Olive Moth Prays Research Articles

Some Biological and Ecological Factors of Olive Moth, Prays oleae (Bern.) in Al-Quneitra Governorate, Southern Syria

Al-Jouri, E., N. Diab and M. Dawoud. 2023. Some Biological and Ecological Factors of Olive Moth, Prays oleae (Bern.) in Al-Quneitra Governorate, Southern Syria. Arab Journal of Plant Protection, 41(3): 233-245. https://doi.org/10.22268/AJPP-41.3.233245 This study was carried out during the 2017 and 2018 seasons in three locations in Al-Quneitra governorate (Saida, Khan Arnabeh, and Hadar), with different heights above sea level, in order to monitor the activity of adult males of the olive moth Prays oleae (Bern.) (Lepidoptera: Yponomeutidae). using pheromone traps. The results obtained showed that the olive moth has three generations per year, and the timing of adult males emergence and the duration of each generation differed according to the studied location and season. Adults of the first generation (Anthophagous) began to appear from the first and second week of March for the seasons 2017 and 2018, respectively, in Saida site, and were delayed until the first and second week of April in Hadar location for the two study seasons, respectively. The duration of the first-generation range was 11-12 weeks, and the butterflies of the second generation (Carpophagous) appeared in the first week of June in the Saida location and the last week of June in Hadar location, and the duration of the generation range was 12-21 weeks. Adults of the third generation (Phyllophagous) began to appear in the second and third week of November for the Saida location in the two study seasons, and the fourth week of September for the locations of Khan Arnabeh and Hadar, with generation duration of 8-11 weeks. The monthly abundance differed during the same season according to the study location, and the population peak of adult olive moths was in Saida location during the two seasons of the study in April (635.67 and 664.33 males/trap, respectively), which significantly outperformed the rest of the months. The two locations of Khan Arnabeh and Hadar had the highest number of adults during the two study seasons in May, with a significant difference compared with the rest of the months with an average of 514.33 and 316.00 males/trap for the 2017 season, respectively, and 651.67 and 411.67 males/trap, respectively, for the 2018 season. By studying the correlation between the population density of adult males and temperature and humidity, it was found that there was a positive correlation with temperatures during the first generation (+0.63), and a weak negative correlation during the second generation (-0.21), and weak positive correlation during the third generation (+ 0.165). Whereas, the correlation was weakly negative between mean relative humidity and moth adults population in all three generations (-0.359, -0.39, -0.264), respectively. Keywords: Olive moth, Prays oleae, biological factors, ecological factors, Al Quneitra governorate, southern Syria.

Study of the Factors Affecting Infestation Rate with Olive Moth Prays oleae (Bernard, 1788) in Three Olive Growing Locations Along the Syrian Coast

Wassouf, Y., A.N. Bashir and Gh. Ibrahim. 2022. Study of the Factors Affecting Infestation Rate with Olive Moth Prays oleae (Bernard, 1788) in Three Olive Growing Locations Along the Syrian Coast. Arab Journal of Plant Protection, 40(3): 193-200. https://doi.org/10.22268/AJPP-40.3.193200 This study aimed to investigate the effect of the most important factors affecting the infestation rate with the olive moth, Prays oleae (Lepidoptera: Yponomeutidae), in three olive growing locations in Lattakia and Tartus Governorates (Al-Sawda, Ain Shiqaq and AlBarqiah). The study was carried out during the period 2019-2020. Results obtained showed that the location had an effect on the infestation rate, and the highest average infestation rate was 33.53% in Al-Barqiah location, followed by 20.86% in Ain Shkak, and the lowest was 16.65% in Al-Sawda location. Results obtained also showed that the insect generation had an effect on the olive moth infestation rate; infestation of the phyllophagous generation was the highest, followed by the antophagous generation and the carpophagous generation in the three locations. The x2 (Chi-square) test showed that there were significant differences between the infestation rate and the total number of biological enemies, the number of predators and the parasitism rate in the three locations. Keywords: Biological factors, olive moth, predators, parasitoids, Ain Shkak, A-Sawda, Al-Barqieh, Syria

Mating Disruption of the Olive Moth Prays oleae (Bernard) in Olive Groves Using Aerosol Dispensers.

