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Rapid Evolution of a Cold Stress Cline in Mediterranean Fruit Fly During Northward Range Expansion.

Timely detection of an invasion event, or a pest outbreak, is an extremely challenging operation of major importance for implementing management action toward eradication and/or containment. Fruit flies—FF—(Diptera: Tephritidae) comprise important invasive and quarantine species that threaten the world fruit and vegetables production. The current manuscript introduces a recently developed McPhail-type electronic trap (e-trap) and provides data on its field performance to surveil three major invasive FF (Ceratitis capitata, Bactrocera dorsalis and B. zonata). Using FF male lures, the e-trap attracts the flies and retains them on a sticky surface placed in the internal part of the trap. The e-trap captures frames of the trapped adults and automatically uploads the images to the remote server for identification conducted on a novel algorithm involving deep learning. Both the e-trap and the developed code were tested in the field in Greece, Austria, Italy, South Africa and Israel. The FF classification code was initially trained using a machine-learning algorithm and FF images derived from laboratory colonies of two of the species (C. capitata and B. zonata). Field tests were then conducted to investigate the electronic, communication and attractive performance of the e-trap, and the model accuracy to classify FFs. Our results demonstrated a relatively good communication, electronic performance and trapping efficacy of the e-trap. The classification model provided average precision results (93–95%) for the three target FFs from images uploaded remotely from e-traps deployed in field conditions. The developed and field tested e-trap system complies with the suggested attributes required for an advanced camera-based smart-trap.

Effects of Thermal Acclimation on the Tolerance of Bactrocera zonata (Diptera: Tephritidae) to Hydric Stress.

Herbivorous insects play important roles in agriculture as pests or as weed biological control agents. Predicting the timing of herbivore insect population development can thus be of paramount importance for agricultural planning and sustainable land management. Numerical simulation models driven by temperature are often used to predict insect pest population build-up in agriculture. Such simulation models intend to use station-derived temperatures to drive the development of the target insect, although this temperature may differ substantially from that experienced by the insect on the plant. To improve the estimations, it has been suggested to replace air temperature in the model by land surface temperature (LST) data. Here, we use a numerical simulation model of insect population dynamics driven by either air temperature (combined with atmospheric temperature soundings) or land surface temperature derived from satellites to predict the population trends of the leaf beetle Ophraella communa, a potential biological control agent of Ambrosia artemisiifolia in Europe. For this, we conducted an extensive field experiment that included caged O. communa populations at five sites along an altitudinal gradient (125–1250 m a.s.l.) in Northern Italy during 2015 and 2016. We compared our model predictions using air or land surface temperature with observed beetle population build-up. Model predictions with both air and land surface temperatures predicted a similar phenology to observed populations but overestimated the abundance of the observed populations. When taking into consideration the error of the two measurement methods, the predictions of the model were in overlapping timeframes. Therefore, the current model driven by LST can be used as a proxy for herbivore impact, which is a novel tool for weed biocontrol.

The cotton bollworm (Helicoverpa armigera) is among the most damaging agricultural insect pests in the world. The life cycle of H. armigera is temperature dependent and as such modeling its population dynamics for integrated pest management (IPM) purposes requires accurate temperature information throughout the area of interest, which is not always available. We present, for the first time, a continuous age-structured insect population model driven by satellite-derived land surface temperature (LST) to derive population dynamics of H. armigera. We use LST data from the Moderate resolution imaging spectroradiometer (MODIS) conducting model simulations and validating the model with H. armigera larvae counts from in-field scout reports in nine sweet corn (Zea mays convar) and four tomato (Solanum lycopersicum) crop fields in Northern Israel. We compared our results with a similar model that uses air temperature derived from the nearest weather station as an input. To accurately predict population dynamics, we used different model initiation scenarios considering pesticide application and migration patterns between neighboring corn and tomato fields, which were identified as sink and source of the adult population. Results show that our LST-driven model outperformed the model driven by ambient air temperature. Model simulations generally followed the larval population development observed in the field when the model was initiated the day before the first larvae were detected, providing realistic population dynamics. Simulations with different adult population migration rates showed the importance of including between-field migration in the LST-driven model. In conclusion, this study provides a basis for future development of real-time IPM support systems, particularly when combining a temperature-driven age-structured insect population model with real-time satellite-derived information.

We provide an extensive review on current knowledge and future research paths on the topic of resource allocation and compensation during development in holometabolous insects, emphasizing the role of resource management during development, and how compensatory mechanisms may be acting to remediate nutritional deficiencies carried over from earlier stages of development. We first review resource allocation in "open" and "closed" developmental stages and then move on to the topic of modelling resource allocation and its trade-offs. In doing so, we review novel methodological developments such as response-surface methods and mixture experiments as well as nutritional geometry. We also dwell on the fascinating topic of compensatory physiology and behavior. We finish by discussing future research paths, among them the emerging field of nutrigenomics and gut microbiome, which will shed light into the yet poorly understood role of the symbiotic microbiota in nutrient compensation or assimilation.

