Olive Fly Research Articles

First study of ovipositional preference and developmental performance of Bactrocera oleae (Diptera: Tephritidae) in an arid zone (Laghouat: Algeria)

The present study evaluated the susceptibility of varieties (Sevillano, Sigoise, Chemlal and Dahbia) to Bactrocera oleae and their infestation rates by studying some physical characteristics of fruits and evaluated the performance of B. oleae in these varieties in an arid zone (Algeria). Results showed that Dahbia variety, the recorded more infestation in 2020 than in 2019. While Sevillano showed maximum infestation in 2020 with highest MI and larger olives, and Chemlal with smaller olives showed minimum infestation. Maturity, weight, volume having a positive correlation with the infestation for all varieties, while roundness at length was significantly and positively correlated with infestation only for Dahbia. Dahbia has had the poor performance to the total number of pupae produced and the mean number of individuals per olive. The pupation time varied by temperature but not with varieties. The percentage of emerged adults was high for all varieties. Sex ratio and parasitism rate was no significant difference between varieties or lots. Finally, the susceptibility of varieties to B. oleae contributes to the invasion of this pest in the arid zone in Algeria.

Bactrocera oleae (Rossi) (Diptera: Tephritidae) Response to Different Blends of Olive Fruit Fly-Associated Yeast Volatile Compounds as Attractants

The olive fruit fly, Bactrocera oleae (Rossi) is economically the most important olive pest, causing yield losses in all olive growing areas where is detected. Considering that EU requires the reduction of pesticide use by up to 100% by 2050, more effective non-pesticide lures for B. oleae monitoring and/or controlling are needed. This research was aimed at investigating the attractiveness of different blends of olive fruit fly-associated yeast volatiles toward B. oleae. Three blends of olive fruit fly-associated yeast volatiles: isoamyl alcohol and 2-phenethyl alcohol; isoamyl alcohol, 2-phenethyl alcohol and 2-phenethyl acetate; and isoamyl alcohol, 2-phenethyl acetate and isobutyl acetate were selected and tested on yellow sticky traps for attraction of B. oleae in olive orchard. Results showed that traps containing all tested blends of olive fruit fly-associated yeast volatile compounds, in total, were significantly more attractive to B. oleae and were not significantly attractive to green lacewings, compared to the control. Among them, the most promising was the one containing the blend of isoamyl alcohol, 2-phenethyl acetate and isobutyl acetate because its attractiveness was constantly significant during investigation compared to the others. This blend in the future could lead us to the discovery of a new attractant for the monitoring and/or controlling of B. oleae.

Olive Landscape Affects Bactrocera oleae Abundance, Movement and Infestation

The economic importance of Bactrocera oleae (Rossi) and the problems associated with insecticides make necessary new management approaches, including deeper biological knowledge and its relationship with landscape structure. Landscape complexity reduces B. oleae abundance in late summer–autumn in areas of high dominance of olive groves, but the effect of landscape structure in spring and in areas less dominated by olive groves has not been studied. It is also unknown whether the insect disperses from olive groves, using other land uses as a refugee in summer. This work evaluates the effect of landscape structure on olive fruit fly abundance and movement in spring and autumn, and infestation in autumn, in central Spain, an area where the olive crop does not dominate the landscape. A cost–distance analysis is used to evaluate the movement of the fly, especially trying to know whether the insects move away from olive groves in summer. The results indicate that B. oleae abundance is consistently lower in complex landscapes with high scrubland area (CAS), patch richness (PR) and Simpson landscape diversity index (SIEI), and low olive grove area (CAO). The cost–distance analysis shows that the fly moves mainly in spring, and amongst olive groves, but there is no evidence that land uses other than olive groves serve as a summer refuge. Olive fly infestation decreased with decreasing CAO and increasing CAS and SIEI, accordingly with the effect of landscape on abundance. Thus, mixing olive groves with other land uses, which are not a source of flies, can help improve control of this important pest.

