The banana weevil, Cosmopolites sordidus (Germar), is a potential vector of Xanthomonas campestris pv. musacearum in bananas

Figures & data

Table 1. Proportion of weevils that had Xcm on the external and internal body surfaces captured from ‘Mbwazirume’ and ‘Kayinja’ fields with banana Xanthomonas wilt symptomatic plants.

	Proportion of weevils with Xcm
	External surface (%)	Internal organs (%)	Total (external and internal) (%)
Field of ‘Mbwazirume’ (n = 68)	55.9 b	45.4 b	66.4 b
Field of ‘Kayinja’ (n = 68)	41.9 a	17.7 a	50 a
Lsd	4.69***	4.89***	5.28***
Cv%	66.6	107.6	63.1

*** denotes highly significant differences (P ≤ 0.001) between the treatments within each cultivar. Values followed by the same letter within columns are not significantly different at 5% LSD.

Fig. 1 Agarose gel photo of PCR amplification of Xcm isolates from different studies. Lane 1 to 5: denotes DNA fragments of Xcm isolates from weevils captured from ‘Kayinja’ and ‘Mbwazirume’ fields; Lane 6 to 9: DNA fragments of Xcm isolates from ‘Kayinja’, ‘Musakala’, ‘Nakitembe’ and ‘Mpologoma’, respectively, inoculated with weevils previously fed on Xcm oozing corms; and Lane 10 to 12: DNA fragments of Xcm isolates from weevil head (including mouth parts), thorax and abdomen. M is a 1kb ladder.

Fig. 2 Xanthomonas campestris pv. musacearum incidence (a) and bacterial load (CFU mL⁻¹) (b) on the body surface, within the internal organs and the faecal matter of the banana weevil.

Table 2. Presence and absence of banana Xanthomonas wilt characteristic symptoms on plants treated with 1 weevil (T1), 5 weevils (T5) and 10 weevils (T10) 60 days post-inoculation. Positive controls were inoculated with known Xcm isolate while the negative controls did not receive any treatment.

Cultivar	Negative	Positive	T1	T5	T10
‘Kayinja’	0^a	100^a	0^a	0^a	0^a
‘Mpologoma’	0^a	100^a	33^b	100^b	67^b
‘Musakala’	0^a	100^a	67^c	100^b	100^c
‘Nakitembe’	0^a	100^a	67^c	100^b	100^c
CV%	38.9
LSD (5%)	0.2***

*** denotes highly significant differences (P ≤ 0.001) in the different columns between the treatments within each cultivar. Values followed by the same letter within columns are not significantly different at 5% LSD.

Fig. 3 Xanthomonas campestris pv. musacearum (Xcm) incidence (a) and bacterial load (CFU g⁻¹) (b) for the different cultivars treated with 1 weevil (T1), 5 weevils (T5) and 10 weevils (T10) previously fed on Xcm oozing corms 60 days post-inoculation.