Drosophila suzukii is a polyphagous pest of small and soft fruit, originating from Asia, which ha... more Drosophila suzukii is a polyphagous pest of small and soft fruit, originating from Asia, which has spread and established in Europe and the USA. Adults exhibit seasonal phenotypes, i.e., summer morphs (SM) and winter morphs (WM) to cope with fluctuating environmental conditions. WM have a darker cuticle and larger wings compared to SM, while WM females experience reproductive dormancy. We studied the life history traits (lifespan, female reproductive status and number of produced offspring) of WM and SM that were exposed to winter field conditions of a coastal and a mainland agricultural area, with mild and cold winter climates, respectively. Mated adults of each phenotype were individually placed in vials bearing nutritional/oviposition substrate, and transferred to the field from November 2019 to May 2020, when the death of the last individual was recorded. Almost all SM females (90%) and no WM female carried mature ovarioles before being transferred to the field. WM exhibited a l...
Despite the recent invasion and wide spread of Drosophila suzukii Matsumura (Diptera: Drosophilid... more Despite the recent invasion and wide spread of Drosophila suzukii Matsumura (Diptera: Drosophilidae) in Europe, little is known regarding its population trends in coastal areas of the southern Mediterranean countries. Using adult trapping and fruit sampling, we studied the population dynamics of D. suzukii in coastal and mainland (semi-highland) cherry orchards of Greece, from 2018 to 2020. Adults were captured in traps baited with apple cider vinegar, placed in conventional and unmanaged sweet-cherry orchards, and in neighbouring wild growing hosts. Sampling of sweet-cherry fruit to assess infestation levels was conducted from early and late-ripening cherry cultivars in both areas. Adults were captured throughout the year in the coastal area with two peaks registered in spring and late-autumn. Captures were nearly zero during the hot summer months. Flight activity exhibited only one peak in autumn at the mainland area, and ceased during winter and spring. Captures in wild hosts wer...
BACKGROUND Linalool is a natural scent, found in essential oils (EOs) of several plants. It is wi... more BACKGROUND Linalool is a natural scent, found in essential oils (EOs) of several plants. It is widely used as a fragrant, also possessing toxic, oviposition deterrent, and repellent properties against many insect species. Ceratitis capitata (medfly) is one of the most notorious insect pests for international fresh fruit production. Despite the available information on the repellent effects of EOs on herbivorous insects, possible ovipositional deterrent effects of linalool against C. capitata remain unknown. OBJECTIVES AND RESULTS We tested whether different linalool concentrations, application methods on fruit hosts and time since application elicited oviposition-deterrence on medfly, from bitter oranges, apples and nectarines, under constant laboratory conditions. We also tested possible repellent properties of linalool on adult medflies in field conditions. Females drilled less oviposition stings and deposited fewer eggs per fruit in all linalool-treated hosts. Spraying and topical-droplet application were the most efficient methods on bitter oranges, although spraying was the least effective one in apples. Bitter oranges and nectarines that were offered to females immediately after exposure to linalool received more oviposition stings and eggs than those offered three days post-exposure to linalool solutions. Conversely, apples tested three days following linalool application received significantly more oviposition stings and eggs than those tested immediately and one day post exposure. More adults in total and more females were captured in traps located on untreated-control than on linalool treated trees, especially in citrus hosts. CONCLUSION Linalool has a potential future use in environmental friendly control strategies against C. capitata. This article is protected by copyright. All rights reserved.
The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a key pest for the ch... more The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a key pest for the cherry production industry in Europe and west Asia that has recently invaded North America. Insecticide applications are frequently employed to control this devastating pest, often without considering its population trends. We developed a novel decision support system (DSS), and field tested it in commercial sweet cherry orchards in central Greece. The DSS includes two algorithms that predict the timing of adult activity in the wild and support pest management decisions, based on R. cerasi population trends and pesticide properties, respectively. Preparatory monitoring of the testing area during 2014, using adult traps, revealed high population densities of R. cerasi in non-managed sweet cherry orchards and low densities in commercial ones. Implementation of the DSS during 2015 resulted in low R. cerasi adult population densities and zero fruit infestation rates in commercial cherry orchar...
