Descrição de novas espécies de ácaros edáficos Rhodacaridae e predação de Ceratitis capitata (Díptera: Tephritidae) por Macrocheles Roquenesis (Acari: Macrochelidae)

Abstract

The objective of the present study was to consolidate recent taxonomic discoveries of new soil mite taxons (Acari: Rhodacaridae), as well as to verify the potential of the predatory mite Macrocheles roquensis Mendes & Lizaso on immature forms of Ceratitis capitata Wiedemann (Diptera: Tephritidae). Descriptions of the new species were made from mites collected in the decaying organic matter and soil in the domestic orchard and native vegetation in the municipalities of Palmeira dos Índios and Teotônio Vilela/Alagoas. Morphological and morphometric characters were observed from the literature and from observations made directly on the specimens, using phase contrast microscopes and interference microscopes. The taxonomically relevant structures were illustrated with the use of a digital camera connected to the phase contrast or interference microscope. Subsequently, these were processed with a digital tablet, using the program Adobe Illustrator®. The measurements were made with the use of a graded ocular. For each structure, the mean and the corresponding range (for variable measurements) were given in micrometers. The predator used in the predation test was obtained in cow manure in the city of Craíbas, Alagoas. Maintenance colonies with the following food substrates: one with nematode Protorhabditis sp. and another with a mixture of this nematode and C. capitata eggs were kept in the Laboratório de Entomologia/Acarologia da Universidade Federal de Alagoas, Campus Arapiraca. 35 experimental units of each acarine population were tested. Four adult females of M. roquensis and five third instar larvae of C. capitata were transferred to each unit, each plate being closed with PVC film (Magipack®). During 11 consecutive days predation levels and oviposition of the predator were evaluated using a stereoscopic microscope, replacing all larvae offered as prey daily. For analyzes done in EthoVision® XT, images of arenas containing 2 C. capitata larvae in the absence and presence of the predatory mite were captured during 30 minutes. A new genus for Rhodacaridae and two new species, Afrodacarellus alagoensis Santos & Castilho and Afrodacarellus xucurukariri Santos & Castilho (Rhodacaridae), have been described. The proportion of insects consumed was 23.0 ± 4.4 and 25.3 ± 6.0 respectively and the insect emergence ratio was 51.7 ± 5 and 49.4 ± 6.5 respectively for the two treatments, whereas in the control the emergency proportion was 79.3 ± 16.2. The oviposition rate was 2.5 ± 0.5 and 2.5 ± 0.3 eggs per day per experimental unit for mites fed with nematodes or nematode and C. capitata eggs, respectively.