Prays oleae (Bernard)
Taxonomic placing: Insecta, Holometabola, Lepidoptera, Yponomeutidae.
Common name: Olive kernel borer.
Geographic distribution Southern Europe, the Mediterranean Region and North Africa.
Host plants: Olive and other Oleaceae (Ligustrum, Phillyrea and jasmine).
Economic importance: Damage is due to the destruction of flowers in spring and to causing considerable (over 40%) fruit drop in summer.
Morphology: The body of the female is gray, about 6-7 mm long, with grayish forewings covered by small scattered dark spots, hindwings gray with fringed margins. The larvae are greenish with brown spots, length 8-9 mm.
Life Cycle: Adults of the first generation emerge in spring from infested leaves and oviposit in flower buds. The emerging larvae enter the buds to feed, thereby destroying several flowers; this is termed the anthophagous stage. Later they spin webbing there and pupate. Females of the second generation oviposit on the small olives and their larvae enter the fruit and attack the kernel (the carpophagous stage). Such fruit later drop and the pest pupates therein. Adults of the third generation lay eggs on the leaves (the phyllophagous stage) and their larvae feed and pupate in the soil. The larvae of each generation thus feed on different parts of the tree and there is a long temporal distance between the occurrence of the second (the most harmful) and the third generations.
Management
Monitoring: Pheromone-based monitoring of P. oleae flight activity is used to follow its population trends and to decide when to initiate control measures.
Mating disruption: Mating disruption applied in Egypt during three years gradually, from year to year, reduced moth populations.
Chemical control: Organophosphates and Bacillus thuringiensis compounds applied against the anthophagous stage larvae may provide good control.
Biological control: The borer is attacked by several parasitoids. These include the egg parasitoid Trichogramma evanescens Westwood (Trichigrammatidae), which in Egypt reduced pest attack by 43-70%, and by the polyembryonic Ageniaspis fuscicollis (Dalman) (Encyrtidae). In Portugal and Spain ants, predatory beetles and Chrysopids feed on P. oleae. Predation by the latter may reach 34% of the carpophagous generation.
References
Agamy, E. 2010. Field evaluation of the egg parasitoid, Trichogramma evanescens West. against the olive moth Prays oleae (Bern.) in Egypt. Journal of Pest Science 83: 53-58.
Bento, A., Lopes, J., Torres, L. and Passos-Carvalho, P. 1999. Biological control of Prays oleae (Bern.) by chrysopids in Tras-Os-Montes region (Northeastern Portugal). Acta Horticulturae 474: 535-539.
Hegazi, E.M., Konstantopoulou, M.A. (and 7 co-authors) 2009. Is mating disruption effective in controlling the olive moth, Prays oleae? Crop Protection 28: 181-189.
Kavallieratos, N.G., Athanassiou, C.G., Balotis, G.N., Tatsi, G.T. and Mazomenos, B.E. 2005. Factors affecting male Prays oleae (Lepidoptera: Yponomeutidae) captures in pheromone-baited traps in olive orchards. Journal of Economic Entomology 98: 1499-1505.
Morris, T.I., Symondson, W.O.C., Kidd, N.A.C. and Campos, M. 2002. The effect of different ant species on the olive moth, Prays oleae (Bern.), in Spanish olive orchards. Journal of Applied Entomology 126: 224-230.
Ramos, P., Campos, M. and Ramos, J. M., 1998. Long-term study on the evaluation of yield and economic losses caused by Prays oleae Bern. in the olive crop of Granada (southern Spain). Crop Protection 17: 645–647.
Younis, M., Seplyarsky, V. and Nestel D. 2013. Olive moth (Prays oleae): an important pest of olives in Israel. Alon Hanotea 67: 36-38 (in Hebrew).
Web sites: http://en.wikipedia.org/wiki/Prays_oleae