Back-yard medfly is a key factor in area-wide management in Southern Europe. Data from Attiki Greece, 38

A twelve month Mediterranean fruit-fly, medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) record was kept in a small back-yard with 8 medfly host fruit trees in a neighborhood about 7 km from the center of Athens, from November 2015 till November 2016. Similar small back-yards exist in the whole area. Large commercial host tree plantations exist at about 80 km west of Athens, while backyards with fruit trees exist in villages or small towns in-between. McPhail yellow bottom traps (one per tree) with Biolure (3 separate dispensers of ammonium acetate, trimethylamine, and putrescine) and a water solution of 1.5% sodium tetraborate and a few drops of kitchen detergent were used. Traps were examined approximately every week and water solution renewed. The Biolure dispensers were renewed every 3-4 months. On the average (medflies per tree-trap per day) 1.4 flies were trapped in November, less than 1 were trapped between December and early May, except mid-April when 1.7 flies were trapped.From June till October high records were detected. In June-July records up to over 52.7 flies were observed (highest population peak in the year), while in September October records up to 34.3 flies were observed (second highest population peak in the year). The sex ratio of trapped flies was almost always in favor of females, usually between 60-100%. An increase of medfly catches was always detected following Biolure dispensers renewal. In case Area-wide SITapplications are considered, the reproductive behavior of released flies in these special environments must be well investigated

Genetic elimination of field-cage populations of Mediterranean fruit flies

The Mediterranean fruit fly (medfly, Ceratitis capitata Wiedemann) is a pest of over 300 fruits, vegetables and nuts. The sterile insect technique (SIT) is a control measure used to reduce the reproductive potential of populations through the mass release of sterilized male insects that mate with wild females. However, SIT flies can display poor field performance, due to the effects of mass-rearing and of the irradiation process used for sterilization. The development of female-lethal RIDL (release of insects carrying a dominant lethal) strains for medfly can overcome many of the problems of SIT associated with irradiation. Here, we present life-history characterizations for two medfly RIDL strains, OX3864A and OX3647Q. Our results show (i) full functionality of RIDL, (ii) equivalency of RIDL and wild-type strains for life-history characteristics, and (iii) a high level of sexual competitiveness against both wild-type and wild-derived males. We also present the first proof-of-principle experiment on the use of RIDL to eliminate medfly populations. Weekly releases of OX3864A males into stable populations of wild-type medfly caused a successive decline in numbers, leading to eradication. The results show that genetic control can provide an effective alternative to SIT for the control of pest insects

Review of the role of gut microbiota in mass rearing of the olive fruit fly, Bactrocera oleae, and its parasitoids

The olive fruit fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), is the major insect pest in commercial olive (Olea europaea L., Oleaceae) production worldwide. Its population management is largely based on the use of insecticides. However, concerns about the impact of insecticides on the environment and human health along with increasing resistance development calls for novel and environment-friendly approaches for population management. Integrated pest management programmes with a sterile insect technique (SIT) component and parasitoids are currently considered for the control of B. oleae. A major challenge for the development of such tools is mass rearing of both host and parasitoids. In this review, we consider the role of endogenous microbiota and its potential exploitation for improving the efficacy, quality, and cost effectiveness of mass rearing B. oleae as well as their parasitoids

Plant chemicals and the sexual behavior of male tephritid fruit flies

Plant compounds affect insects in many different ways. In addition to being a food source, plants also contain secondary metabolites that may have positive and negative impacts on insects. The influence of these compounds on sexual behavior, in particular, has been the focus of many recent studies. Here, we review the existing literature on the effects of plant compounds on the sexual behavior of tephritid fruit fly males. We put special focus on polyphagous species whose males congregate in leks, where females exert strong mate selection. We first summarize the main findings related to plant compounds that increase male signaling behavior and attraction of females and consequently increase mating frequency, a phenomenon that has been recorded mainly for species of Anastrepha and Ceratitis. In other tephritid species, males are attracted to phenylpropanoids produced by plants (such as methyl eugenol or raspberry ketone) that, upon encounter, are consumed and sequestered by males. These compounds, or metabolic derivatives, which normally have negligible nutritional value, are included in the pheromone and also confer advantages in a sexual context: enhanced female attraction and improved male mating success. These phenomena have been reported for several Bactrocera species as well as for Zeugodacus cucurbitae. Because many tephritid species are serious pests, the effect of plant compounds on male behavior has been explored for potential incorporation into control strategies such as the sterile insect technique (SIT). We conclude noting several factors, such as age and nutrition during larval and adult stage, that modulate the effect of plant compounds on male mating behavior as well as some prominent gaps that preclude a thorough understanding of the plant-mediated enhancement of male sexual performance and hence limit our ability to effectively utilize phytochemicals in pest control strategies.Instituto de GenéticaFil: Segura, Diego Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Belliard, Silvina A. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vera, María Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Bachmann, Guillermo Enrique. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruiz, María Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Jofre-Barud, Flavia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lopez, M. Liza. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Shelly, Todd E. United States Department of Agriculture. Animal and Plant Health Inspection Service; Estados Unido

