Southern Pine Beetle – Dendroctonus spp.

Southern Pine Beetle (Dendroctonus spp.) Latin Name: Dendroctonus Zimmermann Common Name: Southern pine bark beetle, bark beetle Appearance:

• Eggs are around 1.5 X 1.0 mm, oval in form, lustrous, opaque, and pearly white.
• Larvae are wrinkled, legless, yellowish-white with reddish heads and range from 2 to 7 mm in length.
• Pupae are the same overall hue as larvae and the same general shape and size as adults.
• Adults are 2 to 4 mm long, have short legs, are cylindrical, and are brown to black. The wide and large male head features a characteristic notch or frontal groove on male beetles. A wide, raised transverse ridge (mycangium) runs along the anterior pronotum of females.
• Adults have a rounded back end or abdomen. Callow (new) adults gradually change color from yellowish-white to yellowish-brown to reddish-brown to dark brown.

Host plants:

1. frontalis will feed on various coniferous hosts, including exotic Pinus species, Picea species, and Tsuga species. The commercially significant species of southern yellow pine is a key host in the southern United States. Longleaf pine, P. palustris, is the most resistant to colonization by this insect among the southern yellow pines.

Territory: The southern pine beetle has historically had a widespread distribution in the southern, southeastern, and northeastern United States. Damage caused by Southern pine bark beetle: The southern pine beetle (SPB), Dendroctonus frontalis Zimmermann, is the pine’s most damaging insect pest in the southern United States. In east Texas, it colonizes sensitive pine trees in large numbers, producing damage that leads to fast decline and death of afflicted trees, medically innocuous. Infested trees perish swiftly owing to gallery girdling and a blue stain fungus. Before dropping, the needles of infected pines become yellow, then crimson. Life history and Habits: Adults leave a host tree and fly to a new host tree, where they begin digging into the bark to build galleries. They emit an attractant chemical (pheromone) that attracts and mates additional beetles. Adult females lay eggs in galleries and hatch into cream-colored, legless grub-like larvae with brown heads in 3 to 34 days, depending on temperature. Larvae grow through four stages (instars) until they reach about 1/4 inch in length before pupating, which takes 15 to 40 days. Adults emerge in 17 days. A generation might take anywhere from 26 to 54 days to complete. In Texas, seven to nine generations (several of which overlap) might occur each year.