Survey of Florida Olive Groves during Olive Fruit Development: Monitoring for Stink Bugs and Olive Fruit Flies

Olives, Olea europaea L. (Oleaceae), are an emerging commercial crop in Florida; however, potential arthropod threats during olive tree establishment and fruit development remain uncharacterized. Two potential pests that may threaten olive fruit production directly are native and invasive pentatomid stink bugs, which are important pest species of many crops in the southeast, and the invasive olive fruit fly, Bactrocera oleae (Gmelin) (Diptera: Tephritidae),which is not known to be established in Florida. Monitoring for stink bugs during fruit maturation was done using dual funnel tube traps baited with stink bug lures. Yellow sticky card traps baited with food and pheromone lures were used to monitor for the olive fruit fly. Both trap types were placed in tree canopies in 4 North Central Florida olive groves during the anticipated fruit development period for 2 growing seasons. Whereas neither of the invasive species targeted (Halyomorpha halys Stål [Hemiptera: Pentatomidae] or B. oleae) were detected, several other potential pests were identified including brown stink bugs (Euschistus spp.; Hemiptera: Pentatomidae), glassy winged sharpshooters, Homalodisca vitripennis Germar (Hemiptera: Cicadellidae), and grasshoppers. No fruit damage attributable to arthropod pests was detected although fruit production was very low with limited samples. These results contribute to awareness of potential pests that may jeopardize olive fruit production and aid in the future studies to develop effective monitoring activities for Florida growers.

Agent Based Modeling and Simulation of the Olive Fly (Bactrocera Oleae) in Turkey

In this paper, the relationship of the olive fly with the olive has been closely examined and the life cycle of the olive fly and olive are modeled in the Repast Simphony agent-based simulation environment to show how the population of olive flies changes and how the growing population affects olives. Using data, it has been observed how an olive fly reproduces in a short time and turns into many new generations. Increased olive fly population constitutes a serious threat to the success of control methods used for the damages of olives. In line with the data obtained from this study, olive fly population and damages to olives can be estimated for future years. Olive fly has been determined that the olive fly reduces the yield of the olive tree and it is necessary to combat the olive fly. It is very important to control the olive fly. Therefore, various control methods should be tried. An effective method for increasing the number of olive flies has been investigated. Olive fly numbers were obtained at the end of cultural biological and chemical struggles. In this study, the biological developmental stages of olive fly and olive can be observed. In line with the data obtained from this study, future years and damage to olives can be estimated.

Choice response of the olive fruit fly, Bactrocera oleae, to various bait/insecticide combinations: hydrolyzed proteins or ammonium salts?

Key to the success of the ground bait spray application method (‘attract and kill’) against Bactrocera oleae is to effectively suppress its population by inducing good levels of attraction and stimulate flies to ingest a lethal dose of the toxicant. A 2-year long field bioassay (fly captures to sticky panels) was developed to evaluate the exposure and response of olive flies to hydrolyzed protein based and ammonium salt baits in combination with various insecticides. A significantly higher attractive response of fruit flies was recorded in the case of the protein Entomella/phosmet combinations among protein bait/combination. Though next year, an enhanced attractive effect and a longer residual activity of ammonium salts compared to the tested protein to the olive fruit fly was clearly demonstrated. Especially in the case of beta-cyfluthrin mixed with ammonium salts, the mean number of captured flies were at least 3 to 11-fold (depending on the salt) higher compared to the respective protein-containing mixture baits instead of the organophosphate phosmet. Ammonium salts can successfully replace proteins in bait sprays.

Characterization of Fungi Associated with Olive Fruit Rot and Olive Oil Degradation in Crete, Southern Greece.

