Table 7.

Environmental variables and distribution of Anopheles larvae at Ghibe River basin (November 2014–October 2016)

Environmental factors	An. gambiae (s. l.)			An. christyi			An. pharoensis
	Mean rank	U	p	Mean rank	U	p	Mean rank	U	p
Habitat permanence
Temporary	81.69	3137	0.455	79.9	2960.5	0.019*	81.46	3115	0.047*
Permanent	87.37			89.96			87.69
Presence of algae
Present	90.08	2808	0.235	91.56	2722.5	0.09	84.85	3111.5	0.686
Absent	80.77			79.98			83.55
Surface debris
Absent	90.21	2117	0.009*	79.05	2267	0.00*	83.23	2746	0.429
Present	68.6			96.27			85.92
Intensity of light
Shade	41.5	228	0.028*	74	423	0.36	93.42	426.5	0.237
Lit	85.58			84.37			83.65

	An. gambiae (s.l.)				An. christyi				An. pharoensis
	Mean rank	χ2	df	p	Mean rank	χ2	df	p	Mean rank	χ2	df	p
Water perimeter (m)
< 10 m	85.96	5.17	2	0.075	83.45	2.13	2	0.343	81.3	68.74	2	0.00*
10–100 m	83.3				90.88				83.23
> 100 m	40.25				74				150
Turbidity
Low	87.31	0.58	2	0.748	90.33	5.34	2	0.06	85.71	1.95	2	0.376
Medium	80.54				79.9				85
High	83.78				80.67				80.69
Distance to nearest house (m)
≤ 100	94.62	10.57	3	0.014*	76.04	24.91	3	0.00*	81.14	4.57	3	0.206
101–200	82.36				83.41				88.31
201–300	63.26				99.83				84.69
301–400	60.9				116.33				79
Canopy cover
Open	89.75	7.955	2	0.019*	84.42	0.454	2	0.797	81.54	9.469	2	0.009*
Tree	64.32				83.36				92.86
Shrub	83.33				74				79
Emergent plant
Absent	93.22	8.65	3	0.034*	82.33	7.54	3	0.057	81.29	11.84	3	0.008*
Grass	71.81				91.57				80.28
Weeds	89				82.3				86.75
Grass + weeds	68.9				73.5				95.6
Substrate type
Gravel	71.69	2.066	2	0.356	94.44	21.06	2	0.00*	84.03	0.838	2	0.658
Mud	87.37				77.66				84.81
Stone	78.42				100.24				81.3

*Statistically significant at p < 0.05

Df degree of freedom