Importance of wild host plants for stem borer parasitoid diversity and control of parasitism in cereal cropping ecosystems in Kenya

Figures & data

Table 1. Summary description of four different study localities in Kenya

					Mean annual
Locality (Region)	Latitude	Longitude	Altitude (m a.s.l.)	Rainfall distribution	Precipitation (mm)	Temperature (min–max °C)	Vegetation mosaic
Kakamega (Western)	0°10′–0°13′ N	34°54′–34°56′ E	1555–1702	Bimodal	1570	12.7–27.1	Guineo–Congolian rain forest type
Mtito Andei (Eastern)	2°39′–2°40′ S	38°10′–38°21′ E	663–851	Single	665	16.8–29.1	Somalia and Masai Acacia bushland/thicket mosaic
Muhaka (Coastal)	4°18′–4°19′ S	39°31′–39°33′ E	21–54	Bimodal	1210	22.0–30.4	East African coastal mosaic
Suam (Rift Valley)	1°11′–1°12′ N	34°46′–34°48′ E	1665–2035	Single	1190	12.5–26.8	Rain forest and secondary grassland mosaic

Table 2. Summary of field collections according to host plant family in four different localities in Kenya

		Host plants inspected		Stem borers recovered		Parasitoids recovered
Locality	Plant family	Number of species	Number of individuals	Number of species	Number of individuals	Number of species	Number of individuals
Kakamega	Poaceae	13	13,200	12	589	9	25
	Cyperaceae	8	2400	5	259	6	22
	Typhaceae	1	600	1	1
Mtito Andei	Poaceae	11	7350	9	459	3	8
	Cyperaceae	3	1000	4	31	2	3
	Typhaceae	1	700	2	150	2	3
Muhaka	Poaceae	11	20,350	10	1816	9	58
	Cyperaceae	2	2150	6	19	2	2
Suam	Poaceae	12	5420	10	318	7	10
	Cyperaceae	7	2700	3	39
	Typhaceae	1	300

Table 3. Stem borer abundance, density and parasitism across host plant families in four different localities in Kenya

		Stem borer
Locality	Plant family	Abundance	Density (per plant)	Parasitism (%)
Kakamega	Cyperaceae (a)	2.15 ± 0.06	3.75 ± 0.69	25.79 ± 9.08
	Poaceae (b)	2.81 ± 0.04	3.57 ± 0.56	24.63 ± 2.59
	Typhaceae (c)	1.19 ± 0.02	6.39 ± 1.01	0.00 ± 0.00
	df	2, 167	3, 141	3, 167
	P-value	<0.0001	ns	<0.0001
	a vs b	<0.0001		<0.0001
	a vs c	<0.0001		<0.0001
	b vs c	0.0006		0.0006
Mtito Andei	Cyperaceae (a)	1.13 ± 0.17	3.47 ± 0.79	1.67 ± 0.13
	Poaceae (b)	3.05 ± 0.04	2.78 ± 0.48	0.59 ± 0.08
	Typhaceae (c)	2.67 ± 0.08	1.68 ± 0.87	0.03 ± 0.001
	df	2, 89	2, 85	2, 89
	P-value	<0.0001	ns	<0.0001
	a vs b	0.0111		<0.0001
	a vs c	<0.0001		<0.0001
	b vs c	<0.0001		ns
Muhaka	Cyperaceae	0.05 ± 0.01	4.91 ± 1.59	1.16 ± 0.12
	Poaceae	2.22 ± 0.02	2.47 ± 0.23	1.14 ± 0.04
	df	1, 217	1, 216	1, 217
	P-value	<0.0001	ns	ns
Suam	Cyperaceae (a)	1.21 ± 0.11	3.41 ± 1.08	0.46 ± 0.15
	Poaceae (b)	2.55 ± 0.06	3.52 ± 0.81	0.22 ± 0.16
	Typhaceae (c)	0.79 ± 0.31	3.94 ± 0.15	0.09 ± 0.16
	df	2, 84	2, 80	2, 84
	P-value	0.0118	ns	<0.0001
	a vs b	0.0053		0.0001
	a vs c	ns		<0.0001
	b vs c	ns		<0.0001
Note: df, degrees of freedom; P-value, probability value; ns, not significant; vs, versus.

