Anticura, AND

Minoshima, Yûsuke N., Fikáček, Martin, Gunter, Nicole & Leschen, Richard A. B., 2015, Larval Morphology and Biology of the New Zealand-Chilean Genera Cylomissus Broun and Anticura Spangler (Coleoptera: Hydrophilidae: Rygmodinae), The Coleopterists Bulletin 69 (4), pp. 687-712 : 708-709

BIOLOGY OF ANTICURA AND CYLOMISSUS

Our fieldwork in New Zealand and Chile indicated that the biology of Anticura and Cylomissus are essentially the same: both genera are aquatic to semi-aquatic, inhabiting streams and smaller rivers in forested areas. Adults and larvae share microhabitats and may be most easily found by floating wet moss, usually growing on stones at the sides or within the stream/river, either at water level or in the splash zone just above it ( Figs. 2F–K , 9F–L , white bars). Cylomissus glabratus larvae inhabit mainly the fully submerged microhabitats, whereas adults are more often found in the splash zone above the waterline. On several occasions, we collected larvae of C. glabratus also from algal mats growing in the thin film of water flowing over streamside stones, indicating that this species is not confined to wet moss. Our collecting method mostly included collecting moss growing at water level and in the splash zone into a net, and floating the material in a white pan filled with water ( Figs. 2F , 9F ) – in time, adults and larvae floated at the water surface once they lost firm hold of the moss.

In Río Anticura , Chile, we also collected and floated wet debris that had accumulated within a logjam consisting of a mix of large trunks and twigs accumulated along/within the stream during floods/high-water ( Fig. 2I ), similar to the situation described by Spangler (1979). Larvae and adults of Anticura were found in this microhabitat, although not that many were collected as by floating moss. This suggests that Anticura inhabits various types of suitable microhabitats (watersoaked plant matter/debris) available in and along streams. Logjams and flood debris were not sampled in New Zealand.

In Chile and New Zealand, wet moss on stones hosting Cylomissus and Anticura are frequently co-inhabited by numerous larvae and adults of the genus Hydora Broun, 1882 ( Coleoptera : Elmidae : Larainae), even though the overlap of the microhabitats of hydrophilid and elmid beetles seemed partial. Adults of Hydora were usually found only in completely submerged moss, whereas Cylomissus and Anticura were more frequent at the water line. Moreover, the microhabitat of Hydora is variable among the species (e.g., Lambert et al. 2015), and some of the overlap could have been incidental.

Anticura was rare and localized in localities we sampled in Chile. We usually found one or few spots where multiple specimens (adults and larvae) were collected, but collecting in other same-looking microhabitats along the same stream (or in nearby streams) produced singletons or no specimens. In contrast, Cylomissus seemed to be much more common in New Zealand. It was usually found in larger numbers in all suitable microhabitats along the stream, and we did not experience its absence in the localities sampled.

Figures

Fig. 2. Anticura flinti. A) First instar, dorsal view, B–D) Third instar, dorsal, lateral, and ventral views, E) Adult, F) Detail of microhabitat in Parque Nacional Villarica, with the plastic box used for floating the specimens from moss, G) Parque Nacional Villarica, Río Palguín, 21.8 km SE of Pucón, Chile, H) Parque Nacional Puyehue, Río Anticura, Chile, I) Logjam at side of the river from which the accumulated debris was also floated and some Anticura collected, J) Parque Nacional Nahuelbuta, Estero Agua de Los Gringos, Chile, K) Detail of microhabitat Parque Nacional Nahuelbuta from which Anticura were collected. Photograph J by D. Vondráček.

Fig. 9. Cylomissus glabratus. A) First instar, dorsal view, B–D) Third instar, dorsal, lateral, and ventral views, E) Adult, F) Taranaki, Mt. Egmont National Park, Te Popo stream at Curtis Falls Track, New Zealand; M. Fikáček placing floating mosses in a plastic jar, G) Gisborne, Te Urewera National Park, Te Kumi stream at Waipai-Ruapani Track, New Zealand, H) Details of mosses at Wharekai Te Kou Walk from which Cylomissus was collected, I) Westland, Wharekai Te Kou Walk NNW of Jackson Bay, New Zealand, J) Taranaki, Mt. Egmont National Park, unnamed stream 0.2 km S of Pukeiti Garden, New Zealand, K) Westland, Mount Aspiring National Park, Mur Creek at Pleasant Flat, New Zealand, L) Detail of mosses in Mur Creek with Cylomissus. Photographs F–G and J by J. Hájek.