Ernobius

C.G. Thomson, 1859

deathwatch cone beetles

Species Guides

Ernobius crotchii(Crotch's deathwatch beetle)
Ernobius filicornis
Ernobius granulatus
Ernobius mollis(pine knot borer)

Ernobius is a of small beetles in the Ptinidae (formerly Anobiidae), containing approximately 90 distributed primarily across North America, Europe, and North Africa. Species are commonly known as deathwatch cone beetles due to their specialized association with conifer cones. Several species are significant forest pests that reduce seed storage in commercially important conifers.

Ernobius mollis by (c) Donald Hobern, some rights reserved (CC BY). Used under a CC-BY license.

Ernobius granulatus by (c) Adrienne van den Beemt, some rights reserved (CC BY), uploaded by Adrienne van den Beemt. Used under a CC-BY license.

Pronunciation

How to pronounce Ernobius: /ɛrˈnoʊ.bi.əs/

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

Images

Habitat

Cones of coniferous trees, particularly of Pinus and Picea. Specific documented associations include Pinus radiata cones and Picea mariana (black spruce) cones.

Distribution

North America, Europe, and North Africa. Specific regional records include Newfoundland (Ernobius bicolor) and Scandinavia (Denmark, Norway, Sweden).

Seasonality

from cones peaks February through April for at least some .

Host Associations

Pinus radiata - infests conesErnobius punctulatus
Picea mariana - infests cones, reduces seed storageErnobius bicolor
Fusarium subglutinans f. sp. pini - carries fungal Ernobius punctulatus ; 30.1% carry , with seasonal variation 0-67%
Cephalonomia utahensis - of larvaeHymenoptera: Bethylidae; frequently observed in late-instar larvae of Ernobius punctulatus

Life Cycle

Larval development occurs within conifer cones. Late-instar larvae of Ernobius punctulatus have been observed with the Cephalonomia utahensis.

Behavior

emerge from cones with seasonal peaks. Co-occurrence with other cone-feeding beetles has been documented; Ernobius punctulatus cohabited 26% of cones with Conophthorus radiatae. Potential for interspecific transmission of fungal between .

Ecological Role

Seed in conifer cones, reducing natural seed storage. Potential of pitch canker fungus (Fusarium subglutinans f. sp. pini). for that may further transmit fungal to other prey .

Human Relevance

Ernobius bicolor reduces black spruce seed storage in Newfoundland, with up to 50% of cone crops damaged at some locations and damage averaging 18% across 33 locations (1963-1979). Substantial seed losses occur when infested cones are harvested for seed extraction, threatening natural stand after harvest or fire.

Similar Taxa

ConophthorusBoth infest conifer cones; Ernobius punctulatus co-occurred with Conophthorus radiatae in 26% of Pinus radiata cones, but differs in (Anobiidae/Ptinidae vs. Curculionidae: Scolytinae) and likely .