In November 2019, a severe outbreak of fruit rot was observed in olive orchards in Crete, southern Greece. Symptoms appeared primarily on fruits and stalks, resembling those caused by anthracnose. Typical symptoms were fruit rot, shrinkage, and mummification, associated commonly with stalk discoloration and fruit drop. Disease incidence was estimated at up to 100% in some cases, and an unprecedented increase in olive oil acidity reaching up to 8% (percentage of oleic acid) in severely affected olive groves was recorded. Thirty-two olive groves were then surveyed, and samples of fruit, stalk, leaf, and shoot were collected. Visual, stereoscopic, and microscopic observations revealed several fungi belonging to the genera Alternaria, Botryosphaeria, Capnodium, Colletotrichum, Fusarium, and Pseudocercospora. Fungal infection in fruits was commonly associated with concomitant infestation by the olive fruit fly Bactrocera oleae along with increased air temperature and relative humidity conditions that prevailed in October and November 2019. Twenty representative fungal strains isolated from symptomatic fruits and stalks were characterized by morphological, physiological, and molecular analyses. By internal transcribed spacer regions of ribosomal DNA region and translation elongation factor 1-α gene sequencing analysis, these isolates were identified as Alternaria spp., A. infectoria, Botryosphaeria dothidea, Colletotrichum boninense sensu lato, Fusarium lateritium, F. solani species complex and Stemphylium amaranthi. Pathogenicity tests on punctured fruits revealed that all isolates were pathogenic; however, F. solani isolates along with B. dothidea were the most virulent, and wounds were necessary for efficient fungal infection. Moreover, as few as 10 spores of F. solani were sufficient to cause significant infection in punctured fruits. F. solani was also capable of infecting olive fruits in the presence of B. oleae, with no additional wounding, in artificial inoculation experiments. Moreover, it was capable of colonizing and affecting olive blossoms. Further analyses of olive oil extracted from fruits artificially inoculated with F. solani indicated a significant increase in oil acidity, K232, K270, and peroxide value, whereas total phenol content was significantly decreased. To the best of our knowledge, this is the first report of F. solani associated with olive fruit rot and olive oil degradation worldwide.

Bioactivity of Carlina acaulis Essential Oil and Its Main Component towards the Olive Fruit Fly, Bactroceraoleae: Ingestion Toxicity, Electrophysiological and Behavioral Insights.

Simple SummaryIn recent years, botanical insecticides based on essential oils (EOs), or their main components, have received much attention as promising tools for Integrated Pest Management, due to their environmental safety and low side effects on non-target organisms. In this study, Carlina acaulis EO and its main component, carlina oxide, recently proven to be effective larvicidal and adulticidal agents against some insect pests, were analyzed for their toxicity, electroantennographic (EAG), and behavioral responses to adult olive fruit fly (Bactrocera oleae). The C. acaulis EO was more toxic to the tephritid than the carlina oxide, and both were more toxic to the same insect pest than EOs from other plant species tested in previous studies. The EAG responses evoked by the EO were significantly higher than those elicited by the carlina oxide. Carlina oxide did not lead to attraction or repellency responses in B. oleae males and females. Overall, our results highlight the potential employ of C. acaulis-borne products in the development of effective eco-friendly “lure and kill” formulations to be used in tephritid management.Among botanical insecticides based on essential oils (EOs) or their main components, Carlina acaulis EO and the aromatic polyacetylene carlina oxide, constituting more than 90% of its EO, were recently proven to be effective against the larvae and adults of some insect vectors and pests. In this study, the toxicity of C. acaulis EO and carlina oxide were tested on Bactrocera oleae adults using a protein bait formulation. The LC50 values of the C. acaulis EO and carlina oxide were 706 ppm and 1052 ppm, respectively. Electroantennographic (EAG) tests on B. oleae adults showed that both carlina EO and oxide elicited EAG dose-dependent responses in male and female antennae. The responses to the EO were significantly higher than those to carlina oxide, indicating that other compounds, despite their lower concentrations, can play a relevant role. Moreover, Y-tube assays carried out to assess the potential attractiveness or repellency of carlina oxide LC90 to B. oleae adults showed that it was unattractive to both males and females of B. oleae, and the time spent by both sexes in either the control or the treatment arm did not differ significantly. Overall, this study points out the potential use of C. acaulis EO and carlina oxide for the development of green and effective “lure-and-kill” tools.

