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 (Krüger) comb. n., Pirateolea piscator (Fletcher) comb. n., Pirateolea argocyma (Fletcher) comb. n., Pirateolea cyclophora (Fletcher) comb. n., Pirateolea ochroneura (Fletcher) comb. n., Pirateolea funebris (Krüger) comb. n., Feraxinia nyei (Fletcher) comb. n., Feraxinia jemjemensis (Laporte) comb. n. and Carelis biluma (Nye) comb. n.

Phylogeography and population genetics of the maize stalk borer Busseola fusca (Lepidoptera, Noctuidae) in sub-Saharan Africa.

The population genetics and phylogeography of African phytophagous insects have received little attention. Some, such as the maize stalk borer Busseola fusca, display significant geographic differences in ecological preferences that may be congruent with patterns of molecular variation. To test this, we collected 307 individuals of this species from maize and cultivated sorghum at 52 localities in West, Central and East Africa during the growing season. For all collected individuals, we sequenced a fragment of the mitochondrial cytochrome b. We tested hypotheses concerning the history and demographic structure of this species. Phylogenetic analyses and nested clade phylogeographic analyses (NCPA) separated the populations into three mitochondrial clades, one from West Africa, and two--Kenya I and Kenya II--from East and Central Africa. The similar nucleotide divergence between clades and nucleotide diversity within clades suggest that they became isolated at about the same time in three different refuges in sub-Saharan Africa and have similar demographic histories. The results of mismatch distribution analyses were consistent with the demographic expansion of these clades. Analysis of molecular variance (amova) indicated a high level of geographic differentiation at different hierarchical levels. NCPA suggested that the observed distribution of haplotypes at several hierarchical levels within the three major clades is best accounted for by restricted gene flow with isolation by distance. The domestication of sorghum and the introduction of maize in Africa had no visible effect on the geographic patterns observed in the B. fusca mitochondrial genome.

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.