Fruit Fly Control Research Articles

Natal host and learning as factors in host preference by Spalangia cameroni Perkins (Hymenoptera: Pteromalidae)

The parasitoid Spalangia cameroni Perkins is a commercially available biocontrol agent of filth flies that is also used, especially through inundative releases, for the biological control of fruit flies. Adequate host selection behaviour is essential to the reproductive performance of parasitoid females, and innate and learned host species preferences play a key role in it. Therefore, in this study, the effect of natal host species [the medfly Ceratitis capitata (Wiedemann) or the house fly Musca domestica Linnaeus], either an innate or learned host, on later S. cameroni female host preference was assessed. In both innate and learned host preference experiments, most examined variables (realized fecundity, total progeny, induced mortality and sex ratio) did not differ significantly for the parasitoid line (parasitoids reared on medfly or house fly), but they did differ for the two attacked hosts, with the variables being higher in the house fly. In the learned host preference experiment, these variables did not differ significantly with experience (i.e., the host species on which parasitoids had performed previous parasitic activity). Superparasitism (the number of pupae with supernumerary eggs) differed significantly for the two attacked hosts and with experience, being higher in the house fly and in females experienced with medfly, respectively, but it did not influence the total progeny. The lower realized fecundity and induced mortality shown by experienced S. cameroni females compared to inexperienced females may be due to the fact that experienced females could be less likely to accept novel host types than naive females. These results indicate that rearing S. cameroni on medfly or house fly pupae seems to have little influence on the later performance of this parasitoid in its subsequent use against populations of both fly pests.

Surveying and screening South African entomopathogenic nematodes for the control of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann)

The polyphagous Mediterranean fruit fly or Medfly, Ceratitis capitata, which is an economically important pest species to fruit growers globally, including those in South Africa, spends part of its life cycle in the soil as a final instar larva and pupa. Entomopathogenic nematodes (EPNs) of the families Steinernematidae and Heterorhabditidae are insect-killing parasites that occur naturally in soils worldwide. The main aim of this study was to identify local, South African EPN species highly pathogenic against Medfly larvae entering the soil to pupate. Eighty soil samples were taken from fruit orchards in the Western and Northern Cape provinces of South Africa, and baited with susceptible host insects, including the target pest. The identity of the EPNs isolated was verified using molecular techniques. The pathogenicity of five local EPN species were screened in the laboratory by inoculating single third instar Medfly larvae with 100 infective juveniles (IJs) in 50 μl of water. After 48 h, high Medfly larval mortality was obtained, with no significant difference being found between the nematode species, and the experiment was therefore repeated at a lower concentration of infective juveniles. The pathogenicity of the most virulent EPN, Heterorhabditis noenieputensis, along with Steinernema yirgalemense, was further tested by inoculating 100 ml of sterilised sand with 2000 IJs. After 24 h, 10 third instar Medfly larvae were added to the sand. High mortality of Medfly larvae, using H. noenieputensis, promises well for local EPN species, which could be used as a biological control agent against the Medfly, within an integrated pest management system.

Residual degradation and toxicity of insecticides against Bactrocera oleae.

Field and lab trials took place in Crete (July to September 2016), concerning the residual degradation and toxicity of seven active ingredients applied as bait sprays against the olive fruit fly. Highest residues were recorded in olive leaves for dimethoate and phosmet (~60mg/kg) immediately after application (day 1+), while a threefold and fivefold reduction was observed 1week later, respectively. Residues of pyrethroids were determined at lower levels (<10mg/kg) but remained almost stable for a longer period of time. Finally, thiacloprid and spinosad residues were determined at 5.81 and 0.19mg/kg respectively (day 1+), and rapidly decreased below the LOQ. Highest toxicity against the olive fruit fly was observed just right after the application of dimethoate (100%), a-cypermethrin (80%), and L-cyhalothrin (72.92%). Although the toxicity of dimethoate was significantly reduced 1week after the application (80%) and then minimized, toxicity of pyrethroids remained almost stable (>60%) for the first 2weeks and then decreased to 30-40%, which remained stable up to the end of the study (8weeks). Concerning phosmet, its toxicity ranged from 35 to 56% for 3weeks with no significant reduction, while spinosad presented a lower toxicity profile (50% only for 1week). The benefits of these results in the knowledge of insecticide residues and their toxicity against olive fruit fly can be used for improving olive fruit fly control.