Olive fruit fly and its obligate symbiont Candidatus Erwinia dacicola: Two new symbiont haplotypes in the Mediterranean basin.

The olive fruit fly, specialized to become monophagous during several life stages, remains the most important olive tree pest with high direct production losses, but also affecting the quality, composition, and inherent properties of the olives. Thought to have originated in Africa is nowadays present wherever olive groves are grown. The olive fruit fly evolved to harbor a vertically transmitted and obligate bacterial symbiont -Candidatus Erwinia dacicola- leading thus to a tight evolutionary history between olive tree, fruit fly and obligate, vertical transmitted symbiotic bacterium. Considering this linkage, the genetic diversity (at a 16S fragment) of this obligate symbiont was added in the understanding of the distribution pattern of the holobiont at nine locations throughout four countries in the Mediterranean Basin. This was complemented with mitochondrial (four mtDNA fragments) and nuclear (ten microsatellites) data of the host. We focused on the previously established Iberian cluster for the B. oleae structure and hypothesised that the Tunisian samples would fall into a differentiated cluster. From the host point of view, we were unable to confirm this hypothesis. Looking at the symbiont, however, two new 16S haplotypes were found exclusively in the populations from Tunisia. This finding is discussed in the frame of host-symbiont specificity and transmission mode. To understand olive fruit fly population diversity and dispersion, the dynamics of the symbiont also needs to be taken into consideration, as it enables the fly to, so efficiently and uniquely, exploit the olive fruit resource.

Climate Change and Major Pests of Mediterranean Olive Orchards: Are We Ready to Face the Global Heating?

Simple SummaryThe phenomenon of climate change affects the entire world, especially the most vulnerable areas such as the Mediterranean. Since the olive growing is one of the main economic sources for the Mediterranean countries, investigations on olive pests under global heating are necessary. Nowadays, knowledge on the topic is scarce, and nothing is known about the effects of climate change on olive pest parasitoids and predators. This information could be fundamental to understand the phenomena of pest outbreaks that are spreading in the Mediterranean olive orchards. The use of prevention tools (e.g., monitoring, prediction models) may help in controlling olive pests under a climate change scenario.Evidence of the impact of climate change on natural and agroecosystems is nowadays established worldwide, especially in the Mediterranean Basin, an area known to be very susceptible to heatwaves and drought. Olea europaea is one of the main income sources for the Mediterranean agroeconomy, and it is considered a sensitive indicator of the climate change degree because of the tight relationship between its biology and temperature trend. Despite the economic importance of the olive, few studies are nowadays available concerning the consequences that global heating may have on its major pests. Among the climatic parameters, temperature is the key one influencing the relation between the olive tree and its most threatening parasites, including Bactrocera oleae and Prays oleae. Therefore, several prediction models are based on this climatic parameter (e.g., cumulative degree day models). Even if the use of models could be a promising tool to improve pest control strategies and to safeguard the Mediterranean olive patrimony, they are not currently available for most O. europaea pests, and they have to be used considering their limits. This work stresses the lack of knowledge about the biology and the ethology of olive pests under a climate change scenario, inviting the scientific community to focus on the topic.

