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

MITE PATHOGENS IN IPM
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in Italy on Phytoptus avellanae, a mite causing big bud disease in ornamental and
fruiting hazel (Corylus avellana). Experiments were carried out with the fungus
isolate from C. ribis to infect the European red mite Panonychus ulmi and the
eriophyids Aceria hippocastani (from horse chestnut) and Cecidophyes galii (from
goosegrass). The fungus proved to be pathogenic for the first two species, but no
infection was obtained in C. galii. The fungus has also been reported by Baker and
Neunzig (1968): high infection rates were noted in the blueberry bud mite Aceria
vaccinii (Eriophyidae) in North Carolina, USA, when high temperatures coincided
with heavy rainfall and high relative humidity. Disease incidence declined from
August onwards, when conditions were less favorable for the fungus. The population
density of the blueberry mites then increased.
One of the earliest experiments in which a fungus was tested against a
phytophagous mite was a field application of B. bassiana spores for the control of
the twospotted spider mite T. urticae (Dresner, 1949). Mites were treated with a dust
containing 0.5% spores of the fungus, resulting in a mortality of 71%. However,
these experiments did not lead to the development of a microbial acaricide.
Deuteromycetes have widely been studied for the control of insect (and in a few
instances mite) pests. A number of these fungi (e.g. Metarhizium, Beauveria) have a
broad host spectrum and can easily be mass produced on relatively simple culture
media. In Brazil, research is being conducted to evaluate several Deuteromycetes as
possible control agent of the twospotted spider mite (Tamai, Alves, Lopes & Neves
1998). They tested 152 different isolates for the fungi B. bassiana, B. brongniartii,
Beauveria sp., Metarhizium sp., Paecilomyces lilacinus and P. farinosus. Only
isolates of Beauveria spp. caused mortality between 35 and 95%. The pathogenicity
of some isolates was further tested: one isolate gave even better control than
obtained with chemical pesticides. The fungus was also effective against other pests
in chrysanthemum, such as thrips and aphids (Alves, Tamai, & Lopes, 1998).
Three different fungus species were investigated by Peña et al. (1996) with
respect to their potential as biological control agent of the broad mite
Polyphagotarsonemus latus (Tarsonemidae). This very polyphagous pest species
thrives under warm and humid conditions, and this seemed to be a good reason to
study the feasibility of using fungi as control agents. Three fungi were tested: B.
bassiana, H. thompsonii and Paecilomyces fumosoroseus under controlled
temperature and humidity conditions in the laboratory and in the greenhouse. All
fungi were capable to infect the mites: higher doses resulted in a faster death of the
mites, while density of the mites also affected disease incidence. The authors
concluded from their experiments that the fungus selected should cause epizootics
within 2–3 days following application. Promising results for the control of the broad
mite on mulberry have been obtained with M. anisopliae by Maketon, Orosz-
Coghlan, and Sinprasert (2008). The fungus is effective against larvae and adults,
but no ovicidal effect was noted. The broad mite has also been found in association
with Hirsutella nodulosa (Peña et al., 1996). No other associations of this mite with
fungi have been reported.
Shi, Feng, and Liu (2008) noted an ovicidal effect of sprays of an emulsifiable
B. bassiana formulation against the twospotted spider mite T. urticae. The fungal
isolate was obtained from mycosed aphids and has been formulated for the control