Kajian Perlakuan Dingin Untuk Pengendalian Lalat Buah Pada Jeruk Mandarin

Kajian Perlakuan Dingin Untuk Pengendalian Lalat Buah Pada Jeruk Mandarin

Sublethal Effects in Pest Management: A Surrogate Species Perspective on Fruit Fly Control.

Tephritid fruit flies are economically important orchard pests globally. While much effort has focused on controlling individual species with a combination of pesticides and biological control, less attention has been paid to managing assemblages of species. Although several tephritid species may co-occur in orchards/cultivated areas, especially in mixed-cropping schemes, their responses to pesticides may be highly variable. Furthermore, predictive efforts about toxicant effects are generally based on acute toxicity, with little or no regard to long-term population effects. Using a simple matrix model parameterized with life history data, we quantified the responses of several tephritid species to the sublethal effects of a toxicant acting on fecundity. Using a critical threshold to determine levels of fecundity reduction below which species are driven to local extinction, we determined that threshold levels vary widely for the three tephritid species. In particular, Bactrocera dorsalis was the most robust of the three species, followed by Ceratitis capitata, and then B. cucurbitae, suggesting individual species responses should be taken into account when planning for area-wide pest control. The rank-order of susceptibility contrasts with results from several field/lab studies testing the same species, suggesting that considering a combination of life history traits and individual species susceptibility is necessary for understanding population responses of species assemblages to toxicant exposure.

Parasitism of Psytallia concolor (Hymenoptera: Braconidae) on Bactrocera oleae (Diptera: Tephritidae) infesting different olive varieties

Psytallia concolor (Szepligeti) is a koinobiont endoparasitoid of many Tephritidae larvae, including Bactrocera oleae (Rossi), and has been used in Mediterranean areas for biological control of olive fruit fly by inundative release. The present study evaluates the influence of olive fruit variety (Amfissis, Arbequina, Branquita de Elvas, Carolea, Kalamon, Koroneiki, Leccino, Manzanilla, Mastoidis, Moroccan Picholine and Picholine) on P. concolor parasitism efficiency and performance in the field during two successive years. The results showed that the percentage of parasitism was significantly higher (>30%) in Mastoidis and Koroneiki (light-weight varieties 4.21 mg) as well as the length of the developed adult parasitoids (>3.5 cm) in Mastoidis and Manzanilla were significantly higher than these individuals developed from other varieties such as Koroneiki and Kalamon. Finally, the optimal host fruit for P. concolor development seems to be Mastoidis variety with great biological parameters and percentage of parasitism.

AN INNOVATED OF AN AIRFLOW OLFACTOMETER FOR MEASURING RESPONSE OF THE MEDITERRANEAN FRUIT FLY, CERATITIS CAPITATA (WEID.) TO ODORS

the present work was carried out to describe a new innovation of a simple detachable olfactometer for measuring the olfactory responses of fruit flies to different odors. Such device may be useful to discover the efficiency of current attractive or repellent odors or new odors that could be used for controlling fruit flies in fields. It could save effort, time and money required to investigate any new attractive or repellent material prior usage in the field Many experiments were conducted to standardize this device using the standard attractive material Buminal . These trials included determination of optimum concentration of test odor, optimum dose to test, velocity of air flow inside device, optimum number of flies that could be used in every test, optimum light intensity, best exposure time to test material and relationship between response of flies to test odor and temperature.

Attraction and consumption of methyl eugenol by male Bactrocera umbrosa Fabricius (Diptera: Tephritidae) promotes conspecific sexual communication and mating performance.

The Artocarpus fruit fly, Bactrocera umbrosa (Fabricius) (Diptera: Tephritidae), is an oligophagous fruit pest infesting Moraceae fruits, including jackfruit (Artocarpus heterophyllus Lamarck), a fruit commodity of high value in Malaysia. The scarcity of fundamental biological, physiological and ecological information on this pest, particularly in relation to behavioural response to phytochemical lures, which are instrumental to the success of many area-wide fruit fly control and management programmes, underpins the need for studies on this much-underrated pest. The positive response of B. umbrosa males to methyl eugenol (ME), a highly potent phytochemical lure, which attracts mainly males of many Bactrocera species, was shown to increase with increasing age. As early as 7 days after emergence (DAE), ca. 22% of males had responded to ME and over 50% by 10 DAE, despite no occurrence of matings (i.e. the males were still sexually immature). Male attraction to ME peaked from 10 to 27 DAE, which corresponded with the flies' attainment of sexual maturity. In wind-tunnel assays during the dusk courtship period, ME-fed males exhibited earlier calling activity and attracted a significantly higher percentage of virgin females compared with ME-deprived males. ME-fed males enjoyed a higher mating success than ME-deprived males at 1-day post ME feeding in semi-field assays. ME consumption also promotes aggregation behaviour in B. umbrosa males, as demonstrated in wind-tunnel and semi-field assays. We suggest that ME plays a prominent role in promoting sexual communication and enhancing mating performance of the Artocarpus fruit fly, a finding that is congruent with previous reports on the consequences of ME acquisition by other economically important Bactrocera species.

