Prays Oleae Bern Research Articles

Probability analysis of pheromone trapping for olive moths, Prays oleae Bern. (Lepidoptera: Yponomeutidae) and a regional decision-making algorithm for spraying for fruit generation

Probability analysis of pheromone trapping for olive moths, Prays oleae Bern. (Lepidoptera: Yponomeutidae) and a regional decision-making algorithm for spraying for fruit generation

Determination of Distribution, Population Change, Infestation and Damage situation of Olive Moth, Prays oleae (Bernard) (Lepidoptera: Praydidae) Causing Damage in Olive Orchards

This study was conducted to determine adult population change, infestation and damage rate of Prays oleae Bern. (Lepidoptera: Praydidae) generations which are in leaves, flowers and fruits. Studies were conducted in 30 olive orchards in the Dara village and Derik district of Mardin province in 2016–2017 in Turkey. Samples were collected from three different orchards containing at least 30–40 olive trees. Samplings were done weekly by pheromone traps, visual inspection and shoot methods. As a result of the study, it was determined that Olive moth was distributed in the village of Dara and districts of Derik and Nusaybin, but was not distributed in districts of Kiziltepe of Mardin province. The general infestation ratio of the pest was 73.33% and olive moth had three peak points in a year, such as in early May, second week of June and in early October in the Mardin province. It was found that it had three generations in a year and adults of the pest appeared from April to November in Mardin province. It was also determined that the damage rate of the pest was between 12–21% in leaf generations, 2–5% in flower generations, and between 0.8–5% in fruit generations based on the years and the orchards.

Monitoring and population characteristics of Prays oleae (Lepidoptera: Yponomeutidae) on different insecticidal treatments

The presence of olive moth (Prays oleae Bern.) and effectiveness of different control treatment against it has been conducted on 160 olive trees of Leccino variety in Istria, Croatia. The treatments were: dimethoate, Bacillus thuringiensis var. kurstaki (Bt), pyrethrins, consociation of olive and planted pyrethrum and control. Olive moth has been monitored weekly using pheromone-baited delta traps and different coloured sticky plates in 12 and eight monitoring. Moth's life stages (non-destroyed, destroyed eggs and larvae) has been counted in seven monitoring. The predator activity has been determined as the ratio of destroyed eggs in the total number of observed eggs on 50 randomly chosen samples of flowers and fruits. On pheromone traps, the maximum catch has been determined on May 15th on control, when maximum of moth's flight on control, dimethoate and pyrethrins treatments coincided in time. There were more adults detected on pheromone traps then on sticky traps (16.8 times over). With time, moth's first preference was red and then blue sticky plates. The highest number of eggs ( non-destroyed and destroyed) has been found on dimethoate on May 15th ( 2.8 ± 1.1 and 4.5 ± 1.6) and June 18th ( 0.8 ± 0.5) as a consequence of accidental high oviposition rate at dimethoate plots before treatment applications. The highest number of larvae were detected on control on July 2nd ( 2.0 ± 0.7)

Uncovered variability in olive moth (Prays oleae) questions species monophyly.

The olive moth -Prays oleae Bern.- remains a significant pest of olive trees showing situation dependent changes in population densities and in severity of damages. The genetic variability of olive moth was assessed on three main olive orchards regions in Portugal by three different markers (COI, nad5 and RpS5), suggesting high species diversity albeit with no obvious relation with a regional pattern nor to an identified ecological niche. Selected COI sequences obtained in this study were combined with those available in the databases for Prays genus to generate a global dataset. The reconstruction of the Prays phylogeny based on this marker revealed the need to revise Prays oleae to confirm its status of single species: COI data suggests the co-existence of two sympatric evolutionary lineages of morphologically cryptic olive moth. We show, however, that the distinct mitochondrial subdivision observed in the partial COI gene fragment is not corroborated by the other DNA sequences. There is the need of understanding this paradigm and the extent of Prays variability, as the disclosure of lineage-specific differences in biological traits between the identified lineages is fundamental for the development of appropriate pest management practices.