Simple SummaryAccording to official data, the world production of olive oil in the 2020–2021 period was about 3,197,000 tons; in the EU alone, the number of olive trees is over 737 million. The olive moth Prays oleae is one of the most damaging and devastating olive tree pests in the Mediterranean basin. Damage caused by this moth can reduce production by 50–60%, causing large losses in olive oil production. The use of an insect pheromone mating disruption strategy is a sustainable and environmentally friendly tool for Integrated Pest Management, reducing the use of chemical pesticides to control olive pests. In the present study, a mating disruption system based on aerosol dispensers was developed to control P. oleae moth populations. Overall, our results demonstrated at all experimental sites over 2 years that mating disruption using aerosols in the management of P. oleae registered a high suppression of male captures, as well as significantly reducing affected inflorescence and fruit infestation when compared to the untreated control.The olive moth (OM), Prays oleae (Bern.) (Lepidoptera: Yponomeutidae), is a major olive grove pest worldwide; however, until now, very few studies have investigated the effectiveness of mating disruption (MD) techniques against this pest. Experiments were carried out for two successive years (2019 and 2020) in three different olive groves in Andalucía (Southern Spain) to evaluate mating disruption’s efficacy in controlling the OM from the first to the third generation. The effectiveness of MD formulations against the three generations of OM was assessed by determining the percentage of infested olive fruits, the reduction of pheromone trap catches, and the number of affected inflorescences in both MD-treated and untreated control olive groves. The number of release points (one or two aerosol devices per ha) was also evaluated. In all years and trials, the mean number of males caught in traps placed in the MD-treated plots was significantly lower than untreated sites. Mating disruption registered a high suppression of male captures (>75%) in treated plots for two consecutive seasons. Concerning infested olive fruits, substantial reductions (about 80%) were observed in the MD plots of locations B and C, and a reduction of about 40% was detected in location A, compared to the control plot. Results showed that the installation of two aerosol devices/ha reduced fruit damage below 20% of infested olive fruits except for one site where a reduction of about 71% in the MD plot was recorded in 2019. Although few significant differences were associated with OM male catches and infested olive fruits between plots treated with one aerosol/ha and two aerosols/ha in most of the comparisons, significant differences in the number of olive inflorescences infested by P. oleae were found, suggesting a similar performance between the two tested aerosol densities. Results of two-year field trials in Andalucía demonstrated the potential of Mister P X841 aerosol devices as an effective tool for controlling the olive moth, P. oleae.

Do non-crop areas and landscape structure influence dispersal and population densities of male olive moth?

The permeability of the crop surroundings to pests and the landscape structure can influence pest dispersal between crop patches as well as its abundance within the crop. In this work, we analyzed the dispersal of the olive moth Prays oleae (Bernard) throughout the olive grove surroundings and their abundance within the crop following three approaches: (i) pollen grains settled on bodies of olive moths collected in olive groves were identified and compared with flora occurring on the surrounding patches; (ii) the capability of P. oleae males to penetrate non-crop patches was analyzed (iii) the effect of the landscape structure on the abundance of the three generations of the olive moth was studied. Pollen grains of scrubs and other trees occurring in the crop surroundings, such as Cistus sp., Quercus sp., Juniperus-type or Pinaceae were identified on P. oleae bodies suggesting that P. oleae penetrates into non-crop habitats. Additionally, woody and, to a lesser degree, herbaceous patches, did not constitute barriers for P. oleae. Finally, more complex and heterogeneous patches presented lower numbers of captures of P. oleae. These results give new insights into the movements of the olive moth in the olive grove surroundings and suggest that the management of non-crop areas could influence this pest abundance.

A cohort-based modelling approach for managing olive moth Prays oleae (Bernard, 1788) populations in olive orchards

The olive moth, Prays oleae (Bernard, 1788) is considered as one of the most serious pests of the olive culture in the Mediterranean basin, causing significant damages and yield losses. P. oleae is associated with a complex-level system interactions with its host, the olive tree. This paper presents a novel cohort-based approach to model P. oleae population dynamics using three interlinked sub-models regarding the following key components: P. oleae, olive tree and economic thresholds. To better explicitly understand biotic and abiotic features interplaying, the P. oleae sub-model was structured taking into account daily cohorts considering the respective developmental stage (egg, pupa, larva and adult). The obtained results depicted realistic population trends such as unsynchronized population dynamics and the dependence interaction established between the P. oleae and the olive tree. The realism of the simulated trends for different environmental scenarios shows its potential of being used as an auxiliary tool for olive orchards pest management.

Plant-mediated effects on entomopathogenic fungi: how the olive tree influences fungal enemies of the olive moth, Prays oleae

The community of entomopathogenic fungi associated with the olive moth Prays oleae is specific for each generation of this insect. The entomopathogen Beauveria bassiana is almost exclusive to the phyllophagous or leaf generation, whereas Paecilomyces formosa mainly occurs in the carpophagous or fruit generation. The main objective of this work was to evaluate olive plant-mediated effects on the development (germination, growth, sporulation and spore viability) of both entomopathogens. While B. bassiana was strongly inhibited by olives, P. formosa development was more restricted by leaves. These inhibitory effects were caused by both volatile and diffusible compounds produced by olives and leaves. Specifically, the effects of two leaf volatile compounds, (Z)-3-hexen-1-ol and (Z)-3-hexenyl acetate were studied. The results suggest that olive plant organs affect entomopathogens by controlling their abundance and function, which may partly explain the occurrence of a fungal species in a specific P. oleae generation.