Changes in Chemical and Physical Quality Attributes of Olives as Influenced by Chemical Control of the Olive Fruit Fly, Bactrocera oleae (Rossi) (Diptera, Tephritidae) in Jordan

The olive fruit fly, Bactrocera oleae (Rossi) (Diptera, Tephritidae) is the most devastating insect pest possessing severe economic threats for the olive growers in Jordan. Therefore, the current study aimed at determining the effect of insecticidal applications against B. oleae on olive quantity, as well as physical (refractive index, fruit weight, diameter and volume, and weight of seed and flesh, as well as oil percentage) and chemical (olive oil acidity and peroxide value parameters). The experiment was conducted using Nabali olive cultivar in Karak District-Jordan in the year 2016. Three insecticides; Karate, Fytoclean, and Dursban used in the spraying operations, and trees were sprayed twice. Insecticidal spraying significantly (P<0.05) reduced olive oil acidity, peroxide value, and refractive index, and increased olive fruit’s weight, diameter and volume, and seed, and flesh weight compared to the untreated trees. In conclusion, the application of insecticides against B. oleae improved the olive quantity and tested quality parameters.

Ecological niche models of biotic interactions predict increasing pest risk to olive cultivars with changing climate

AbstractSimple, single‐species approaches in distributional ecology leave open questions of possible roles of biotic interactions. We sought to understand impacts of climate change on current and future potential distributions of Olea europaea sensu lato (host) and Bactrocera oleae (parasite) in Europe, the Middle East, and Africa (EMEA), taking into account potential interspecific interactions. We used ecological niche modeling approaches: For biotic interactions, an initial host model was incorporated into the calibration of the parasite model and an initial parasite model was incorporated into calibration of the host model, as host and parasite populations may respond to the presence of the other species. Absence of olive fruits could reduce the flight ability of the fly parasite, whereas presence of the parasite may make a site less suitable for the olives. The host model was improved by inclusion of the parasite information; the converse was not true for the parasite model. Our results anticipated a significant reduction in the potential distribution of Olea europeae in Africa and Europe under future climate scenarios; in contrast, future climates appear more broadly favorable for the parasite species, which poses new and increasing risks for olive cultivation in the Mediterranean region.

Determination of volatile substances in olives and their effect on reproduction of the olive fruit fly

AbstractFemales of the olive fruit fly Bactrocera oleae lay their eggs in olives mainly using fruit volatile stimuli. Using GC‐MS analysis, we determined the chemical composition of the volatile blend emitted from field‐collected olive fruit of cv. Megaritiki, at different stages of maturity. GC‐MS analysis demonstrated qualitative and quantitative differences in the headspace blend emitted by the olive fruit. Certain chemicals such as toluene, n‐octane, α‐pinene, limonene, ethyl hexanol, nonanal n‐dodecane, decanal and n‐tetradecane were detected in greater amounts, irrespective of the growth stage of the fruit. The flies’ exposure to a number of these chemicals, such as n‐octane and α‐pinene, as well as to a mixture consisting of n‐octane, α‐pinene, limonene, ethyl hexanol, nonanal, n‐dodecane, decanal and n–tetradecane favoured successful mating and egg production. The results may contribute to the improvement of the mass rearing of the fly, through these findings, which illustrate the positive effect that certain fruit volatile chemicals have on the fly's reproduction and offer a better understanding of the relation between the fly and the host fruit.

Türkiye’nin Marmara Bölgesindeki Türk Zeytin Üreticilerinin İyi Tarım Uygulamalarını Benimsemesini Etkileyen Faktörlerin Belirlenmesi

This study was carried out with 63 farmers using good agricultural practices (GAP) in olive production in five districts of Balıkesir, Bursa and Tekirdag provinces located in the Marmara Region of Turkey by conducting a questionnaire survey. The farmers with GAP certificate produce either Gemlik (71.4%) or (28.6%) Ayvalık varieties. Survey forms were handed out to contract-based producers in November 2017 during olive harvest period. The data were evaluated using SPSS statistical program. The results showed that average size of farms producing olive oil with GAP are generally 60-65 decares (da) in size. The average age of olive producers is 58.7, who have been producing olives for an average of 39 years with an average GAP experience of 2.4 years. A positive relationship was evident between lower level of education and late adoption of GAP. The most important problem faced by growers was Verticillium wilting, followed by olive fly in recent years. The study revealed that the absence of a significant difference in the prices of olives and olive oils grown with or without GAP reduced the attractiveness of GAP production. Moreover, because of the lack of price policy in olives grown with GAP, olives are marketed along with conventionally produced ones in an equal conditions in the domestic market.

