Biological control of California red scale, Aonidiella aurantii (Hemiptera: Diaspididae): spatial and temporal distribution of natural enemies, parasitism levels and climate effects

Abstract

A mi padre, fuente constante de inspiración, apoyo y admiración There is a pleasure in a forest without path; there is an ecstasy in a solitarybeach. The bridges of Madison CountyHay un placer en un bosque sin sendero, hay un éxtasis en una playa solitaria. Los puentes de MadisonRobert JamesWaller Note: Present book has been organized so that the main results have been written in the form of scientific articles published in international Journals, or in process of being published. The chapters containing these articles are 4, 5 and 6. All figures, photos and charts were made by the author unless other is indicated in the footnotes.i Summary .In many citrus areas around the world the California red scale (CRS) Aonidiella aurantii (Hemiptera: Diaspididae) is considered a key pest. In eastern Spain it has spread during the last decades up to cover a vast extension of citrus landscapes. The chemical control of CRS is difficult, and is frequently followed by recurrent infestations in a short period, the appearance of resistance to different products used for its control and the elimination of natural enemies present in the field. The improvement of integrated pest management and biological control techniques for CRS requires the knowledge of the natural enemy species composition in each climatic zone, their seasonal fluctuation in abundance, parasitism and predatory levels, how they distribute in the plant, and how they are affected by the climate.Although much has been studied in laboratory about the Aphytis (Hymenoptera: Aphelinidae) parasitoids, the main control agents of CRS, it is still not well-known which combination of natural enemies achieves better host control in the field, how parasitism rate varies along the year or how parasitoids distribute and compete in the field in relation to climate. The action of Aphytis, ectoparasitoids, is complemented in many citrus areas by the endoparasitoids Comperiella bifasciata (Hymenoptera: Encyrtidae) and Encarsia perniciosi (Hymenoptera: Aphelinidae) which can parasitize different scale instars than Aphytis species. Very little is known about the fitness and the biological responses under different climate conditions of these endoparasitoids. Similarly, the impact of predators on the scale population has been rarely studied.Currently, in Eastern Spain, A. melinus, an introduced species and the superior competitor, has displaced the native parasitoid Aphytis chrysomphali from hot and dry areas (inland and southern areas) as it can better tolerate summer hot temperatures. However, in contrast to what it happens in most citrus areas around the world, both A. melinus and A. chrysomphali coexist along the coast. The relative abundance of A. chrysomphali increases from south to north, being in higher percentage in the northern areas where summer is milder. Declining temperatures during autumn and winter have a greater negative effect on A. melinus than A. chrysomphali, since the indigenous A. chrysomphali is more cold-tolerant and better adapted to these ii weather condit...

Evaluation of d-Limonene and β-Ocimene as Attractants of Aphytis melinus (Hymenoptera: Aphelinidae), a Parasitoid of Aonidiella aurantii (Hemiptera: Diaspididae) on Citrus spp.

“…This is economically important as the presence of this scale on fruit considerably reduces their market value, causing huge economic losses [7]. Chemical control of A. aurantii is difficult and is frequently followed by reinfestation within a short period, resistance to different products used for its control, and the risk of eliminating natural enemies present in the field [8].…”