Detection of Acaromyces ingoldii, an acaropathogenic fungus, on citrus rust mite (Phyllocoptruta oleivora) in the Çukurova Region of Turkey and its efficacy under growth chamber conditions


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SATAR S. , Lafcı M., Doylu E., AKGÜL D. S.

7th International Entomopathogens and Microbial Control Congress, Kayseri, Turkey, 11 - 13 September 2019, pp.21

  • Publication Type: Conference Paper / Summary Text
  • City: Kayseri
  • Country: Turkey
  • Page Numbers: pp.21

Abstract

Citrus rust mite, Phyllocopturuta oleivora (Ashmead), is one of the most important pests in citrus groves of the Çukurova Region, Turkey. Initially, it causes tiny spots on young fruits, then fruits become darker, till they are completely brown and typical shark skin symptoms appear. These fruits would not marketable and growers would account with economical losses. Chemical spray is the only method used by citrus growers to control citrus rust mite in the Çukurova Region.  In 2018 September, a variety of fungal contaminations has been observed on the adults of this pest, on a Washington Navel orange grove located in Havutlu, Adana, Turkey. Under a stereo microscope, the adults and larvae have been observed to be covered with a creamy mycelium and it was estimated to be an acaropathogenic infection. The fungus was directly isolated by transferring contaminated adults on potato dextrose agar (PDA). After that, light brown, superficial, slow growing fungal colonies were observed around dead adults and mycelia were sub-cultured to fresh PDA for further examinations. Mycelium type, colony-conidium morphology and conidial dimensions were detailed and photographed under light microscope. For molecular identification, DNA was extracted from mycelial mats, ribosomal DNA fragments (ITS regions) were amplified with ITS4-ITS5 primers and PCR products were sequenced. The sequence was compared with those deposited in NCBI Gene Bank database and the fungus was identified as Acaromyces ingoldii (Basidiomycota). Conidial suspension (1x107 conidia·ml-1) of fungus was sprayed on citrus rust mite infested orange fruits and the eggs, nymphs and adults were examined for fungal parasitism and mortality after 1h, 12h, 1, 4, 7, 10 and 14 days later, under growth chamber conditions (25°C, 80% RH). The results indicated that A. ingoldii might be a potential acaropathogenic species for biological control of citrus rust mite. To our knowledge, this is the first record of A. ingoldii causing acaropathogenic infections on P. oleivora in Turkey.