Distinct Particle Films Impacts on Olive Leaf Optical Properties and Plant Physiology.

The olive fruit fly is worldwide considered a major harmful pest of the olive agroecosystem. In Italy, the fruit fly infestation is traditionally countered by spraying chemical insecticides (e.g., dimethoate), but due to the recent ban of dimethoate by the Reg EU2019/1090 and the increasing awareness of consumers of food sustainability, the interest in developing chemical-free alternatives to pesticides, such as the use of particle-films, is rising. A field experiment was conducted to assess the effect of different particle films (kaolin-base and zeolitite-base) on leaf gas exchanges and leaf optical properties. Results showed that with the dust accumulation on the leaves’ surface, photosynthesis, stomatal conductance, transpiration and water use efficiency were significantly lower in kaolin-treated olive trees compared to those treated with zeolitite and to the control, while olive trees treated with zeolitite showed physiological parameters similar to the untreated plants. Microstructural differences of different particle film on the leaf and olive surfaces emerged by ESEM observations also influenced leaf optical properties. Oils produced by zeolitite-treated plants show higher intensities of gustatory and olfactory secondary flavors compared to kaolin and test oils.

Activity Monitoring of Olive Fruit Fly, Bactrocera oleae (Rossi) Males, and Effect of Temperature and Relative Humidity, at Al Quneitra Governorate, Southern Syria

This study was carried out in Al Quneitra governorate, Syria during 2017 and 2018 seasons with the aim of monitoring the activity of olive fruit fly Bactrocera oleae (Rossi) (Diptera: Tephritidae) males, in three locations of similar altitude (945-989 m above sea level), in addition to evaluating the effect of temperature and relative humidity on males activity using pheromone traps. The results obtained showed that olive fruit fly male adults activity began in the last week of May 2017 season and in the 3rd week of May 2018 season. Male adult's population reached a peak in the 4 th week of September, with an average of 126.43±33.70 males/trap in 2017 season, whereas their peak in 2018 season wasreached in mid-September with an average of 205.2±15.51 males/trap. Number of activity periods for males differed according to the season of study, and number of activity periods was 3 in 2017 and 4 in 2018. The duration of the activity period ranged from 4 to 11 weeks. The results obtained also showed a weak correlation effect of temperature and relative humidity on males activity during the two seasons, and its value was +0.16, +0.048, respectively. The monthly abundance of males differed during one season. Statistical analysis showed that the highest monthly abundance in 2017 season was in October, with an average of 192.07±14.94 males/trap with a significant difference in relation to the rest of the months, whereas in 2018 season it reached the highest monthly abundance in September, with an average of 420.33±15.18 males/trap, which significantly outperformed the rest of the months. Seasonal abundance of 2018 was significantly higher than in 2017. Keywords: Olive fruit fly, Bactrocera oleae, males’ activity, pheromone traps, temperature, relative humidity, Al Quneitra

Laboratory Study of the Effect of Some Factors on the Parasitoid, Psyttalia concolor (Szépligeti), of the Olive Fruit Fly

