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Screening of oomycete fungi for their potential role in reducing the biting midge (Diptera: Ceratopogonidae) larval populations in Hervey Bay, Queensland, Australia.

Stephen K, Kurtböke DI - Int J Environ Res Public Health (2011)

Bottom Line: These results were then correlated to local environmental conditions and naturally occurring entomopathogenic fungal flora, in particular the Oomycete fungi, to determine their reducing effect on insect immature stages in the search for biological control agents in the region.Within this intertidal zone, the presence of C. subimmaculatus larvae was found to be influenced by both sediment size and distance from shore.However, the association was found to be surface colonization rather than invasion causing the death of the host.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, QLD 4558, Australia. kirsty.stephen@gmail.com

ABSTRACT
Biting midges are globally distributed pests causing significant economic losses and transmitting arbovirus diseases to both animals and humans. Current biological and chemical control strategies for biting midge target destruction of adult forms, but strategies directed at immature stages of the insect have yet to be explored in Australia. In the present study, coastal waters of Hervey Bay region in Queensland, Australia were screened to detect the habitats of biting midge at immature stages. These results were then correlated to local environmental conditions and naturally occurring entomopathogenic fungal flora, in particular the Oomycete fungi, to determine their reducing effect on insect immature stages in the search for biological control agents in the region. The dominant species of biting midge found within this study was Culicoides subimmaculatus occuring between mean high water neaps and mean high water spring tide levels. Within this intertidal zone, the presence of C. subimmaculatus larvae was found to be influenced by both sediment size and distance from shore. Halophytophthora isolates colonized both dead and alive pupae. However, the association was found to be surface colonization rather than invasion causing the death of the host. Lack of aggressive oomycete fungal antagonists towards midge larvae might correlate with increased incidences of biting midge infestations in the region.

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(a) Growth patterns of Halophytophthora isolates; (b) Sporangia produced by some of the Halophytophthora isolates; (c) Zoospores of a Halophytophthora isolate.
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Related In: Results  -  Collection

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f4-ijerph-08-01560: (a) Growth patterns of Halophytophthora isolates; (b) Sporangia produced by some of the Halophytophthora isolates; (c) Zoospores of a Halophytophthora isolate.

Mentions: Twenty-six marine Halophytophthora isolates were isolated from Hervey Bay; all resulting from leaf samples of varying decomposition, collected throughout individual transects (Table 2, Figures 4a, b, and c). Halophytophthora isolates were detected mostly in environments with median salinity of 33.16 ppt, temperature of 22.38 °C, and a pH of 7.78 (Table 3).


Screening of oomycete fungi for their potential role in reducing the biting midge (Diptera: Ceratopogonidae) larval populations in Hervey Bay, Queensland, Australia.

Stephen K, Kurtböke DI - Int J Environ Res Public Health (2011)

(a) Growth patterns of Halophytophthora isolates; (b) Sporangia produced by some of the Halophytophthora isolates; (c) Zoospores of a Halophytophthora isolate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3108127&req=5

f4-ijerph-08-01560: (a) Growth patterns of Halophytophthora isolates; (b) Sporangia produced by some of the Halophytophthora isolates; (c) Zoospores of a Halophytophthora isolate.
Mentions: Twenty-six marine Halophytophthora isolates were isolated from Hervey Bay; all resulting from leaf samples of varying decomposition, collected throughout individual transects (Table 2, Figures 4a, b, and c). Halophytophthora isolates were detected mostly in environments with median salinity of 33.16 ppt, temperature of 22.38 °C, and a pH of 7.78 (Table 3).

Bottom Line: These results were then correlated to local environmental conditions and naturally occurring entomopathogenic fungal flora, in particular the Oomycete fungi, to determine their reducing effect on insect immature stages in the search for biological control agents in the region.Within this intertidal zone, the presence of C. subimmaculatus larvae was found to be influenced by both sediment size and distance from shore.However, the association was found to be surface colonization rather than invasion causing the death of the host.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC, QLD 4558, Australia. kirsty.stephen@gmail.com

ABSTRACT
Biting midges are globally distributed pests causing significant economic losses and transmitting arbovirus diseases to both animals and humans. Current biological and chemical control strategies for biting midge target destruction of adult forms, but strategies directed at immature stages of the insect have yet to be explored in Australia. In the present study, coastal waters of Hervey Bay region in Queensland, Australia were screened to detect the habitats of biting midge at immature stages. These results were then correlated to local environmental conditions and naturally occurring entomopathogenic fungal flora, in particular the Oomycete fungi, to determine their reducing effect on insect immature stages in the search for biological control agents in the region. The dominant species of biting midge found within this study was Culicoides subimmaculatus occuring between mean high water neaps and mean high water spring tide levels. Within this intertidal zone, the presence of C. subimmaculatus larvae was found to be influenced by both sediment size and distance from shore. Halophytophthora isolates colonized both dead and alive pupae. However, the association was found to be surface colonization rather than invasion causing the death of the host. Lack of aggressive oomycete fungal antagonists towards midge larvae might correlate with increased incidences of biting midge infestations in the region.

Show MeSH
Related in: MedlinePlus