A Decision Support System (DSS) was developed and evaluated to control the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedermann), by incorporating a semi-automatic pest monitoring and a precision targeting approach in multi-varietal orchards. The DSS consists of three algorithms. DSS1, based on the degree days calculation, defines when the traps should be deployed in the field initiating the medfly population monitoring. DSS2 defines the areas to be treated and the type of treatment based on the number of adult medfly captures, harvesting time, and phenological stage of the host cultivar. DSS3 defines the spraying procedure considering the technical registration properties of the selected insecticide (e.g., withholding period and efficacy duration time) and weather conditions. The DSS was tested in commercial orchard conditions near Rome, central Italy, with a randomized complete blocks experimental design, comparing DSS-assisted and conventional management. In the DSS-assisted plots, a semi-automatic adult medfly monitoring system was deployed, composed of real-time, wireless electronic traps. The output of the functioning DSS is a map of spraying recommendation, reporting the areas to be treated and the treatment type (bait or cover insecticide spraying). The farmer was left free to follow, or not, the DSS indications. The first medfly captures were observed on June 30, whereas the DD threshold was reached on July 3 when the DSS started to operate. The field test produced 29 DSS decisions from July 3 to September 1 and confirmed that medfly management using the DSS substantially reduced the number of pesticide applications, the treated area, and the volumes of pesticide utilization. No significant differences in infested fruit were observed between DSS-assisted and conventional management. The level of acceptance of the DSS by the farmer was 78%. This evidence confirmed the requirement of fully involving farmers and pest managers during the evaluation process of DSS.

Modern agriculture requires technology to give precise measures about relevant parameters such as pest control. Here, we developed a decision support system (DSS) based on semi-automatic pest monitoring for managing the olive fruit fly Bactrocera oleae (Rossi), in Mallorca (Balearic Islands, Spain). The DSS was based on an algorithm that took into account spatial and temporal patterns of olive fruit fly population in an orchard where all trees were georeferenced, thus precise treatments against the pest were conducted through a location aware system (LAS). The olive fruit fly adult population was monitored by using ad hoc off-the-grid autonomous electronic traps.The results were compared with those obtained with conventional methods. For a pilot trial, we selected an olive-producing orchard, where from June to October 2015, three plots using LAS management and three plots under conventional control (NO-LAS plots) were compared. Spray threshold considered both adult population and fruit damage. An additional non-sprayed plot was selected for assessing biological control due to the parasitoid, Psyttalia concolor (Sz&eacute, pligeti). Results showed that the use of DSS reduced by 36.84% the volume of insecticide used in LAS compared to NO-LAS plots. Accordingly, time and distance needed for spraying were also reduced. Adult olive fruit fly population was lower in the LAS plots when compared with the NO-LAS plots, conversely, fruit infestation was higher in LAS compared with NO-LAS. The implementation of LAS and DSS at field level allowed real-time monitoring of adult olive flies, thereby increasing the accuracy and precision of sprays in time and space and decreasing impact on natural enemies.

The Ethiopian fruit fly (EFF), Dacus ciliatus, is a key, invasive pest of melons in the Middle East. We developed and implemented a novel decision support system (DSS) to manage this pest in a greenhouse environment in Southern Israel. Dacus ciliatus is commonly controlled in Israel with repeated calendar-sprayings (every 15 days) of pyrethroid pesticides. The current study compares the performance of a DSS against calendar-spraying management (CSM). DSS was based on EFF population monitoring and infestation. DSS took into consideration concerns and observations of expert managers and farmers. During 2014, EFF damage was concentrated in the spring melon production season. Fall and winter production did not show important damage. Damage during the spring of 2014 started to increase when average EFF/trap/day reached 0.3. This value was suggested as the threshold to implement pesticide spraying in DSS greenhouses. EFF/trap/day trends were derived from monitoring with conventional traps and a novel electronic remote sensing trap, developed by our group. CSM during the spring of 2015 included 3 EFF control sprays, while DSS-managed greenhouses were only sprayed once. At the end of the spring season, damage was slightly higher in DSS greenhouses (1.5%), but not significantly different to that found in CSM greenhouses (0.5%). Results support continuing DSS research and optimization to reduce/remove pesticide use against EFF in melon greenhouses. Interactions with farmers and managers is suggested as essential to increase adoption of DSS in agriculture.

We investigated the survival of Mediterranean fruit fly (Medfly) larval stages on yellow peppers stored for 21 d in cold environments (1.5, 4 and 7 °C), and the differences in larval mortality rates of Medflies exposed to 1.5 °C storage environments between yellow and red peppers. In addition, we investigated the effect of packing yellow peppers and exposing them to cold environments for 21 d on the quality of the fruits. The aim of the study was to investigate packing and shipping post-harvest protocols as a preliminary investigation to explore cold environments as a system to assure the export of quality peppers with low risks of surviving Medfly immature stages. This exploratory study showed that storing yellow peppers for 21 d in lined boxes (20-μm-thick macroperforated Xtend film) at 1.5 and 4 °C protected the quality of the fruit, and precluded the survival of Medfly eggs and larval stages (L1, L2 and L3). In contrast, peppers stored at 7 °C for 21 d did not completely kill immature stages of the Medfly. In addition, the study showed that Medfly larval stages exposed to 1.5 °C environments on yellow and red peppers have different tolerances to cold. Sensitivity to cold in red pepper was higher than in yellow for all larval stages. In addition, sensitivity to cold between larval stages varied between yellow and red peppers: for yellow, sensitivity preceded as follows L1 > L2 > L3, while in red peppers it was L2 > L1 > L3. Abilities to accumulate lipids and protein by feeding Medfly larvae suggest that palatability and nutrition may be partially responsible for the differences in cold tolerance.

