Broad-necked Root Borer

Prionus laticollis

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Coleoptera
Suborder: Polyphaga
Superfamily: Chrysomeloidea
Family: Cerambycidae
Subfamily: Prioninae
Tribe: Prionini
Genus: Prionus
Species: laticollis

Pronunciation

How to pronounce Prionus laticollis: /ˈpriː.ə.nəs ˌlæ.tɪˈkoʊ.lɪs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Prionus Laticollis with ovipositer extended laying eggs by Cute Little Sweet Rainbow Stag Beetles. Used under a CC BY-SA 4.0 license.

Three eggs laid by Prionus laticollis on July 18, 2017 by Cute Little Sweet Rainbow Stag Beetles. Used under a CC BY-SA 4.0 license.

Illustrations of Exotic Entomology I 37 by Plates: Dru Drury (1725–1803). Text: John Obadiah Westwood (1805–1893). Used under a Public domain license.

Prionus laticollis by Cute Little Sweet Rainbow Stag Beetles. Used under a CC BY-SA 4.0 license.

The flower and the bee; plant life and pollination (1918) (14592681790) by Lovell, John Harvey, 1860-1939. Used under a No restrictions license.

Prionus laticollis eggs taken 9 days after laid by Cute Little Sweet Rainbow Stag Beetles. Used under a CC BY-SA 4.0 license.

Summary

Prionus laticollis, or Broad-necked Root Borers, is a root-boring longhorn beetle noted for its size dimorphism, with females being flightless and larger than males. Its larvae are destructive to roots of various trees and shrubs, requiring careful management in affected areas.

Physical Characteristics

20-50 mm in length, very dark coloration, with irregular punctures on elytra and three indistinct longitudinal ridges. Pronotum is as broad as the base of elytra and has three blunt lateral teeth on each side. Antennae have 12-13 segments. Females are larger than males and are reported to be flightless or nearly so.

Identification Tips

Distinctive rugose-punctate elytral texture and antennae with 12 antennomeres. Compared to Prionus pocularis, which is more brown with a narrower base of pronotum and different elytral punctation.

Habitat

Deciduous forests, commonly found at the base of oak trees and other food sources.

Distribution

Widespread throughout eastern North America, ranging from Quebec in the northeast to Arkansas in the southwest.

Diet

Adults eat foliage and may damage fruit trees and grapevines. Larvae feed on the living roots of various trees and shrubs, may initially feed on bark before progressing to hollow the roots.

Life Cycle

The life cycle is probably three years; pupation occurs in spring about 10 cm under the ground.

Reproduction

Females lay eggs in groups (usually twos or threes) in the soil or under litter using an ovipositor, which they position down into the soil. Eggs change color as they develop, going from white to deep yellow, then to light washed pink, and finally ivory as larvae grow.

Ecosystem Role

Larvae can damage trees and other plants by feeding on their roots, impacting tree health.

Collecting Methods

Light trapping (for males)
Hand collecting