Comparative Field Studies of Various Traps and Attractants for the Olive Fruit fly, Bαctrocerα oleαe

In the framework of an ongoing effort for development of an effective trap for the control of the olive fruit fly, Bactrocera oleae (Gmelin) (Diptera, Tephrifidae), by mass trapping, four trap types (wood, cloth, laminate, McPhail), seven different colors of laminate traps, different food attractants, attractant combinations or formulations (total of ten cases), and two insecticides (deltamethrin, b-cyfluthrin) used as killing agents on the traps, were compared under field conditions. The following conclusions may be drawn: Laminate traps (paper envelopes with a polyethylene lining inside, 15×20 cm in size, containing 70 g of ammonium bicarbonate salt and impregnated with 15 mg (a.i.) of an insecticide), were more effective than wood traps. Effectiveness of laminate traps can be enhanced by using an attracting color or in the case of the food attractant ammonium bicarbonate, by incorporating copper oxychloride. Combinations of two protein hydrolysates were more effective than one hydrolysate alone. Effectiveness of protein hydrolysates is not constantly higher than that of ammonium bicarbonate, the use of which is more economic and convenient. The insecticide b-cyfluthrin may be used on traps instead of deltamethrin, which is known to have a repellent effect on the olive fly, especially Linder high concentrations, and is unstable under natural UV light.

Comparative field studies of various traps and attractants for the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae) in fall

To clarify questions regarding the effectiveness of the many different types of traps and semiochemicals used for the monitoring and the control of the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann) (Diptera: Τephrititae), seven trap types, four food attractants, one sex attractant and a combination of food and sex attractant, were evaluated under field conditions in orange orchards in fall. No major differences were observed between trap designs resembling the original McPhail glass trap. The plastic bottle trap of 1,5L volume, with four side openings for one-way fly entrance, proved very efficient when filled with a proteinaceous food attractant Ζ1. From the attractants, two of them, Ζ1 and Entomela showed the best performance. The combination of food and a sex attractant showed no significant synergistic effects on trap efficiency. The findings allow a better choice among trap types and attractants, available today in the market, for Medfly monitoring and control.

Laboratory evaluation on a potential birth control diet for fruit fly sterile insect technique (SIT)

Sterile insect technique (SIT) is one of the most effective fruit fly control technologies. Irradiation has been used to sterilize male fruit flies before release to the field to compete with the wild males for females. Imagine an environmental and cost effective method using a rearing diet that can make insects sterile indefinitely, by feeding for 7days before release. This could replace costly irradiation process. A potential birth control diet was evaluated on fertility, mating, survival, and protein analysis for fruit fly species in Hawaii. Insects were continuously fed an agar diet with lufenuron (LFN) for 7d after emergence and then switched to a control diet to simulate the actual field condition. The influence on egg hatch was dose dependent. With dose of 2–4mg/g in the diet, egg hatch from LFN-fed was almost 100% suppressed for 24 experimental days if adults of Ceratitia capitate (Widemann), Bactrocera dorsalis (Hendel), and B. latifrons (Hendel) continued to feed on LFN diet. B. cucurbitae (Coquillett) was not affected by LFN. However, egg hatch from LFN fed B. latifrons and B. dorsalis were suppressed for at least 2weeks after switching to the control diet at 7d. Egg hatch did not recover >4% up to 24d. Proteome analysis revealed that ABD-4 protein was under expressed by 70–83% on LFN fed females and males of B. latifrons and B. dorsalis while Pbprp2 protein was significantly over expressed by 6–12 fold on LFN fed males only. These two proteins were not expressed in C. capitata and B. cucurbitae. Therefore, this report focused more on B. latifrons and B. dorsalis. This finding suggested a great potential for one alternative to sterilize fruit flies for SIT without irradiation.

