First records of Phytoseiidae (Acari: Mesostigmata) from one island of the Comoros archipelago

The Comoros Archipelago is constituted of four islands. These islands are located in the North Mozambique Channel in the Indian Ocean, one of the world’s hotspots of biodiversity. Despite this status of hotspot, only one species of Phytoseiidae was known from this Archipelago, from Mayotte: Phytoseius mayottae. No species were recorded from the three other islands. We report in this paper the results of a preliminary survey in Great Comoro or “Grande Comore” Island also called Ngazidja in the Comorian language (= Shikomori) with five species recorded

Neoseiulus Hughes

Genus Neoseiulus Hughes Neoseiulus Hughes, 1948: 141.Published as part of Kreiter, Serge, Payet, Rose-My, Fillâtre, Jacques & Azali, Hamza Abdou, 2018, First records of Phytoseiidae (Acari: Mesostigmata) from one island of the Comoros Archipelago, pp. 529-545 in Acarologia 58 (3) on page 538, DOI: 10.24349/acarologia/20184256, http://zenodo.org/record/450252

First records of Phytoseiidae (Acari: Mesostigmata) from one island of the Comoros archipelago

International audienceThe Comoros Archipelago is constituted of four islands. These islands are located in the North Mozambique Channel in the Indian Ocean, one of the world’s hotspots of biodiversity. Despite this status of hotspot, only one species of Phytoseiidae was known from this Archipelago, from Mayotte: Phytoseius mayottae. No species were recorded from the three other islands. We report in this paper the results of a preliminary survey in Great Comoro or “Grande Comore” Island also called Ngazidja in the Comorian language (= Shikomori) with five species recorded

Phytoseiidae of La Réunion Island (Acari: Mesostigmata): three new species and two males described, new synonymies, and new records

International audienceThe Indian Ocean includes several Islands and Archipelagos and a survey of the fauna of Phytoseiidae was realized recently in these poorly known territories, despite La Réunion Island is located in an area being a hotspot of biodiversity. The Phytoseiidae fauna of La Réunion Island has been poorly investigated so far with only 33-recorded species including 24 Amblyseiinae, 5 Phytoseiinae and 4 Typhlodrominae, among which 8 species that had been described as new. All data concerning La Réunion have been published in nine papers until now. New results of surveys done recently (2015-2018) are presented in this tenth paper and add 19 newly recorded species among which 3 are new to Science and 21 already known species but with additional data. Among these 19 species, at least nine are already well known as biological control agents (BCA). Demonstration of the natural occurrence of already known efficient BCA in these territories is consequently of great agricultural and commercial interests, in addition of the contribution to fundamental knowledge of biodiversity of these poorly known territories

OTELHO : Vers une horticulture connectée, suivi des macroorganismes pour réduire les pesticides

L’acceptabilité environnementale des cultures horticoles est questionnée aujourd’hui notamment au regard de l’usage des pesticides. Le projet OTELHO a développé un outil d’aide à la décision nommé S@M, utile au suivi des cultures et à la connaissance des épidémies, étape indispensable à la prise de décision d’intervention. Pour répondre aux enjeux environnementaux et de santé, les partenaires de ce projet DEPHY EXPE ont construit à la fois un réseau expérimental et une méthode de travail centrée sur la co-conception. Ils ont éprouvé l’outil S@M et caractérisé une combinaison de solutions techniques viables permettant de réduire significativement l’usage des pesticides en horticulture. Les travaux ont été conduits à la fois en station expérimentale et en exploitation sur trois systèmes, les plantes en pots, le gerbera fleurs coupées, le rosier fleurs coupées. A l’issue de six années de prototypage de l’OAD S@M divers modules sont aujourd’hui stabilisés et utilisés par les expérimentateurs et les conseillers en entreprise. Les essais sur les différents systèmes de culture ont permis de valider dans certaines conditions des combinaisons de leviers pour réduire l’usage des pesticides de plus de 50%.The environmental acceptability of horticultural crops is questioned today, particularly with regard to the use of pesticides. The OTELHO project has developed a S@M decision support tool, useful for crop monitoring and knowledge of epidemics, an essential step in decision making. To meet the environmental and health challenges, DEPHY EXPE project partners have built both an experimental network and a co-design-centered work method to test the S@M tool and characterize a combination of technical viable solutions to significantly reduce the use of pesticides in horticulture. The work was conducted both in experimental station and in farms on three systems, potted plants, gerbera cut flowers, rose cut flowers. After six years of prototyping the OAD S@M various decision support modules are now stabilized and used by the experimenters and business consultants. Trials on different cropping systems made it possible to validate combinations of levers under certain conditions to reduce the use of pesticides by more than 50%

Genetic Diversity of the Ralstonia solanacearum Species Complex in the Southwest Indian Ocean Islands

Epidemiological surveillance of plant pathogens based on genotyping methods is mandatory to improve disease management strategies. In the Southwest Indian Ocean (SWIO) islands, bacterial wilt (BW) caused by the Ralstonia solanacearum species complex (RSSC) is hampering the production of many sustainable and cash crops. To thoroughly analyze the genetic diversity of the RSSC in the SWIO, we performed a wide sampling survey (in Comoros, Mauritius, Reunion, Rodrigues, and Seychelles) that yielded 1,704 isolates from 129 plots, mainly from solanaceous crops. Classification of the isolates to the four major RSSC phylogenetic groups, named phylotypes, showed that 87% were phylotype I, representing the most prevalent strain in each of the SWIO islands. Additionally, 9.7% were phylotype II, and 3.3% were phylotype III; however, these isolates were found only in Reunion. Phylotype IV (2 isolates), known to be restricted to Indonesia-Australia-Japan, was reported in Mauritius, representing the first report of this group in the SWIO. Partial endoglucanase (egl) sequencing, based on the selection of 145 isolates covering the geographic and host diversity in the SWIO (also including strains from Mayotte and Madagascar), revealed 14 sequevars with Reunion and Mauritius displaying the highest sequevar diversity. Through a multilocus sequence analysis (MLSA) scheme based on the partial sequencing of 6 housekeeping genes (gdhA, gyrB, rplB, leuS, adk, and mutS) and 1 virulence-associated gene (egl), we inferred the phylogenetic relationships between these 145 SWIO isolates and 90 worldwide RSSC reference strains. Phylotype I was the most recombinogenic, although recombination events were detected among all phylotypes. A multilocus sequence typing (MLST) scheme identified 29 sequence types (STs) with variable geographic distributions in the SWIO. The outstanding epidemiologic feature was STI-13 (sequevar I-31), which was overrepresented in the SWIO and obviously reflected a lineage strongly adapted to the SWIO environment. A goeBURST analysis identified eight clonal complexes (CCs) including SWIO isolates, four CCs being geographically restricted to the SWIO, and four CCs being widespread beyond the SWIO. This work, which highlights notable genetic links between African and SWIO strains, provides a basis for the epidemiological surveillance of RSSC and will contribute to BW management in the SWIO