[Edited_by_A._Ciancio,_C.N.R.,_Bari,_Italy_and_K.(Bookos.org)

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L. ZAPPALÀ
(Hymenoptera: Aphelinidae) introduced in Italy from California in 1973 (Viggiani
& Mazzone, 1978). The entomophagous was distributed throughout the main citrus
growing areas of Southern Italy using plants or parts of plants bearing Citrus
whitefly parasitized colonies. It permanently established and managed to effectively
control the populations of the pest which rapidly became a species of minor
importance in Italian citrus orchards (Longo et al., 1994).
In 1990 the Japanese bayberry whitefly, P. myricae, was reported for the first
time in Italy (Rapisarda, Siscaro, Leocata, & Asero, 1990). This polivoltine,
polyphagous homopteran, with a strong tendency to parthenogenesis, is highly
efficient in colonizing new areas. It mainly develops on new shoots and frequently
lays eggs along the leaf margin which at maturity show a typical serrate aspect.
Several parasitoids, such as the aphelinids C. noacki and Encarsia meritoria Gahan,
adapted to develop on this whitefly without, however, successfully containing its
populations. Therefore, in order to enlarge the parasitic complex, the aphelinid
Eretmocerus debachi Rose & Rosen was imported from Israel in several citrus
growing regions. The newly introduced entomophagous established, rapidly reached
parasitization levels of 20–30% and showed a remarkable spreading capacity.
Thanks to these characteristics the endoparasitoid managed to successfully control
the whitefly as it had already happened in other Mediterranean citrus growing areas
(Rose, De Bach, & Woolley, 1981). The Japanese bayberry whitefly is now only
very rarely present in citrus orchards and no chemical treatment is required, because
of the effective control performed by its natural enemies.
Finally, other pests, which are normally considered as secondary since they are
kept under control by a rational agronomic management of the orchard, by a reduced
use of pesticides and by an effective natural enemies complex, are: the soft scales
Ceroplastes rusci, Coccus hesperidum L. and Saissetia oleae, the armoured scale
Parlatoria pergandii, the moths Prays citri Mill. and Archips rosanus. Three species
of aphids [Aphis spiraecola, A. gossypii and Toxoptera aurantii (B.d.F.)] are
considered particularly noxious to young and regrafted trees. However, the direct
damage caused by these pests is by far less important than the indirect damage
related to their capacity of transmitting viral diseases and namely the Citrus Tristeza
Virus. In particular A. gossypii is considered, in the Mediterranean basin as well as
in other citrus growing regions of the world, the main vector of this virus in those
areas where its most efficient specific aphid vector (Toxoptera citricidus) is still
absent (Bar-Joseph & Loebenstein, 1973; Yokomi, Joost, & Backus, 2005).
REFERENCES
Argov, Y. (2000). Biological control of Phyllocnistis citrella in Israel. Proceedings of the 9th
International Citrus Congress, 829–831.
Argov, Y., & Rössler, Y. (1996). Introduction, release recovery of several exotic natural enemies for
biological control of the citrus leafminer, Phyllocnistis citrella, in Israel. Phytoparasitica, 24, 33–38.
Argov, Y., & Rössler, Y. (1998). Rearing methods for the citrus leafminer, Phyllocnistis citrella Stainton
and its parasitoids in Israel. Biological Control, 11, 18–21.
Argov, Y., Rössler, Y., & Rosen, D. (1995). Estado y perspectives para el control del minador de las
hojas de los citricos en Israel. Phytoma España, 72, 146–148.