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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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Related in: MedlinePlus

Sample distances within intertidal zones along the mud or ripple plain where biting midge larvae populations were located.
© Copyright Policy - open-access
Related In: Results  -  Collection

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f2-ijerph-08-01560: Sample distances within intertidal zones along the mud or ripple plain where biting midge larvae populations were located.

Mentions: Furthermore, the larvae were found in large numbers within the 0–20 m zones over the sandy and ripple plains. A Kruskal-Wallis test showed that there was a significant association between the distance within the intertidal zones sampled and the abundance of larvae present (χ2 = 53.894, p ≤ 0.001). A chi square test for independence showed there was a significant association between larvae presence/absence with distance zones over the sandy ripple plain (χ2 = 71.752, p ≤ 0.001) (Figure 2).


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)

Sample distances within intertidal zones along the mud or ripple plain where biting midge larvae populations were located.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f2-ijerph-08-01560: Sample distances within intertidal zones along the mud or ripple plain where biting midge larvae populations were located.
Mentions: Furthermore, the larvae were found in large numbers within the 0–20 m zones over the sandy and ripple plains. A Kruskal-Wallis test showed that there was a significant association between the distance within the intertidal zones sampled and the abundance of larvae present (χ2 = 53.894, p ≤ 0.001). A chi square test for independence showed there was a significant association between larvae presence/absence with distance zones over the sandy ripple plain (χ2 = 71.752, p ≤ 0.001) (Figure 2).

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