"Singing on the wing" as a mechanism for species recognition in the malarial mosquito Anopheles gambiae.
Anopheles gambiae, responsible for the majority of malaria deaths annually, is a complex of seven species and several chromosomal/molecular forms. The complexity of malaria epidemiology and control is due in part to An. gambiae's remarkable genetic plasticity, enabling its adaptation to a range of human-influenced habitats. This leads to rapid ecological speciation when reproductive isolation mechanisms develop [1-6]. Although reproductive isolation is essential for speciation, little is known about how it occurs in sympatric populations of incipient species [2]. We show that in such a population of "M" and "S" molecular forms, a novel mechanism of sexual recognition (male-female flight-tone matching [7-9]) also confers the capability of mate recognition, an essential precursor to assortative mating; frequency matching occurs more consistently in same-form pairs than in mixed-form pairs (p = 0.001). [corrected] Furthermore, the key to frequency matching is "difference tones" produced in the nonlinear vibrations of the antenna by the combined flight tones of a pair of mosquitoes and detected by the Johnston's organ. By altering their wing-beat frequencies to minimize these difference tones, mosquitoes can match flight-tone harmonic frequencies above their auditory range. This is the first description of close-range mating interactions in incipient An. gambiae species.
Pennetier
Cédric
C
School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK.
Warren
Ben
B
Dabiré
K Roch
KR
Russell
Ian J
IJ
Gibson
Gabriella
G
D000819:Animal Communication; D000818:Animals; D000852:Anopheles / Q000502:physiology*; D005260:Female; D006309:Hearing; D008297:Male; D012726:Sexual Behavior, Animal; D013045:Species Specificity