Biotecnologia

July - August 2010

601

BIOLOGICAL CONTROL

Chilled Packing Systems for Fruit Flies (Diptera: Tephritidae) in the Sterile Insect Technique
EMILIO HERNÁNDEZ, ARSENY ESCOBAR, BIGAIL BRAVO, PABLO MONTOYA
Programa Moscafrut, SAGARPA – IICA, Central Poniente 14, Col Centro, 30700 Tapachula, Chiapas, México Edited by Dori E Nava – ESALQ/USP Neotropical Entomology 39(4):601-607 (2010) ABSTRACT- We evaluated three packing systems (PARC boxes, “GT” screen towers and “MX” screen towers) for the emergence and sexual maturation of sterile fruit flies, at three adult fly densities (1, 1.2 and 1.3 fly/cm2) and three food types. At the lowest density, results showed no significant differences in the longevity and flight ability of adult Anastrepha ludens (Loew) and Anastrepha obliqua Macquart amongthe three packing systems. Higher densities resulted in a decrease in these parameters. In the evaluation of the three food types, no significant differences were found either on longevity or flight ability of A. ludens. However, the greatest longevity for both sexes A. obliqua was obtained with commercial powdered Mb® and the mix of sugar, protein and corn starch on paper (SPCP) food types. Thehighest value for flight ability in A. obliqua males was obtained with powdered Mb® and SPCP food types, and for females with Mb® powdered food. Our data indicated that GT and MX screen tower packing systems are an alternative to the PARC boxes, since they were suitable for adult fly sexual maturation without any harm to their longevity or flight ability. The tested foods were equivalent in both fruitfly species, with the exception of the agar type for A. obliqua, which yielded the lowest biological parameters evaluated. Our results contribute to the application of new methods for the packing and release of sterile flies in large-scale programs. KEY WORDS: Longevity, flight ability, emergence tower, Anastrepha ludens, Anastrepha obliqua The Sterile Insect Technique (SIT) was first successfullyapplied in the 1950s against the New World screwworm, Cochliomyia hominivorax (Coquerel), leading to the eradication of this pest from the USA, Mexico, and Central America after 43 years (Klassen & Curtis 2005). Currently, the technique is more broadly used against Tephritidae fruit flies (Enkerlin 2005). A successful example of the SIT is the program against the Mediterranean fruit fly, Ceratitiscapitata (Wied.), established in the 1970s in order to prevent the invasion of this pest in southeastern Mexico (Hendrichs et al 1983). In Mexico, the SIT has been applied against Anastrepha ludens (Loew) since 1994 (Reyes et al 2000), and Anastrepha obliqua (Macquart) since 2001 (Artiaga-López et al 2004). The final step in the SIT is the release of sterile flies in the field. For this purpose, flies arepacked at their pupal stage in diverse containers, such as PARC (Plastic Adult Release Container) emergence boxes or towers for their emergence and sexual maturation, and finally released in the field using the “chilled adult” system (Villaseñor 1985, Salvato et al 2004, Dowell et al 2005, Shelly et al 2006). This release system is the most commonly used since it favors a more homogeneousdistribution of the sterile material in the field and avoids the dissemination of undesirable residue (i.e., the remains of bags and pupae) during the release process. The packing units, by design, differ in volume and resting area that causes variations in fly density, a factor that may affect the quality of the released males. In the PARC boxes, flies are packed in paper bags, increasing the resting surface(Dowell et al 2005). The Guatemala (GT)-type towers have conduits integrated within the sieve frame and a ventilation area measuring 9,504 cm2. In the Mexico (MX)-type towers, pupae are packed in paper bags, and the units are twice the height of the Guatemalan type, achieving a ventilation area measuring 14,938 cm2, which permits a more efficient dissipation of the moisture and heat generated by...