Species-Specific Floral Scents as Olfactory Cues in Pollinator Moths

AbstractMate recognition in animals evolves during niche adaptation and involves habitat and social olfactory signals. Drosophila melanogaster is attracted to fermenting fruit for feeding and egg-laying. We show that, in addition, female flies release a pheromone (Z)-4-undecenal (Z4-11Al), that elicits flight attraction in both sexes. The biosynthetic precursor of Z4-11Al is the cuticular hydrocarbon (Z,Z)-7,11-heptacosadiene (7,11-HD), which is known to afford reproductive isolation between the sibling species D. melanogaster and D. simulans. A pair of alternatively spliced receptors, Or69aB and Or69aA, is tuned to Z4-11Al and to food olfactory cues, respectively. These receptors are co-expressed in the same olfactory sensory neurons, and feed into a neural circuit mediating species-specific, long-range communication: the close relative D. simulans, which shares food resources and co-occurs with D. melanogaster, does not respond. That Or69aA and Or69aB have adopted dual olfactory traits highlights the interplay of habitat and social signals in mate finding. These olfactory receptor genes afford a collaboration between natural and sexual selection, which has the potential to drive phylogenetic divergence.Significance StatementVolatile insect sex pheromones carry a message over a distance, they are perceived by dedicated olfactory receptors, and elicit a sequence of innate behaviours. Pheromones mediate specific mate recognition, but are embedded in and perceived together with environmental olfactory cues. We have identified the first long-range, species-specific pheromone in Drosophila melanogaster. A pair of spliced olfactory receptors, feeding into the same neural circuit, has developed a dual affinity to this pheromone and kairomones, encoding adult and larval food. Blends of this pheromone and kairomone specifically attract D. melanogaster, but not the close relative D. simulans. This becomes an excellent paradigm to study the interaction of social signals and habitat olfactory cues in premating reproductive isolation and phylogenetic divergence.

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Parasite and predator risk assessment: nuanced use of olfactory cues

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.1941 ◽

2015 ◽

Vol 282 (1817) ◽

pp. 20151941 ◽

Cited By ~ 12

Author(s):

John G. Sharp ◽

Sarah Garnick ◽

Mark A. Elgar ◽

Graeme Coulson

Keyword(s):

Risk Assessment ◽

Parasite Fauna ◽

Olfactory Cues ◽

Gastrointestinal Parasite ◽

Risk Of Predation ◽

Predator Risk ◽

Single Field ◽

Species Specific ◽

Free Ranging

Foraging herbivores face twin threats of predation and parasite infection, but the risk of predation has received much more attention. We evaluated, experimentally, the role of olfactory cues in predator and parasite risk assessment on the foraging behaviour of a population of marked, free-ranging, red-necked wallabies ( Macropus rufogriseus ). The wallabies adjusted their behaviour according to these olfactory cues. They foraged less, were more vigilant and spent less time at feeders placed in the vicinity of faeces from dogs that had consumed wallaby or kangaroo meat compared with that of dogs feeding on sheep, rabbit or possum meat. Wallabies also showed a species-specific faecal aversion by consuming less food from feeders contaminated with wallaby faeces compared with sympatric kangaroo faeces, whose gastrointestinal parasite fauna differs from that of the wallabies. Combining both parasite and predation cues in a single field experiment revealed that these risks had an additive effect, rather than the wallabies compromising their response to one risk at the expense of the other.

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The males of the parasitoid wasp, Nasonia vitripennis, can identify which fly hosts contain females

10.1101/2021.04.06.438549 ◽

2021 ◽

Author(s):

Garima Prazapati ◽

Ankit Yadav ◽

Anoop Ambili ◽

Abhilasha Sharma ◽

Rhitoban Raychoudhury

Keyword(s):

Reproductive Success ◽

Parasitoid Wasp ◽

Olfactory Cues ◽

Nasonia Vitripennis ◽

Mate Finding ◽

Adult Females ◽

Species Specific ◽

Female Specific ◽

Male Specific ◽

Behavioral Assays

The reproductive success of a male is limited by the number of females it can mate with. Thus, males deploy elaborate mate-finding strategies to maximize access to females. In the haplodiploid wasp genus, Nasonia, which are parasitoids of cyclorrhaphous flies, mate-finding is restricted to the natal patch, where males compete for access to females. This study investigates whether there are any additional mate finding strategies of males, especially, whether they can identify the presence of adult females which are still inside the fly host. Results reveal that only one out of the four species, N. vitripennis, can distinguish which hosts specifically have adult female wasps indicating a species-specific unique mate-finding capability. Behavioral assays revealed that the cues used by N. vitripennis males are olfactory in nature and not auditory or visual. GC-MS analyses show that these olfactory cues are female-specific cuticular hydrocarbons (CHCs), possibly emanating from within the fly puparium. Further assays indicated that N. vitripennis males can also detect differences in the concentrations of compounds to identify female-specific cues from male-specific ones. This study, therefore, uncovers a previously unknown mate-finding strategy in one of the most widely studied parasitoid wasp.

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Electron Microscopy in the Study of Natural Phytoplankton Assemblages

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119831 ◽

1985 ◽

Vol 43 ◽

pp. 620-623

Author(s):

Linda Sicko-Goad

Keyword(s):

Electron Microscopy ◽

Aquatic Environment ◽

Size Range ◽

Physical Parameters ◽

Specific Information ◽

Phytoplankton Assemblages ◽

Phytoplankton Productivity ◽

Ecosystem Effects ◽

Time Of Year ◽

Species Specific

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.

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