Orientation by gravid Australian sheep blowflies, <i>Lucilia cuprina</i> (Diptera: Calliphoridae), to fleece and synthetic chemical attractants in laboratory bioassays

Abstract. A comprehensive simulation model for sheep blowfly strike due to Lucilia sericata (Meigen) (Diptera: Calliphoridae), which builds on previously published versions but also incorporates important new empirical data, is used to explain patterns of lamb and ewe strike recorded on 370 farms in south-west, south-east and central England and Wales. The model is able to explain a significant percentage of the variance in lamb strike incidence in all four regions, and ewe strike in three of the four regions. The model is able to predict the start of seasonal blowfly strike within one week in three of the four regions for both ewes and lambs, and within 3 weeks in the fourth region. It is concluded that the accuracy of the model will allow it to be used to assess the likely efficacy of new control techniques and the effects of changes in existing husbandry practices on strike incidence. The model could also be used to give sheep farmers advance warning of approaching strike problems. However, the ability to forecast future strike patterns is dependent on the accuracy of the weather projections; the more long-term the forecast, the more approximate the prediction is likely to be. When applied on a regional basis, model forecasts indicate expected average patterns of strike incidence and may not therefore be appropriate for individual farmers whose husbandry practices differ substantially from the average.

Section: Methodsmentioning

confidence: 99%

Development and validation of a simulation model for blowfly strike of sheep

Wall

Cruickshank

Smith

et al. 2002

“…In recent work, gravid L. cuprina were found to be more attracted to decaying liver than to fresh liver, although the strongest oviposition behaviour was observed on fresh liver (G. Yan, unpublished data). Similarly, gravid flies do not show a preference in attraction between wet and dry wool, although there is a correlation between egg laying and moisture content (Eisemann, ; A. C. Schlink, G. Yan & J. C. Greeff, unpublished data). It is therefore clear that a greater attractiveness for a resource does not guarantee oviposition, and vice versa.…”

Section: Discussionmentioning

confidence: 99%

“…First, only fleece odour was considered as a factor in the present study and so fleece were samples in the season of least flystrike to exclude the effect of other important factors (e.g. dags, urine, faeces and moisture) that are very likely to attract L. cuprina (Eisemann, ; Greeff et al ., ). Previous studies have shown that the attractiveness of wool samples from fly‐struck sheep declines rapidly over time after removal from the sheep (Mackerras & Mackerras, ), ostensibly as a result of the loss of critical attractive volatile compounds.…”

Section: Discussionmentioning

confidence: 99%

Volatiles from Merino fleece evoke antennal and behavioural responses in the Australian sheep blow fly Lucilia cuprina

Yan

Liu

Schlink

et al. 2019

To identify flystrike‐related volatile compounds in wool from Merino sheep, the attractiveness of wool to Lucilia cuprina Wiedmann (Diptera: Calliphoridae) was examined. First, a selection of wool samples guided by previous knowledge of sheep lines, predicted to be more susceptible or more resistant to flystrike, was tested. The attractiveness of the 10 samples selected was not associated with field susceptibility: two samples from the more resistant line were identified as most attractive and two samples from the more susceptible line were identified as least attractive, based on the behavioural assays with gravid flies. Comparison of the headspace volatiles of these samples, using solid phase microextraction and gas chromatography‐mass spectrometry‐electroantennographic detection, revealed octanal and nonanal to be present in the attractive wool samples that elicited responses from the fly antenna. Furthermore, the two compounds were not present in wool that was least attractive to L. cuprina. In laboratory bioassays, octanal and nonanal evoked antennal and behavioural responses in gravid L. cuprina, thus confirming their potential role as semiochemicals responsible for attracting L. cuprina to Merino sheep.

“…The bioassay described here can be contrasted with the olfactometer of Urech et al (1994) and laboratory trapping as described by Eisemann (1985Eisemann ( , 1995, both of which have been used to demonstrate responses to odours in L.cuprina. These two methods tested whether L.cuprinu would congregate towards a concentration of odour, but the mechanism, whether by anemotaxis, chemotaxis, kineses or a combination of all three was not differentiated.…”

Section: Discussionmentioning

confidence: 99%

The responses of Lucilia cuprina to odours from sheep, offal and bacterial cultures

Morris

Joyce

Heath

et al. 1997

The responses of gravid female Lucilia cuprina to odours from sheep urine, faeces and gut mucus, and to odours from liver/sodium sulphide mixtures was tested using a bioassay which measured the movement and probing response of walking flies. The same bioassay was used to test the response to odours from cultures of bacteria isolated from liver/sodium sulphide and liver/water mixtures. A significant movement towards odours from faeces, gut mucus and urine was observed. Odours from cultures of the bacteria Proteus mirabilis, Dermatophilus congolensis and Serratia marcescens also elicited significant movement. A probing response was elicited by odours from gut mucus, fresh urine, liver/sodium sulphide mixtures and cultures of P.mirabilis, D.congolensis and gram-positive species. Odours from cultures of Pseudomonas aeruginosa, Enterobacter aerogenes and Citrobacter freundii did not elicit significant movement or probing. The movement and probing responses are discussed with reference to the possible uses of the substances tested as a bait for attracting L.cuprina.