Evaluation of Mass Trapping and Bait Stations to Control Anastrepha (Diptera: Tephritidae) Fruit Flies in Mango Orchards of Chiapas, Mexico

The use of insecticide baits is one of the most common and efficient methods worldwide to control fruit flies (Diptera: Tephritidae). However, this strategy has commonly been associated with environmental contamination and undesirable effects on non-target organisms. The use of lure-and-kill devices (bait stations) or mass trapping could be alternative control methods to overcome these ecological concerns. In this study, we evaluated several mass trapping devices and attractants in comparison with ground-applied insecticide bait sprays for the control of Anastrepha obliqua (Macquart) and Anastrepha ludens (Loew) (Diptera: Tephritidae) in mango orchards in Chiapas, Mexico. Among the bait stations evaluated, we found that a wide-mouth 2 L plastic bottle baited with Cera Trap®, an enzymatic hydrolyzed protein, and used at the density of 25 traps per ha was most efficient at reducing the fruit fly populations. Our results showed that bait stations to control fruit flies, in addition to using less insecticide, were as effective as ground sprays and were superior under rainy conditions. These properties represent a great advantage considering the tropical conditions in several mango production zones around the world.

Novel insecticides and bait stations for the control of Anastrepha fruit flies in mango orchards

Agricultural pests represent a limiting factor for safety food production. Environmental friendly alternatives to the use of synthetic pesticides are required. Here we evaluated the effect of a novel insecticide and a new designed bait station using Anastrepha ludens sterile flies in release–recapture tests in mango orchards. Seven treatments were distributed in 35 plots of one hectare each in a five blocks arrangement. Spinosad (GF-120), malathion and abamectin, Fly-catch bait station (FC): baited with 95% water, 4% hydrolyzed protein (Captor 300) and 1% malathion, 1.5 L plastic bottle bait station (PB) baited with 250 mL of CeraTrap, Papaya Leaf Mimic station: Sprayed with GF-120, untreated plots (control) were used as treatments. Half of the trees of each plot received the treatment. Approximately 5000 flies per plot were released at 15-day intervals, in four consecutive replicates. For monitoring, two Multilure traps/plot baited with BioLure were revised weekly. Wild populations of A. serpentina and A. obliqua were censored. Abamectin sprays and the FC induced the highest reduction in A. ludens captures (up to 50% with respect to the untreated plots). No clear effects were observed in the wild populations, since more flies were captured in some treatments than in the untreated plots, but here the initial population density and distribution was unknown. Traps in the FC treatment captured less nontarget insects than other treatments. Overall, the results indicate that the abamectin and the attract-and-kill bait stations, especially the FC, can be useful alternatives for the control of Anastrepha flies.

Flight control of fruit flies: dynamic response to optic flow and headwind.

Insects are magnificent fliers that are capable of performing many complex tasks such as speed regulation, smooth landings and collision avoidance, even though their computational abilities are limited by their small brain. To investigate how flying insects respond to changes in wind speed and surrounding optic flow, the open-loop sensorimotor response of female Queensland fruit flies (Bactrocera tryoni) was examined. A total of 136 flies were exposed to stimuli comprising sinusoidally varying optic flow and air flow (simulating forward movement) under tethered conditions in a virtual reality arena. Two responses were measured: the thrust and the abdomen pitch. The dynamics of the responses to optic flow and air flow were measured at various frequencies, and modelled as a multicompartment linear system, which accurately captured the behavioural responses of the fruit flies. The results indicate that these two behavioural responses are concurrently sensitive to changes of optic flow as well as wind. The abdomen pitch showed a streamlining response, where the abdomen was raised higher as the magnitude of either stimulus was increased. The thrust, in contrast, exhibited a counter-phase response where maximum thrust occurred when the optic flow or wind flow was at a minimum, indicating that the flies were attempting to maintain an ideal flight speed. When the changes in the wind and optic flow were in phase (i.e. did not contradict each other), the net responses (thrust and abdomen pitch) were well approximated by an equally weighted sum of the responses to the individual stimuli. However, when the optic flow and wind stimuli were presented in counterphase, the flies seemed to respond to only one stimulus or the other, demonstrating a form of 'selective attention'.

