Variability in the reproductive biology and in resistance against Cotesia sesamiae among two Busseola fusca populations

Abstract

Two mitotypes of Busseola fusca (Fuller) (Lepidoptera: Noctuidae) named KI and KII, co‐exist in Kenya. Individuals of KII are more widely distributed than those of KI. The present study assessed whether this was due to differences in their reproductive potential and/or in their resistance to the braconid Cotesia sesamiae Cameron, which is the most common larval parasitoid of B. fusca in the region. Two populations of the parasitoid, one from the coastal and one from the inland regions of Kenya, which differ in their ability to develop in B. fusca, were tested. Virgin KII females started to call sooner during the night than KI females. Female fecundity and egg viability were significantly lower for the heterogamous than the homogamous crosses. Cotesia sesamiae from the inland produced larger progeny in KI than in KII host. Cotesia sesamiae from the coast did not develop in either host. Despite their long time co‐existence in the same geographical area, KII and KI conserved biological differences in terms of time of calling, fecundity, fertility and resistance against the larval parasitoid, C. sesamiae. This might explain the wider distribution of KII as compared to KI in Kenya.

Variation in a Host–Parasitoid Interaction across Independent Populations

“…However, in the latter case, there was partial reproductive isolation between populations using different hosts due to Wolbachia infection [ 12 , 67 ]. Population-level differences in the encapsulation ability of the host are not surprising as such differences have been found previously, even in Cotesia - Lepidoptera interactions [ 45 ], and encapsulation ability of M. cinxia is known to vary among families and with stress [ 8 , 56 ].…”

“…In the stem-boring moth system, the virulence of the generalist parasitoid Cotesia sesamiae and host resistance have been measured in terms of host encapsulation. Encapsulation rate varies geographically [ 44 ], with parasitoid and host population [ 12 , 45 ], host species [ 7 ], and in association with a Wolbachia endosymbiont [ 12 ]. In each study system, there is evidence that resistance to parasitoids comes at a cost to hosts [ 46 , 47 , 48 ] and that increased virulence comes at a cost to parasitoids [ 46 , 49 , 50 ].…”

Ecology of the African Maize Stalk Borer, Busseola fusca (Lepidoptera: Noctuidae) with Special Reference to Insect-Plant Interactions

“…During the last decade, the interactions of this insect pest with plants (e.g., [ 14 , 15 ]) as well as its reproductive biology (e.g., [ 16 , 17 , 18 , 19 ] and genetics e.g., [ 20 ]) have been well documented. This review provides updated information on the biology, distribution, genetics, host plant range and preference as well as management of B. fusca .…”

Suitability of cereal stemborers in Cameroon to Kenyan populations of the braconid larval parasitoid Cotesia sesamiae

“…In this study, the performance of the parasitoid was influenced by both host species/populations and parasitoid populations, although the B. fusca population had a minor effect. Calatayud et al. (2010) explained the differences in the occurrence of two populations of B. fusca in Kenya by the differences in parasitism by C. sesamiae .…”

“…In this study, the performance of the parasitoid was influenced by both host species/populations and parasitoid populations, although the B. fusca population had a minor effect. Calatayud et al (2010) explained the differences in the occurrence of two populations of B. fusca in Kenya by the differences in parasitism by C. sesamiae. However, the Kenyan populations belonged to different whereas the Cameroon populations belonged to the same mitochondrial clade (Sezonlin et al 2006; M. Sezolin, unpublished data).…”