In the last years, the honeybee population is facing growing threats such as expansion 4 of pathogens, the incorrect use of phytosanitary products and environmental 5 contaminants, loss or fragmentation of habitat, invasive species and climate change. In 6 Spain, the citrus cultivation in integrated pest management (IPM) attempts the most 7 available use of strategies for the control of pests populations by means of taking 8 actions that prevent problems, remove levels of damage and use of chemical control 9 only when and where is necessary. The purpose of this work is to develop a simple 10 analytical method that permits to evaluate the pesticide residue levels in honeybees 11 and corbicular pollen when honeybees are exposed to plant protection products (PPPs) 12 used in integrated management fields of citrus orchards. The proposed method is 13 based in an ultrasound assisted extraction procedure followed by a dispersive solid 14 phase extraction (d-SPE) clean-up with alumina and LC-MS/MS determination. The 15 method was validated in samples of honeybee and corbicular pollen for the 10 16 pesticides mostly used in citrus orchards with IPM. This procedure was compared with 17 QuEChERS methodologies for these matrices. The developed method was applied to 18 the determination of these pesticides in both matrices in a two -year study in citrus 19 orchards. 20

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 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 1 st and 2 nd 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.Additional key words: Aonidiella aurantii; California red scale; Catalonia; Diaspididae; population dynamics. Resumen Dinámica poblacional y estacional del piojo rojo de California (Aonidiella aurantii Maskell) en cítricos del norte de EspañaEl 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 míni-mo 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.

Ants play important ecological roles, such as predation on other arthropods, seed dispersal, and soil structure maintenance. In citrus agroecosystems, ants are considered a secondary pest. The damage they cause is indirect through the disruption of the biological control of pests, especially honeydew producers. In integrated pest management programs, adequate and precise sampling methods are required to accurately determine the need for chemical ant control to minimize the economic and environmental costs of unnecessary chemical treatments and to reduce the risk of crop loss by pests. In Mediterranean citrus groves, eight ant species that differed in abundance and frequency have been found foraging on citrus trees: Lasius grandis Forel, Pheidole pallidula (Nylander), Plagiolepis pygmaea (Latreille), Formica gerardi Bondroit, Formica rufibarbis Fabricius, Camponotus sylvaticus (Olivier), Linepithema humile (Mayr), and Tapinoma erraticum (Latreille) (all Hymenoptera: Formicidae). The trunk was selected as the most efficient sampling unit to establish the monitoring method. Aggregation indices on the trunk of these species were calculated, and enumerative and binomial sampling methods were developed for the most frequent species, L. grandis and Ph. pallidula. Ant species differed in spatial distributions within citrus orchards, and required different sample sizes to estimate population abundance. The minimum sample size required, taking into account the maximum average abundance found -44.1 L. humile, 17.3 L. grandis, and 3.5 Ph. pallidula per trunk per min -, would be 28, 25, and 54 trees, respectively.

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Seasonal trends and the parasitoid complex of Chinese wax scale (Ceroplastes sinensis) was studied from July 2010 to February 2013. Six commercial citrus groves located in northeastern Spain were sampled fortnightly. Chinese wax scale completed a single annual generation. Egg oviposition started in May and continued until mid-July. Egg hatching began in mid-June, and in the first quarter of August, the maximum percentage of hatched eggs was reached. In the same groves, the parasitoid species of C. sinensis were determined together with their seasonal trends, relative abundance and occurrence on C. sinensis. Four hymenoptera were found parasitizing C. sinensis, mainly on third instars and females: Coccophagus ceroplastae (Aphelinidae), Metaphycus helvolus (Encyrtidae), Scutellista caerulea (Pteromalidae) and Aprostocetus ceroplastae (Eulophidae). The most abundant species was A. ceroplastae, corresponding to 54% of the parasitoids emerged. Coccophagus ceroplastae and M. helvolus represented 19%, whereas S. caerulea comprised 8% of the total. This study is the first published record of C. ceroplastae in Spain and the first record of M. helvolus on C. sinensis in Spain. Concerning the economical thresholds normally used, sampling plans developed for the management of C. sinensis in citrus groves should target population densities of around 12–20% of invaded twigs, equivalent to 0.2–0.5 females per twig. The sample size necessary to achieve the desired integrated pest management precision is 90–160 twigs per grove for the enumerative plan and about 160–245 twigs per grove for the binomial plan.