The apparent congruence between these two different mechanisms of sexual selection may be the reason that head width and mouthpart size are all positively allometric in males when compared with other morphological traits (Table S1, Fig. S2).
To estimate body size, I conducted principal components analysis for head width and hind femur length.
Significant correlations among males were also found between head length and width (r = -0.379, P = 0.0006), head length and axoneme length (r = -0.349, P = 0.0016), axoneme length and total length (r = 0.954, P < 0.0001), and head width and midpiece area (r = 0.565, P < 0.0001; Table 1).
Adult body size was based on head width, and was modeled by dry weight, intertegular width, sex, and an interaction between intertegular width and sex.
Three biometric variables, head length, head width, and mentum width, were measured for each head capsule.
Each mini-nest was given 15 small workers (<1.4 mm head width), 4 intermediate-sized workers (1.4 1.8 mm head width) and 2 large workers (>1.8 mm head width).
Individuals captured during 2007 and 2008 were also measured for limb length, tail length, tail height, tail width, head width and body width.
In G. vernalis, latitude and elevation were significant factors for both head width and mirror area.
Zone had a significant effect for head width and mirror area in G. vernalis (Table 2).
Elevation was a significant factor for head width and thorax length.
