Acanalonia bivittata (Say, 1825)

Sanna, Francesco & Poggi, Francesco, 2022, First record of three alien Auchenorrhyncha species from Europe: Acanalonia bivittata (Say, 1825), Branchana xanthota Li, 2011, and Dryadomorpha pallida Kirkaldy 1906 (Hemiptera: Auchenorrhyncha: Acanaloniidae, Cicadellidae), Zootaxa 5194 (2), pp. 273-282 : 274-275

Acanalonia bivittata (Say, 1825)

Systematics and distribution. The planthopper genus Acanalonia Spinola, 1839 , type species A. servillei Spinola, 1839 , includes so far 62 described species, occurring in the Nearctic and Neotropical regions (Bourgoin T., 2021 onward), one of which, A. conica (Say, 1830) , has been introduced in Europe (northern Italy) since 2003 (D’Urso & Uliana, 2004) and is reported so far from France, Switzerland, Austria, Italy, Slovenia, Hungary, and Romania (Bourgoin T., 2021 onward).

Acanalonia bivittata is the second species of the family introduced in Europe. It is reported from Canada (Ontario), eastern and south USA (where it ranges from Maine to Florida, and west to Minnesota, Kansas, Texas, and Arizona) and Mexico ( Bartlett et al., 2014). The species was collected by the first author in northern Italy (Veneto region) in the summer of 2021 and 2022 .

Material examined. 1 ♂, Italy, Veneto, prov. Verona, Bovolone , 23 m, 45.275991, 11.142022, from sweeping on herbs and grasses, 15.VIII.2021, F.Sanna leg. ( CS) .

2♂♂, Italy, Veneto, prov. Verona, Bovolone , 23 m, 45.275973, 11.142518, from sweeping on herbs and grasses, 23.VII.2022, F.Sanna leg. ( CS) .

Morphology. Adult ( Figs 1A–B ); body length 6.5–8.4 mm; body laterally compressed, light green in live specimens and yellowish green after death; forewings subrectangular, with prominent and reticulate venation; two brown stripes extending posteriorly from eye along lateral margins of thorax to inner margins of clavus.

Male genitalia; directed posterodorsally; aedeagus with dorsal expansion elongated, widened at the apex, with small teeth on dorsal aspect, emerging dorsally from styles; lateral processes subcylindrical; caudal processes widened distally, abruptly narrowing apically, short acute extension on apex ( Fig. 1C ). A more detailed description and drawings of male genitalia is provided by Freund & Wilson (1995).

Biology and host plants. According to Wilson & McPherson (1981), who studied the life history of Acanalonia bivittata in southern Illinois, the species is univoltine and adults hatch from mid-July and can be found up to October. According to Wilson & McPherson (1980) and again based on observations made in Illinois, the species is highly polyphagous. In Italy, from observations made in 2022 adults were seen or captured on Erigeron canadensis L. ( Asteraceae ), Equisetum ramosissimum Desf. (Equisetaceae) , Oxalis corniculata L. ( Oxalidaceae ), Populus alba L. ( Salicaceae ), Setaria pumila (Poir.) Roem. & Schult. (poaceae) and other plants, data which confirm the high polyphagy of the species.

Remarks. Regarding the two Acanalonia species present in Europe, A. bivittata can be easily distinguished from A. conica by the two, prominent brown stripes extending posteriorly from behind the eye along lateral margins of thorax to inner margins of clavus, as well as for the smaller size.

Figures

FIGURE 1. Acanalonia bivittata (male from Italy, Veneto). A. dorsal habitus; B. lateral habitus; C. male genitalia, lateral view.