Taxonomie et écologie des psylles (Hemiptera : Psylloidea) inféodés aux plantes du plateau de l’Adamaoua-Cameroun

Abstract

Prospection have been leading in different localities of the Adamawa Region of Cameroon from April 2011 to July 2015 and permitted us to collect adult psyllids with entomological net and a mouth aspirator then preserved in 70 % ethanol. The taxonomic study of these psyllids permits to identify 33 species whose 28 are probably new species for science belonging to 15 genera and 6 families. Triozidae family consist of 1 genus, Pauropsylla with 8 species described: Pauropsylla sp.1, Pauropsylla sp. 2 and Pauropsylla sp.3 of Ficus sycomorus (Moraceae), Pauropsylla sp.4, Pauropsylla sp.5 and Pauropsylla sp.6, psyllids of Ficus vallis, Pauropsylla trichaeta, psyllid of Ficus sur, Pauropsylla sp.7, psyllid of Vittelaria paradoxa (Sapotaceae). The first six and the seventeen species are described for the first time in Cameroon; Pauropsylla trichaeta is rewritten. These species provoke galls on upper face of the leaves and this induces the puffiness of leaves. The Homotomidae family consist of 1 subfamily, that of Macrohomotominae, with 1 genus and 2 species: Pseudoeriopsylla sp.1, psyllid of Ficus glumosa, Pseudoeriopsylla sp.2, psyllid of Ficus trichopoda. Pseudoeriopsylla sp.2 provokes formation of little galls on upper face of the leaves. The Aphalaridae family consist of 1 subfamily, that of Spondyliapidinae, with 1 genus and 1 known species: Blastopsylla occidentalis, psyllid of Eucalyptus camaldulensis (Myrtaceae). This species induces the yellow round stain on upper face of the leaves. The Psyllidae family consist of 2 subfamilies. The Aphalaroidinae subfamily consists of 1 genus and 5 probably news species : Yangus sp.1, psyllid of Albizia adianthifolia (Fabaceae), Yangus sp.2, psyllid of Albizia zygia, Yangus sp.3, psyllid of Albizia julibrissin, Yangus sp.4, psyllid of Parkia biglobosa (Fabaceae), Yangus sp.5, psyllid of Albizia chevalieri. The lasted three described for the first time in Cameroon. The Ciriacreminae subfamily consists of 1 genus and one known species: Heteropsylla cubana of Leucaena glauca (Fabaceae). The Psyllinae subfamily consist of 5 genera whose 3 news genera and 7 species: Palaeolindbergiella sp., psyllid of Gardenia erubescens (Rubiaceae), Psylla sp.1, psyllid of Pterocarpus lucens (Fabaceae), Psylla sp.2, psyllid of Berlinia doka (Fabaceae), Psylla sp.3, psyllid of Entada abyssinica (Fabaceae). The psyllids of Psyllidae family are associated with Combretaceae, Fabaceae and Rubiaceae. They provoke formation of little galls on upper face of the leaves, discolouration of leaves which finally provokes necrosis of leaves, distortion of leaves and etc. The Phacopteronidae family consist of 1 genus and 1 probably new species: Pseudophacopteron sp., psyllid of Khaya senegalensis (Meliaceae). This species provokes the formation of galls on both upper and lower face of the leaves. The Liviidae consist of 2 subfamilies. The Euphyllurinae subfamily consists of 1 genus and 3 probably news species: Diaphorina sp.1, psyllid of Maytenus senegalensis (Celastraceae), Diaphorina sp.2, psyllid of Strychnos spinosa (Loganiaceae) and Diaphorina sp.3, psyllid of Strychnos innocua. The Liviinae subfamily consists of 3 genera and 4 probably news species: Paurocephala sp., psyllid of Psorospermum febrifugum (Hypericaceae), Diclidophlebia andjigae sp.n., psyllid of Grewia venusta (Tilliaceae), Syntomoza sp.1 and Syntomoza sp.2, psyllid of Flacourtia indica (Flacourtiaceae). The psyllids of the Liviidae family live on Celastraceae, Flacourtiaceae, Hypericaceae, Loganiaceae and Tilliaceae. The species of this family provoke puffiness of the leaves in which the larvae are hosted, discolouration and necrosis of leaves, distortion of the bud and leaves. The taxonomic study on all psyllids collected in Adamawa Region has permitted us to describe 33 species belonging to 15 genera. 28 species are described for the first times in Cameroon and they are probably news species. The faunistic study revealed that the outbreak periods of psyllids species depend on the phenology of host plants, which are source of food and psyllids shelter. The numerical variation numbers of psyllids is not directly related to climatic factors (precipitation and temperature) for many species. Nonetheless, a significant correlation between abundance of psyllids and climatic (precipitation and temperature) factors is noted for some species on Ficus sycomorus, Strychnos spinosa and Psorospermum febrifugum. Two species have been frequently recorded with the most representative size : Pauropsylla trichaeta, psyllids of Ficus sur collected 24/24 months with 9, 86% and Pauropsylla sp.1, sp.2 and sp.3., psyllids of Ficus sycomorus collected 23/24 months with 11,44%.