Arilus carinatus (Forster, 1771)

Arilus carinatus (Forster, 1771) View in CoL

Because of the outstanding shape of their pronotum and large size, species of Arilus Hahn, 1831 stand out for laymen. However, the species included in this genus need revision. The species separation is still based on old compilations of short diagnoses, such as that of Stål (1872).

Arilus carinatus View in CoL is frequently found on vegetation; their early instar nymphs have a blackish head and the pronotum, legs and abdomen mostly reddish, while the coloration of last instar nymphs is more similar to the adults, but with a flat pronotum. The characteristically enlarged, rounded, subhemispherical and denticulated dorsal protusion of the pronotum (in lateral view) is present in the adults only ( Fig. 3C View Figures 3 ). The general coloration of the latter is dark brownish, with variable reddish tinge on the femora, the tibiae being paler. Larger individuals may reach about 30 mm in length ( Figs. 3 View Figures 3 B-C). The species of Arilus View in CoL are generalist insect predators (see Laiton-J. et al. 2021 for a synthesis of the literature). A female of Ar. carinatus View in CoL was recorded preying on a specimen of Nezara viridula (Linnaeus, 1758) ( Hemiptera View in CoL : Pentatomidae View in CoL ) ( Figs. 3 View Figures 3 D-E). It should be pointed out that N. viridula is one of the principal phytophagous Heteroptera associated with canola plantations in Brazil ( Marsaro Júnior et al. 2017; Bianchi et al. 2019).

Distribution. Brazil, Ecuador, Peru ( Maldonado Capriles 1990), Paraguay ( Michel 1993).