Effect of soil tillage on natural occurrence of fungal entomopathogens associated to Prays oleae Bern.

The olive tree is one of the most important crops in Portugal, where tillage is still a normal practice performed by the growers. This work intends to evaluate the effect of tillage practices on the diversity and abundance of entomopathogenic fungi associated to Prays oleae Bern. population in the olive grove ecosystem. In order to achieve this, three tilled and three non-tilled groves were sampled for P. oleae larvae and pupae, during two consecutive years. The fungi were isolated from diseased larvae and pupae and identified by rDNA sequencing. One hundred and twenty isolates of fungi described as entomopathogenic were found, belonging to 8 different species. The most abundant species were Beauveria bassiana (60%), Cladosporium cladosporioides (18%) and Cladosporium oxysporum (14%). Olive groves under no-till system showed higher occurrence (2.7%), diversity (7 species) and abundance (65 isolates) of entomopathogenic fungi than tilled system (2.3%, 4 species and 55 isolates). Although these differences were found to be not significant, the results suggested that no-tilled olive groves with natural vegetation presented the most suitable conditions to increase the probability of P. oleae infection by entomopathogenic fungi. The highest number of exclusive species found in non-tilled groves (4 species) when compared to tilled ones (1 species) also reinforce this fact and indicated that vegetation cover may act as a reservoir for fungal species.

An Architecture for Performance Optimization in a Collaborative Knowledge-Based Approach for Wireless Sensor Networks

Over the past few years, Intelligent Spaces (ISs) have received the attention of many Wireless Sensor Network researchers. Recently, several studies have been devoted to identify their common capacities and to set up ISs over these networks. However, little attention has been paid to integrating Fuzzy Rule-Based Systems into collaborative Wireless Sensor Networks for the purpose of implementing ISs. This work presents a distributed architecture proposal for collaborative Fuzzy Rule-Based Systems embedded in Wireless Sensor Networks, which has been designed to optimize the implementation of ISs. This architecture includes the following: (a) an optimized design for the inference engine; (b) a visual interface; (c) a module to reduce the redundancy and complexity of the knowledge bases; (d) a module to evaluate the accuracy of the new knowledge base; (e) a module to adapt the format of the rules to the structure used by the inference engine; and (f) a communications protocol. As a real-world application of this architecture and the proposed methodologies, we show an application to the problem of modeling two plagues of the olive tree: prays (olive moth, Prays oleae Bern.) and repilo (caused by the fungus Spilocaea oleagina). The results show that the architecture presented in this paper significantly decreases the consumption of resources (memory, CPU and battery) without a substantial decrease in the accuracy of the inferred values.

The use of ethylene diffusers is comparable to treatments with sprayed ethylene to reduce the damage caused by the olive moth (Prays oleae Bern.)

In 2002 and 2003, six field experiments were conducted at three olive groves of southern Spain in order to compare the effects of two types of ethylene treatments (sprayed and diffusers) on the olive losses caused by the olive moth (Prays oleae Bern.) as well as on the activity and effectiveness of oofagous predators. Both treatments showed to be effective to control the pest; in the two years studied the mean reduction in final infestation due to ethylene was of 35% with respect to the controls trees, and none affected negatively the action of natural predators of P. oleae. In addition, the use of diffusers set on the trees at the end of flowering period will help the farmers to overcome the problems of determination of optimum time for sprayed treatments of ethylene.

Are indigenous strains of Trichogramma sp. (Hym., Trichogrammatidae) better candidates for biological control of lepidopterous pests of the olive tree?