Fruit flies in the genus Bactrocera are among the most destructive insect pests of fruits and vegetables throughout the world. A number of studies have identified volatiles from fruit flies, but few reports have demonstrated behavioral effects or sensitivities of fly antennae to these compounds. We applied a recently developed method of automated headspace analysis using SPME (Solid Phase Microextraction) fibers and GC–MS (gas chromatography mass spectrometry), termed SSGA, to reveal volatiles specific to each sex of B. zonata that are emitted in a diel periodicity. The volatiles released primarily at dusk were identified by GC–MS and chemical syntheses as several spiroacetals, pyrazines, and ethyl esters. Solvent extraction of male rectal glands or airborne collections from each sex, followed by GC–MS, showed that certain of the volatiles increase or decrease in quantity sex-specifically with age of the flies. Electroantennographic (EAG) analysis of dose-response indicates differences in sensitivities of male and female antenna to the various volatiles. Our study provides a comprehensive analysis of the volatile chemicals produced and released by B. zonata and their antennal responses. The possible pheromone and semiochemical roles of the various volatiles released by each sex and the difficulties of establishing behavioral functions are discussed.

During the last decades, the economic importance of tephritid fruit flies (FF) has increased worldwide because of recurrent invasions and expansions into new areas, and reduced control capabilities of current control systems. Efficient monitoring systems, thus, are required to provide fast information to act promptly. With this aim in mind, we developed two electronic trap (e‐trap) versions for adult FF: one with specific volatiles for male and female adult Ceratitis capitata, and the second, based on the attraction of adult FF to yellow colour, targeting Dacus ciliatus, Rhagoletis cerasi and Bactrocera oleae. In the case of B. oleae, the female pheromone and ammonium bicarbonate were added as synergists. In the two versions, attracted FF were retained in the trap on glued surfaces. Real‐time images of the surfaces were automatically taken and transmitted to a server. We tested the two e‐trap versions in insect‐proof cages, where flies were released and recaptured, and in commercial orchards throughout the Mediterranean: C. capitata in peach orchards in Italy; R. cerasi in cherry orchards in Greece; B. oleae in olive orchards in Spain and in Greece; and D. ciliatus in melons in plastic tunnels in Israel. The e‐trap showed excellent abilities to transmit real‐time images of trapped FF and a high specificity for trapping different FF species. The ability of the entomologist to correctly classify FF from images in the office was >88%. In addition, average number of flies/trap in e‐trap grids did not differ from numbers reported on grids of conventional traps that were operating simultaneously. The e‐traps developed and tested in this study provide the basis for the real‐time monitoring of FF were no olfactory attractants are available, and for the surveillance of alien FF incursions where generic, but not specific, olfactory attractants exists.

a b s t r a c t The simulation of insect pest populations in agricultural and forest ecosystems is an important and useful tool for integrated pest management (IPM). Insect population models are mainly driven by envi- ronmental temperature data, which are usually collected from agrometeorological stations or derived from geographic statistical extrapolations. The present study describes the modeling of olive fly (Bac- trocera oleae) populations in the Eastern Mediterranean region using the MODIS (Moderate Resolution Image Spectro Radiometer) land surface temperature (LST) product from NASA TERRA satellite. These data, together with in situ temperature data, were used to estimate the tree-canopy temperatures at the pixel resolution (1 km). The estimated canopy temperature was used as input for the olive fly population model. Our main aim was to demonstrate the use of satellite-acquired information for modelling bio- logical and ecological phenomena. Eleven years (2001-2012) of olive fly population fluctuations were simulated for three different geographic locations, representing different geo-climatic conditions. The model successfully simulated the seasonal population fluctuations throughout the 11-year period and did a good job of connecting all of the life stages of the insect. To evaluate the validity of these findings, we compared them with adult olive-fly trapping data. We observed a high degree of correlation between the trapping data and our model's predictions. Here, we demonstrate that satellite thermal data can be used to predict insect pest population fluctuations for IPM purposes. The study also advances some new modelling concepts, such as the "window of opportunity" which links physiological development with chronological age.

As part of the development of a sterile insect technique (SIT) application for the Ethiopian fruit fly, Dacus ciliatus, we studied the mating behaviour of a laboratory-adapted strain (a 4-year-old colony kept for more than 40 generations) and a wild population. Effects of laboratory rearing and irradiation were assessed by carrying out mating compatibility and male mating competitiveness tests using a 1:1 ratio between irradiated (120 Gy) laboratory males and non-irradiated wild males. Mating behaviour was studied on host and non-host plants under field cage conditions. To assess the effect of mass rearing upon male performance, we repeated the mating competitiveness test using non-irradiated laboratory insects. The findings indicated a high degree of compatibility among the two populations and satisfactory competitiveness of the irradiated laboratory males (ca. 35%). The competitiveness of non-irradiated laboratory males was also ca. 35%, suggesting that no adverse effects resulted from their irradiation. Mating occurred only at twilight and mainly on the underside of leaves of non-host plants (lemon trees). Findings are discussed in view of their implications for a future application of SIT against this fruit fly pest.

