Popillia biguttata (Wiedemann in Wiedemann & Germar, 1821 )

Telnov, Dmitry & Zorn, Carsten, 2019, Popillia biguttata (Wiedemann in Wiedemann & Germar, 1821) (Coleoptera Scarabaeidae: Rutelinae) established on New Guinea? With an illustrated key to Sundaland Popillia Dejean species, Zootaxa 4683 (4), pp. 577-588 : 577-579

Popillia biguttata (Wiedemann in Wiedemann & Germar, 1821)

( Figs. 1–5 )

Material examined: Indonesia E, North New Guinea, Sentani N env., foothills of Cyclops Mts. , 2°32’49”S, 40°30’45”E, 03.IV.2014, forest edge, leg. D.Telnov (3♂ DTC) .

In April 2018, Popillia biguttata was observed in northern New Guinea, around Sentani, in the foothills of the Cyclops Mountains. Three specimens were found feeding on the flowers of Catharanthus roseus (L.) G. Don ( Apocynaceae ), commonly known as Madagascar periwinkle or rose periwinkle, non-native but widespread in eastern Indonesia. This flowering plant is not uncommon in urban and village gardens in Indonesian New Guinea, as observed by the first author.

In the foothills of the Cyclops Mountains, at the edge of Kota Sentani not far from the World Wildlife Fund office at the end of an asphalt road, where gardens merge with natural rainforest vegetation ( Fig. 6 ), a group of flowering C. roseus in the shade of young trees was inspected for Coleoptera . Considering the fact that C. roseus is poisonous to many organisms ( Plaizier 1981; Barrales-Cureño et al. 2019), it was quite surprising to find Rutelinae beetles on these flowers. According to Miyajima (2004), C. roseus is pollinated by foraging insects. However, due to peculiarities of the flower structure, only butterflies and moths with a long proboscis can reach the anthers and stigmas of C. roseus flowers ( Miyajima 2004). The three observed specimens of P. biguttata were positioned on nearby C. rosaceus flowers, apparently digging into them but with their bodies still half-exposed and visible from above.

Considering the fact that three specimens were observed, and not in a garden area but in an intermixing zone with natural vegetation, we assume P. biguttata is successfully established in New Guinea.

Studied Papuan specimens were compared with specimens from Java (see localities in the Checklist below).

Figures

FIGURE 6. Habitat of Popillia biguttata (Wiedemann in Wiedemann & Germar, 1821) in Cyclops Mountains, North New Guinea. Photographed ~300 m above the discussed observation spot (photo: L. Wagner).

FIGURES 1–5. Popillia biguttata (Wiedemann in Wiedemann & Germar, 1821), ♂. 1: habitus, lateral view; 2: habitus, dorsal view; 3: aedeagus, dorsal view; 4: aedeagus, ventral view; 5: aedeagus, lateral view. Not reproduced to the same scale.