The main objective of this study was to study the effect of some influencing factors on Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae) parasitism, which is one of the most important insect parasitoids used in biological control of the olive fruit fly. The study was carried out at the Biological Control Studies and Research Center, Faculty of Agriculture, Damascus University. Results obtained indicated that the parasitoid prefers the third larval instar, followed by the fully-grown larvae. The effect of olive (Olea europaea L.) fruit size on parasitism rate was quantified within one olive cultivar (Kaisi) and across four different olive cultivars (Mawi, Istanboli, Sorani and Kaisi, in increasing order of fruit size). Parasitism was examined under two different host distributions: variable distribution in which insect host density increased with decrease in olive fruit size; and uniform distribution in which insect host density was more or less similar across olive fruit sizes. The results obtained showed that the parasitism rate decreased as the size of the olive fruit increased. In addition, parasitism rate was influenced by the olive variety, olive fruit size and the age of the insect host larvae. Furthermore, the parasitoid preferred the third larval stage, thus it is recommended to release the parasitoid in commercial olive orchards at the time when the third larval stage of the olive fruit fly is prevalent, and such date could vary from one region to another. Keyword: Parasitoid, natural enemies, Kaisi variety, olive, Psyttalia

(Invited) Sensors for Agricultural Pests Management

Pests are undesired living organisms which cause major threat to plants, animals, humans and other organisms. It can directly feed on the crops and indirectly spread diseases and decrease the productivity of plants. Traditionally we have been using pesticides to get rid of them, but these pesticides are chemicals which tend to accumulate in the soil and water and pose detrimental effects to all the living creatures. To reduce the major loss in food production and use of chemical pesticides, we have come up with a few innovative approaches to control pests and also detect the toxic pesticides in an easy, affordable and eco-friendly way using sensors. We had developed sensors for effective use of biopesticides such as Helicoverpa armigera nuclear polyhedrosis virus (HaNPV), Spodoptera litura nuclear polyhedrosis virus (SlNPV) and Spilosoma obliqua nuclear polyhedrosis virus (SpilNPV). We had also designed a silicon dioxide-based microelectro-mechanical system (MEMS) sensors as tool for an early selective pest detection of female sex pheromones of Helicoverpa armigera and Bactrocera oleae. This robust device can also be used to selectively measure the pheromone at femtogram levels, and it is handy for early detection of pests. The device works well in both rainy and peak summer seasons. Using these systems farmers can take necessary measures in the pest attack region without using pesticides and would be able to support organic farming.

Sex pheromones: Made with a little help from my (bacterial) friends

Males of the olive fruit fly Bactrocera dorsalis team up with Bacillus bacteria in their rectal glands to synthesize 2,3,5-trimethylpyrazine (TMP) and 2,3,5,6-tetramethylpyrazine (TTMP) from glucose and threonine. The bacterially produced TMP and TTMP are utilized as sex pheromones to attract virgin females.

Application of oviposition deterrent compounds for the control of olive fruit fly, Bactrocera oleae Rossi. (Dip. Tephritidae) control

Olive Fruit Fly Bactrocera oleae Rossi (Dip.: Tephritidae) which reduces the quantity and quality of olive products and oil, is considered as the most serious olive pest in the world, also in Iran. The present study was conducted in the Roudbar olive Research Station in Guilan, Iran between 2015 to 2017 regarding the efficiency of several oviposition deterrent compounds to reduce olive fruit fly damage. The treatments included kaolin 5% (Sepidan®), kaolin 4% (Sepidan®), kaolin 5% (Sepidan®)+ copper hydroxide, kaolin 4% (Sepidan®)+ copper hydroxide, copper hydroxide, and water as control. The experiment was performed in a (CRBD). Spraying was done three times a year. First, at the time of the pit hardening of the olive fruit, which was in late June. Second, with the activity onset of the second generation of the pest in early September and third with the appearance of the third generation of pests in early October. As a result, kaolin 5% + copper hydroxide had the highest oviposition deterrents effect on the olive fruit fly. In the first year of the study, the lowest level of total fruit infestation in this compound was 5.00 ± 1.46. In the second year, it was 5.00 ± 1.26. In the third year, the total fruit infestation was 2.42 ± 1.04 for kaolin 5% + copper hydroxide and 2.85 ± 1.22 for copper hydroxide which showed the lowest level of infestation of fruits. The results showed that copper hydroxide alone or combined with kaolin 5% with at least two sprays is recommended for controlling B. oleae and reducing the fruit damage.