The Ethiopian fruit fly, Dacus ciliatus (Loew) (Diptera: Tephritidae), is a significant pest of cucurbit crops in Asia and Africa and is currently controlled with insecticides. The sterilizing effect of gamma radiation on D. ciliatus adults was investigated to assess the suitability of sterile insect technique (SIT) for use as an alternative, non-chemical strategy for the control of this pest. Late pupae (48 h before emergence) were irradiated with 60, 80, 100, 120, and 140 Gy of gamma rays emitted by a 60Co source. Following emergence, the biological characteristics of the experimental cohorts (including all possible male-female combinations of irradiated and untreated flies) were recorded. No significant negative effects of irradiation on pupal eclosion or the ability of newly emerged flies to fly were observed. Samples of eggs at reproductive fly-ages (12-, 15-, and 17-day-old pairs) were collected and their hatch rates were assessed. At 60 Gy, females were completely sterilized, whereas complete sterilization of the males was observed only at 140 Gy (a small amount of fertility persisted even at 120 Gy). In addition to the above experiments, three fruit infestation trials were conducted with zucchini [Cucurbita pepo L. (Cucurbitaceae)] as the plant host and the pupae produced in those trials were collected and recorded. We observed significant (ca. 10%) infestation following treatment with up to 120 Gy and zero progeny only at 140 Gy, mirroring the egg-hatch results. Our findings support the feasibility of SIT for the control of D. ciliatus.

The present study investigated the patterns of microorganisms in an artificial larval diet during Dacus ciliatus (Diptera; Tephritidae) larval development. Microbial population contents in the diet of total heterotrophic bacteria, yeast and molds, coliform and lactobacilli, and their dynamics during development, were monitored. Initially, the microbial composition in diet trays failing to produce viable pupae and in trays successfully producing pupae and adult flies was characterized. The failing diet trays contained large populations of lactobacilli that increased during larval development, and low populations of coliforms. In contrast, the successful diet showed an increasing population of coliforms and a low, or undetected, population of lactobacilli. To study the hypothesis that lactobacilli affect D. ciliatus larval development, we conducted controlled inoculation experiments in which Lactobacillus plantarum was added into fresh diet at the time of egg seeding. L. plantarum inoculated trays showed no production of D. ciliatus. Control trays without lactobacilli inoculation showed variable results. One tray successfully produced viable pupae and adults, and showed a slight and slow increase in the indigenous populations of lactobacilli. The second tray, however, failed to produce pupae and showed a fast increase of the indigenous lactobacilli to very high levels. Monitored pH trends in L. plantarum-inoculated diet showed a sharp pH decrease during the first 4 days of larval development from 5 to less than 4 units, while successful diet, producing viable D. ciliatus pupae and adults, showed a moderate pH drop during most of the larval development period. The paper discusses the possible ecological interactions between D. ciliatus larvae, the microbial content of the diet and the physical properties of the diet. The discussion also points out at the usefulness of this approach in understanding and managing mass production parameters of tephritid fruit flies industrial diets used for Sterile Insect Technique.

In the inquiry on the age related dietary assessment of an organism, knowledge of the distributional patterns of food intake throughout the entire life span is very important, however, age related nutritional studies often lack robust feeding quantification methods due to their limitations in obtaining short-term food-intake measurements. In this study, we developed and standardized a capillary method allowing precise life-time measurements of food consumption by individual adult medflies, Ceratitis capitata (Diptera: Tephritidae), under laboratory conditions. Protein or sugar solutions were offered via capillaries to individual adults for a 5 h interval daily and their consumption was measured, while individuals had lifetime ad libitum access to sugar or protein, respectively, in solid form. Daily egg production was also measured. The multivariate data-set (i.e., the age-dependent variations in the amount of sugar and protein ingestion and their relation to egg production) was analyzed using event history charts and 3D interpolation models. Maximum sugar intake was recorded early in adult life; afterwards, ingestion progressively dropped. On the other hand, maximum levels of protein intake were observed at mid-ages; consumption during early and late adult ages was kept at constant levels. During the first 30 days of age, type of diet and sex significantly contributed to the observed difference in diet intake while number of laid eggs varied independently. Male and female adult longevity was differentially affected by diet: protein ingestion extended the lifespan, especially, of males. Smooth surface models revealed a significant relationship between the age dependent dietary intake and reproduction. Both sugar and protein related egg-production have a bell-shaped relationship, and the association between protein and egg-production is better described by a 3D Lorenzian function. Additionally, the proposed 3D interpolation models produced good estimates of egg production and diet intake as affected by age, providing us with a reliable multivariate analytical tool to model nutritional trends in insects, and other organisms, and their effect upon life history traits. The modeling also strengthened the knowledge that egg production is closely related to protein consumption, as suggested by the shape of the medfly reproduction-response function and its functional relationship to diet intake and age.

In this study, the effects of yeast protein hydrolysate (YPH): sucrose proportions in the adult diet of the Ethiopian fruit fly Dacus ciliatus Loew on survival, pupal production, and endogenous lipid and protein contents were investigated. Small populations of the fly were fed diets containing various proportions of YPH and sucrose under low-humidity and high-humidity conditions. The YPH: sucrose proportions ranged from 20 to 50%. We monitored the patterns of survival, pupal production, and individual endogenous protein and lipid loads (only under high-humidity conditions) in flies maintained on various adult diets. The survival patterns of both males and females under high-humidity conditions were inversely proportional to the proportion of YPH in the diet. Mortality of some adult flies was related to the stickiness of the highly hygroscopic adult food mix. By contrast, the survival patterns of males and females maintained under low-humidity conditions were directly proportional to the proportion of YPH in the diet. Apparently, there was no effect of diet type on the number of pupae produced; on the sucrose-only diet, flies produced significantly fewer pupae. Protein content in the flies increased significantly as the proportion of protein in the diet increased, but lipid content was clearly not related to food constitution. Based on these results and recent evidence from studies in other fruit fly species, we concluded that a large amount of protein is deleterious to the fruit flies. Workers in rearing facilities should investigate and tailor different food-delivery systems, e.g. separate dishes for carbohydrates and the food mix, and reduce the amount of YPH used in industrial adult diets.

