Eotetranychus lewisi (McGregor, 1943)

Naves, Pedro, Nóbrega, Filomena & Auger, Philippe, 2021, Updated and annotated review of Tetranychidae occurring in mainland Portugal, the Azores, and Madeira Archipelagos, Acarologia 61 (2), pp. 380-393 : 386

Eotetranychus lewisi (McGregor, 1943)

The Lewis spider mite, E. lewisi was reported by Carmona (1992) on plants of poinsettia

Euphorbia pulcherrima and on Vitis sp. in Funchal, Madeira Island, included in the INIAV collection. After this finding there are few additional references to this species in Madeira,

but from 2017 onwards E. lewisi was again detected in poinsettia plants growing wild and in gardens ( EPPO, 2020).

The Lewis spider mite is regulated as an A1 quarantine pest for the EU (Annex II - Part A:

Pests not known to occur in the Union territory) (EU 2019) and has the potential to establish in large parts of the EU territory (EFSA 2017). In Europe, E. lewisi has been reported from

Norway, Germany, the UK (EFSA 2017) and Poland ( Labanowski 2009), mostly from imported plants kept in glasshouses, but it was successfully eradicated in all the outbreaks (EFSA 2017).

A new outbreak was recently reported from nurseries producing poinsettias under greenhouses in Germany, with eradication ongoing ( EPPO, 2020).

In continental Portugal, the Lewis spider mite was recently identified from samples collected by the national plant health authority, DGAV - Direção-Geral de Alimentação e Veterinária,

in two localities in the Algarve District (Portimão and Loulé county), in 2019 and 2020.

Identified specimens were found on leaves E of. pulcherrima grown in gardens, confirming high preference for this plant host ( Andrews and Poe 1980 ; Goff 1986 ; Carmona 1992 ; Ho and

Shih 2004; Ho 2007). Examined leaves of E. pulcherrima contained abundant numbers of eggs,

immature stages and adults of both sexes, this being the first record for mainland Portugal and continental Europe of an established population in outdoor conditions.

Molecular analysis endorsed the morphological identification: BLAST analysis of the sequences of ITS2 region (447 bp) were 99,76% and 99,55% identical to the only two E.

lewisi sequences ( JF774172 and EU007694 , respectively) available in the GenBank. The new sequences were deposited to GenBank database (NCBI) under the accession numbers

MW524100 to MW524105 . For the COI region (530 bp), the BLAST analysis showed that this primer combination amplified mtDNA of the mite, but in the absence of COI region sequences for this species in the GenBank, it is not possible to determine homology. The sequences were deposited to GenBank database (NCBI) under the accession numbers MW538643 to

MW538648 . Voucher specimens mounted in slides are deposited in the INIAV acarological collection, reference numbers SV-19-00673, SV-19-02071 and SV-20-01735.