Foraging behaviours of Diachasmimorpha kraussii (Fullaway) (Hymenoptera: Braconidae) and its host Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) in a nectarine (Prunus persica (L.) Batsch var. nectarina (Aiton) Maxim) orchard

Abstract

Foraging behaviours of Diachasmimorpha kraussii (Fullaway) (Hymenoptera: Braconidae) and its host Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) in a nectarine (Prunus persica (L.) Batsch var. nectarina (Aiton) Maxim) orcharda en_821 234..240 AbstractDiachasmimorpha kraussii is a larval parasitoid of dacine fruit flies. Host utilisation behaviour, including field foraging behaviour, is poorly known in this species. The diurnal foraging behaviour of D. kraussii and one of its common hosts, Bactrocera tryoni, in a nectarine orchard was concurrently recorded. Observations of mating, resting, feeding and oviposition were taken two-hourly on 42 trees, commencing at 07:00 h and terminating at 17:30 h, for 17 days. Resting and oviposition were common events within the orchard for both species, while mating behaviours were not recorded in the orchard for either species. Feeding was not observed for D. kraussii and was rare for B. tryoni. At the level of the individual tree there was a very weak, but significant correlation between parasitoid and fly abundance over a day, but when broken down to the individual observation periods the correlations were absent, or were weakly significant in an inconsistent manner (i.e. sometimes positively correlated, sometimes negatively correlated). At the orchard level, abundance of the parasitoid was not correlated with adult fly abundance. Results suggest that D. kraussii forage independently to adult B. tryoni, a result consistent with a prediction that their foraging is largely driven by larval or plant damage cues.

Resting sites, edge effects and dispersion of a polyphagous Bactrocera fruit fly within crops of different architecture

“…The lack of female sampling in the strawberry study is a weakness, but we do not think critically so for interpreting the data. A close correlation between male and female B. tryoni numbers has been previously demonstrated in field studies (Clarke and Dominiak 2010;Ero et al 2011) and was again found in the apple orchards. Thus, while the strawberry and apple studies show different patterns of fly distribution, we do not think it is because of sex-biased sampling.…”

“…5), the answer to this may well be preferred resting sites. Bactrocera tryoni is known to spend a large percentage of its time resting (Weldon et al 2010;Ero et al 2011). While a preference for particular resting sites based on plant architecture has not been previously demonstrated for this species, it has for other tephritid fruit flies including Rhagoletis indifferens (Senger et al2009) and R. completa (Guill en et al 2011), Toxotrypana curvicauda (Aluja et al 1997) and several Bactrocera and Dacus species (Raghu et al 2004; et al 2012).…”

“…; Ero et al. ). While a preference for particular resting sites based on plant architecture has not been previously demonstrated for this species, it has for other tephritid fruit flies including Rhagoletis indifferens (Senger et al …”

The mating system of the true fruit flyBactrocera tryoniand its sister species,Bactrocera neohumeralis

“…There has been direct conflict in the literature on whether Bactrocera species have a resource, or nonresource, based mating system (for supportive papers of resource‐based mating systems see Drew & Lloyd, ; Drew et al ., ; for nonsupportive papers see Raghu et al ., ; Ero et al ., ). We found no evidence for a resource‐based mating system in our direct test which simultaneously offered “fruiting” and “nonfruiting” plants.…”

From laboratory to the field: consistent effects of experience on host location by the fruit fly parasitoid Diachasmimorpha kraussii (Hymenoptera: Braconidae)

“…Gourmet premium). The two fruit types are both major hosts of B. tryoni (Hancock et al, 2000) and the wasp is known to orientate to both (Ero et al, 2011a;Ero & Clarke, 2012). All fruits had an average weight of 120 ± 10 g. Before use, fruit was wiped with a weak antifungal solution of nipagin 2.5 g/L water and then washed in tap water.…”