Management of the olive fly using environmentally friendly methods includes strategies based on lure and kill and/or mass-trapping. Despite a wealth of studies related to the efficacy of different lure and kill and mass-trapping systems in several olive producing areas, there are few known regarding the performance of such systems in low input olive farms of the desert-like areas of the Middle East. The present study reports on the control of the olive fly using both lure and kill and mass-trapping devices in low-input farms in the region of Tubas, Palestine, between 2010 and 2012. The effect of environmental factors, such as elevation, on general patterns of olive fly infestation and the lure and kill system's performance was also studied. Our final goal included the development of a general strategy to produce organic olive oil using alternative olive fly control methods. Initially we used a commercially available lure and kill device, the Eco-Trap®. The Eco-Trap performed relatively well during the three years of study, significantly reducing olive fly damage levels. Eco-Trap effectiveness was more evident at elevation above 400 m, where damage in the region of Tubas was more intense than at lower elevations. In a subsequent trial we tested a low-cost mass-trapping device. This device demonstrated similar levels of protection to the one seen with the Eco-Trap. Results showed that lure and kill and mass-trapping tactics can be effectively applied in the region of Tubas, and that accessible devices can be adopted to reduce control costs. The results also showed differential levels of damage throughout the region, which were related to elevation above sea level. The possibility of applying a regional management concept throughout the area by a centralized organization, such as a farmer's union based on mass-trapping systems seems feasible and is discussed.

A method to estimate olive canopy temperature from satellite data was developed. Moderate Resolution Imaging Spectrometer (MODIS) Land Surface Temperature (LST, 1 km) and Normalized Difference Vegetation Index (NDVI, 250 m) products were used. The deviation of LST from the canopy temperature measurements collected with data loggers in different regions and olive orchard environments of the East Mediterranean showed seasonal behavior (i.e. large deviations at summer and small at winter). We built a correction function for the LST, representing the seasonal behavior of the deviation of LST from the in situ canopy temperature. NDVI was used to set the parameters for the correction function. We calculated the average absolute errors of (a) the satellite based estimation of the canopy temperature, (b) LST and (c) air temperature from the nearest meteorological station with respect to the in situ canopy temperature. The satellite-based estimation of canopy temperature was found more accurate than using LST or air temperature from meteorological station, as commonly used in ecological modeling. Therefore, it is expected that the correction function developed in this study will improve the capability to model pest population trends, and other agronomic traits of olive plantations, enhancing orchard management in time and space.

The effect of a sub-sterilizing gamma radiation dose on Dacus ciliatus adults was investigated to assess the suitability of the sterile insect technique (SIT) as an alternative method to control this pest. Late pupae (48 h prior to adult emergence) from a laboratory strain were irradiated with 120 Gy of gamma rays emitted by a 60Co source. Following adult emergence, the mortality of irradiated and non-irradiated cohorts was recorded. Over a period of 50 days after emergence, no significant negative effects of irradiation upon the longevity of male or female laboratory flies were observed. A laboratory competitiveness study (Fried test), using irradiated laboratory and wild males at a ratio of 3:1 was conducted to assess the ability of irradiated males to reduce the egg hatch rates of a wild population. The overall competitiveness was found to be ca. 0.32, suggesting a reduced, but satisfactory, quality of irradiated laboratory as compared with wild males. Based on the above findings, we calculated and proposed effective male release ratios for field application of SIT against D. ciliatus.

The present essay links historical socioeconomic processes with pest control activities and research and development (R&D) trends in plant protection. We selected the olive orchard agroecosystem, especially in Southern Europe, as a model system. We specifically followed the evolution of olive fly (Bactrocera oleae) control strategies and research activities and linked them with economic processes in the producing countries and with European policy directives. Our analysis includes the period following the Second World War and until recent times. Our main aim was to understand the socioeconomic forces that shape agroecosystem management, especially pest control. Although we only developed the case for the olive fly in Southern Europe, we believe that most human agricultural environments are subjected to similar economic, social, and environmental processes and forces. This historical account shows the complexity involved in the management of the agroecosystem and the effect of global and local factors on plant protection activities and developments, highlighting the need for a holistic approach when agricultural and research policies are formulated.

Sweet pepper (Capsicum annuum L.) is one of the most important fruit crops in Israel and other Mediterranean countries. Various pepper-importing countries, such as the USA, demand quarantine security protocols to diminish the risk of accidental introduction of the Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) on imported fruit. Effective quarantine treatment protocols must combine complete insect kill, minimal damage to plant tissue, and reasonable cost. Recently, we developed a method for the successful artificial infestation of sweet pepper fruit with medfly eggs, and improved this protocol to allow medfly larvae to proceed to the L1, L2 and L3 stages, and then to subject them to cold-treatments tests. Our results showed that all tested stages (egg, L1, L2 and L3) were totally killed by simulated in-transit cold quarantine treatments at 1.5 °C or 4 °C for 21 d, which represents an average ship journey from Israel to distant markets such as Japan or the USA. Based on emerging pupae in the control, average numbers of viable organisms under the different treatments were approx. 6235 eggs, and 1000–1250 organisms in each of the treatments with advanced stages (L1–L3). These two cold quarantine treatments, especially the one at 1.5 °C, caused very little chilling redcution in fruit quality of the bag-packed pepper fruit, i.e., chilling injury complied with a commercially required reasonable level of overall quality. In contrast, unbagged peppers suffered significantly higher chilling injury than bagged ones, with accelerated decay and water loss. In conclusion, our results provide the basis for the future establishment of an export quarantine treatment protocol for bell pepper fruit. It should be based on in-transit storage at temperatures of 1.5 °C for 21 d to eliminate the medfly eggs and larval instars from pepper fruit while maintaining the commercial quality of the fruit.

