Identification and control of red wood bark elephant, a pest of Korean pine

Why is the red wood bark elephant an important pest of young Korean pine trees?

Because the larvae of the red wood bark elephant drill under the skin of the branches of Pinus koraiensis, causing the main and lateral shoots to die. It not only affects the growth of Pinus koraiensis, but also makes the branches dry and split, weakens the growth of the tree, and leads to the invasion and harm of other diseases and insect pests. Moreover, because most of the life cycle of the insect is spent under the bark of branches, it is difficult to control. Once it happens in the forest, it may bring serious consequences of deforestation.

How to identify the mahogany elephant?

The adult is a small beetle, belonging to the weevil class. Dark brown body, long 8~9mm (mm), wide 3~4mm. There is a nose sticking out in front of the head, which is the mouthparts of pests. There are a pair of round white spots on the back and the front of the front wing, and there are "X" white bands at the back end of the front wing. Oval, long 1mm, milky white. The mature larvae are 6~8mm in body length and milky white. The head is yellowish, there are 4 yellow burrs on the tail, and the head and tail are bent to the abdomen. The pupa has long 7~8mm, self-colored milk, yellowish compound eyes and 4 yellow burrs on the tail.

How to master the occurrence law of the mahogany beetle?

The insect occurs for one generation in one year. In early October, the larvae overwintered one after another in the decay path of the trunk phloem. In the second year, the activity began in late April, pupated in late May, adults were found in late June, and mating and oviposition in the first and middle of August. Adults need to feed on Pinus koraiensis treetops before they can lay eggs. Adults have false death and have weak ability to fly. After mating, the female bites a small hole in the branch and lays eggs in the hole. After hatching, the larvae are endangered under the bark, and most of them feed from the bottom up, and the eaten dust and feces are left in the decay path. The larvae have two harmful periods in one year, the first is before June, and the second is from September to October.

The insect mostly occurs in Korean pine plantation at the age of 10 to 30 years, but not under 10 years old. The trees growing on the sunny slope suffered more seriously than the shady slope, the sparse woodland was heavier than the dense forest, and the forest edge was heavier than the inner forest.

How to control the mahogany weevil?

Advocate afforestation under the canopy. Try to avoid afforestation on all-felled land. Avoid building a pure Korean pine forest.

Strengthen forest management measures and remove seriously damaged trees in a timely manner. The pure forest was transformed into coniferous and broad-leaved mixed forest.

In the adult stage, spray 40% dimethoate EC 250 times or 50 fenitrothion EC 500 times to control adults.