Dispersal ability of marked, irradiated olive fruit flies [Bactrocera oleae (Rossi) (Diptera : Tephritidae)] in arid regions

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.10 page(s

Επίδραση της διατροφής ενηλίκων στην επιβίωση,γονιμότητα και γονιμοποίηση ωαρίων άγριων και εργαστηριακών στελεχών της μύγας της μεσογείου,Ceratitis capitata(Diptera:Tephritidae)

The Mediterranean fruit fly Ceratitis capitata (Wiedemann) is one of the world's most important agricultural insect pests. It has many fruit and vegetable hosts and a worldwide distribution. For successful control, chemical as well as biological methods (usually the Sterile Insect Technique) are used against it. The quality of sterile males is of decisive significance for the success of the SIT. Studies on the nutrition of Tephritids in connection with SIT include the role of protein: carbohydrate ratio, natural food sources and the end effect on longevity, fecundity and fertility. The effect of adult nutrition on adult longevity, fecundity and fertility was examined during this study. The results were in accordance with the theory of food selection by insects in nature, as an optimizing factor of nutritional exploitation of natural resources. Furthermore, it was shown that natural food which consists only of carbohydrates cannot support prolonged longevity neither fecundity. Fruit juice (sliced fruit interior offered) was found to be adequate for survival and egg production of laboratory and wild medflies, but with differences on the rate and duration of egg laying period when compared with artificial diet. The 3 different kinds of honeydews studied showed differences in their nutritional value. Significant differences were also found between wild and laboratory insects on the ability to survive and reproduce on different honeydews. The differences concerned longevity, fecundity and fertility of medfly adults. In all cases the laboratory adult diet proved to be better than honeydews. Finally, it was found that laboratory insects couldn't live for more than 4 days without a source of carbohydrate, and that insect's excreta had little nutritional value.Η μύγα της Μεσογείου Ceratitis capitata (Wiedemann), αποτελεί έναν σημαντικό εχθρό των εσπεριδοειδών και πολλών άλλων φρούτων, και η εξάπλωση της είναι ιδιαίτερα ευρεία. Για την καταπολέμηση της χρησιμοποιούνται συμβατικές μέθοδοι, αλλά και βιολογικές όπως η τεχνική του στείρου εντόμου (SIT). Ζητούμενο σε προγράμματα εξαπόλυσης στείρων αρσενικών είναι να μην εμφανίζεται μειωμένη ποιότητα των μαζικά εκτρεφόμενων εντόμων σε σχέση με τον άγριο πληθυσμό, και να μπορούν τα εξαπολυόμενα στείρα αρσενικά να τραφούν και να ζήσουν για αρκετό διάστημα στον αγρό. Οι μελέτες σχετικά με την διατροφή αντιπροσώπων της οικογένειας Tephritidae, περιλαμβάνουν την επίδραση της αναλογίας πρωτεϊνών : υδατάνθρακες, τις φυσικές θρεπτικές πηγές καθώς και την σχέση τους με παραμέτρους όπως η επιβίωση, η γονιμότητα των θηλυκών και η γονιμοποίηση των ωαρίων. Η επίδραση της διατροφής ενηλίκων από άγρια και εργαστηριακά στελέχη στην επιβίωση, ωοπαραγωγή και εκκολαπτικότητα των αυγών, μελετήθηκε στην παρούσα εργασία. Τα αποτελέσματα ενισχύουν την άποψη περί της επιλογής βέλτιστου διαιτολογίου από τα έντομα στην φύση, καθώς και της μειωμένης απόδοσης τους σε παραγωγή αυγών και επιβίωση όταν αυτά τρέφονται μόνο με πηγές υδατανθράκων. Οι φυσικές τροφές που αποτελούνταν από φρούτα έδειξαν να είναι επαρκείς για την επιβίωση και την παραγωγή αυγών τόσο σε άγρια όσο και σε εργαστηριακά έντομα, με σημαντικά όμως μικρότερες τιμές από την δίαιτα μαζικής εκτροφής στον συνολικό αριθμό παραγόμενων αυγών, και με πιο μακρά περίοδο ωαπόθεσης. Οι μελιτώδεις ουσίες έδειξαν διαφορές μεταξύ τους στην θρεπτική αξία, αλλά διαφορές παρατηρήθηκαν και στην αξιοποίηση τους από τα άγρια και εργαστηριακά έντομα. Οι διαφορές αυτές αφορούν στην επιβίωση των εντόμων, όπου η εργαστηριακή τροφή είχε τα καλύτερα αποτελέσματα, αλλά και στην παραγωγή αυγών, ενώ οι διαφορές στην εκκολαπτικότητα μεταξύ αγρίων και εργαστηριακών εντόμων ήταν σημαντικές. Τα εργαστηριακά έντομα δεν μπορούν να επιβιώσουν για πάνω από 4 μέρες χωρίς πηγή υδατάνθρακα, και δεν μπορούν να τραφούν ικανοποιητικά με περιττώματα εντόμων του ίδιου είδους, ανεξαρτήτως της σύνθεσης των περιττωμάτων αυτών

