Agrilus concinnus

Distinguished from other Agrilus species by its relatively large size, vivid red pronotum contrasting with black elytra, and late-season adult activity period. Most other eastern North American Agrilus species are active in spring rather than late summer. Association with Hibiscus host plants in wetland habitats provides additional diagnostic context. Similar in color pattern to Agrilus fuscipennis and A. vittaticollis, but differs in host plant association and seasonal timing.

Relatively large for the genus Agrilus, with a vivid red pronotum and black elytra. Considered by some entomologists to be the most beautiful species in the genus in North America. The striking color combination of bright red and black distinguishes it from the typically smaller, more drab members of this hyperdiverse genus.

Wetland habitats supporting stands of Hibiscus species, particularly sloughs, wet bottomland forests, and areas where water tends to stand. Associated with mature, natural stands of host plants rather than disturbed or recently established populations. In Missouri, found in the southeastern lowlands region.

North America: documented from Missouri, Kansas, Florida, Georgia, Illinois, and Texas. In Missouri, concentrated in the southeastern lowlands. The species appears to be more widespread than historically recognized, but remains localized to suitable wetland habitats with established Hibiscus populations.

Adults active from late July through early August, with peak activity coinciding with Hibiscus bloom period. This represents an unusually late seasonal occurrence compared to most other eastern North American Agrilus species, which are typically spring-active. The late seasonality contributed to its historical perception as rare.

Larvae mine the crowns and main roots of living Hibiscus plants. Adults feed on upper leaf surfaces of host plants.

• Hibiscus lasiocarpus - larval hosthairy mallow, rose mallow; primary host documented in Missouri
• Hibiscus moscheutos - larval hostincluding subspecies lasiocarpos
• Hibiscus laevis - adult associationadults collected on this host but larval association not confirmed

Larvae develop as miners in living host plant tissue, specifically in the crown and main root areas of Hibiscus plants. This biology differs from many other Agrilus species that develop in dead wood. Adults emerge in late summer when host plants are flowering.

Adults perch, mate, and feed on upper leaf surfaces of host plants. They are active during daylight hours and can be located by searching Hibiscus plants in peak bloom. Adults are capable of flight and will move between host plants.

As a specialist herbivore on Hibiscus, contributes to the natural herbivore load on wetland mallow populations. Larval mining in living root tissue may influence plant vigor in dense infestations, though population levels are typically low.

No significant economic impact. Of interest to coleopterists due to its striking appearance and historical rarity. The species has been used as an example of how apparent rarity in insects often reflects inadequate knowledge of biology and phenology rather than true scarcity.

• Agrilus fuscipennisSimilar large size and red-and-black color pattern, but associated with Diospyros virginiana (persimmon) rather than Hibiscus, and active earlier in season
• Agrilus vittaticollisSimilar color pattern with red pronotum and dark elytra, but associated with Amelanchier (serviceberry)
• Agrilus impexusAnother large, striking Agrilus species, but associated with prairie vegetation rather than wetlands and with different coloration
• Paragrilus tenuisAlso associated with Hibiscus, but much smaller (~5 mm), with different antennal structure (antennae received in grooves along pronotum sides), and active earlier in season

Formerly considered one of the rarest Agrilus species in North America based on few museum specimens and limited records. This apparent rarity was largely an artifact of its late-season adult activity period and specific association with living Hibiscus plants, which were not routinely sampled by collectors focused on spring-active species and dead wood habitats.

• Buprestidae
• jewel beetle
• wetland specialist
• Hibiscus associate
• late-season phenology
• North America
• southeastern Missouri
• red-and-black coloration
• living host miner

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• Agrilus fuscipennis on Persimmon | Beetles In The Bush
• North America’s Most Beautiful Agrilus Jewel Beetle | Beetles In The Bush
• One-shot Wednesday: The “other” hibiscus jewel beetle | Beetles In The Bush
• Life at 8X—hibiscus flea beetle | Beetles In The Bush
• Art and Bob and Ted’s Excellent Adventure | Beetles In The Bush
• August | 2022 | Beetles In The Bush