonemus ananas Tryon, occurs uni-
versally on the growing plant, developing infl orescence, fruit and crown. The
fruit mites feed on developing trichomes on the white basal leaf tissue and
fl ower bracts and sepals, causing light brown necrotic areas. The pineapple red
mite, Dolichotetranychus fl oridanus Banks, feeds on the white basal leaf tissue,
particularly of the crown. Severe damage occurs when the fruits mature under
drought conditions, and it may cause death of the basal crown leaves, thereby
af ecting fruit quality (Rohrbach and Schmitt, 1994).
Other insects are mentioned frequently in the literature. In Latin America
and in some Caribbean islands the larvae of the Thecla butterfl y ( Thecla
brasiliodes ) cause fruit damage, occasionally in serious proportions. Dusting
or spraying the fruit at fl owering stage with appropriate insecticides has given
satisfactory control. In the Caribbean region, the larvae of the Batrachedra
butterfl y ( Batrachedra sp.) damage fruit at the fl owering stage, causing
gummosis. Field observations in Jamaica during 1972 showed high incidence
of damage in 'Red Spanish' but not in 'Smooth Cayenne'.
Weed control
Weeds can cause serious crop losses, and on small farms, neglect of weeding at
monthly intervals can result in 20-40% declines in yields. Average fruit weight
in Guinea can be 0.60 kg from an unweeded fi eld, as compared to 1.55 kg with
good weed control. Weed control is a major cost item in pineapple production
and is essential to assure high yields as well as removal of plants that host or
harbour nematodes and insects such as mealy bugs. The weed problem can be
lessened by complete mulching of the beds and interbeds, hence delaying or