Mating activity of olive fruit fly Bactrocera oleae (Rossi) (Diptera Tephritidae): Time duration related with phtoperiod and temperature: Wild and laboratory insects

The olive fruit fly is the single insect key pest for olive culture, in the majority of the areas where this is practiced, causing major economic loss during favourable for the insect periods of the year. So far, main control measures against this insect include chemical insecticides, with all the adverse side effects on the produce and the environment. Experiments related with the sterile insect technique, showed that a considerable degree of mating isolation occurs between wild and laboratory mass-reared insects, due to differential mating time within the day. This could result in failure of this particular methodology. In nature, Bactrocera species mate at the end of the natural photophase, during dusk. The present thesis aimed at investigating the environmental factors which affect the time of mating activity of the olive fruit fly. Laboratory and wild populations of the insect were studied under various photoperiodic and temperature regimes. Experiments were also conducted in order to clarify the influence of environmental conditions on timing and duration of copulation, and to explore the speed of adaptation in new photoperiods. The inheritance of circadian copulation pattern was also studied. The present results indicated that: 1) Both wild and laboratory strains of the olive fruit fly mate towards the end of photophase, with the activity of wild flies occurring mostly within 1 ½ - 2 hours before the onset of darkness, while the mating activity of lab insects expanded over 4 ½ hours before the onset of scotophase, respectively. 2) Under long daylight photophase regime, the initiation of copulations tends to occur earlier within the photophase. 3) The duration of copulation (time in copula) increases with that of photophase. 4) Temperature was found to affect strongly the timing and duration of copulations. The combination of temperature with photophase duration affected even stronger the timing of copulation. 5) The above findings apply to both laboratory and wild olive fly strains. 6) Insects adapted their mating timing to a new photoperiodic regime within 24 hours. This makes difficult an absolute synchronization of released and wild population mating activities in SIT methodologies. 7) Ten generations of selection of laboratory strain to early or late within photophase copulation, resulted in no difference when compared with the standard strain mating timing.Ο δάκος της ελιάς αποτελεί τον κυριότερο εχθρό για την ελαιοκαλλιέργεια στις περισσότερες περιοχές όπου αυτή εξασκείται, προκαλώντας μεγάλες οικονομικές ζημίες σε ευνοικές για τον πληθυσμό του περιόδους του έτους. Ο κυριότερος τρόπος καταπολέμησης του, παρά την εκτεταμένη έρευνα σε πολλά πεδία της συμπεριφοράς και της γενικότερης βιολογίας του, είναι η χρήση χημικών σκευασμάτων μέχρι και τις μέρες μας, με το πλήθος των αρνητικών παρενεργειών που αυτή συνεπάγεται για το περιβάλλον. Πειράματα σχετιζόμενα με την μέθοδο καταπολέμησης με εξαπόλυση στείρων εντόμων, έδειξαν ότι, μεταξύ άλλων, υπάρχει αξιόλογη συζευκτική απομόνωση μεταξύ των δυο πληθυσμών (άγρια και εργαστηριακά), εξαιτίας της διαφορετικής ώρας σύζευξης σε αυτούς, με αποτέλεσμα να δυσχεραίνεται η επιτυχής καταπολέμηση του εντόμου με την συγκεκριμένη