Six insecticides (Malathion, Quik, Cidial, Dimethoate, Actellic, Deltamethrin) and two mineral oils (Super misrona and Kemesol) are currently used to control the most important pests in Mediterranean olive cultivation (olive fly, olive moth and black scale). Potential side-effects of these compounds were tested on the egg parasitoid Trichogramma cacoeciae Marchal, following recommendations of the working group ÔPesticides and Beneficial OrganismsÕ of the International Organization for Biological Control, West Palaearctic Regional Section (IOBC/ WPRS). In the present study, three different types of test methods were carried out: (1) initial toxicity dose-response test on adult wasps; (2) initial toxicity test on pupae, using field recommended rates; and (3) persistent test on olive foliage to assess the duration of harmful activity. The six insecticides tested reduced parasitism by 80-95% and rated as moderately harmful at the field recommended doses. The two mineral oils reduced parasitism up to 25% and were therefore rated as harmless to the adult stage of the parasitoid. The results of the pupal test (parasitoid pupa inside the host egg) showed that Malathion was harmless; Quik, Actellic and Cidial were slightly harmful, while Dimethoate and Deltamethrin were moderately harmful. The results of the persistence test on olive foliage showed that Malathion, Quik and Actellic were slightly persistent, while Cidial, Dimethoate and Deltamethrin were moderately persistent.
A survey of egg parasitoids of the genus Trichogramma (Hymenoptera, Trichogrammatidae) was carried out in olive groves in Portugal, Greece, Egypt, and Tunisia during the years 2002-2004. Parasitoids were obtained either by exposing sentinel eggs (Sitotroga cerealella Olivier or Ephestia kuehniella Zeller) on olive trees or by collecting eggs of lepidopterous olive pests. Parasitized egg samples were reared separately in the laboratory for emergence of parasitoids. These were further reared in separate lines and processed by morphological and molecular biology techniques for species characterization. The recorded fauna of Trichogramma parasitoids in olive groves was species poor and consisted of species mainly known from the Mediterranean region. Trichogramma bourarachae Pintureau and Babault was found in Tunisia and Egypt, T. cordubensis Vargas and Cabello, and T. euproctidis Girault in Egypt, Trichogramma cacoeciae Marchal in Portugal, Greece, Egypt, Tunisia and Trichogramma nerudai Pintureau and Gerding in Portugal. Apart from that, Trichogramma oleae Voegelé and Pointel was collected in Tunisia. This species is probably not indigenous, but has established after several releases of a French strain were made in recent years. For selected strains, the sequence of the internal transcribed spacer 2 (ITS-2) region of rDNA was determined and deposited in the GenBank database. Differences in important biological attributes were found among collected strains of T. bourarachae, suggesting the existence of biotypes. The results contribute to the limited knowledge on distribution and biodiversity of the genus Trichogramma in the Mediterranean region. They can be helpful for the preservation and use of indigenous Trichogramma species in biological control of lepidopterous pests in olive and other local crops.
1 The leopard moth Zeuzera pyrina L. (ZP) is an invasive pest from Europe of increasing significance in North Africa, in particular for olive cultivation. We followed the temporal dynamics by combined light/pheromone trapping over a 10-year period (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011) in a 240-ha olive farm in Northern Egypt. 2 The ZP had an annual cycle with one or two peak flights, from late April until October.Time series analysis showed a 2-year cycle of trap catch. This cycle is likely related to the 'on/off' bearing pattern of the olive, where years of high and low yield are observed to alternate. 3 Larval damage in both 'on' and 'off' years in the infested trees gave fruit yield losses of 37-42%. The loss was estimated to 2.1-4.8 t/ha among susceptible varieties. The relative losses were the same during on and off years. 4 Infestation of four susceptible and five resistant olive cultivars in different cropping systems varied within and between adjacent plots. The results suggest less infestation by intercropping of resistant varieties, which could assist in ZP management. 5 Both temporal and spatial dynamics strongly influence population dynamics and the dynamics are related to variation in the moth host plant.
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