The olive fruit fly, Bactrocera oleae (Diptera: Tephritidae), uses 1,7-dioxaspiro[5.5]undecane ("olean"), produced primarily by females, as a sex pheromone. We used sequential solid phase microextraction-gas chromatography mass spectrometry (SPME-GCMS) analysis to show that female olive flies release about 1000 ng of pheromone at the onset of scotophase for several weeks, while males release about 1/100 as much during the first week after eclosion. The present research demonstrates details of employing SPME-GCMS with the partially known pheromone system of the olive fruit fly as a model for pheromone identification and diurnal release patterns in insects, especially fruit flies. The sequential SPME-GCMS method will readily allow detection and semi-quantification of semiochemicals released by insects in minute amounts throughout the diurnal cycle.

Area-wide integrated pest management requires an understanding of insect population dynamics and definition of suitable techniques to quantify spatio-temporal variability to make better pest management decisions. However, the viability of area-wide integrated pest management has often been questioned because of the high monitoring costs. The present study aimed to: (i) analyse the spatial and temporal dynamics of the olive fruit fly over a large olive growing area (Ormylia, Greece), and (ii) define a methodology to determine monitoring zones to optimize the monitoring effort over space and time in area-wide integrated pest management programmes. Data from an olive fruit fly monitoring network based on McPhail traps were utilized. The multi-variate spatial (elevation) and temporal (6 periods) data of olive fruit fly population density were analysed by principal component analysis, co-kriging and factor kriging to produce thematic maps and to delineate monitoring zones. Olive fruit fly density was spatially correlated from 200 to 4 000 m. The spatial pattern changed over the monitoring season. Areas with high density of olive fruit flies shifted from high altitudes in summer to lower altitudes towards autumn. Three recommended levels of monitoring intensity were defined, thus delineating homogeneous monitoring zones for summer (July to September) and October. It was concluded that delineating monitoring zones through multi-variate geostatistics is a suitable approach for optimising the monitoring effort, because population density distribution is spatially structured over large areas and changes over time.

The Ethiopian fruit fly, Dacus ciliatus, is an important pest of cucurbits, which recently invaded the Middle East. The genetics and cytogenetics of D. ciliatus have been scarcely studied. Such information is, however, an essential basis for understanding the biology of insect pests, as well as for the design of modern control strategies. We report here the mitotic karyotype and detailed photographic maps of the salivary gland polytene chromosomes of this species. The mitotic metaphase complement consists of six pairs of chromosomes, including one pair of heteromorphic sex (XX/XY) chromosomes. The heterogametic sex is ascribed to the male. The analysis of the salivary gland polytene complement shows a total number of five long chromosomes (10 polytene arms), which correspond to the five autosomes of the mitotic nuclei, and a heterochromatic mass corresponding to the sex chromosomes. Banding patterns, as well as the most characteristic features and prominent landmarks of each polytene chromosome are presented and discussed. Chromosomal homologies between D. ciliatus and Bactrocera oleae are proposed by comparing chromosome banding patterns and by in situ hybridization of the hsp70 gene.

The dispersal of marked, irradiated olive fruit flies originating from a hybrid laboratory strain was studied in an olive groove located in the arid regions of southern Israel. Release–recapture experiments (eight in total) were conducted throughout a period of 5 months (July–December 2008). In each experiment, ca. 5000 flies were released. Recapture of flies was conducted using a grid of 30 yellow sticky traps set in expanding semicircles from the centre of release. Service of traps was conducted 3 and 15 days after the release. Fly quality and adult food type (only sucrose and protein + sucrose) before release was also investigated. Results point at an average dispersal distance of marked, irradiated olive flies of ca. 50 m. Pre-release adult diet did not affect dispersal ability. Fly recovery averaged ca. 3.5% during summer and ca. 1.5% during autumn. Most of the recovery concentrated during the first 3 days after releases, suggesting low survival of the released flies afterwards. As inferred from circular statistics, direction of dispersal was non-random with a significant directionality to the north-west. Results are discussed in view of environmental temperatures and wind direction.

The olive fly (OLF), Bactrocera oleae (Rossi), is an invasive tephritid fruit fly that causes extensive damage to olive crops around the world (especially in the Mediterranean basin and North America). Previous attempts to use the Sterile Insect Technique (SIT) for the OLF were not successful because of the inability to rear high quality OLF in the laboratory on an artificial diet. New improvements in rearing methods and additional understanding of the basic biology of the OLF have led to a renewal of interest in using SIT for OLF. This review discusses the history, difficulties, improvements and future directions of OLF mass-rearing. Issues include: the design of cages and oviposition substrates, cost and quality of artificial diets, maintenance of endosymbiotic microbiota, control of pathogenic microbes, collection of pupae, the fitness of adults, and the competitiveness of sterilized laboratory males released to the field.

