New Record of Tetranychus merganser (Acari: Tetranychidae) on Eustoma grandiflorum (Gentianales: Gentianaceae) in Northeastern Mexico

Abstract

Most species of spider mites belonging to the family Tetranychidae are polyphagous and are found on major food crops and ornamental plants of economic importance (Zhang 2003, CABI Publishing, Wallingford, Oxon, UK).The red spider mite, Tetranychus merganser Boudreaux, is found in China (Oriental), Mexico, Thailand, and the United States.This mite feeds on different plant species of economic importance, such as, Capsicum annuum L. (Solanaceae), Carica papaya L. (Caricaceae), Cucurbita máxima Duchesne (Cucurbitaceae), and Opuntia ficus-indica (L.) Mill (Cactaceae) (Migeon y Dorkeld 2023, http://www.montpellier.inra.fr/CBGP/spmweb,accessed 11 August 2023).Its feeding habits cause small white spots on the leaves and, when the T. merganser populations are high, the spots can merge, causing the leaves to turn completely white (López-Bautista et al. 2016, Int.J. Acarol.42:303-309).Herein, we report lisianthus, Eustoma grandiflorum (Raf.)Shinners (Gentianaceae), as a new host for T. merganser in northeastern Mexico.Our discovery was serendipitous in that our objective was to evaluate the response of E. grandiflorum plants to different fertilization levels and the use of Trichoderma harzianum Rifai as a biologically based fungicide under greenhouse conditions (Moreno-Ramírez 2023, Investigation Project: Comportamiento agronómico y evaluación de poscosecha de variedades de lisianthus (Eustoma grandiflorum (Raf.)Shinn).Ciudad Victoria, Tamaulipas, Mexico.http://dx.doi.org/10.13140/RG.2.2.23324.05764,accessed 11 August 2023).In May 2023, three plants with signs and symptoms of the presence of mites were separated, and the remainder of the plants (50 plants) were treated with a