Population dynamics and seasonal trend of California red scale (Aonidiella aurantii Maskell) in citrus in Northern Spain

The California red scale, Aonidiella aurantii (Maskell), was first detected in citrus groves in Catalonia, Northern Spain, in 2000, and has since spread slowly and irregularly. New foci of infestation are currently found in citrus-growing areas of southern Tarragona. As Catalonia is the northernmost citrus growing area in Spain, between 2002 and 2009, A. aurantii population dynamics and seasonal trends were studied in two citrus groves and compared with other regions and countries. The population dynamics showed that there were four male flights (including that of the overwintering generation): in May, mid June-mid July, August and October, the most abundant being that of August (over 60% of the males captured during the year). The thermal constant estimated between male flights, using 11.7°C as the lower threshold temperature, was 611.8 ± 35.5 degree-days. Three peaks of 1st and 2nd nymph instars were observed: in early June, late July-early August, and late September. The number of crawlers captured on sticky tapes reached a first maximum on 27th May (± 1.85 days). The male flight abundance showed a positive relationship between two consecutive generations, revealing the stability of A. aurantii populations.info:eu-repo/semantics/publishedVersio

Dinámica poblacional y estacional del piojo rojo de California (Aonidiella aurantii Maskell) en cítricos del norte de España

The California red scale, Aonidiella aurantii (Maskell), was detected in citrus in Catalonia, Northern Spain, in 2000, and has since spread slowly and irregularly southwards, with foci of infestation currently found in southern Tarragona citrus-growing areas. Since Catalonia is the northern citrus growing area in Spain, between 2002 and 2009, the A. aurantii biological cycle (male flights and seasonal history) was studied in two citrus groves and compared with other regions and countries. Population dynamics showed that 4 male flights occur (including that of the overwintering generation) in May, mid June-mid July, August and in October, the most abundant being in August (over 60% of males captured throughout the year). The thermal constant estimated between male flights, using 11.7 ºC as the lower threshold temperature, was 611.8 ± 35.5 DD. Three peaks of sensitive instar were also observed, in early June, late July-early August, and late September. The number of crawlers captured reached a maximum on 27 May (± 1.85 days), 24.8 ± 2.5 days (184.2 ± 18.1 DD) after the first male flight. The male flight abundance showed there was a relationship only between two consecutive generations, revealing the rapid shifts in population abundance. We estimated when the first sensitive instar peak occurred through a non-destructive method, based on the peak of males captured during the first flight.El piojo rojo de California, Aonidiella aurantii (Maskell), fue detectado en el año 2000 en Cataluña, y desde entonces hasta la actualidad esta plaga ha experimentado una lenta e irregular expansión; actualmente se pueden encontrar focos de infestación de la plaga en todas las áreas de cultivo citrícolas del sur de Tarragona. En la zona citrícola de Cataluña, que es la más septentrional de España, desde 2002 a 2009, se llevaron a cabo estudios del ciclo biológico y vuelos de machos en dos fincas de cítricos para compararlos con otras regiones y países. De acuerdo con la dinámica poblacional observada, se produjeron cuatro vuelos de machos (incluyendo el de las poblaciones invernantes): en mayo, desde mediados de junio a mediados de julio, en agosto y durante octubre, siendo el tercero el más abundante, que representa alrededor del 60% del total de machos capturados. La constante térmica estimada entre dos vuelos consecutivos, empleando como umbral mínimo 11,7°C, fue de 611,8 ± 35,5 grados-día. Además se observaron tres máximos de ninfas de primera y segunda edad: a primeros de junio, entre finales de julio y primeros de agosto, y a finales de septiembre. El número de ninfas móviles de primera edad alcanzó un primer máximo el 27 de mayo (± 1,85 días). La abundancia de machos en los vuelos mostró una relación positiva entre vuelos consecutivos, mostrando la estabilidad de las poblaciones de A. aurantii

Seasonal and annual trends in field populations of Mediterranean fruit fly, Ceratitis capitata, in Mediterranean citrus groves: comparison of two geographic areas in eastern Spain

Seasonal and annual trends in Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) populations were analyzed to determine the factors that influence population fluctuations in the field. Adult flies were monitored along 2003-07 in two citrus areas in eastern Spain with similar climate, Valencia and Tarragona. Adults were present throughout the study period, even in winter. The initial annual population increase was related to previous winter and spring temperatures. Captures started to increase in April-May and usually reached a peak in July. This peak corresponded to the maximum capture period in Valencia, but not in Tarragona, where there was usually a second peak in autumn, with capture levels similar to the first peak. Gravid females were found throughout the year, even in overwintering populations of medfly. The availability of other host fruit species in the vicinity of the citrus groves may explain the differences in annual abundance and distribution of captures between the two areas studied.Se analizó la evolución estacional de las poblaciones de Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) para determinar los factores que influencian sus fluctuaciones poblacionales en campo. Se muestreó la población de adultos entre 2003 y 2007 en dos áreas citrícolas del este de España con clima similar, Valencia y Tarragona. Se encontraron adultos a lo largo de todo el periodo de estudio, incluso en invierno. El primer incremento anual de la población estuvo relacionado con las temperaturas previas del invierno y la primavera. Las capturas comenzaron a incrementarse en abril-mayo y generalmente alcanzaron un máximo en julio. Este máximo correspondió al máximo periodo de capturas en Valencia, pero no en Tarragona, donde hubo generalmente un segundo máximo en otoño, con niveles de captura similares al primer máximo. Se encontraron hembras grávidas a lo largo de todo el año, incluso en las poblaciones invernantes de mosca de la fruta. La disponibilidad de otras especies de frutales hospedantes cercanas a las parcelas de cítricos puede explicar las diferencias en abundancia anual y distribución estacional de capturas entre las dos áreas estudiadas