Prays oleae

Specific scopeThis standard describes the conduct of trials for the efficacy evaluation of insecticides against olive moth Prays oleae on olive.Specific approval and amendmentFirst approved in 1987–09.Revision approved in 2012–09.

Statistical optimization of low-cost medium for economical production of Bacillus subtilis biosurfactant, a biocontrol agent for the olive moth Prays oleae

Biosurfactants are currently not a feasible alternative to chemically synthesized surfactants as a result of their potentially high production costs. In this work, Bacillus subtilis SPB1 biosurfactant was shown to be efficient in the biocontrol of the olive mothPrays oleae. Its production was improved by optimizing the medium components using inexpensive substrates. The effect of orange peels, soya bean and diluted sea water on SPB1 biosurfactant production was studied and was adjusted using central composite design. The experimental results were fitted to a second-order polynomial model that yielded a determination coefficient of R2=0.932. The optimal medium for biosurfactant production was found to be composed only by orange peels (15.5 g/L), soya bean (10 g/L) and diluted sea water (30%). The predicted and observed response were 4.3 g/L (with desirability = 0. 21) and 4.45 g/L, respectively. In comparison to original level production, two fold increases had been obtained. Key words: Bacillus subtilis, biosurfactant, central composite design, optimization, Prays oleae.

Temperature and strain effects on reproduction and survival of Trichogramma oleae and Trichogramma cacoeciae (Hymenoptera: Trichogrammatidae)

To assess differences in temperature sensitivity during development, life tables for two lines derived from the species Trichogramma oleae Voegelé and Pointel and a strain of Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae) were elaborated at 15, 20, 25, 30, 35, 36, and 37°C in the laboratory. Eggs of Ephestia kuehniella Zeller together with a fresh drop of honey were supplied every 2 days until the death of the test females, and the removed host egg batches were placed in the equivalent rearing cabinet. The line ‘2F’ of T. oleae was found to be the most efficient at any range of temperatures except at 20 and 37°C, in comparison to the other tested strains. For all species, no progeny emerged from eggs incubated at 36°C and none of the parasitized eggs turned black at 37°C. The better performance at a broader range of temperatures by T. oleae (line 2 F) might be caused by a shorter history in artificial rearing in comparison to the other strains. Fewer generations at laboratory conditions and frequent multiplication on eggs of its natural host (the olive moth Prays oleae) may have prevented a deterioration in the rearing population of this strain, maintaining its genetic diversity at a higher scale. Applying varying temperature regimes on the rearing stock at regular intervals during the mass production process may help to maintain the essential quality of the biological control agents for field performance at higher temperatures.

Field evaluation of the egg parasitoid, Trichogramma evanescens West. against the olive moth Prays oleae (Bern.) in Egypt

In Egypt, Trichogramma evanescens Westwood (TE) is extensively used in inundative releases against a number of lepidopterous pests of several crops. However, the wasp had not been collected from olive groves. Field trials on the use of commercially available TE against the olive moth, Prays oleae (Bern.) (OM) were carried out for three successive years (2002–2004). The objective of this study was to evaluate the efficacy of inundative releases of this wasp on damage reduction. The obtained results were encouraging since OM attacks were reduced by 42.9,71 and 69.9% and TE-treated trees yielded significantly bigger olive fruits by 10.5 and 12.5% than untreated trees in 2002 and 2004 olive seasons, respectively. However, parasitization levels indicated that the wasp is not well adapted to local environmental conditions of olive groves. The suggested measure to improve the quality of released wasps is to mass release of local wasps isolated during the present study, i.e., T. cordubensis Vargas and Cabello and T. euproctidis Girault.

Mating disruption for the control of the olive moth, Prays oleae (Bern) (Lep., Yponomeutidae) with the ajor sex pheromone component

Abstract: Mating disruption to control the olive moth Prays oleae (Bern) was tested from 1992 to 1996 in olive groves in Greece. The major sex pheromone component (Z)‐7‐tetradecenal was formulated in β‐cyclodextrin (β‐CD) and polyvinyl chloride (PVC) polymers. Pheromone trap catches were reduced by up to 96–100% in the mating‐disruption plots. During the first year of mating disruption a treatment with Bacillus thuringiensis (var. kurstaki) (Bt) was applied to reduce the first generation or larvae. Fruit damage in the mating disruption plots was lower compared with the fruit damage in Bt, insecticide and untreated plots. In high fruiting years, the proportion of fruit damage was lower than in low fruiting years. Mating disruption applied in the same olive grove over several years progressively reduced the olive moth population from year to year.