Mortality in Tephritid Fruit Fry Puparia and Adults Caused by Metarhizium Anisopliae, Paecilomyces Fumosoroseus and Beauveria Bassiana

Tephritid fruit flies are recognized as the most economically important group of phytophagous Diptera, and cause large losses to fruits and vegetables throughout the world. In the small developing island state, Mauritius, the key major pest of fruits and vegetables are Bactrocera zonata (Saunders) and B. cucurbitae (Coquillett), respectively. At present, growers have recourse to chemical pesticides which are hazardous to both the environment and human health. The objective of the study was to evaluate entomopathogenic fungi isolated from the soils of Mauritius as biocontrol agents of fruit flies. The pathogenicity of six isolates of M. anisopliae, three isolates of B. bassiana and one isolate of P. fumosoroseus were determined for late third-instar larvae, puparia and emerging adults of B. zonata and B. cucurbitae. A standard concentration of 1 x 108 conidia/ml (5 ml) was used to inoculate 50 g lots of sand. Twenty mature third-instar larvae of either B. zonata or B. cucurbitae that were ready to pupate within the next 24 h were then introduced into each Petri dish for pupation. The overall result showed a significant reduction in adult emergence for both fruit fly species. For B. zonata, the percentage adult emergence varied from 60 to 93% in fungal treated sand; while, 1 to 30% of the puparia showed visible signs of mycosis. As regards B. cucurbitae, adult emergence ranged from 52 to 92% in fungal-treated sand and the highest percentage of mycosed puparia recorded with an isolate of M. anisopliae was 48%. Given the fact that there was significant reduction in adult emergence and a corresponding large mortality on puparia, the most virulent isolates could be potential candidates for soil application against fruit flies.Keywords: Bactrocera cucurbitae, Bactrocera zonata, fruit flies, pupae,biocontro

Distribution and genetic diversity of five invasive pests of Eucalyptus in sub-Saharan Africa

Eucalyptus is one of the most planted tree genera across the world, but is heavily challenged by invasive insect pests originating from the native range of these trees. The rate of introduction of non-native Eucalyptus-feeding insects has increased globally, including in sub-Saharan Africa where Eucalyptus trees have an important socio-economic role. In this study, we mapped the distribution and examined the genetic diversity of non-native Eucalyptus insect pests in 14 countries across sub-Saharan Africa. We focused on five foliage-feeding insect pests of Eucalyptus which are known to be present in the region, namely the bluegum chalcid wasp, Leptocybe invasa; the redgum lerp psyllid, Glycaspis brimblecombei; the bronze bug, Thaumastocoris peregrinus; the Eucalyptus weevil, Gonipterus sp.n.2; and the Eucalyptus gall wasp, Ophelimus maskelli. Insect samples were collected through structured surveys and small-scale sampling which were both combined with published literature to determine the distribution of these insect pests. Genetic diversity of each of these insect pests was estimated/assessed based on mitochondrial cytochrome oxidase I (COI) or cytochrome b (Cyt b) sequence data. Except O. maskelli, which is a relatively recent arrival, the other insect pests were found broadly distributed across the sampled countries, with first reports in many countries. Analysis of genetic diversity confirmed a common origin of geographically distant populations for G. brimblecombei and O. maskelli, moderate diversity for T. peregrinus and Gonipterus sp.n.2 and at least two distinct lineages for L. invasa. Two divergent haplogroups of L. invasa, with overlapping geographic range were confirmed in Ghana, Malawi, Sierra Leone, South Africa and Zimbabwe. Compared to published literature, new haplotypes were detected for T. peregrinus, Gonipterus sp.n.2 and L. invasa, suggesting multiple introduction of those pests in the region. Results of this study will have implications for quarantine, management and future research of Eucalyptus insect pests in the region and beyond.Supplementary material ESM 1 : Sample collection localities and number of insect used in this study.Members of Tree Protection Cooperative Program (TPCP), Centre for Tree Health Biotechnology (CTHP), Sustainable Afforestation Association (SAA), MIRO Forestry Company, The Food and Agriculture Organization of the United Nation (FAO), the European Union: European regional development fund (ERDF, INTERREG V program), the Conseil Re´gional de la Re´union, the Centre de Coope´ration internationale en Recherche agronomique pour le De´veloppement (CIRAD) and Ethiopian Environment and Forest Research Institute (EEFRI).http://link.springer.com/journal/105302021-03-28hj2020BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyZoology and Entomolog