Male‐biased sexual size dimorphism and sex ratio in the New Zealand Giraffe Weevil, Lasiorhynchus barbicornis (Fabricius, 1775) (Coleoptera: Brentidae)

• DOI: 10.1111/aen.12080
• Publication Date: 2014-03-14T03:16:58Z
• Authors: Christina J Painting; Thomas R Buckley; Gregory I Holwell
• Keywords: Sexual dimorphism; Rostrum; Callosobruchus chinensis; Operational sex ratio; Sex allocation

Abstract Both the sex ratio and extent of sexual size dimorphism ( SSD ) can have important implications for mating system a species. In particular, that is limited (generally female) often subject intense competition, which drive changes in behaviour morphology to increase competitive ability more abundant sex. The N ew Z ealand giraffe weevil, L asiorhynchus barbicornis F abricius, 1775), large charismatic species found across much ealand, but very little known about its natural history. We determined population structure ecology . from single wild over 3 years. was be highly warmer months, between ovember M ay, showed peak abundance ebruary arch each year. consistently male‐biased throughout breeding season (mean seasons 0.59 ± 0.02). Univariate multivariate analyses sexually size‐dimorphic mostly because extreme elongation rostrum male. All body parts males were also variable than those females, particularly head length, as shown by higher coefficients variation. There was, however, no significant seasonal variation These data are crucial gain an understanding factors driving this key components likely driven competitive, defence‐based observed.