μέθοδο. Η φυσική ώρα έναρξης της σύζευξης στα είδη Bactrocera και ιδιαίτερα στο δάκο είναι στο τέλος της φυσικής φωτόφασης, στο λυκόφως. Η παρούσα διδακτορική διατριβή είχε σαν στόχο να διερευνήσει σε βάθος τους περιβαλλοντικούς παράγοντες που επηρεάζουν τον χρόνο συζευκτικής δραστηριότητας του εντόμου. Για τον σκοπό αυτό, μελετήθηκαν εργαστηριακοί και άγριοι πληθυσμοί του εντόμου υπό διάφορες συνθήκες φωτοπεριόδου, θερμοκρασίας και συνδυασμού αυτών. Τα πειράματα είχαν ως σκοπό να αποσαφηνίσουν την επίδραση των περιβαλλοντικών συνθηκών στην ώρα και διάρκεια σύζευξης, και να καταδείξουν την σημασία της ταχείας προσαρμογής σε νέες συνθήκες, και της κληρονόμησης του κιρκάδιου μηχανισμού ρύθμισης της σύζευξης. Τα αποτελέσματα έδειξαν ότι : Α) Τόσο τα άγρια όσο και τα εργαστηριακά έντομα συζεύγνηνται στο τέλος της φωτόφασης, πλην όμως η συζευκτική δραστηριότητα των αγρίων καταλαμβάνει τις τελευταίες 1 ½ - 2 ώρες φωτόφασης, ενώ των εργαστηριακών απλώνεται στις τελευταίες 4 ½ ώρες φωτόφασης. Β) Όσο μεγαλώνει η φωτόφαση τόσο τα έντομα τείνουν να επεκτείνουν ενωρίτερα μέσα σε αυτήν τις συζεύξεις τους. Γ) Η διάρκεια σύζευξης μεταβάλλεται ανάλογα με το μήκος της φωτόφασης. Δ) Η θερμοκρασία φαίνεται να έχει ισχυρή επίδραση στην κατανομή και στην διάρκεια των συζεύξεων, και ο συνδυασμός θερμοκρασίας-φωτοπεριόδου λειτουργεί συνεργιστικά στα ανωτέρω. Ε) Τα ανωτέρω παρατηρήθηκαν τόσο σε άγρια όσο και σε εργαστηριακά έντομα. Ζ) Τα έντομα έχουν την ικανότητα να προσαρμόζουν τον χρόνο σύζευξης σε νέα φωτοπερίοδο μέσα σε ένα εικοσιτετράωρο, γεγονός που αποκλείει την χρήση της φωτοπεριόδου για εξασφάλιση ταυτότητας χρόνου σύζευξης μεταξύ στείρων εντόμων και άγριου πληθυσμού στο φυσικό περιβάλλον. Η) Η δημιουργία στελεχών μέσω επιλογής όσον αφορά στην ώρα σύζευξης (πείραμα 10 διαδοχικών γενεών), δεν φαίνεται να δείχνει σημαντικές διαφορές σε σχέση με τον πληθυσμό ελέγχου

Olive fruit fly [Bactrocera (Dacus) oleae (Rossi) (Diptera: Tephritidae)] adult rearing diet without antibiotic

The olive fruit fly [Bactrocera (Dacus) oleae (Rossi) (Diptera: Tephritidae)] adult diet since its development in the 1960’s regularly incorporates antibiotic. Considering recent findings on the importance and function of the indigenous microbial flora of insects, the effects of antibiotic removal were measured on the survival and egg laying of wild flies derived from McPhail trappings and from field infested olive fruits. In the first case wild flies fed no antibiotic laid significantly greater numbers of eggs for two generations (in 5 out of 10 and 2 out of 10 counting dates for G1 and G2 respectively), while there were no significant differences in survival in either test (P = 0.221 for P generation, P = 0.988 for G1 generation from McPhail traps, P = 0.056 for flies from infested fruits). Percent egg–pupa recovery and adult emergence were not significantly affected by lack of antibiotic. An antibiotic-free strain has been maintained for eight generations, showing acceptable performance when compared to the long-reared standard ‘Laboratory’ strain. Overall results suggest the feasibility of an adult diet free of antibiotic without negative effects on colony survival and performance.8 page(s

Laboratory longevity and competitiveness of Dacus ciliatus Loew (Diptera : Tephritidae) following sub-sterilizing gamma irradiation

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.5 page(s