Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Cercosporella unguis-cati, the causal agent of the leaf spot of Dolichandra unguis-cati, reported from Paraguay.

Abstract

Silva et al. (2012) found leaf spots on D. unguis-cati in Brazil caused by Pseudocercospora unguis-cati. Lesions are subcircular, well delimited, dark brown surrounded by a purplish brown halo, 2-6 mm, coalescing, and infection leads to severe defoliation. This was by far the most common disease of D. unguis-cati reported from surveys in Brazil and Paraguay. Dried specimens from these surveys were deposited in the herbarium of the Universidade Federal de Viçosa (UFV, Minas Gerais, Brazil). Disease symptoms on D. unguis-cati were recognised as similar to leaf spots caused by Cercosporella dolichandrae, and questions emerged as to whether P. unguis-cati and C. dolichandrae are conspecific. A fresh specimen of the leaf spot was collected in June 2013 from General Higinio Morínigo (Caazapa Department, Paraguay). Based on morphological characteristics, DNA sequencing and pathogenicity, the pathogen was identified as C. dolichandrae. Cercosporella unguis-cati, originally collected on D. unguis-cati in Argentina and described by Spegazzini (1911), is morphologically identical to the fungal isolates from South Africa, Brazil and Paraguay. The earlier name of C. unguis-cati takes priority over Pseudocercospora unguis-cati and C. dolichandrae, which are now considered synonyms. This is thought to be the first record of C. unguis-cati from Paraguay.