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

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L. ZAPPALÀ
encyrtid A. citricola, native to Taiwan, Thailand and Vietnam, has been used in
biological control programs in several citrus regions: Algeria, Argentina, Australia,
Bahamas, Brazil, Cyprus, Colombia, Florida, Greece, Honduras, Israel, Louisiana,
Morocco, Mexico, Oman, Peru, Syria, Spain, Texas, Tunisia, Turkey and Venezuela
(Berkani & Mouats, 1998; Schauff et al., 1998; Siscaro, Longo, & Mineo, 2000).
Figure 5. Ageniaspis citricola, ovipositing adult female.
In Italy, the encyrtid has been introduced and reared since 1995 (Siscaro,
Barbagallo, Longo, & Patti, 1997; Siscaro & Mazzeo, 1997). Nearly 15,000 adults
have been released in Eastern Sicily and Calabria during 1996–2000 (Siscaro,
Longo, & Mineo, 2000). The species was recovered in some coastal lemon orchards
where it overwintered in 1998 (Siscaro et al., 1999a) and this strain, collected in the field,
has been reared and released in the following years, although without any permanent
establishment (Siscaro, Barbagallo, Longo, Reina, & Zappalà, 1999b). The encyrtid is,
however, one of the major CLM antagonists in several countries (Argentina, Australia,
Bahamas, Brazil, Canary Islands, Florida, Honduras, Louisiana and Venezuela), where it
has permanently established. Therefore A. citricola appears to be climatically adapted to
humid tropical and subtropical climates (Hoy & Nguyen, 1997).
Laboratory observations have shown that the species, at the pupal stage, has a great
resistance to low temperatures (5–10°C); adults survive longer at 10°C while individuals
exposed to temperatures higher than 25°C die in less than 24 h. High mortality of adults
at 25–35°C suggests that the parasitoid is unsuitable to the biological control of P.
citrella in Mediterranean citrus orchards (Zappalà & Siscaro, 2004).
Quadrastichus citrella is an ectoparasitoid of CLM second and third instar
larvae. Its biological cycle lasts about 20 days at 20°C and R.H. > 80%. At the same
temperature the adults survive up to 40 days (Argov & Rössler, 1998; Llácer,