Tile Horned Prionus

Large Beetle
Location: Norfolk, Virginia USA
June 6, 2011 10:31 am
This was on my front door lastnight, cant find a discription of any like it online. It was app. three inches long.
Signature: Bugman

Tile Horned Prionus

This is a Root Borer in the genus Prionus.  It is a male Tile Horned Prionus, Prionus imbricornis.  BugGuide provides this identification information:  “Huge longhorn, dark brown and shining. Antennae have 18-20 overlapping segments (male):  Female has 16-18 serrated segments. Other eastern Prionus have 12-13 antennal segments.”  BugGuide also provides this information which may explain this Tile Horned Prionus’s appearance on your porch if the light was left on:  “On mid-summer nights, these hit lighted windows so hard at my house in Durham, North Carolina, that I fear the glass will break. Seems that mostly males come to lights.”

4 thoughts on “Tile Horned Prionus”

  1. So I know the diet of the larvae consists of the roots of trees, but does anyone know what the diet is of the mature life stage? I’m assuming there is no difference in the diet between the male and female form. And how about the duration of each of the different life cycles. Any thoughts?

    • According to the Utah State University Integrated Pest Management site: “Adults emerge from pupae in the soil in July in northern Utah. The beetles fly at night in search of mates, and eggs are laid in the soil soon thereafter. Young larvae tunnel into the soil to seek out tree roots. Research in a Utah sweet cherry orchard suggests that the younger larvae begin feeding on smaller diameter roots and ultimately reach the tree crown as mature larvae as they move inward and upward along larger roots. The ‘crown’ refers to the region of the trunk (usually at or near the soil level) that represents the transition between below-ground (roots) and above-ground (trunk) growth. In cherries, a greater proportion of the larvae found at the crown were large, mature larvae, while most of the smaller, younger larvae were found in roots. Following 3 or more years of root and crown feeding and upward movement, the insect pupates close to the soil surface. The adults then emerge and seek out mates.” Nothing is said of the diet of adults. We would presume that if they eat at all, the adult Prionids would be attracted to sweet sticky things like sap. We will continue to research this matter.


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