Previous studies have suggested that social interactions (e.g., the actions and reactions elicited by the interaction of co-specific individuals) induce individual fruit flies (Tephritidae) to ingest more food, especially protein-rich food. Changes in feeding behavior related to social interactions have been associated with reproduction (e.g., when different sexes are present), reproductive facilitation (e.g., when two females interact) and stress and aggression (e.g., flies of the same sex, or crowdedness). The present study investigated the effect of social interaction on the feeding, longevity and resource management of the Ethiopian fruit fly, Dacus ciliatus. Single flies and pairs of flies (of the same or different sexes) were confined to a small arena (the PUB system), in which we measured the amount of liquid food ingested daily by each fly. In addition, we sampled flies of different ages, extracted and quantified their lipid and protein contents, and related individual metabolic contents to the ingestion of a fructose and protein hydrolysate solution. Results showed that individual ingestion was significantly higher in flies maintained in pairs than in flies kept as solitary individuals. The highest intake rates were observed for the female-female pairs. In general, females ingested significantly greater volumes than males. Lipid contents tended to decrease progressively with age in flies kept as solitary individuals, especially in female flies, while lipid levels decreased and then increased in flies maintained in pairs. Protein trends were similar, although less pronounced than the patterns observed for the lipids. The flies kept as solitary individuals lived significantly longer than those kept in pairs. A resource-management analysis points to a decreased metabolic rate in flies kept as solitary individuals, as compared to paired flies. Results are discussed in view of theories of resource management and survival strategies.

The Ethiopian fruit fly, Dacus ciliatus, is an oligophagous pest of cucurbit crops, particularly melons, cucumbers, and marrows (summer squash). The present study aimed to identify host attractants for D. ciliatus and was guided by a behavioral bioassay and an electrophysiological assay. We tested volatile compounds from the fruits of a host plant, ripe and unripe Galia melon, Cucumis melo var. reticulates. Both sexes were attracted to melon volatiles. Those of ripe melon were preferred. Gas chromatography-electroantennographic detection analysis of the behaviorally active ripe melon volatiles consistently showed that 14 compounds elicited similar antennal responses from both sexes. Twelve compounds were identified by gas chromatography-mass spectrometry (GC-MS) using GC-MS libraries, retention indices (RI), and authentic standards. The electrophysiological activities of the compounds that were present at sufficient levels for identification, benzyl acetate, hexanyl acetate, (Z)-3-hexenyl acetate, (Z)-3-octenyl acetate, octanyl acetate, (Z)-3-decenyl acetate, and (E)-beta-farnesene, were evaluated at six different dosage levels by using electroantennography (EAG). Benzyl and hexanyl acetates elicited dose responses only in males, while other tested compounds elicited dose responses in both sexes. The strongest responses were observed for doses between 100 ng and 10 microg. The dose response, in terms of attractiveness to synthetic compounds within the active range (as determined by EAG), also was evaluated in the behavioral bioassay. Synthetic acetates were attractive to both sexes when tested individually. Significant attraction was observed when individual compounds were applied in the bioassay arena at doses of 0.5-1 microg/dispenser. Blends of compounds in equal proportions also were attractive to the insects. The most attractive blend was a mixture of four or five identified acetates. The addition of an equal proportion of (E)-beta-farnesene to this mixture had a deterrent effect.

The spatio-temporal patterns of olive fly populations in a managed olive-growing region in the area of Chalkidiki in northern Greece were followed during 2005. The trapping grid consisted of 700 traps. Throughout the growing season (July‐October), McPhail traps loaded with ammonium sulphate were inspected at 5-day intervals. Trapping data were analysed using Getis‐Ord local spatial statistics. Clustering of trapped flies was significantly related to elevation, which ranged from sea level to 700 m above sea level. The effect of elevation upon clustering depended on seasonal climatic patterns. During the summer, ‘hotspots’ (i.e. significant aggregations of captured insects) were located at intermediate to high elevations and ‘cold-spots’ (i.e. areas with significantly low numbers of captured insects) were found in the valleys. In contrast, during the fall, ‘hot-spots’ were detected at lower elevations and ‘cold-spots’ at higher elevations. Population phenology seemed to affect spatial patterns. During periods of low population levels across the entire region, clusters of traps with relatively high amounts of captured insects were found at lower elevations. Pest management activities may have affected population levels throughout the region, but our data set does not allow quantifying their effectiveness. Our data suggest that differences in environmental temperature, as a result of altitudinal cline and season, may affect both the size of the olive fly population and its spatial patterns. The implementation of spatio-temporal analyses for management of the olive fly is discussed. J. Appl. Entomol.

The pattern of gas-exchange (CO2 emission) was investigated for developing Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) pupae incubated at different temperatures. This study was undertaken to explore the usefulness of gas-exchange systems in the determination of physiological age in developing pupae that are mass produced for sterile insect technique projects. The rate of CO2 emission was measured in a closed flow-through system connected to commercial infrared gas analysis equipment. Metabolic activity (rate of CO2 emission) was related to pupal eye-color, which is the current technique used to determine physiological age. Eye-color was characterized digitally with 3 variables (Hue, Saturation and Intensity), and color separated by discriminant analysis. The rate of CO2 emission throughout pupal development followed a U-shape, with high levels of emission during pupariation, pupal transformation and final pharate adult stages. Temperature affected the development time of pupae...

