Presence of Putative Male-Produced Sex Pheromone inLutzomyia cruciata(Diptera: Psychodidae), Vector ofLeishmania mexicana

Abstract

Lutzomyia cruciata (Coquillet) is a vector of cutaneous leishmaniasis in Mexico and Central America. However, several aspects of its ecology and behavior are unknown, including whether a male pheromone partially mediates the sexual behavior of this sand fly. In this study, we evaluated the behavioral response of females to male abdominal extracts in a Y-tube olfactometer. The volatile compounds from male abdominal extracts were identified by gas chromatography-mass spectrometry and compared with those of female abdominal extracts. Finally, the disseminating structures of the putative sex pheromone were examined by scanning electron microscopy in the male abdomen. Females were more attracted to male abdominal extract than to the hexane control, suggesting the presence of male-produced sex pheromone. The male abdominal extracts were characterized by the presence of 12 sesquiterpene compounds. The major component, an unknown sesquiterpene with an abundance of 60%, had a mass spectrum with molecular ion of m/z 262. In contrast, the abdominal female extracts contained saturated fatty acids. Finally, we detected the presence of small "papules" with a mammiform morphology distributed on the abdominal surface of tergites IV-VII of male Lu. cruciata These structures are not present in females. We conclude that Lu. cruciata males likely produce a pheromone involved in attracting or courting females.

An overview of studies on sex pheromones of insect vectors of pathogenic trypanosomatids of medical and veterinary importance

“…Papules of Lutzomyia pessoai are similar to those found in L. longipalpis and L. cruzi although they are distributed from III to VII tergal segments (Ward et al, 1993). Whereas in Lutzomyia cruciata the disseminating structures presented a mammiform appearance and they are located in IV-VII tergites (Serrano et al, 2016).…”

A temporal comparison of sex-aggregation pheromone gland content and dynamics of release in three members of the Lutzomyia longipalpis (Diptera: Psychodidae) species complex

“…carmelinoi [ 19 ] and L . cruciata [ 20 ]. They have also been found in the closely related genus Sergentomyia , e.g.…”

Interior of sand fly (Diptera: Psychodidae) abdomen reveals novel structures involved in pheromone release: discovering the Manifold

“…For example, in Evandromyia lenti and E. carmelinoi, appleshaped structures (2.7±0.1 µm in diameter x 1.6±0.1 µm in height and 2.5±0.2 µm in diameter and 1.2±0.2 µm in height respectively) with a central pore are present on the V and VI tergal segments (Spiegel et al 2002). Terpenoids including oxygenated compounds are produced in some of these other species, but they do not appear to be present in all those that have structures (Hamilton et al 2002;Hamilton et al 1999;Serrano et al 2016) and behavioural evidence for pheromonal activity for any of these compounds is lacking. SEM analysis of the tergal structures in M. migonei have revealed that they form of a shallow crater (average diameter ca.…”