Popillia quadriguttata

Potential Invader

Common name(s)

none known

Taxonomy

Family: Scarabaeidae Subfamily: Rutelinae Genus: Popillia Species: Popillia quadriguttata (Fabricius, 1787)

Adult diagnosis

Total body length 8.0–11.0 mm (0.31–0.43 in). Body oval-shaped. Color shining green, sometimes with reddish sheen; elytra shiny brownish. Clypeus rounded; apex somewhat recurved; narrowing toward apex. Front claw toothed, male with toothed claw more robust than in female. Pronotum with dense punctation near anterior border; punctures distinct. Pygidium with 2 vaguely oval-shaped patches formed by dense whitish hairs (sometimes absent in worn specimens).

Larval diagnosis

Undescribed. For Popillia spp. (Ritcher, 1966): Grub C-shaped, not hump-backed, cylindrical, whitish. Maxilla with galea and lacinia fused or nearly so. Frons sparsely punctate. Labrum asymmetrical. Claws sharply pointed. Spiracles on 7th and 8th abdominal segments nearly equal in size. Dorsa of 9th and 10th abdominal segments not fused. Septula shaped like an equilateral triangle, palidia strongly diverging posteriorly; each palidium with 5–7 (rarely 8) long, ensiform pali. Venter of last abdominal segment with 14 or more preseptular, hooked setae.

Native range

East Asia. This species is known from a wide area of East Asia, ranging from North Vietnam, China, Taiwan, to Korea (Lee et al., 2007). Records from the Russian Far East are also known (Chen et al., 2014).

Plant host(s)

(Lee et al., 2002): Like the related Japanese Beetle (Popillia japonica), this species is known to feed on a broad range of host plants from a broad range of plant families. Recorded hosts of adult beetles include: Acalypha australis, indigo bush (Amorpha fruticosa), Artesmia princeps, feather fingergrass (Chloris virgata), Asian hazel (Corylus heterophylla), Dioscorea septembola, soybean (Glycine max), bush clover (Lespedeza cyrtobotrya), Amur privet (Ligustrum obtusifolium), spicebush (Lindera erythrocarpa), Lysimachia burystachys, Herlicteres angustifolia, paradise apple (Malus pumila), Persicaria senticosa, bracken (Pteridium aquilinum), Pyrus spp., sargent cherry (Prunus sargentii), Rhapontica uniflora, Asian raspberry (Rubus parvifolius), bao li (Quercus serrata), Korean willow (Salix koreansis), lyreleaf nightshade (Solanum lyratum), Siberan elm (Ulmus pumila), Japanese wisteria (Wistaria floribunda), Zanthoxylum spp., and corn (Zea mays). Larvae mostly feed on grass roots, though soybeans are also known as hosts (Chen et al., 2014).

Life history

(Lee et al., 2002): In Korea, this species was found to fly most actively between noon and 2 p.m., with particularly vigorous activity occurring on sunny days after a rain. Adults are strictly diurnal and do not come to lights at night. Adults were encountered from late June to late July with abundance peaking in early July. Notably, the appearance of adults corresponded with the onset of the Korean rainy season.

Pest potential

Significant. This species is known to damage a variety of commercially valuable plants, both as adults (Chen et al., 2014) and as larvae (Lee et al., 2002). In China, this species is considered a major pest of soybean (Glycine max). Adults cause significant damage to foliage, buds, and stems, while larvae destroy roots (Chen et al., 2014). In Korea, Popillia quadriguttata is a pest of corn (Zea mays) and fruit trees. Larvae are recognized as important turf-grass pests, particularly on golf courses. The larvae cause direct damage by feeding on the roots of turf-grass, and further harm is inflicted when wildlife dig up turf in search of grubs (Lee et al., 2002).

Status in Hawaii

Not established or recorded. This species has not been recorded in Hawaii, but because it is a widespread pest in East Asia, it has a high potential for introduction.

Status in Guam

Not established or recorded. This species has not been recorded in Guam, but because it is a widespread pest in East Asia, it has a high potential for introduction.

Potential distribution and dispersal pathway

With a native range that spans from tropical Vietnam to the cold temperate forests of the Russian Far East, this beetle is a biosecurity threat not only to Hawaii and Guam, but also to the contiguous U.S. If established, Popillia quadriguttata could become a pest of corn and soybeans in the midwestern U.S., a region similar in climate to northeastern China and Korea. Because adults of this species congregate on foliage, they could be transported on nursery stock. It is also plausible that larvae or eggs could be transported in turf grass or plant roots, the probable manner of the U.S. introduction of the related Popillia japonica (Krischik, 2011).

Similar species

Two Popillia species are recorded from Hawaii and Guam: the well-known Popillia japonica and Popillia lewisi. Popillia quadriguttata is quite similar to both. These species can be separated by examination of the pronotal punctation (P. quadriguttata with dense, distinct punctures near the anterior border versus P. lewisi with sparse, indistinct punctures near the anterior border), pygidium (P. quadriguttata with two vaguely oval-shaped patches of white setae versus P. lewisi with crescent-shaped patches), clypeus (P. quadriguttata with clypeus narrowing at apex, somewhat recurved versus P. japonica with clypeus barely narrowed at apex, strongly recurved), and often size (P. quadriguttata at 8.0–11.0 mm [0.31–0.43 in] versus P. japonica at 9.0–13.7 mm [0.35–0.54 in]).

Other names (synonyms)

Trichius biguttatus Fabricius, Popillia bogdanowi Ballion, Popillia castanoptera Hope, Popillia chinensis Frivaldszky, Popillia dichroa Blanchard, Popillia frivaldszkyi Kraatz, Popillia purpurarescens Kraatz, Popillia ruficollis Kraatz, Popillia sordida Kraatz, Popillia straminipennis Kraatz, Popillia uchidai Niijima and Kinoshita

Report your observation

In Hawaii, this species represents a new invasive species. Prevent the spread of this species by reporting your observation at our iNaturalist project.

Popillia quadriguttata female; photo by E.L. Engasser

Popillia quadriguttata female; photo by E.L. Engasser

Popillia quadriguttata female; photo by E.L. Engasser

Popillia quadriguttata female; photo by E.L. Engasser

Popillia quadriguttata male; photo by E.L. Engasser

Popillia quadriguttata male; photo by E.L. Engasser

Popillia quadriguttata female pygidium, caudal view; photo by E.L. Engasser

Popillia quadriguttata female pygidium, caudal view; photo by E.L. Engasser

Popillia quadriguttata male foretibia; photo by E.L. Engasser

Popillia quadriguttata male foretibia; photo by E.L. Engasser

Popillia quadriguttata female foretibia; photo by E.L. Engasser

Popillia quadriguttata female foretibia; photo by E.L. Engasser

Popillia quadriguttata male foreclaw; photo by E.L. Engasser

Popillia quadriguttata male foreclaw; photo by E.L. Engasser

Popillia quadriguttata female foreclaw; photo by E.L. Engasser

Popillia quadriguttata female foreclaw; photo by E.L. Engasser

Popillia quadriguttata male genitalia, caudal view; photo by E.L. Engasser

Popillia quadriguttata male genitalia, caudal view; photo by E.L. Engasser

Popillia quadriguttata male genitalia, lateral view; photo by E.L. Engasser

Popillia quadriguttata male genitalia, lateral view; photo by E.L. Engasser