Irradiation of pupae in sterile insect technique (SIT) projects is usually undertaken in hypoxic atmospheres, which have been shown to lessen the deleterious effects of irradiation on the quality of adult sterile flies. Although this is the accepted technology in most mass-rearing and sterilization facilities, to date no information has been generated on the actual levels of oxygen (O2) in pupae-packing containers during irradiation. The present study utilized recently-developed technology to investigate the O2 level inside bags in which pupae of Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) are packed prior to irradiation, the ability of pupae to create hypoxic environments in these bags, and the effect of O2 atmospheres on the quality of irradiated males. Pupae, 1 d before adult emergence, were shown to deplete the O2 level in sealed bags in approximately 1 h. The rate of O2 consumption was dependent upon pupal age and incubation temperature. Incubation temperature did not sig...

Despite of the economic importance of the olive fly (Bactrocera oleae) and the large amount of biological and ecological studies on the insect, the factors driving its population dynamics (i.e., population persistence and regulation) had not been analytically investigated until the present study. Specifically, our study investigated the autoregressive process of the olive fly populations, and the joint role of intrinsic and extrinsic factors molding the population dynamics of the insect. Accounting for endogenous dynamics and the influences of exogenous factors such as olive grove temperature, the North Atlantic Oscillation and the presence of potential host fruit, we modeled olive fly populations in five locations in the Eastern Mediterranean region. Our models indicate that the rate of population change is mainly shaped by first and higher order non-monotonic, endogenous dynamics (i.e., density-dependent population feedback). The olive grove temperature was the main exogenous driver, while the North Atlantic Oscillation and fruit availability acted as significant exogenous factors in one of the five populations. Seasonal influences were also relevant for three of the populations. In spite of exogenous effects, the rate of population change was fairly stable along time. We propose that a special reproductive mechanism, such as reproductive quiescence, allows populations of monophagous fruit flies such as the olive fly to remain stable. Further, we discuss how weather factors could impinge constraints on the population dynamics at the local level. Particularly, local temperature dynamics could provide forecasting cues for management guidelines. Jointly, our results advocate for establishing monitoring programs and for a major focus of research on the relationship between life history traits and populations dynamics. Fil: Ordano, Mariano Andrés. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científico y Técnicas. Centro Científico Tecnológico Tucumán. Unidad Ejecutora Lillo; Argentina Fil: Engelhard, Izhar. Institute of Plant Protection; Israel Fil: Rempoulakis, Polychronis. Institute of Plant Protection; Israel Fil: Nemny Lavy, Esther. Institute of Plant Protection; Israel Fil: Blum, Moshe. Bar-Ilan University; Israel Fil: Yasin, Sami. Nippon International Cooperation for Community Development; Palestina (ANP) Fil: Lensky, Itamar M.. Bar-Ilan University; Israel Fil: Papadopoulos, Nikos T.. University of Thessaly; Grecia Fil: Nestel, David. Institute of Plant Protection; Israel

The Mediterranean fruit fly ( Ceratitis capitata ) is a cosmopolitan pest of hundreds of species of commercial and wild fruits. It is considered a major economic pest of commercial fruits in the world. Adult Mediterranean fruit flies feed on all sorts of protein sources, including animal excreta, in order to develop eggs. After reaching sexual maturity and copulating, female flies lay eggs in fruit by puncturing the skin with their ovipositors and injecting batches of eggs into the wounds. In view of the increase in food-borne illnesses associated with consumption of fresh produce and unpasteurized fruit juices, we investigated the potential of Mediterranean fruit fly to serve as a vector for transmission of human pathogens to fruits. Addition of green fluorescent protein (GFP)-tagged Escherichia coli to a Mediterranean fruit fly feeding solution resulted in a dose-dependent increase in the fly's bacterial load. Flies exposed to fecal material enriched with GFP-tagged E. coli were similarly contaminated and were capable of transmitting E. coli to intact apples in a cage model system. Washing contaminated apples with tap water did not eliminate the E. coli . Flies inoculated with E. coli harbored the bacteria for up to 7 days following contamination. Fluorescence microscopy demonstrated that the majority of fluorescent bacteria were confined along the pseudotrachea in the labelum edge of the fly proboscis. Wild flies captured at various geographic locations were found to carry coliforms, and in some cases presumptive identification of E. coli was made. These findings support the hypothesis that the common Mediterranean fruit fly is a potential vector of human pathogens to fruits.

Survival and egg-laying trends were investigated in Mediterranean fruit flies (Ceratitis capitata) adults maintained on a sucrose-only diet, or on a full diet that consisted of a 3:1 sucrose and yeast hydrolizate mixture. In addition, we followed the total individual lipid and protein contents of aging flies in a cohort. Survival trends and life expectancy parameters at eclosion for males and females on full diet and for males on sucrose only were very similar. In contrast, the mortality of females on sucrose only was high early in life, but then slowed down. Egg-laying was ten times greater in female flies on full diet than in flies on sucrose only. Lipid contents in males and females on both types of diets were very similar, and harmonically oscillated with an amplitude of approximately 10 days. Successive crests of lipids tended to be smaller with the ageing of the cohort, and lipids contents significantly dropped at very advanced ages and close to the maximal age of the whole cohort. Protein contents of flies maintained on a full diet were high and stayed at a constant level throughout the entire life of the cohort. Protein levels in males and females on sucrose only dropped drastically during the first days of adult life, but then stayed stable at a low level until advanced ages. We propose that the synchronous rhythmic oscillation in lipid contents of male and female flies seems to be independently set by an internal clock. Protein reserves are allocated according to the access to protein food sources and these levels of protein are closely associated to egg production and mortality. Our results are discussed in view of resource allocation during reproduction and senescence.