LIBRO-CONGRESO-CITRUS

S16O01
The status of citrus IPM in California
Grafton-Cardwell E. E.
University of California Riverside (UCR), Entomology, USA. eegraftoncardwell@ucanr.edu
Citrus is grown in 4 distinct regions of California and climatic differences influence the citrus varieties grown
and the pests and natural enemies that develop. The heaviest insecticide treatments occur in the San Joaquin
Valley where extremes of heat and cold reduce the efficacy of natural enemies. In the San Joaquin Valley, citrus
thrips Scirtothrips citri and California red scale Aonidiella aurantii have been primary pests for many decades.
Forktailed bush katydid Scudderia furcata and citricola scale Coccus pseudomagnoliarum became primary
pests when selective insecticides replaced organophosphate and carbamate insecticides. San Joaquin Valley
growers maintain their integrated pest management (IPM) program by utilizing low rates of pyrethroids or
organophosphate insecticides for katydids and applying organophosphates for citricola scale in alternate years
– resulting in an average of 3-4 treatments for all pests per year. In 2008, the Asian citrus psyllid, Diaphorina
citri, was discovered and in 2012 huanglongbing disease was found in California. While the majority of find
sites of the psyllid have been in residential areas of the state, it is expected that the pest and disease will
become established in commercial citrus in the near future. Because the disease is difficult to detect when
trees first become infected and there is no cure for the disease, psyllid population reduction in combination
with infected tree removal is currently the most effective strategy for preventing disease spread. Because
the most effective treatments for Asian citrus psyllid are broad spectrum in nature, California citrus IPM
will experience major disruptions. Regional differences in the risk of Asian citrus psyllid and huanglongbing
establishment and the impact of treatments for the psyllid on the IPM program are discussed.
S16O02
The status of citrus IPM in South Africa
Grout T.G.
Citrus Research International (CRI), Nelspruit, South Africa. tg@cri.co.za
Four years ago citrus IPM in South Africa was largely defined by the use of biorational control strategies such as
microbial control, sterile insect release, mating disruption, attract-and-kill and soil- and stem-applied systemics.
This is still the case but pressure from export markets on quarantine pests and diseases has increased, together
with further residue restrictions. Due to concerns about citrus black spot, Guignardia citricarpa, mancozeb
applications have increased in the Eastern Cape province and are likely responsible for a decline in numbers of the
phytoseiid mite Euseius addoensis. This has resulted in greater populations of citrus thrips, Scirtothrips aurantii,
early in the season and led to the use of longer-residual thripicides such as chlorfenapyr. This product is harmful to
both phytoseiids and hymenopterous parasitoids of quarantine pests such as certain mealybug species and false
codling moth (FCM), Thaumatotibia leucotreta. Attempts to redress these imbalances are sometimes made by
releasing the FCM parasitoid Trichogrammatoidea cryptophlebiae and Coccidoxenoides perminutus for mealybug,
but the latter is not very effective against indigenous mealybug species. Although California red scale (CRS),
Aonidiella aurantii, is not a quarantine pest for most export markets, it must be controlled preventively where
biological control is compromised by disruptive thripicides. This requirement, coupled with the increased price
of spray oil, has resulted in widespread use of generic imidacloprid SC formulations as soil drenches. Although
spirotetramat was recently registered in South Africa for the control of CRS and it appears to be IPM-compatible,
its cost is high relative to other scalicides. The only new citrus pest that has become established in the last four
years is the woolly whitefly, Aleurothrixus floccosus. The fruit fly Bactrocera invadens has spread throughout the
rest of Africa south of the Sahara but is not yet established in South Africa.
S16O03
Integrated pest management in Spanish citrus: current status of biological control.
Urbaneja A. 1 , Tena A. 1 , and Jacas J.A. 2
1 Instituto Valenciano de Investigaciones Agrarias (IVIA), Protección Vegetal y Biotecnología, Spain; and 2 Universitat Jaume I (UJI),
Cièncias Agràries i del Medi Natural, Spain. aurbaneja@ivia.es
Biological control has been and will definitively continue to be an increasingly important part of citrus crop
protection practices in Spain and elsewhere. Classical Biological Control (BC) has been actively practiced in
XII INTERNATIONAL CITRUS CONGRESS 2012 - 275
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