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How to identify it
- Adults are oval, light brown to black, and about 5.9 to 7.6 mm (0.23 to 0.30 inch) long.[1]
- A deep, sharply cut line runs along the front edge of the pronotum, the plate behind the head; this and body size are the main features that set it apart.[1]
- Like most burrower bugs, it has legs built for digging; its shins carry many stiff spines angled at about 45 degrees.[1]
- Nymphs look like small, lighter brown adults. The youngest are beige, and the last stage is darker with visible wing pads.[1]
- Eggs are about 1 mm long, light yellow to white, and develop two small red eyespots before hatching.[1]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| White-margined burrower bug | Another burrower bug found in peanut fields. In South Carolina its nymphs showed up in May and June, probably drawn by henbit seeds, and none were present during pod formation; only the peanut burrower bug was tied to kernel feeding.[2] |
| Other burrower bugs (Cydnidae) | Many burrower bugs live in crop soils, but of those found in peanut fields the peanut burrower bug is the only economically important one.[1] |
Where it lives
Native to North and Central America. In the US it has been recorded from New York to Florida along the Atlantic coast, west through Ohio, southern Wisconsin and Kansas, and southwest across New Mexico and Arizona into California's Imperial Valley. It is a peanut pest mainly in the Southeast and Texas, and it is one of the primary insect pests in Georgia peanut fields.[1][4]
Biology and life cycle
Adults overwinter in the soil. A Texas study found them 6 to 8 inches deep from December, becoming active again in late February to early March and moving toward the surface; in Georgia, some nymphs stayed active through the winter.[1]
Overwintering adults can already be in a field before peanuts are planted. Females lay eggs in the soil near roots and pods in spring, about 130 eggs per female.[2][1]
There are five nymphal stages, mostly spent below the soil surface feeding on roots or developing kernels. Two to three generations followed the overwintering adults in South Carolina fields, and UF/IFAS cites at least three a year.[1][2]
Few nymphs turn up before the full-seed stage. Populations peak as the kernels reach full size and often stay high until harvest.[2][1]
Strip-tilling peanuts into corn or wheat residue led to more burrower bugs and more kernel feeding than conventional tillage or strip-tilling into rye; cover crops likely give the bugs a place to spend the winter.[2][1]
Damage and signs
- Adults and nymphs feed directly on the peanut seed through the hull. Fed-on kernels show scarred yellow and brown lesions, weigh about 10 percent less, and are unmarketable, which lowers the grade.[1][2]
- In South Carolina, each 10 percent rise in fed-on kernels went with a 1.7 percent drop in sound mature kernels, and feeding on more than 30 percent of kernels raised the risk of damaged-kernel grade penalties.[2]
- The feeding punctures can let in pathogens and aflatoxin. Georgia surveys found preharvest aflatoxin especially where this bug was common, and infested peanuts can lose up to half their value.[1][4][3]
- Infestations are sporadic, and because the bug stays underground the injury often goes unnoticed until after harvest.[1]
Health risk
The sources describe it only as a crop pest. The health concern is indirect: its feeding wounds can be a pathway for aflatoxin contamination of peanut kernels.[1][4]
Control
Prevention
Conventional tillage cuts burrower bug numbers and injury compared with conservation tillage, and fall tillage before a wheat cover crop reduced feeding in one study. Because infestations are sporadic and cover crops and conservation tillage have their own benefits, UF/IFAS does not recommend changing tillage just for this pest.[1][2]
Traps and physical control
There are no economic thresholds or standard sampling plans. Light traps, pitfall traps, inspecting pods and sampling soil are the only known ways to check for it, and trap catches are not yet reliable enough to base decisions on.[1]
Biological control
Little is known about its natural enemies. In laboratory tests, the insect-killing nematode Steinernema carpocapsae killed adults, and combining it with imidacloprid gave significant mortality within three days, but this is still research rather than an established control.[1][3]
Pesticides
Foliar sprays don't reach a pest that attacks pods underground, and UF/IFAS reports no labeled insecticide that gives adequate control.[3][1]
Common questions
- What causes brown, scarred spots on peanut kernels when the shells look fine?
- Peanut burrower bugs feed through the hull from the soil, leaving scarred yellow and brown lesions on the kernels inside.[1]
- Can I spray for burrower bugs in peanuts?
- Not effectively. Foliar sprays don't reach the bugs underground, and no labeled insecticide currently gives adequate control.[3][1]
- Why is it a concern for aflatoxin?
- Its feeding wounds can serve as a pathway for aflatoxin contamination, and Georgia surveys found preharvest aflatoxin especially where the bug was common.[1][4]
Sources
- University of Florida IFAS Extension (EDIS), “The Peanut Burrower Bug, Pangaeus bilineatus (Say) (Hemiptera: Cydnidae) (EENY-821/IN1456).” journals.flvc.org/edis/article/view/137792 (accessed 2026-11-09)
- Entomological Society of America (Journal of Economic Entomology), “Chapin JW, Thomas JS. Burrower bugs (Heteroptera: Cydnidae) in peanut: seasonal species abundance, tillage effects, grade reduction effects, insecticide efficacy, and management. Journal of Economic Entomology 96(4):1142-1152 (2003) (abstract).” doi.org/10.1093/jee/96.4.1142 (accessed 2026-11-09)
- Society of Chemical Industry / Wiley (Pest Management Science), “Mbata GN, Li Y, Shapiro-Ilan D. Evaluation of chemical and microbial control options for Pangaeus bilineatus (Say) (Hemiptera: Cydnidae) infesting peanut crop. Pest Management Science 78(11):4719-4727 (2022) (abstract).” doi.org/10.1002/ps.7092 (accessed 2026-11-09)
- Entomological Society of America (Journal of Economic Entomology), “Danso JK, Mbata GN, Holton RL. Preharvest insect pests of peanuts and associated aflatoxin contaminants in Georgia, USA. Journal of Economic Entomology 117(3):993-1000 (2024) (abstract).” doi.org/10.1093/jee/toae074 (accessed 2026-11-09)
- iNaturalist, “Pangaeus bilineatus taxon page (order and family).” www.inaturalist.org/taxa/152126 (accessed 2026-11-09)