The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is the key pest of ... more The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is the key pest of sweet and sour cherries in many European countries and west Asia. It is a univoltine species of the west Palaearctic zone that undergoes obligatory pupal diapause. In this study, the development of R. cerasi pupae that were brought to an optimum temperature for postdiapause development following a long chilling period is described. The six most representative developmental stages within the puparium are illustrated, and the developmental progression among the stages after the end of the chilling period is quantified. Within 20 d postchilling, there was a gradual progress from stage I to pharate adult. However, ∼30% of the pupae remained at the transitional stage II, after 20 d at 25°C (optimum temperature for development). This suggests that a proportion of pupae remain at an intermediate developmental stage for an extended period of time that goes beyond 20 d postchilling. The pupal sta...
Although the European cherry fruit fly Rhagoletis cerasi L (Diptera: Tephritidae) poses a major t... more Although the European cherry fruit fly Rhagoletis cerasi L (Diptera: Tephritidae) poses a major threat to cherry production in Greece, there are only a few studies on its bioecology. Following extensive fruit sampling (during 2004 – 2008) we studied the geographical distribution of R. cerasi in several areas all over Greece. Infested fruit samples were collected in the areas of Macedonia (Thessaloniki, Katerini, Kozani, Halkidiki, Kavala), Thessaly (Trikala, Magnisia, Larissa, Karditsa), Peloponnesus (Ilea, Achaia), Thrace (Komotini), Crete island (Chania), North Aegean sea (Lesvos island). In addition to sweet cherries, R. cerasi pupae have been recovered from sour cherries (Thessaloniki), wild growing cherries (Prunus spp.) (Kozani, Trikala, Magnisia) and Prunus mahaleb (Trikala). Infestation levels varied greatly among sampling years, areas, and fruit species. Adults obtained from pupae collected from samples, from all the above areas except Crete, were examined for infections by the intracellular bacterium Wolbachia, which is known to exist in many European populations of R. cerasi. All populations were found to be singly infected by the same Wolbachia strain (wCer1). Pupal diapause termination and adult flight have been studied in a lowland – coastal (Kala Nera Magnisias) and a highland area (Dafni Kozanis). Considerable differences exist both in diapause intensity and adult flying period between the two populations. The above data together with earlier data, collected in our laboratory, were used to construct population models for both areas.
Wolbachia pipientis is a widespread endosymbiont of insects and other arthropods exerting a wide ... more Wolbachia pipientis is a widespread endosymbiont of insects and other arthropods exerting a wide range of biological effects on their hosts. A growing number of recent studies document the influence of Wolbachia on reproduction and lifespan of insect host species. However, little is known regarding effects of Wolbachia on the demographic traits of different host populations. Moreover, whether different Wolbachia strains exert different effects on fitness components of their hosts remains largely unknown. We studied the effects of (a) the Wolbachia strain wCer2 on fitness components of two laboratory lines of the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae) and (b) two different Wolbachia strains (wCer2 and wCer4) on one of the Mediterranean fruit fly lines. Wolbachia infection (wCer2) shortens the egg‐to‐adult developmental duration of both C. capitata lines, although it prolongs embryonic development. In one of the two lines, egg‐to‐adult mortality increased. Wolbachia infection shortens adult lifespan (to a different extent in males and females) and reduces female fecundity. The different Wolbachia strains differentially affect both immature mortality and developmental duration, and adult longevity and female fecundity. Our findings demonstrate both differential response of two C. capitata lines to Wolbachia infection and differential effects of two Wolbachia strains on the same Mediterranean fruit fly line. Practical and theoretical implications of our findings are discussed.
