Euwallacea kuroshio Gomez & Hulcr, 2018

Smith, Sarah M., Beaver, Roger A. & Cognato, Anthony I., 2020, A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China, ZooKeys 983, pp. 1-442 : 1

Euwallacea kuroshio Gomez & Hulcr, 2018 Fig. 56A, B, I

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

Type material.

Holotype (NMNH).

Diagnosis.

2.4-2.8 mm long (mean = 2.6 mm; n = 5); 2.17-2.4 × as long as wide. This species is distinguished by the pronotum basic (type 2) when viewed dorsally, anterior margin appearing rounded; declivity rounded; declivital face convex; protibiae outer margins rounded with 8-11 socketed denticles, denticles small, their sockets small; declivital surface shiny; interstriae bearing sparse small granules; and posterolateral declivital margin costate. 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. 2019b). Specimens of E. kuroshio can be morphologically diagnosed through a combination of overlapping elytral and pronotal measurements and number of socketed denticles on the protibiae given in Table 2 .

This species is nearly identical to E. geminus and E. malloti and can be separated by the elytral bases rounded and posterolateral declivital costa carinate and never granulate.

Similar species.

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 E. andamanensis , E. geminus , E. malloti , E. neptis , E. semirudis , E. testudinatus , E. velatus , and Xylosandrus formosae .

Distribution.

This species is reported in the study region from Indonesia, Japan (Okinawa), and Taiwan. It has been introduced to Mexico and the United States (California) ( Stouthamer et al. 2017; Gomez et al. 2018a; Smith et al. 2019b).

Host plants.

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

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).

Figures

Figure 56. Dorsal, lateral and declivital view of Euwallacea kuroshio, 2.4 - 2.8 mm (A, B, I), E. luctuosus holotype, 3.6 mm (C, D, J), E. malloti, 2.4 - 3.0 mm (E, F, K), and E. minutus, 1.8 - 1.9 mm (G, H, L).