Table 3

Dependence of female insemination probability and fecundity upon size, male competition level and strain.*

Experiment
N
Outcome
Parameter
β ± SEM
P

Ifakara strain only
1 & 2
91
Oviposition†
Intercept
-16.5± 5.6
<0.001



Size
5.4 ± 1.8
0.001



Competition
-1.44 ± 0.59
0.009

2
46
Insemination†
Intercept
-38.1 ± 10.7
<0.001



Size
13.1 ± 3.7
<0.001



Competition
1.91 ± 1.0
0.034


Oviposition after insemination†
Intercept
0.15 ± 0.56
0.782



Competition
-1.95 ± 0.95
0.024

All four male-female combinations of Ifakara and Mbita strains
3
180
Insemination†
Intercept
-13.0 ± 3.4
<0.001



Competition
2.37 ± 0.38
<0.001



Size
3.98 ± 1.12
<0.001


180
Oviposition†
Intercept
-10.2 ± 3.1
0.001



Competition
1.83 ± 0.34
<0.001



Size
3.06 ± 1.01
0.003


94
Oviposition after insemination†
Intercept
2.52 ± 0.39
<0.001


87
Egg batch size of ovipositors‡
Intercept
-1.16 ± 0.47
0.017



Size
0.94 ± 0.15
<0.001

* Size was measured as wing length (mm) and male competition was either low or high (5 versus 50 males per cage, respectively, with 30 females). † Logistic regression model fitted by forward conditional stepwise selection ‡ Generalized linear model fitted manually including only terms found to be significant upon testing all candidates. The size of egg batches was log-normally distributed and correspondingly transformed so parameter estimates refer to their influence upon Log 10 (egg batch size +1).

Okanda et al. Malaria Journal 2002 1:10   doi:10.1186/1475-2875-1-10