Drosophila suzukii is a polyphagous pest of small and soft fruit, originating from Asia, which ha... more Drosophila suzukii is a polyphagous pest of small and soft fruit, originating from Asia, which has spread and established in Europe and the USA. Adults exhibit seasonal phenotypes, i.e., summer morphs (SM) and winter morphs (WM) to cope with fluctuating environmental conditions. WM have a darker cuticle and larger wings compared to SM, while WM females experience reproductive dormancy. We studied the life history traits (lifespan, female reproductive status and number of produced offspring) of WM and SM that were exposed to winter field conditions of a coastal and a mainland agricultural area, with mild and cold winter climates, respectively. Mated adults of each phenotype were individually placed in vials bearing nutritional/oviposition substrate, and transferred to the field from November 2019 to May 2020, when the death of the last individual was recorded. Almost all SM females (90%) and no WM female carried mature ovarioles before being transferred to the field. WM exhibited a l...
Despite the recent invasion and wide spread of Drosophila suzukii Matsumura (Diptera: Drosophilid... more Despite the recent invasion and wide spread of Drosophila suzukii Matsumura (Diptera: Drosophilidae) in Europe, little is known regarding its population trends in coastal areas of the southern Mediterranean countries. Using adult trapping and fruit sampling, we studied the population dynamics of D. suzukii in coastal and mainland (semi-highland) cherry orchards of Greece, from 2018 to 2020. Adults were captured in traps baited with apple cider vinegar, placed in conventional and unmanaged sweet-cherry orchards, and in neighbouring wild growing hosts. Sampling of sweet-cherry fruit to assess infestation levels was conducted from early and late-ripening cherry cultivars in both areas. Adults were captured throughout the year in the coastal area with two peaks registered in spring and late-autumn. Captures were nearly zero during the hot summer months. Flight activity exhibited only one peak in autumn at the mainland area, and ceased during winter and spring. Captures in wild hosts wer...
BACKGROUND Linalool is a natural scent, found in essential oils (EOs) of several plants. It is wi... more BACKGROUND Linalool is a natural scent, found in essential oils (EOs) of several plants. It is widely used as a fragrant, also possessing toxic, oviposition deterrent, and repellent properties against many insect species. Ceratitis capitata (medfly) is one of the most notorious insect pests for international fresh fruit production. Despite the available information on the repellent effects of EOs on herbivorous insects, possible ovipositional deterrent effects of linalool against C. capitata remain unknown. OBJECTIVES AND RESULTS We tested whether different linalool concentrations, application methods on fruit hosts and time since application elicited oviposition-deterrence on medfly, from bitter oranges, apples and nectarines, under constant laboratory conditions. We also tested possible repellent properties of linalool on adult medflies in field conditions. Females drilled less oviposition stings and deposited fewer eggs per fruit in all linalool-treated hosts. Spraying and topical-droplet application were the most efficient methods on bitter oranges, although spraying was the least effective one in apples. Bitter oranges and nectarines that were offered to females immediately after exposure to linalool received more oviposition stings and eggs than those offered three days post-exposure to linalool solutions. Conversely, apples tested three days following linalool application received significantly more oviposition stings and eggs than those tested immediately and one day post exposure. More adults in total and more females were captured in traps located on untreated-control than on linalool treated trees, especially in citrus hosts. CONCLUSION Linalool has a potential future use in environmental friendly control strategies against C. capitata. This article is protected by copyright. All rights reserved.
The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a key pest for the ch... more The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a key pest for the cherry production industry in Europe and west Asia that has recently invaded North America. Insecticide applications are frequently employed to control this devastating pest, often without considering its population trends. We developed a novel decision support system (DSS), and field tested it in commercial sweet cherry orchards in central Greece. The DSS includes two algorithms that predict the timing of adult activity in the wild and support pest management decisions, based on R. cerasi population trends and pesticide properties, respectively. Preparatory monitoring of the testing area during 2014, using adult traps, revealed high population densities of R. cerasi in non-managed sweet cherry orchards and low densities in commercial ones. Implementation of the DSS during 2015 resulted in low R. cerasi adult population densities and zero fruit infestation rates in commercial cherry orchar...