Strains of the egg parasitoid, Trichogramma, indigenous in olive groves in the Mediterranean region (T. bourarachae Pintureau & Babault, T. cacoeciae Marchal, T. cordubensis Vargas & Cabello, T. euproctidis Girault, T. nerudai Pintureau & Gerding, T. oleae Voegelé & Pointel) as well as commercially available strains (T. brassicae Bezdenko, T. cacoeciae, T. evanescens Westwood), were assessed in laboratory and semi-field experiments for their attributes as biological control agents for use against lepidopterous olive pests like the olive moth (Prays oleae Bern.) and the jasmine moth (Palpita unionalis Hübn.). In a choice test, an Egyptian strain of T. cordubensis parasitized significantly more olive and jasmine moth eggs than those of the rearing host Sitotroga cerealella Olivier. This strain was also most efficient in finding eggs of the target pests on olive foliage and on potted olive trees. Survival and fecundity of a Tunisian strain of T. bourarachae was not affected when exposed to hot (35°C) and arid (< 40% relative humidity) conditions in comparison to the mild standard of 25°C and 70% relative humidity. It was concluded that indigenous strains collected from olive groves were more effective against the target pests and more tolerant to arid conditions than commercially available parasitoid species, indicating that biological control agents should preferably be isolated from the relevant pest/crop system.

Larval performance in relation to oviposition site preference in olive kernel moth (Prays oleae Bern., Yponomeutidae, Praydina)

Abstract1 The tri‐voltine moth Prays oleae Bern. spends its larval stages on the native olive tree (Olea europaea L. var. sylvestris Brot. and five cultivars, Oleaceae) mining the leaves, the flowers and the fruits in each generation; it seldom switches to other native or introduced confamilial plant species.2 In this study the pattern of oviposition of the olive moth was examined in olive fields and natural vegetation, in relation to in situ recruitment as an outcome of processes such as density dependence or risk spreading.3 Larval body size (width of epicranial sclerites) was also examined and compared between host substrates, years and morphological, physiological, ecological and nutritional attributes of the host.4 The factors influencing the oviposition pattern of the olive moth such as the carbon/nitrogen ratio, number of flowers, branch length and previous leaf damage were ranked differently in different cultivars.5 ‘Hot spots’, i.e. olive trees or parts of trees receiving a high egg load, were found to be the result of in situ recruitment.6 Physiological mortality among first instar larvae was significantly negatively correlated with the number of oviposited upon leaves; suggesting that the adult selects for oviposition the best available substrate.7 As adult moths selected leaves with minimal probability of abscission for oviposition, leaf abscission was not a major mortality factor, although first instar larvae reduced leaf longevity.8 Host quality did not affect all larval stages in the same way.9 The more nutritionally poor the substrate, the longer the duration of the larval stage feeding on it. The phenological timing of the insect life stages very closely tracks the phenological phases of its host plant, primarily focusing on the most nutritious host stage in terms of larval performance.

Long-term study on the evaluation of yield and economic losses caused by Prays oleae Bern. in the olive crop of Granada (southern Spain)

A 28-year study (1970–1997) of olive trees grown in Granada (southern Spain) has revealed the levels of attack by the olive moth ( Prays oleae Bern.), as well as the beneficial action of oophagous predators (Chrysopidae). On the basis of the results, the damage caused by the moth has been divided into three categories, and the yield and economic losses have been evaluated. When the final attack is ‘high’ (more than 40% fruit fall), which occurs approximately one in every three years, the necessity of control methods against the pest should be considered.

The effect of adult nutrition on the fecundity and longevity of the olive moth Prays oleae (Bern.)

AbstractMixed sex pairs of adult olive moths (Prays oleae Bern.) were given different diets in the laboratory and subsequent longevity and fecundity were recorded. Insects given a diet consisting of a 70% sucrose solution lived longer than those given a mixture of sugar, yeast autolysate and water in the ratios 4:7: 10, which in turn lived longer than those with access to water only. Due to their increased longevity, insects in the sugar treatment were able to produce more eggs in their lifetimes than those with access to water only. Mean daily oviposition rate was unaffected by diet.In the field, in comparison with fruits from untreated trees, more moth eggs were found on fruits taken from olive trees (Olea europea L.) that had been sprayed with sugar solutions, but this effect disappeared 3 weeks after spraying.