--- title: African Black Beetle canonical: https://fernland.com.au/problem-solver/african-black-beetle/ dateModified: 2026-08-07 10:04:30 summary: "African black beetle larvae and adults chew turf roots and stems, causing patchy dieback that is often mistaken for drought stress." type: article keywords: [African Black Beetle, Heteronychus arator] --- # African Black Beetle > African black beetle larvae and adults chew turf roots and stems, causing patchy dieback that is often mistaken for drought stress. *Heteronychus arator* African black beetle is a soil-dwelling scarab beetle established across the warmer turf and pasture growing regions of Australia, particularly coastal and near-coastal New South Wales, Queensland and parts of Victoria and Western Australia. It attacks the roots and crowns of turf grasses, as well as maize, sugarcane, vegetable seedlings and pasture, and is most damaging where warm-season turf is grown on lighter, well-drained soils. The adult beetle is shiny black to dark brown, convex and hard-shelled, roughly 12–15 mm long, with short spines on the front legs used for burrowing. Adults live in the soil by day and are most active at night and during warm, humid conditions, particularly after rain. The larva, commonly called a curl grub, is a creamy-white, C-shaped grub with a brown head and three pairs of legs, growing to around 20–25 mm at full size. Larvae feed on organic matter and turf roots in the top 50–100 mm of soil and curl into a tight C-shape when disturbed. Adult beetles cause the most direct damage to turf by chewing through stems and stolons at or just below the soil surface, and by tunnelling into the crown of the plant. Larvae feed mainly on root systems and organic matter, weakening turf indirectly and making it more susceptible to drought and further beetle attack. Populations build through spring and summer, with adults flying to lay eggs in moist soil from late spring into summer. Eggs hatch into larvae that feed through summer and autumn before pupating and emerging as new adults, giving one main generation per year in most regions, though timing shifts with local climate. Management relies on regular monitoring of at-risk turf, maintaining good plant vigour through appropriate irrigation and fertility to help swards recover from and tolerate low-level feeding, and avoiding stress factors such as compaction or drought that make damage more visible. Cultural practices that reduce thatch and improve root depth can lessen the impact of larval feeding. ## How to identify Look for the following signs of African black beetle activity: - **Patchy, thinning turf** that resembles drought or dry patch stress but does not respond to irrigation. - **Wilting or dead stolons and stems** at ground level, often with visible chew marks or severed shoots where adults have tunnelled into the crown. - **Loose, easily lifted turf** where roots have been pruned by larval feeding, similar to the effect seen with other scarab grubs. - **Increased bird or animal activity** such as digging by birds, foxes or possums searching for grubs near the surface.To confirm the pest, cut and peel back a section of affected turf at the margin of a damaged patch and inspect the top 50–100 mm of soil and thatch. Adult beetles are shiny black, hard-bodied and about 12–15 mm long; curl grub larvae are creamy-white, C-shaped with a brown head, up to about 25 mm long. Finding beetles or grubs in this zone, along with chewed stems at ground level, confirms the diagnosis. **Lookalikes:** African black beetle larvae can be confused with other curl grubs such as African black beetle look-alike scarabs or billbug larvae. True curl grubs have a distinct C-shape, three pairs of legs near the head end and a soft, wrinkled abdomen, whereas billbug larvae are legless and more cylindrical. Adult African black beetle can be distinguished from other black ground beetles by its convex, glossy shell and the short digging spines on its front legs. ## Registered products we stock - [Syngenta Acelepryn GR | Professional Granular Insecticide | 4kg & 10kg](https://fernland.com.au/syngenta-acelepryn-gr-professional-granular-insecticide-4kg-10kg/) — Syngenta - [AntStar 2G Bifenthrin Granular Insecticide](https://fernland.com.au/antstar-2g-bifenthrin-granular-insecticide/) — PCT SureFire - [Initiator Systemic Plant Insecticide & Fertiliser Tablets](https://fernland.com.au/initiator-systemic-plant-insecticide-fertiliser-tablets/) — Envu - [Fivestar Insecticide 80SC](https://fernland.com.au/fivestar-insecticide-80sc/) — PCT SureFire - [Spectrum Systemic Insecticide 200SC](https://fernland.com.au/spectrum-systemic-insecticide-200sc/) — PCT SureFire - [Syngenta Acelepryn SC | Professional Liquid Turf Insecticide | 100ml to 5L](https://fernland.com.au/syngenta-acelepryn-sc-professional-liquid-turf-insecticide-100ml-to-5l/) — Syngenta - [Biff 100SC Insecticide](https://fernland.com.au/biff-100sc-insecticide/) — Colin Campbell Chemicals - [Eco-Neem Botanical Insecticide](https://fernland.com.au/eco-neem-botanical-insecticide/) — Organic Crop Protectants - [Tempo Xtra Turf & Ornamental Insecticide](https://fernland.com.au/tempo-xtra-turf-ornamental-insecticide/) — Envu - [Venom Professional 240SC Insecticide](https://fernland.com.au/venom-professional-240sc-insecticide/) — Adama - [Scarlet Trio Advanced Insecticide](https://fernland.com.au/scarlet-trio-advanced-insecticide/) — ProForce - [Meridian Turf Insecticide](https://fernland.com.au/meridian-turf-insecticide/) — Syngenta - [Moxam 250SC Insecticide](https://fernland.com.au/moxam-250sc-insecticide/) — Colin Campbell Chemicals - [Spinner Turf Insecticide](https://fernland.com.au/spinner-turf-insecticide/) — Syngenta ## Image credits - [Photo: Aimee Macarthur via Wikimedia Commons (CC BY 4.0)](https://commons.wikimedia.org/wiki/File:Heteronychus_arator_114050668.jpg) - [Photo: Tom via Wikimedia Commons (CC BY 4.0)](https://commons.wikimedia.org/wiki/File:Heteronychus_arator_128559998.jpg) - [Photo: Aimee Macarthur via Wikimedia Commons (CC BY 4.0)](https://commons.wikimedia.org/wiki/File:Heteronychus_arator_114050827.jpg) - [Photo: Paul via Wikimedia Commons (CC BY 4.0)](https://commons.wikimedia.org/wiki/File:Heteronychus_arator_112499743.jpg)