INVESTIGADORES
CABRERA Gabriela Myriam
congresos y reuniones científicas
Título:
Identification of chemical cues from the larvae of Scarabaeidae that mediate the host-seeking behaviour by the larva of the robber fly Mallophora ruficauda (Diptera: Asilidae).
Autor/es:
CASTELLO MARCELA K; GALLARDO GABRIELA L.; CABRERA GABRIELA M.
Lugar:
Tours, Francia
Reunión:
Congreso; 26th Annual Meeting of the International Society of Chemical Ecology; 2010
Resumen:
For parasitoids host finding is a central problem that has been solved through a variety of behavioural mechanisms. Among species in which females do not contact directly the host, as in many dipteran parasitoids, larvae ha.ve to locate the host in the habitat through chemical cues. Mallophora ruficauda is a pestiferous species common to the open grasslands of the Pampas region of South America. Adults are predators of bees and larvae are solitary parasitoids of soil-dwelling scarab beetle larvae (Coleoptera: Scarabaeidae). Host searching in M. ruficauda is carried out by both larvae and adults. Females lay eggs in clusters on tall grasses. Upon eclosion, larvae fall to the ground, moult to the second instar and actively search for their hosts using chemical cues that originate in the posterior half of the host's body. There are 9 species of potential hosts in the distribution area of this parasitoid. A high preference has been observed for Cyclocephala signaticollis (87% of field parasitism), although the fly parasites other species. The aims of this work were to describe the chemical profile of all potential host species using body homogenates and GC analysis, and to determine which homogenates are attractive for the larvae through behavioral assays in a stationary olfactometer. Analytical procedures revealed the presence of large saturated hydrocarbons in the homogenates as potential components of the attractive cue. Also, the larvae of M. ruficauda showed positive orientation to 4 homogenates, and these results were concordant with the presence of these compounds in the chromatograms.Mallophora ruficauda is a pestiferous species common to the open grasslands of the Pampas region of South America. Adults are predators of bees and larvae are solitary parasitoids of soil-dwelling scarab beetle larvae (Coleoptera: Scarabaeidae). Host searching in M. ruficauda is carried out by both larvae and adults. Females lay eggs in clusters on tall grasses. Upon eclosion, larvae fall to the ground, moult to the second instar and actively search for their hosts using chemical cues that originate in the posterior half of the host's body. There are 9 species of potential hosts in the distribution area of this parasitoid. A high preference has been observed for Cyclocephala signaticollis (87% of field parasitism), although the fly parasites other species. The aims of this work were to describe the chemical profile of all potential host species using body homogenates and GC analysis, and to determine which homogenates are attractive for the larvae through behavioral assays in a stationary olfactometer. Analytical procedures revealed the presence of large saturated hydrocarbons in the homogenates as potential components of the attractive cue. Also, the larvae of M. ruficauda showed positive orientation to 4 homogenates, and these results were concordant with the presence of these compounds in the chromatograms.M. ruficauda is carried out by both larvae and adults. Females lay eggs in clusters on tall grasses. Upon eclosion, larvae fall to the ground, moult to the second instar and actively search for their hosts using chemical cues that originate in the posterior half of the host's body. There are 9 species of potential hosts in the distribution area of this parasitoid. A high preference has been observed for Cyclocephala signaticollis (87% of field parasitism), although the fly parasites other species. The aims of this work were to describe the chemical profile of all potential host species using body homogenates and GC analysis, and to determine which homogenates are attractive for the larvae through behavioral assays in a stationary olfactometer. Analytical procedures revealed the presence of large saturated hydrocarbons in the homogenates as potential components of the attractive cue. Also, the larvae of M. ruficauda showed positive orientation to 4 homogenates, and these results were concordant with the presence of these compounds in the chromatograms.Cyclocephala signaticollis (87% of field parasitism), although the fly parasites other species. The aims of this work were to describe the chemical profile of all potential host species using body homogenates and GC analysis, and to determine which homogenates are attractive for the larvae through behavioral assays in a stationary olfactometer. Analytical procedures revealed the presence of large saturated hydrocarbons in the homogenates as potential components of the attractive cue. Also, the larvae of M. ruficauda showed positive orientation to 4 homogenates, and these results were concordant with the presence of these compounds in the chromatograms.ruficauda showed positive orientation to 4 homogenates, and these results were concordant with the presence of these compounds in the chromatograms.