Table 4. Stem borer diversity indices across host plant families in four different localities in Kenya

		Diversity indices
Locality	Plant family	Margalef's richness	Pielou's evenness	Shannon–Wiener	Berger–Parker
Kakamega	Cyperaceae	0.15 ± 0.06	1.12 ± 0.58	1.32 ± 0.61	1.79 ± 0.81
	Poaceae	1.01 ± 0.20	0.42 ± 0.12	0.37 ± 0.09	0.94 ± 0.08
	Typhaceae
	df	1, 18	1, 18	1, 18	1, 18
	P-value	0.0022	ns	ns	ns
Mtito Andei	Cyperaceae (a)	0.13 ± 0.04	1.36 ± 0.47	1.14 ± 0.37	1.71 ± 0.44
	Poaceae (b)	1.26 ± 0.09	0.73 ± 0.011	0.23 ± 0.07	0.86 ± 0.14
	Typhaceae (c)	0.42 ± 0.11	1.94 ± 0.55	2.32 ± 0.29	2.63 ± 0.41
	df	2, 21	2, 21	2, 21	2, 21
	P-value	<0.0001	ns	ns	ns
	a vs b	0.0020
	c vs d	0.0009
Muhaka	Cyperaceae	1.65 ± 0.57	2.19 ± 0.88	2.56 ± 0.23	2.89 ± 0.24
	Poaceae	1.36 ± 0.45	0.23 ± 0.03	0.09 ± 0.02	0.51 ± 0.15
	df	1, 18	1, 18	1, 18	1, 18
	P-value	<0.0001	0.0226	0.0020	0.0296
Suam	Cyperaceae
	Poaceae	1.48 ± 0.46	2.19 ± 0.53	2.47 ± 1.05	2.81 ± 0.44
	Typhaceae
Note: df, degrees of freedom; P-value, probability value; ns, not significant; vs, versus.

Table 5. Parasitoid diversity indices across plant host families in four different localities in Kenya

		Diversity indices
Locality	Plant family	Margalef's richness	Pielou's evenness	Shannon–Wiener	Berger–Parker
Kakamega	Cyperaceae	0.65 ± 0.04	2.61 ± 0.23	2.14 ± 0.97	2.84 ± 0.83
	Poaceae	0.05 ± 0.01	0.87 ± 0.16	0.84 ± 0.11	1.36 ± 0.66
	Typhaceae
	df	1, 18	1, 15	1, 15	1, 18
	P-value	ns	ns	ns	ns
Mtito Andei	Cyperaceae	2.25 ± 1.33	1.94 ± 0.17	2.32 ± 0.23	2.26 ± 0.41
	Poaceae	0.90 ± 0.05	2.09 ± 0.37	1.99 ± 0.12	2.52 ± 0.36
	Typhaceae
	df	1, 14	1, 14	1, 14	1, 14
	P-value	ns	ns	ns	ns
Muhaka	Cyperaceae	0.99 ± 0.04	1.98 ± 0.34	2.03 ± 0.83	2.55 ± 0.17
	Poaceae	0.43 ± 0.05	0.92 ± 0.09	0.62 ± 0.12	1.22 ± 0.69
	df	1, 18	1, 18	1, 18	1, 18
	P-value	0.0586	ns	ns	ns
Suam	Cyperaceae
	Poaceae	0.69 ± 0.05	1.43 ± 0.52	1.42 ± 0.71	1.92 ± 0.92
	Typhaceae
Note: df, degrees of freedom; P-value, probability value; ns, not significant.

