Buakea (Lepidoptera : Noctuidae), a new genus of African stem borers : morphological, ecological and molecular data

A new genus of African stem borers of the subtribe Sesamiina (Lepidoptera: Noctuidae), Buakea gen. n., is described as well as the three species it includes, two new, B. venusta sp. n. and B. kaeuae sp. n., and a species that until now was placed in the genus Busseola Thurau, B. obliquifascia (Hampson) comb. n. The three species are monophagous on different graminaceous host plants, and the two sister species B. kaeaue and B. obliquifascia were collected in different ecological zones and altitudes, which suggests an ecological mode of speciation. Bayesian and maximum likelihood phylogenies inferred from two mitochondrial genes showed that the genus is monophyletic and does not share a recent common ancestor with the genus Busseola. However no strongly supported phylogenetic relationship could be established with the other six genera of the subtribe included in the analysis

Systematics and molecular phylogeny of two African stem borer genera, Sciomesa Tams & Bowden and Carelis Bowden (Lepidoptera : Noctuidae)

Currently, the systematics of the African noctuid stem borers of the subtribe Sesamiina, which include major pests of cereals, is confused. In addition, their ecology is poorly known, as are the factors influencing their evolution. In this paper, we address these shortcomings for two genera of the Sesamiina, Sciomesa Tams & Bowden and Carelis Bowden. Mixed Bayesian phylogenetic analysis, which included their host plants and two mitochondrial genes, showed the genus Sciomesa to be polyphyletic. Two new genera were created, Pirateolea and Feraxinia. The genus Carelis proved to be paraphyletic and was subdivided into two sub-genera. The genera Sciomesa, Carelis and Pirateolea (named the 'Sciomesa genus group') share morphological traits, and the phylogenetic analysis showed that they had a common ancestor living on Cyperaceae and that they were distant from the genus Feraxinia belonging to another clade which had an ancestor living on Poaceae. Seven new species were described: Sciomesa gnosia sp. n., Sciomesia bua sp. n., Pirateolea nola gen. n, sp. n., Feraxinia serena gen. n., sp. n., Carelis australis sp. n., Carelis transversa sp. n. and Carelis agnae sp. n. Ten species were sunk as synonyms: Sciomesa mesoscia (Hampson) syn. n., Sciomesa mirifica Laporte syn. n., Sciomesa constantini Laporte syn. n. and Sciomesa etchecopari Laporte syn. n. are synonyms of Sciomesa mesophaea (Aurivillius); Acrapex sparsipucta Laporte syn. n. is a synonym of Sciomesa excelsa (Laporte) comb. n.; Acrapex congitae Laporte syn. n., Sesamia minuta Laporte syn. n. and Sesamia minuscula Laporte syn. n. are synonyms of Sciomesa boulardi (Laporte) comb. n.; Acrapex bryae Laporte syn. n. and Acrapex fayei Laporte syn. n. are synonyms of Feraxinia jemjemensis (Laporte) comb. n. Eleven new combinations were created: Sciomesa excelsa (Laporte) comb. n., Sciomesa boulardi (Laporte) comb. n., Sciomesa punctipennis (Kruger) comb. n., Pirateolea piscator (Fletcher) comb. n., Pirateolea argocyma (Fletcher) comb. n., Pirateolea cyclophora (Fletcher) comb. n., Pirateolea ochroneura (Fletcher) comb. n., Pirateolea funebris (Kruger) comb. n., Feraxinia nyei (Fletcher) comb. n., Feraxinia jemjemensis (Laporte) comb. n. and Carelis biluma (Nye) comb. n

Morphological reinforcement, ancient introgressive hybridization and species delimitation in African stem-borer species of the genus Sesamia Guenée (Lepidoptera : Noctuidae)

Species delimitation, an issue central to systematics and biodiversity studies, is addressed in the epunctifera group of the stem borer genus Sesamia Guenee (Lepidoptera: Noctuidae). This group is composed of four sub-Saharan species: Sesamia poephaga Tams & Bowden; Sesamia epunctifera Hampson; Sesamia penniseti Tams & Bowden; and Sesamia poebora Tams & Bowden, the taxonomic status of which was unclear. The first species was considered a possible synonym of the second, and the third species was considered a possible synonym of the fourth. An analysis combining morphological, ecological and molecular data enables us to conclude that S. epunctifera and S. poephaga are different species, and that S. poebora is a synonym of S. penniseti. Two new species were discovered: Sesamia firmata sp.n. and Sesamia veronica sp.n. Sesamia firmata sp.n. has atypical genitalic morphology, suggesting a strong selection resulting in a reinforcement of pre-zygotic isolation. Some specimens previously identified as S. penniseti on the basis of morphology are sisters to S. epunctifera on the mitochondrial tree, and are connected to S. penniseti on the nuclear tree. The mitochondrial distance from S. penniseti and S. epunctifera is 7.6% and 3.9%, respectively, suggesting an ancient mitochondrial introgression from S. epunctifera into S. penniseti. The possible causes of the reinforcement and introgressive hybridization are discussed. This case of mitochondrial introgression, uncommon in Lepidoptera, in which females are the heterogametic sex, may be an exception to Haldane's rule. The hybrid is assigned the rank of species and named Sesamia pennipuncta sp.n

Systematics and molecular phylogeny of two African stem borer genera, Sciomesa...

http://dx.doi.org/10.1017/S000748530999072

Diversity of lepidopteran stem borers on monocotyledonous plants in eastern Africa and the islands of Madagascar and Zanzibar revisited

Surveys were completed in Eritrea, Ethiopia, Kenya, Madagascar, Mozambique, Tanzania, Uganda and Zanzibar to assess the lepidopteran stem borer species diversity on wild host plants. A total of 24,674 larvae belonging to 135 species were collected from 75 species of wild host plants belonging to the Poaceae, Cyperaceae and Typhaceae. Amongst them were 44 noctuid species belonging to at least nine genera, 33 crambids, 15 pyralids, 16 Pyraloidea species not yet identified, 25 tortricids and three cossids. The noctuid larvae represented 73.6% of the total number of larvae collected, with 66.3, 3.5 and 3.8% found on Poaceae, Cyperaceae and Typhaceae, respectively. The Crambidae, Pyralidae, Tortricidae and Cossidae represented 19.8, 1.9, 2.5 and 0.1% of the total larvae collected, respectively, with 90.4% of the Crambidae and Pyralidae collected from Poaceae, and 99.7% of the Tortricidae collected from Cyperaceae. The lepidopteran stem borer species diversity in the wild host plants was far more diverse than previously reported