Towards Citizen–Expert Knowledge Exchange for Biodiversity Informatics: A Conceptual Architecture

This article proposes a conceptual architecture for citizen-expert knowledge exchange in biodiversity management. Expert services, such as taxonomic identification, are required in many biodiversity management activities, yet these services remain inaccessible to poor communities, such as small-scale farmers. The aim of this research was to combine ontology and crowdsourcing technologies to provide taxonomic services to such communities. The study used a design science research (DSR) approach to develop the conceptual architecture. The DSR approach generates knowledge through building and evaluation of novel artefacts. The research instantiated the architecture through the development of a platform for experts and farmers to share knowledge on fruit flies. The platform is intended to support rural fruit farmers in Kenya with control and management of fruit flies. Expert knowledge about fruit flies is captured in an ontology that is integrated into the platform. The non-expert citizen participation includes harnessing crowdsourcing technologies to assist with organism identification. An evaluation of the architecture was done through an experiment of fruit fly identification using the platform. The results showed that the crowds, supported by an ontology of expert knowledge, could identify most samples to species level and in some cases to sub-family level. The conceptual architecture may guide and enable creation of citizen-expert knowledge exchange applications, which may alleviate the taxonomic impediment, as well as allow poor citizens access to expert knowledge. Such a conceptual architecture may also enable the implementation of systems that allow non-experts to participate in sharing of knowledge, thus providing opportunity for the evolution of comprehensive biodiversity knowledge systems.

Proteomic identification of a potential sex biomarker for 2 fruit fly species at pupal stage

Fruit flies are one of the most destructive pests worldwide. The sterile insect technique (SIT) has been one of the most effective fruit fly control techniques. Genetic sexing strains have been developed to facilitate the separation of males and females based on color at the pupal stage for the oriental fruit fly, Bactrocera dorsalis, and the medfly, Ceratitis capitate, known as dorsalis translocation white pupae (DTWP) and temperature sensitive lethal mutation strain (TSL). In both cases, the females are white and the males are brown. By releasing only sterile males, the control efficiency was increased, and fruit damage due to sterile females reduced. There remains, however, a gap in our understanding of this phenomenon because there is no information on the physiological basis of the sex differences. Here, we report the outcome of a study designed to identify pupal proteins related to the sex differences using these two strains. We collected whole pupae of both species each day for first 10days for protein analysis. Protein expression was analyzed by 2D electrophoresis, gel densitometry and mass spectrometry. The general odorant binding protein, OBP56d, was differentially expressed in white pupae versus brown pupae for both species. We also confirmed this result with phenotypical characteristics to prove these proteins were not derived from puparia. These proteins had molecular weights between 10 and 15kDa and a pI of 6.73 for DTWP and 5.71 for TSL.

Evaluation of thiacloprid and clothianidin (neonicotinoids) as alternative to fenthion (organophosphate) for control of Mediterranean fruit fly (Diptera: Tephritidae) in deciduous fruit orchards

Fenthion (organophosphate) was used in Australia to target adults, eggs and larvae of Mediterranean fruit fly (Medfly), Ceratitis capitata Wiedmann (Diptera: Tephritidae) in deciduous fruits. With its removal from use in 2015, clothianidin and thiacloprid (neonicotinoids) were evaluated for any adulticide, ovicide or larvicide (eggs, larvae) activity against Medfly in a series of laboratory and field-cage experiments in peach and nectarine. We included fenthion in all experiments as a positive control. As an adulticide, fenthion had the greatest residual toxicity on fruit, with 7 d old residues killing 44% of adults within 48 h compared to thiacloprid (17%) and clothianidin (30%). When applied as a larvicide to naturally infested peaches, none of the insecticides was 100% effective, though fewest pupae (1.18 ± 0.19 pupae/fruit) (indirect measurement of larval survival) were produced when treated with fenthion, followed by clothianidin (3.40 ± 0.33 pupae/fruit) and thiacloprid (6.88 ± 0.34 pupae/fruit); with 11.35 ± 0.30 pupae/fruit in control (water). In peaches treated 48 h post-infestation, fenthion was most effective in reducing numbers of pupae and adult emergence and with higher percentage of deformed adults, with thiacloprid=clothianidin. In nectarines treated 48 h post-infestation, fenthion was most effective in reducing numbers of pupae and adult emergence as well as with higher percentage of deformed adults, followed by clothianidin. Insecticides were least effective when applied as a preventative 24 h or 7 d prior to infestation, with fenthion more effective than clothianidin. Whilst our study shows that neither clothianidin nor thiacloprid are equivalent to fenthion, they are acceptable substitutes to growers for use for Medfly in deciduous fruits given that fenthion is no longer available to growers in Australia. We recommend that growers incorporate other controls to target the adult stage rather than rely only on new insecticides.

