Horned passalus beetle of the bess beetle family is indigenous to North America, particularly Florida, Massachusetts, Southern Texas, Nebraska, Minnesota, and the Manitoba and Ontario regions of Canada. They belong to the category of saproxylic beetles since wood forms a significant part of their diet. Though researchers have used this beetle to study different aspects of the family they belong to, this species remains rare.
Size: 30 – 40 mm (1.18 – 1.57 inches)
Color: The horned passalus beetles have a shiny, black body with golden hairs seen on their antennae, legs, and pronotum. The hairs are so tiny that they remain out of sight to the naked eye.
Other Characteristic Features: This species does not exhibit sexual dimorphism. The male and female beetles look closely the same in size and appearance. One of their striking features is the deep groove present on their elytra and pronotum’s midline. A curved horn sits on the top of their head and in between their eyes. They even have robust mandibles and ten-segmented antennae.
The larva appears large and white, with grub-like features. , growing up to three instars. They are found in the galleries the adults make in the stumps and decayed rocks. The larvae cannot eat on their own. Their parents mainly feed them predigested wood for a year, which is the time they take to develop.
At the beginning of the pupal phase, they have a pearly white body with a rainbow-like sheen. As they mature, this sheen eventually fades away, and the pupa attains white or earth-toned colorations like gray and brown. When on the verge of emergence, they get translucent. The pupation period’s duration depends on the climatic conditions of the particular place where the pupa inhabits.
The eggs are big, growing to about 3.7 mm in length and 3.2 mm in width just before they hatch.
| Other Names | Patent-leather beetle |
| Adult lifespan | One year |
| Duration of larval stage | 6 – 12 months |
| Distribution | Different parts of North America |
| Habitat | Deciduous forests, mostly where oak and elm trees grown, found within decayed wood |
| Common Predators | Not recorded |
| Seasons active from | March – June |
| Host Plants | Elm, oak |
| Diet of larvae and adults | Larvae: Fungi and predigested wood they get from their parents Adults: Wood |
They do more good than harm since these beetles help to decompose the deadwood by chewing the pulp and then expelling the frass. They would not touch the fresh and good wood since the horned passalus beetle mostly prefers fallen logs or those showing signs of decay. Littered sawdust around and below the logs, then it is a sign of these beetle’s infestation.
Image Source: lh3.ggpht.com, live.staticflickr.com,objects.liquidweb.services, bugguide.net, inaturalist-open-data.s3.amazonaws.com, objects.liquidweb.services
Horned passalus beetle of the bess beetle family is indigenous to North America, particularly Florida, Massachusetts, Southern Texas, Nebraska, Minnesota, and the Manitoba and Ontario regions of Canada. They belong to the category of saproxylic beetles since wood forms a significant part of their diet. Though researchers have used this beetle to study different aspects of the family they belong to, this species remains rare.
Size: 30 – 40 mm (1.18 – 1.57 inches)
Color: The horned passalus beetles have a shiny, black body with golden hairs seen on their antennae, legs, and pronotum. The hairs are so tiny that they remain out of sight to the naked eye.
Other Characteristic Features: This species does not exhibit sexual dimorphism. The male and female beetles look closely the same in size and appearance. One of their striking features is the deep groove present on their elytra and pronotum’s midline. A curved horn sits on the top of their head and in between their eyes. They even have robust mandibles and ten-segmented antennae.
The larva appears large and white, with grub-like features. , growing up to three instars. They are found in the galleries the adults make in the stumps and decayed rocks. The larvae cannot eat on their own. Their parents mainly feed them predigested wood for a year, which is the time they take to develop.
At the beginning of the pupal phase, they have a pearly white body with a rainbow-like sheen. As they mature, this sheen eventually fades away, and the pupa attains white or earth-toned colorations like gray and brown. When on the verge of emergence, they get translucent. The pupation period’s duration depends on the climatic conditions of the particular place where the pupa inhabits.
The eggs are big, growing to about 3.7 mm in length and 3.2 mm in width just before they hatch.
| Other Names | Patent-leather beetle |
| Adult lifespan | One year |
| Duration of larval stage | 6 – 12 months |
| Distribution | Different parts of North America |
| Habitat | Deciduous forests, mostly where oak and elm trees grown, found within decayed wood |
| Common Predators | Not recorded |
| Seasons active from | March – June |
| Host Plants | Elm, oak |
| Diet of larvae and adults | Larvae: Fungi and predigested wood they get from their parents Adults: Wood |
They do more good than harm since these beetles help to decompose the deadwood by chewing the pulp and then expelling the frass. They would not touch the fresh and good wood since the horned passalus beetle mostly prefers fallen logs or those showing signs of decay. Littered sawdust around and below the logs, then it is a sign of these beetle’s infestation.
Image Source: lh3.ggpht.com, live.staticflickr.com,objects.liquidweb.services, bugguide.net, inaturalist-open-data.s3.amazonaws.com, objects.liquidweb.services
