LIBRO-CONGRESO-CITRUS

could be described by the Holling II functional response type. The results suggested that predation ability of N.
cucumeris was strongest to T. flavidulus among three predatory mites and prey density significantly influence
reproductive ability of N. cucumeris and E. nicholsi, but not N. barkeri. Among 10 types of colors sticky cards
i.e., yellow, blue, deep-blue, white, red, green, purple, gray and pink in citrus orchards, T. flavidulus had the
strongest preference to the blue and deep blue sticky cards. The thrip numbers on those cards were significant
different from those on the other eight colors sticky cards. The trapping techniques of blue sticky cards were
discussed. Effect of 16 different plant volatile compounds on the behavior of adult female T. flavidulus thrips
was tested with a Y-tube olfactometer. The results showed that T. flavidulus were attracted by the compound
of benzenoids and monoterpenes isoprenoids. The compound A and E have the significant attraction to thrips
at concentration 10% and 1%.
This work is supported by the earmarked fund for Modern Agro-industry Technology Research System of
China (No. CARS-27), and Special Fund for Agro-scientific Research in the Public Interest (no. 200903032).
S16P21
Thysanoptera occurring in clementine mandarin under three ground cover management
strategies: species composition, abundance and distribution.
Aguilar-Fenollosa E., and Jacas J.A.
Universitat Jaume I (UJI), Ciències Agràries i del Medi Natural, Spain. aguilare@uji.es
There is a complex of Thysanoptera species inhabiting citrus and some of them are considered pests.
This study was aimed at studying the effect of ground cover management on thrips species composition,
abundance and distribution in commercial clementine mandarin orchards. Three ground cover management
systems were compared: resident vegetation cover, Festuca arundinacea Schreber (Poales: Poaceae) cover,
and bare soil. The ground cover influenced the abundance of some thrips species in the cover. Among
the main species causing fruit damage in citrus, we found Frankliniella occidentalis (Pergande) and Thrips
tabaci Lindeman. The F. arundinacea cover strongly depressed the abundance of these thrips species in
ground cover vegetation. The resident vegetation cover could provide a range of suitable hosts supporting
populations of potential thrips pest species out of the main citrus peak blooming period. Apart from that,
the F. arundinacea cover, which hosted Poaceae-specific thrips species, could provide alternative food
enhancing populations of predatory phytoseiid mites which could reduce populations of potential citrus
pests below economic injury level. Our results confirm the suitability of F. arundinacea as a cover crop for
clementine mandarins.
S16P22
Effect of biotic and abiotic factors on the insurgence of fruit scars in Italian orange orchards.
Siscaro G. 1 , Zappalà L. 1 , Biondi A. 1 , Conti F. 2 , and Fisicaro R. 2
1 University of Catania (DiGeSA), Department of Agri-food and Environmental Systems Management, Italy; and 2 Sicilian Region -
Assessorship of Agricultural and Food Resources (SFR - OMP), Regional Plant Health Service, Italy. fconti@regione.sicilia.it
Citrus fruit rind scars are corky tissue formations, the structure, shape and distribution of which may be very
variable on the fruit surface. Such phenomena have been increasingly recorded during the last few years
on lemon and orange fruits, as confirmed by surveys carried out in several Italian packing houses. They are
referred to fruit scars induced by various biotic factors such as thrips feeding and physical damage, mainly
caused by brunch rubbing due to wind or spraying equipments. In 2011, a field survey was conducted in a
Sicilian organic orange orchard, to evaluate possible correlation between thrips infestation, brunch rubbing
and fruit scars. Two plots were evaluated; one planted with the variety Navelina and the other with Tarocco
Scirè. No insecticides were applied during the observation period. Thrips infestation was monitored weekly
from the flowering to fruit-set, and type, incidence and severity of fruit scars were assessed by field direct
observations at fruit-set and harvest. In addition, a survey was carried out in 7 packing houses located in
the same production area to assess the rate of downgrading due to fruit scars. Although very few flowers
and young fruits were found infested by thrips (mainly Pezothrips kellyanus and Frankliniella occidentalis),
XII INTERNATIONAL CITRUS CONGRESS 2012 - 291
S16