Metasternal Gland Volatiles and Sexual Communication in the Triatomine Bug, Rhodnius prolixus

Abstract

Twelve compounds produced by the metasternal glands (MGs) of the triatomine bug Rhodnius prolixus were identified by solid phase microextraction (SPME) combined with coupled gas chromatography-mass spectrometry (GC-MS) using achiral and chiral columns. All substances were ketones or alcohols, and the same compound profile was found in the secretions produced by either sex. The most abundant compounds were 2-methyl-3-buten-2-ol, (2S)-pentanol, (3E)-2-methyl-3-penten-2-ol, and (2R/2S)-4-methyl-3-penten-2-ol. Emission of these compounds was detected more frequently from females than males, and females released them more frequently during the early hours of the scotophase, the period when sexual activity in this species is at its peak. These compounds were also detected in the headspace above mating pairs. Finally, the occlusion of the MG orifices of male or female bugs with paraffin resulted in a significant decrease in copulation frequency compared to sham-operated insects. Together, these data suggest that the MG secretions of R. prolixus may be involved in sexual communication.

The Sexual Behaviour of Chagas' Disease Vectors: Chemical Signals Mediating Communication between Male and Female Triatomine Bugs

“…Because the attractiveness of mating pairs decreased after occluding female metasternal glands, it was suggested that females emit volatile compounds that promote both copulation and male aggregation behaviour. Similar results were obtained with R. prolixus, in which occlusion of male or female metasternal gland orifices induced a decrease in copulation success [16]. Recently, Pontes and Lorenzo [47] have shown that the occlusion of R. prolixus female metasternal glands also prevented male aggregation around mating pairs, whereas the occlusion of male metasternal glands did not affect male aggregation.…”

“…Table 2 summarizes metasternal gland compounds detected in the headspace odours of triatomine bugs in different behavioural contexts. As mentioned, it has been proposed that metasternal gland components may mediate sexual communication between [30] R. prolixus [16] T. brasiliensis [34] T. brasiliensis T. infestans [37] 2-butanone adults of these species [30,34,47]. In T. infestans, the metasternal glands produce a number of volatiles, including the main component 3-pentanone, which was detected in the odours from copulating pairs [30].…”

“…It has been demonstrated that odours from the metasternal glands promote mating in T. infestans and R. prolixus [15,16]. In addition to the volatile compounds secreted by the metasternal glands, it has been suggested that epicuticular lipids may play a role as female recognition signals (i.e., contact pheromones) in T. Infestans, but this needs to be confirmed [17].…”

Biology, diversity and strategies for the monitoring and control of triatomines - Chagas disease vectors

“…This ample knowledge reported by the authors indicates that the development of sampling or detection devices can be based on solid information. Other aspects of triatomine behaviour, such as aggregation and sexual signals, are being studied and may generate further alternatives for interfering with insect communication processes and manipulating their behaviour (Lorenzo et al 2000, Manrique et al 2006, Pontes et al 2008.…”

The Spider Orchid Caladenia crebra Produces Sulfurous Pheromone Mimics to Attract its Male Wasp Pollinator

“…Compounds 2-4 (Figure 2), all ortho-(methylthio)phenols,w ere confirmed to be the natural products by co-injection with the extracts. [7] In the analysis of solvent extracts of wasp body parts, compounds 2 and 3 were successfully extracted from heads with ethanol or dichloromethane as solvents.T he ratios of compounds 2 and 3 differed between the ethanol flower extracts (ca. 10-fold excess of 3)a nd the two ethanol female wasp extracts examined (ca.…”