Protein feeding of Queensland fruit fly Bactrocera tryoni and cucumber fly Zeugodacus cucumis (Diptera: Tephritidae) on non‐host vegetation: effect of plant species and bait height

AbstractPerimeter‐baiting of non‐crop vegetation using toxic protein baits was developed overseas as a technique for control of melon fly, Zeugodacus (Zeugodacus) cucurbitae (Coquillett) (formerly Bactrocera (Zeugodacus) cucurbitae), and evidence suggests that this technique may also be effective in Australia for control of local fruit fly species in vegetable crops. Using field cage trials and laboratory reared flies, primary data were generated to support this approach by testing fruit flies' feeding response to protein when applied to eight plant species (forage sorghum, grain sorghum, sweet corn, sugarcane, eggplant, cassava, lilly pilly and orange jessamine) and applied at three heights (1, 1.5 and 2 m). When compared across the plants, Queensland fruit fly, Bactrocera tryoni (Froggatt), most commonly fed on protein bait applied to sugarcane and cassava, whereas more cucumber fly, Zeugodacus (Austrodacus) cucumis (French) (formerly Bactrocera (Austrodacus) cucumis), fed on bait applied to sweet corn and forage sorghum. When protein bait was applied at different heights, B. tryoni responded most to bait placed in the upper part of the plants (2 m), whereas Z. cucumis preferred bait placed lower on the plants (1 and 1.5 m). These results have implications for optimal placement of protein bait for best practice control of fruit flies in vegetable crops and suggest that the two species exhibit different foraging behaviours.

Precocious Mexican fruit fly methoprene‐fed males inhibit female receptivity and perform sexually as mature males

AbstractThe sterile insect technique (SIT) has been used successfully for the control of fruit flies. The efficiency of this technique can be significantly reduced when sterile released insects are exposed to adverse conditions and predators, as a great number of sterile insects die before reaching sexual maturity and thus fail to mate with wild females. Treatments with juvenile hormone (JH) analogues such as methoprene (M) significantly reduce the time to reach sexual maturity by sterile Anastrepha ludens (Loew) (Diptera: Tephritidae) males. In this study, we compared the sexual performance of non‐treated sexually mature males with young males that had been sexually accelerated with M. Furthermore, we compared the ability of M‐fed males in inhibiting female remating compared with sexually mature males. Results showed that at 5 days M‐fed males had lower mating success than mature males; however, 6‐day‐old (0.1%) M‐fed males had the same amount of matings as mature 13‐day‐old males. Young 5‐ to 10‐day‐old M‐fed males also had similar number of matings as mature non‐treated 12‐ to 17‐day‐old males. There were no differences in copula duration between treatments. Moreover, there were no differences between the fertility, fecundity or refractory period of females mated with either young male fed M or normal sexually mature males. These results indicated that young males that were sexually accelerated with M have the same sexual performance as non‐treated sexually mature males. Implications of using M as a pre‐release treatment for A. ludens controlled through SIT are discussed.

Evaluating potential olive orchard sugar food sources for the olive fly parasitoid Psyttalia concolor

Olive fruit fly Bactrocera oleae (Rossi) (Diptera: Tephritidae) is a major olive pest in the Mediterranean basin where increasing insecticide resistance has enhanced damage and necessitates more reliance on other control strategies, such as biological control. Provision of floral resources has been reported to improve the effectiveness of natural enemies. Here, we tested the effect of six plant nectars and two honeydew sources on the survival of Psyttalia concolor (Szepligeti) (Hymenoptera: Braconidae), a parasitoid wasp used in the biological control of olive fruit fly. Our results showed a positive effect on survival associated with nectars of Anchusa azurea Mill., Rosmarinus officinalis L., Lavatera cretica L. and Calamintha nepeta (L.) Savi, while honeydew proved to be a valuable alternative food source. When offering flowers directly to insects, Anchusa azurea, Lavatera cretica, and Foeniculum vulgare L. were found to be the most beneficial species, indicating also that P. concolor feeds predominantly on shallow corollas.