The effect of sex and mating opportunity on ecological immunity in Brood X cicadas

Figures & data

Fig. 1. Experimental design. The time bar across the top of the figure represents the date and week of mass eclosion in our local area. For both Part 1 and Part 2 experiments, males and females of both M. septendecim and M. cassini were included.

Fig. 2. Mean (± 1 SE) differences in implant thickness among female and male M. septendecim (MS) and M. cassini (MC). Groups that are statistically significantly different according to Tukey’s HSD are shown by different letters (A–C).

Table 1. The effect of species, sex and the interaction between species and sex on implant thickness. Values that are statistically significant at a level of P < 0.05 are in bold text. N = 47–57 individuals per species and sex. See Table S1 in Supplemental Data for full details about sample sizes.

Variable	F	df	P
Species	4.48	1,192	0.036
Sex	55.38	1,192	< 0.0001
Species*sex	2.57	1,192	0.11
Full model	20.90	3,192	< 0.0001

Table 2. The effect of age on implant darkness by species and sex. Nonparametric Wilcoxon/Kruskal-Wallis χ² tests were used. Values that are statistically significant at a level of  P < 0.05 are in bold text. N = 47–57 individuals per species and sex. See Table S1 in supplemental data for full details.

Species, sex	χ^2	P
MS males	27.8	< 0.0001
MS females	0.0002	0.99
MC males	14.8	0.0001
MC females	8.62	0.0033

Fig. 3. Mean (± 1 SE) differences in implant darkness (a) and thickness (b) among young and old adult female and male M. septendecim (MS) and mean (± 1 SE) differences in implant darkness (c) and thickness (d) among young and old adult female and male M. cassini (MC).

Table 3. The effect of age and sex on implant thickness. ANOVAs were performed on each species separately. Values that are statistically significant at a level of P < 0.05 are in bold text. N = 31–46 individuals per species and sex. See Table S7 in Supplemental Data for full details about sample sizes.

Species	Variable	F	df	P
MS	sex	27.8	1, 202	< 0.0001
	age	20.6	1, 202	< 0.0001
	sex*age	0.039	1, 202	0.84
	full model	16.1	3, 202	0.0001
MC	sex	148.7	1, 200	< 0.0001
	age	55.5	1, 200	< 0.0001
	sex*age	9.1	1, 200	0.0029
	full model	72.3	3, 200	< 0.0001

Fig. 4. Mean (± 1 SE) differences in implant darkness (a) and thickness (b) amongst female and male M. septendecim (MS) housed in mixed sex groups (mating) and same sex groups (no mating) and mean (± 1 SE) differences in implant darkness (c) and thickness (d) amongst female and male M. cassini (MC) housed in mixed sex groups (mating) and same sex groups (no mating).