LIBRO-CONGRESO-CITRUS

S16
in the area, the California Red Scale (CRS) Aonidiella aurantii (Maskell). A surface area of 66 ha surrounding the
main urban area was selected for study in 2010. The alternative to the use of synthetic organic pesticides was
the mass release of biological control agents (Aphytis melinus DeBach (Aphelinidae), Rhyzobius lophanthae
(Blaisdell)(Coccinellidae) and Comperiella bifasciata (Howard) (Encyrtidae) and the application of essential oil
(Orizone®) when population of CRS reached a threshold of 2% infested fruits. Additionally, a cover crop was
mechanically managed in a 30 ha surface area and -beneficial fauna identified. The results showed that the
intervention threshold was not reached in 93% of the surface area due to the biological control exerted by the
parasitoid releases as well as by the activity of naturally occurring populations of beneficial insects.
In 2011 we analyzed the real effect of mass releases of A. melinus, considering the high levels of native fauna
observed in the previous year. Different release rates, ranging from 0 to 100,000 A. melinus/ha, were compared.
No differences were observed between orchards with or without releases, nor among different levels of release.
These results confirm the importance of conservation biological control strategies in CRS management.
S16P14
Hyperparasitism may prevent efficient regulation of Aphis spiraecola Patch. (Homoptera:
Aphididae) in citrus orchards by primary parasitoids.
Gómez-Marco F. 1 , Tena A. 1 , Jacas J.A. 2 , and Urbaneja A. 1
1 Instituto Valenciano de Investigaciones Agrarias (IVIA), Unidad Asociada de Entomología UJI-IVIA; Departamento de Entomología,
Spain; and 2 Universitat Jaume I (UJI), Unitat Associada d’Entomologia IVIA-UJI, Spain. fmgomez@ivia.es
Aphis spiraecola Patch., is a key pest of clementine mandarins in Spain. The biological control of this species
is far from satisfactory and we have tried to unravel the reasons for this failure. We sampled mummies of A.
spiraecola during the spring population that this species exhibits in Valencia and kept them until emergence
of the developing parasitic wasp. At least two plausible explanations for deficient biological control have
been found. On the one hand, very few parasitoid species (n=440) could complete their development in this
aphid. Parasitic wasps belonging to the genus Trioxys were the only specimens successfully reared out of
these mummies. Percent parasitism by these wasps accounted for 14 % of total mummies caught. On the
other, hyperparasitism was extremely high (67%) and Syrphophagus aphidivorus, a primary hyperparasitoid,
alone represented more than 55% of all hyperparasitoids found. Molecular tools could probably help to shed
light into the complicated trophic relationships established among A. spiraecola parasitic guild. Disentangling
these relationships will probably pave the way for improving the biological control of this species.
S16P15
Citrus mealybug biological control strategies and large scale implementation on citrus in Turkey.
Erkilic L.B., Demirbas H., and Guven B.
Biological Agriculture Consulting and Engineering Co (BIYOTAR), Biological Control, Turkey. lerzane@superonline.com
Citrus Mealybug, Planococcus citri (Risso) (Hem.: Pseudococcidae) is one of the main pests on citrus in Turkey.
Since 1970 biological control implementation in citrus orchards continue on Citrus mealybug with Cryptolaemus
montrouzieri Mulsant (Col.:Coccinellidae) and Leptomastix dactylopii Howard (Hym.:Encyrtidae). The interests
in biological control tend to be increase due to human and environmental health, food safety and pesticide
residue issues. The application dosages of C. montrouzieri and L. dactylopii range between 10 to 20 individuals
per tree according to the mealybug population level and also the citrus variety. The main strategy is to use
both beneficials C. montrouzieri and L. dactylopii at the early stage of mealybug population. L. dactylopii
can be released at the beginning of mealybug population build up, before mealybug egg production, and C.
montrouzieri should be released when the mealybug population is producing eggs. If the mealybug population
has both, adults and egg masses, then both beneficials should be released together. In large scale application
the early usage sometimes is not possible, because other main pests such as the California Red Scale and
Rust mite are present and chemical applications may take place at the beginning of season. In this case a
compatible pesticide use is preferred to carry out the biological control releases.
In Turkey due to food safety reasons and also Min. of Agriculture subvention given for the usage of biological
control agents would be increase the application area in coming future.
288 - VALENCIA CONFERENCE CENTER, 18th-23rd NOVEMBER 2012