Exposure to competitors influences parasitism decisions in ectoparasitoid fly larvae

Behavioural plasticity induced by intraspecific competition in host orientation in a parasitoid

“…The few studies that have addressed this issue show that pre-parasitism competition can influence foraging decisions (Visser et al, 1992;Goubault et al, 2005;Crespo et al, 2015). However, all of them assume that the individual can somehow acquire or estimate information on the current state of the habitat.…”

“…In the case of M. ruficauda, it has been seen that the order of parasitism events do not determine which larva wins competition (Barrantes, 2009). However, when larvae are raised in an environment with a large amount of competitors, orientation and acceptance of poor-quality hosts increase (Crespo & Castelo, 2009;Crespo et al, 2015). Mallophora ruficauda can discriminate its host regarding its parasitism status and indeed they can recognise but are not attracted to parasitised hosts when raised individually.…”

“…One aspect of the way in which parasitoids can perceive information on host abundance that has received less attention is the influence of conspecifics prior to foraging or parasitising a host. The few studies that have addressed this issue show that pre-parasitism competition can influence foraging decisions (Visser et al, 1992;Goubault et al, 2005;Crespo et al, 2015). Pre-parasitism competition can modify parasitoid strategies like retreating from a patch, increased superparasitism or acceptance of poor-quality hosts (Royer et al, 1999;Goubault et al, 2005;Crespo et al, 2015).…”

“…The few studies that have addressed this issue show that pre-parasitism competition can influence foraging decisions (Visser et al, 1992;Goubault et al, 2005;Crespo et al, 2015). Pre-parasitism competition can modify parasitoid strategies like retreating from a patch, increased superparasitism or acceptance of poor-quality hosts (Royer et al, 1999;Goubault et al, 2005;Crespo et al, 2015). Retreating from a patch can lead to exploiting a new patch, but accepting poor-quality hosts can incur similar risks to superparasitism.…”

“…Mallophora ruficauda can discriminate its host regarding its parasitism status and indeed they can recognise but are not attracted to parasitised hosts when raised individually. However, when larvae are raised in an environment with a large amount of competitors, orientation and acceptance of poor-quality hosts increase (Crespo & Castelo, 2009;Crespo et al, 2015). Despite the fact that M. ruficauda is a solitary parasitoid and shows high levels of host specificity, data from the field show that superparasitism is common, representing almost 50% of the parasitised hosts (Castelo, 2003).…”