The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is the key pest of ... more The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is the key pest of sweet and sour cherries in many European countries and west Asia. It is a univoltine species of the west Palaearctic zone that undergoes obligatory pupal diapause. In this study, the development of R. cerasi pupae that were brought to an optimum temperature for postdiapause development following a long chilling period is described. The six most representative developmental stages within the puparium are illustrated, and the developmental progression among the stages after the end of the chilling period is quantified. Within 20 d postchilling, there was a gradual progress from stage I to pharate adult. However, ∼30% of the pupae remained at the transitional stage II, after 20 d at 25°C (optimum temperature for development). This suggests that a proportion of pupae remain at an intermediate developmental stage for an extended period of time that goes beyond 20 d postchilling. The pupal sta...
Although the European cherry fruit fly Rhagoletis cerasi L (Diptera: Tephritidae) poses a major t... more Although the European cherry fruit fly Rhagoletis cerasi L (Diptera: Tephritidae) poses a major threat to cherry production in Greece, there are only a few studies on its bioecology. Following extensive fruit sampling (during 2004 – 2008) we studied the geographical distribution of R. cerasi in several areas all over Greece. Infested fruit samples were collected in the areas of Macedonia (Thessaloniki, Katerini, Kozani, Halkidiki, Kavala), Thessaly (Trikala, Magnisia, Larissa, Karditsa), Peloponnesus (Ilea, Achaia), Thrace (Komotini), Crete island (Chania), North Aegean sea (Lesvos island). In addition to sweet cherries, R. cerasi pupae have been recovered from sour cherries (Thessaloniki), wild growing cherries (Prunus spp.) (Kozani, Trikala, Magnisia) and Prunus mahaleb (Trikala). Infestation levels varied greatly among sampling years, areas, and fruit species. Adults obtained from pupae collected from samples, from all the above areas except Crete, were examined for infections by the intracellular bacterium Wolbachia, which is known to exist in many European populations of R. cerasi. All populations were found to be singly infected by the same Wolbachia strain (wCer1). Pupal diapause termination and adult flight have been studied in a lowland – coastal (Kala Nera Magnisias) and a highland area (Dafni Kozanis). Considerable differences exist both in diapause intensity and adult flying period between the two populations. The above data together with earlier data, collected in our laboratory, were used to construct population models for both areas.
Wolbachia pipientis is a widespread endosymbiont of insects and other arthropods exerting a wide ... more Wolbachia pipientis is a widespread endosymbiont of insects and other arthropods exerting a wide range of biological effects on their hosts. A growing number of recent studies document the influence of Wolbachia on reproduction and lifespan of insect host species. However, little is known regarding effects of Wolbachia on the demographic traits of different host populations. Moreover, whether different Wolbachia strains exert different effects on fitness components of their hosts remains largely unknown. We studied the effects of (a) the Wolbachia strain wCer2 on fitness components of two laboratory lines of the Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae) and (b) two different Wolbachia strains (wCer2 and wCer4) on one of the Mediterranean fruit fly lines. Wolbachia infection (wCer2) shortens the egg‐to‐adult developmental duration of both C. capitata lines, although it prolongs embryonic development. In one of the two lines, egg‐to‐adult mortality increased. Wolbachia infection shortens adult lifespan (to a different extent in males and females) and reduces female fecundity. The different Wolbachia strains differentially affect both immature mortality and developmental duration, and adult longevity and female fecundity. Our findings demonstrate both differential response of two C. capitata lines to Wolbachia infection and differential effects of two Wolbachia strains on the same Mediterranean fruit fly line. Practical and theoretical implications of our findings are discussed.
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Papers by Stella Papanastasiou