Selection of Oviposition Sites by Libelloides coccajus (Denis & Schiffermüller, 1775) (Neuroptera: Ascalaphidae), North of the Alps: Implications for Nature Conservation

Table 3

Results of a Wilcoxon signed-rank test comparing circular plots with a radius of 20 cm around oviposition sites and the corresponding control plots of all study areas combined. Differences represent the mean difference between each paired control plot and oviposition site, and SD is the respective standard deviation. 𝑉 is the test statistic calculated by the Wilcoxon signed-rank test.

Parameter	Arithmetic mean			SD of difference	𝑉	𝑃
	Oviposition	Control	Difference
Vegetation cover (%)	38.1	61	22.8	33.7	125	0.0007
Number of plant species	7.2	8.9	1.8	3.5	95	0.0081 ^1,2
Vegetation height north (cm)	15.9	30.5	14.6	8.7	6	<0.0001 ^1
Vegetation height east (cm)	14.4	31.2	15.5	10.2	18.5	<0.0001 ^1,2
Vegetation height south (cm)	13.4	28.4	15.3	10.4	28.5	<0.0001 ^1
Vegetation height west (cm)	14.4	28.5	15	11	50	<0.0001 ^1
	Mean indicator values according to Landolt [34]
Moisture	1.9	1.9	0.03	0.3	281	0.4184^1
Light	3.6	3.6	0.04	0.2	267.5	0.3071^1
Temperature	3.5	3.6	0.02	0.3	302	0.6357
Soil reaction	3.4	3.4	0.07	0.3	293	0.5393
Soil nutrients	2.2	2.1	0.01	0.3	284	0.4507
Moisture variability	0.2	0.3	−0.03	0.2	289	0.4274^1,2

1Estimated 𝑃 values due to the occurrence of ties; ²estimated 𝑃 values because of zeros.