Table 6. Stem borer diversity indices affecting parasitism in different host plant families in four different localities in Kenya

		Plant family
		Cyperaceae			Poaceae			Typhaceae			Total
Locality	Diversity indices	Deviance	df	P-value	Deviance	df	P-value	Deviance	df	P-value	Deviance	df	P-value
Kakamega	Constant	206.63	9		38.64	9					253.19	18
	Margalef's richness	201.57	1	0.0245	36.95	1	ns				253.19	1	ns
	Pielou's evenness	189.79	1	<0.0001	25.18	1	0.0002				250.63	1	ns
	Shannon–Wiener	202.27	1	0.0368	37.69	1	ns				252.98	1	ns
	Berger–Parker	198.61	1	0.0046	34.61	1	0.0446				253.19	1	ns
Mtito Andei	Constant	72.08	7		20.86	7		18.21	7		126.46	21
	Margalef's richness	6.71	1	<0.0001	12.11	1	0.0031	18.12	1	ns	102.23	1	<0.0001
	Pielou's evenness	0.03	1	<0.0001	15.13	1	0.0166	15.97	1	ns	85.44	1	<0.0001
	Shannon–Wiener	5.69	1	<0.0001	15.14	1	0.0167	17.11	1	ns	79.77	1	<0.0001
	Berger–Parker	3.12	1	<0.0001	12.53	1	0.0039	17.86	1	ns	74.73	1	<0.0001
Muhaka	Constant	147.68	9		22.99	9					177.69	18
	Margalef's richness	146.08	1	ns	22.29	1	ns				169.19	1	0.0036
	Pielou's evenness	136.89	1	0.001	15.83	1	0.0074				174.12	1	0.0013
	Shannon–Wiener	137.89	1	0.001	17.56	1	0.0197				162.52	1	<0.0001
	Berger–Parker	136.89	1	0.001	17.52	1	0.0193				162.37	1	<0.0001
Suam	Constant				59.43	8
	Margalef's richness				56.95	1	ns
	Pielou's evenness				53.22	1	0.0421
	Shannon–Wiener				55.61	1	0.0211
	Berger–Parker				50.72	1	0.0032
Notes: df, degrees of freedom; P-value, probability value; ns, not significant. All diversity indices were positively correlated with parasitism.

Table 7. Parasitoid diversity indices affecting stem borer parasitism in different host plant families in four different localities in Kenya

		Plant family
		Cyperaceae			Poaceae			Total
Locality	Diversity indices	Deviance	df	P-value	Deviance	df	P-value	Deviance	df	P-value
Kakamega	Constant	206.63	9		38.64	9		253.19	18
	Margalef's richness	178.24	1	<0.0001	29.08	1	0.0022	219.67	1	<0.0001
	Pielou's evenness	185.93	1	0.0041	33.49	1	0.0232	238.24	1	<0.0001
	Shannon–Wiener	182.12	1	0.0231	30.31	1	0.0039	233.95	1	<0.0001
	Berger–Parker	171.23	1	0.0011	30.83	1	0.0052	253.19	1	<0.0001
Mtito Andei	Constant	72.08	7		20.86	7		100.51	21
	Margalef's richness	59.73	1	0.0004	16.28	1	0.0322	96.88	1	0.0566
	Pielou's evenness	60.57	1	0.0021	14.65	1	0.0083	79.56	1	0.0009
	Shannon–Wiener	54.29	1	0.0032	17.22	1	0.0005	87.65	1	0.0003
	Berger–Parker	69.22	1	0.0024	16.64	1	0.0389	85.17	1	<0.0001
Muhaka	Constant	147.95	9		20.53	9		177.69	18
	Margalef's richness	147.82	1	ns	4.69	1	<0.0001	176.52	1	ns
	Pielou's evenness	139.54	1	ns	8.95	1	0.0001	175.33	1	ns
	Shannon–Wiener	141.33	1	ns	2.87	1	<0.0001	176.61	1	ns
	Berger–Parker	146.88	1	ns	3.71	1	<0.0001	176.77	1	0.0382
Suam	Constant				59.43	8
	Margalef's richness				51.21	1	0.0041
	Pielou's evenness				50.55	1	0.0009
	Shannon–Wiener				51.66	1	0.0039
	Berger–Parker				55.37	1	0.0021
Notes: df, degrees of freedom; P-value, probability value; ns, not significant. All diversity indices were positively correlated with parasitism.