M. De Coss-romero et Je. Pena, Relationship of broad mite (Acari : Tarsonemidae) to host phenology and injury levels in Capsicum annuum, FLA ENTOMOL, 81(4), 1998, pp. 515-526
The responses of broad mite, Polyphagotarsonemus latus Banks (Acarina: Tars
onemidae), were studied on four phenological stages of pepper plants: veget
ative (V), blossoming (B), early fruiting (EF) and late fruiting (LF) stage
s. All stages of the mite preferred the undersides of the leaves to the upp
ersides. Plants in V, B, and EF stages had higher numbers of mites per cm(2
) of foliage than plants in the late fruiting stage. A damage index scale (
0-6) was developed to assess broad mite injury to pepper plants. Eight to n
ine cumulative mite days/cm(2) were needed to reach a damage index equal to
3 for V, B and EF plant stages. The damage index was also used to relate b
road mite injury to leaf area, height, water content, number of leaves, flo
wers, buds, fruits and fruit weight of plants infested at four different ph
enological stages. Plants infested when 14 weeks old (late fruiting stage),
had less damage, significantly higher number of fruits and fruit weight th
an plants infested at earlier plant stages, i.e., vegetative, flowering or
early fruiting. The relationship between the damage rating (x) and fruit nu
mbers per plant (y(1)) and fruit weight in grams (y(2)) was given by y(1) =
2.83-0.45x and y(2) = 232.5-37.234x, respectively.