Taxonomic history

Euwallacea kurishio Gomez & Hulcr 2018 (in Gomez et al. 2018b): 9.

Diagnosis

2.4–2.8 mm long (mean = 2.6 mm; n = 10); 2.17–2.4 times as long as wide. This species is distinguished by the pronotum basic (type 2) when viewed dorsally, anterior margin appearing rounded; elytral declivity rounded; declivital face convex; protibia outer margin rounded with 8−11 socketed denticles, denticles small, their sockets small; declivital surface shining; interstriae bearing sparse small granules, posterolateral margin of declivity costate. This species is nearly identical to E. malloti and E. n. sp. 5 and can be separated by the elytral bases rounded and posterolateral declivital costa carinate and never granulate.

This species is part of the Euwallacea fornicatus species complex, and the most reliable method to ensure accurate identification of these species is through generation of COI barcoding sequences (Gomez et al. 2018b, Smith et al. 2019). Gomez et al. (2018b; figure 1) provide morphological characters for separating the species based on measurements of elytral length (lateral view; diagonally measured from the elytral base to the apex) and pronotal length (lateral view; on a diagonal from pronotal apex to pronotal base). Species can be diagnosed using the combination of measurements given in Smith et al. 2019:

species total length
(dorsal)
length/width ratio
(dorsal)
elytral length
(lateral; diagonal)
pronotal length
(lateral; diagonal)
elytral width
(dorsal)
pronotal width
(dorsal)
protibial
denticles
E. fornicatior 2.20–2.37 2.15−2.35 1.40–1.46 1.02–1.06 0.48–0.52 1.00–1.06 6−7
E. fornicatus 2.60−2.70 2.25−2.36 1.44–1.72 1.02–1.16 0.48–0.62 1.00–1.14 8–9
E. kuroshio 2.40−2.80 2.17−2.40 1.50–1.82 1.08–1.16 0.52–0.56 1.06–1.16 8−11
E. perbrevis 2.30−2.50 2.46−2.55 1.42–1.68 1.04–1.16 0.48–0.56 1.02–1.14 7−10

 

May be confused with

This species is part of the Euwallacea fornicatus species complex along with E. fornicatior, E. fornicatus and E. perbrevis from which it is difficult to distinguish. The species is also similar to Coptodryas inornata, E. andamanensis, E. geminus, E. malloti, E. neptis, E. semirudis, E. testudinatus, E. velatus, and Xylosandrus formosae.

Distribution

Indonesia (East Java), Japan (Okinawa), Taiwan. This species has been introduced into Mexico and the United States (California) (García-Avila et al. 2016, Gomez et al. 2018b, Stouthamer et al. 2017, Smith et al. 2019).

Host plants

This species is known from Sambucus (Adoxaceae), Liquidambar (Altingiaceae), Schinus, Searsia (Anacardiaceae), Ambrosia, Baccharis (Asteraceae), Alnus (Betulaceae), Ricinus (Euphorbiaceae), Quercus (Fagaceae), Cassia, Persea (Lauraceae), Ficus (Moraceae), Eucalyptus (Myrtaceae), Juglans, Pterocarya (Juglandaceae), Magnolia (Magnoliaceae), Fraxinus (Oleaceae), Platanus (Platanaceae), Populus, Salix (Salicaceae), Nicotiana (Solanaceae), Tamarix (Tamaricaceae) (Boland 2016, Na et al. 2018, Coleman et al. 2019, Smith et al. 2019).

Remarks

This species is commonly known as the Kuroshio shot hole borer (KSHB) and has been referred to as this in publications before the species was formally described (e.g. Stouthamer et al. 2017).

DNA data

Sequences are available from COI and CAD.

COI: MN619937

CAD: MN620212

The holotype has been sequenced for COI (KU727004). Additional COI sequences can be found in Gomez et al. (2018b) and Smith et al. (2019)