LIBRO-CONGRESO-CITRUS

S13P03
An early step toward the development of a method to predict Mediterranean fruit fly adult
emergence under different soil moisture and temperature regimes
Garrido-Jurado I., Valverde-García P., and Quesada-Moraga E.
University of Córdoba (UCO), Agricultural and Forestry Sciences, Spain. g72gajui@uco.es
The most important insect pest of citrus crops in the Mediterranean Basin is the medfly Ceratitis capitata
(Wiedemann). The fly lays its eggs in citrus fruit and the larvae feed and grow in the mesocarp. During
development, third instar larvae drop from fruits to the ground, burrow into the soil, and form a puparium
overwintering as pupa several cm below the soil. To this end, entomapathogenic fungi that have the advantage
of contact action, may be used for medfly microbial control either targeting adults or pupating larvae and pupae
in the soil beneath the tree canopy. However, optimizing the timing of soil fungal application for maximum
pupa and adult control at the onset of adult emergence from the soil would need a better understanding of
the effect of soil temperature and humidity on pre-imaginal development. An approach based on a lognormal
parametric survival model was used to define the effects of soil moisture and temperature on pre-imaginal
medfly mortality and to understand the relationship between both factors and their interaction as influences
on the development of pre-imaginal medflies in the soil. The number of days required for the immature flies
to complete their development and reach the adult stage (DT) were studied at five temperatures (15, 20,
25, 30 and 35ºC) and under five soil moisture regimes 1, 5.0, 9.0, 13.0 and 17.0% (wt:wt).The model was
significant for C. capitata pre-imaginal development, with DT 50 (the development time for 50% of the preimaginal
C. capitata to reach the adult stage) ranging from 12.8 to 32.4 days. The average development time
of the medfly pre-imaginals reaching the adult stage was inversely related to temperature and ranged from
7.4 to 26.1 days. This model could allow the monitoring of medfly pre-imaginal natural mortality in the soil,
and therefore, the identification of suitable application times in the medfly lifecycle to achieve the maximum
degree of adult and pre-imaginal control
S13P04
Fruit flies in orange plantations of TicoFrut - Costa Rica
Camacho H.
TicoFrut. University of Costa Rica: Fabio Baudrit Agricultural Research Station, Costa Rica. hcamachov@hotmail.com
TicoFrut Company, Central America’s largest industrial fruit production and processing enterprise, operates
its plants and plantations in the northern region of Costa Rica. In order to best ascertain how to select the
most effective and suitable strategies for tephritid control, the diverse tephritid populations were studied.
The study was carried out at six orange plantations (5,604 hectares) during the harvest periods of 2007 -
2009. Multilure traps baited with Nu Lure were used, with checks each week. Weekly sampling of 60 ripe
oranges took place in the same lots where the traps had been placed. Larvae and pupae were collected on
a weekly basis to identify them. In a total of 1093 traps were set in the plantations, 9,009 dipterous flies
were collected: among these 69 were Tephritidae, 803 Lonchaeidae, and 907 Ulididae. There were only 2
Anastrepha ludens and 2 Ceratitis capitata captured. Other flies trapped of the Anastrepha genus: 14 A.
striata, 33 A. obliqua, 5 A serpentina and, 2 A. fraterculus. None of these specimens were collected in or
on fruits, but rather only in traps. In the orange crop sampling, 22,920 fruits were analyzed (a total of 382
samples) and the following flies were obtained: 1,154 Lonchaeidae, 380 Muscidae, but no Tephritidae or
Ulididae flies. An unforeseen outcome was that the Lonchaeidae Neosilba batesi was caught in traps and in
the fruit sampling and the number of the Ulididae Xanthacrona bipustulata captured in traps. The largest
number and widest diversity of tephritids were captured in the area of the industrial plant facilities. In
2007, 112 traps were set and 1,360 Diptera were collected: 152 were tephritids (6 A. ludens, 1 C. capitata,
116 A. striata, 18 A. obliqua and 4 A. fraterculus) and 85 lonchaeids. In 2008-2009, 75 traps were set, and
these caught 383 flies: 28 were tephritids (2 A. ludens, 2 C. capitata, 18 A. striata and 6 A. obliqua). This
observed greater diversity was due to the large quantity of fruit stored at this locale which were originating
from many sites around the country.
XII INTERNATIONAL CITRUS CONGRESS 2012 - 225
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