Compatibilidad para el apareamiento entre distintas poblaciones de la mosca sudamericana de la fruta, Anastrepha fraterculus (Wiedemann)

Mating compatibility among different populations of the South American fruit fly, Anastrepha fraterculus (Wiedemann) was assessed through mating tests in pairwise combinations. Screened cages, inside a greenhouse, containing Citrus trees were used. Mating compatibility was determined using the Index of Sexual Isolation. Most of the populations were non-compatible with each other and thus sexually isolated. Of these, Tucumán (Argentina) and Piracicaba (Brazil) populations showed a lower degree of isolation, while the other tested combinations were highly isolated. Full mating compatibility was detected only between two Argentinean (Concordia and Tucumán) and two Peruvian populations (La Molina and Piura+La Molina). Flies were sexually active at different times of the day: Tucumán, Concordia and Piracicaba populations presented an early morning peak, La Molina and Piura+La Molina were active around midday and Ibague (Colombia) late in the afternoon. Manipulation of light-phase conditions, to match the times of maximum sexual activity, did not increase the compatibility between La Molina and Tucumán. Based on these behavioral results, which confirm morphometric, genetic and other evidence, the taxonomic revision of this cryptic species complex is warranted. One practical implication is that colonies of this pest to be used in any sterile insect technique approach should be derived from the target population or from a compatible one. Regional efforts should be initiated to determine the distribution of each subgroup and their relationship with each other in terms of compatibility.Se evaluó la compatibilidad para el apareamiento entre distintas poblaciones de la mosca Sudamericana de la fruta, Anastrepha fraterculus (Wiedemann), mediante pruebas de apareamiento confrontando dos poblaciones por vez. Se utilizaron jaulas con árboles de Citrus limon (L.) en un invernadero. La compatibilidad para el apareamiento se determinó con el ṍndice de aislamiento sexual. La mayorṍa de las poblaciones fueron no compatibles y consecuentemente estuvieron aisladas entre sṍ. Entre estas, las poblaciones de Tucumán (Argentina) y Piracicaba (Brasil) presentaron el menor grado de aislamiento, mientras que las otras presentaron alto aislamiento. Se detectó compatibilidad solamente entre dos poblaciones argentinas (Concordia y Tucumán) y dos poblaciones peruanas (La Molina y Piura ⫹ La Molina). Las poblaciones estuvieron sexualmente activas en distintos momentos del día: Tucumán, Concordia y Piracicaba presentaron un pico de actividad al amanecer, La Molina y Piura ⫹ La Molina al mediodía e Ibague (Colombia) al atardecer. La manipulación de los horarios del ciclo de luz-oscuridad, para coincidir la hora de máxima actividad sexual, no aumentó la compatibilidad entre La Molina y Tucumán. Basándonos en estos resultados comportamentales, que confirman las evidencias genéticas y morfológicas registradas, es necesaria una revisión taxonómica de este complejo de especies. Una consecuencia práctica sería que las colonias a utilizar para la cría masiva de insectos estériles para la implementación de la técnica del insecto estéril para el control de esta plaga deben originarse de la población a controlar o de una población compatible. Se deben iniciar esfuerzos regionales para determinar la distribución de cada subgrupo y su relación en términos de compatibilidad.Fil: Vera, María Teresa. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Cáceres, Carlos. Agriculture and Biotechnology Laboratory; AustriaFil: Wornayporn, Viwat. Agriculture and Biotechnology Laboratory; AustriaFil: Islam, Amirul. Agriculture and Biotechnology Laboratory; AustriaFil: Robinson, Alan S.. Agriculture and Biotechnology Laboratory; AustriaFil: de la Vega, Marcelo Horacio. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Hendrichs, J.. Division of Nuclear Techniques in Food and Agriculture; AustriaFil: Cayol, J-P. Division of Nuclear Techniques in Food and Agriculture; Austri

Evaluation of quality production parameters and mating behavior of novel genetic sexing strains of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera : Tephritidae)

The Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is one of the most important pest of fruits and vegetables in tropical and subtropical countries. The sterile insect technique (SIT) as a component of area-wide integrated pest management (AW-IPM) approaches is being used for the successful management of this pest. VIENNA 8 is a genetic sexing strain (GSS) that has a white pupae (wp) and temperature sensitive lethal (tsl) mutation, the latter killing all female embryos when eggs are exposed to high temperatures (34°C). The use of this GSS permits production and the release of only males which has increased the cost effectiveness of the SIT several fold for this pest. An efficient method of identification of recaptured sterile males can further increase the cost effectiveness of the SIT for this pest. Therefore, VIENNA 8-Sergeant2 (Sr²) strain and the transgenic strain VIENNA 8–1260 having visible markers were constructed. All three strains were evaluated for egg production, egg hatch, and egg sterility parameters under semi mass-rearing conditions and mating competitiveness in field cages. VIENNA 8–1260 females produced significantly fewer eggs as compared with the two other strains, which produced similar numbers of eggs. However, egg hatch of all strains was similar. Egg hatch of eggs produced by untreated females that had mated with adult males that had been irradiated with 100 Gy as pupae 2 days before emergence, was different for the three strains, i.e., egg hatch of 0.63%, 0.77%, 0.89% for VIENNA 8, VIENNA 8–1260, and VIENNA 8-Sr², respectively. Differences in male mating competitiveness of the three strains against wild-type males were gradually reduced with successive generations under semi mass-rearing conditions. However, VIENNA 8 males adapted faster to laboratory conditions as compared with VIENNA 8-Sr² and VIENNA 8–1260 males with respect to mating competitiveness. VIENNA 8 males of the F10 generation were equally competitive with wild-type males, whereas the mating competitiveness of VIENNA 8-Sr² and VIENNA 8–1260 males was similar but lower as compared with wild-type males. Males from all three strains copulated earlier than wild-type males. Results are discussed in relation with the potential benefits of incorporating novel strains for more effective SIT application.14 page(s

Mediterranean fruit fly genetic sexing strains VIENNA 8, VIENNA 8-Sr² and VIENNA 8–1260 egg hatch (% ± SD) data during the course of eight generations under semi mass-rearing conditions.

<p>Mediterranean fruit fly genetic sexing strains VIENNA 8, VIENNA 8-Sr² and VIENNA 8–1260 egg hatch (% ± SD) data during the course of eight generations under semi mass-rearing conditions.</p

RSI indices from mating competitiveness experiments with three laboratory strains of the Mediterranean fruit fly tested against a wild-type Argentina population in field cages.

<p>Couples observed for each type of mating, RSI values± SD with chi-square results (<i>p</i> > 0.05) showed equal mating propensity. Number of couples from each strain followed by same letter are not significantly different from each other (Tukey-Kramer HSD, α = 0.05) and numbers of cages that have been taken into account (>50% of total expected) in parenthesis.</p

Number of eggs (± SD) produced per female per day by the Mediterranean fruit fly genetic sexing strains VIENNA 8, VIENNA 8-Sr² and VIENNA 8–1260 under semi mass-rearing conditions.

<p>Means followed by the same letter do no differ significantly (Tukey-Kramer HSD, α = 0.05).</p

Mating latency (min) and mating duration (min) among three laboratory strains of Mediterranean fruit fly and a wild-type Argentina strain.

<p>Average mating latency or duration ± standard deviation is presented, couples observed are presented in parenthesis. First column for each parameter presents results collected from competitiveness study cages, second column presents results collected from control cages. Within the columns, numbers followed by the same letter do no differ significantly (Tukey-Kramer HSD, α = 0.05).</p

Egg hatch (%) of three strains of Mediterranean fruit fly, presenting the effect of irradiation on males and females at different generations under mass-rearing conditions (10 days of egg collection for each generation were tested for successful hatching).

<p>For the sterile sex of each one of the following combinations, the sterilizing dose was 100 Gy delivered from Co⁶⁰ source. Average and standard deviation of egg hatch percentage are presented, total number of eggs examined are presented in parenthesis.</p