Protaetia fusca (Herbst, 1790)

Sub family: Cetoniinae / Tribe: Cetoniini / Genus: Protaetia / Subgenus: Protaetia

Medium sized polygonal shaped and dorsoventrally flattened beetles. Body length 12-17mm,  body colour dull matte dark grey/brown, reddish brown to black. Can also be occasionally metallic/shiny green. Speckled areas of cream/white microtrichia present. Clypeus subquadrate, occasionally slightly emarginate, densley punctured and setose. Pronotum smooth with irregular punctures, denser towards lateral margins. Elytra with 4-5 longitudonal grooves, elytral suture raised into a keel. Males with apical spines protruding from rear of elytral suture. Mesometasternum with a large, shiny smooth intercoxal process.

Detailed larval descriptions are given in Simpson (1990).

While the genus Protaetia contains 34 different Subgenera, and over 250 species, only two species are known from mainland Australia- P. fusca and the little known P. advena. Two other species are only known from Coccus (Keeling) or Christmas Island territories.

Glycyphana is the only other representative of Cetoniini in Australia.

Protaetia can be separated from G. stolata through its larger size (12-17mm compared to 8-11mm) and differing scale patterning, the presence of longitudonal grooves on the elytra, lack of c-shaped punctures covering the pronotum, and a more pronounced emargination of the posterior margin of the pronotum around the scutellum. The mesometasternal process is also smooth and intact, lacking a setal covered lateral groove.

It can be readily separated from the exotic Tropinota hirta presented in the key here, which is smaller in size (8-13mm), a grey black body colouration and densely covered in white/yellow setae.

Protaetia fusca is a recognised minor pest species. While the larvae have been described as important plant detritus feeders, the adults feed on flowers, new growth and fruit of a wide range of plants. Their damage is mechanical, with beetles heavily damaging flowers to obtain pollen/nectar. They are also known to damage growing points, feeding on sap from the wounds. In Australia they have been known to cause damage to avocado, citrus, fig, peach and rose, and have been observed on young apple trees. Their host list is much more extensive and includes cassia, coconut, ginger, mango, lychee, corn and even poinciana trees.

P. fusca has shown considerable invasive spread beyond its native range. It is distributed throughout the Oriental region, from India, China and throughout South-East Asia. It has been introduced into Hawaii, Mauritius, Japan, Fiji, the USA, and the West Indies. In Australia it is present across QLD and NSW, into NT and more recently WA.

Flower Chafers of NSW Fact Sheet: https://keys.lucidcentral.org/keys/v3/aus_museum/flower_chafers/key/Cetoniinae/Media/Html/pfusca.htm

Hawaiian Scarab ID Fact Sheet: http://idtools.org/id/beetles/scarab/factsheet.php?name=15219

Simpson, G.B. 1990. Immature stages of Protaetia fusca (Herbst) (Coleoptera: Scarabaeidae: Cetoniinae) with notes on biology. Journal of the Australian Entomological Society 29: 67-73

Woodruff, R. 2006. The Asian mango flower beetle, Protaetia fusca (Herbst), and Euphoria sepulcralis (Fabricius) in Florida and the West Indies (Coleoptera: Scarabaeidae: Cetoniinae). Insecta Mundi 20: 227-232