Some biological characteristics of longhorn beetle Monochamus alternatus Hope (Coleoptera: Cerambycidae) hamrful Pinus massoniana in some province North Vietnam

Abstract

By the method of rearing in the laboratory combined with field
investigation, some biological characteristics of the species longhorn beetle
(M. alternatus) have been determined: when rearing in an artificial food
environment (t
o
= 25
o
C, w%=70%), the average life cycle completion time
is 222,66 days. When rearing in the environment as natural food
(t
o
=28.6
o
C; w%=78.9%), the average time was 239,8 days. Adult of
longhorn beetle lay eggs and when there are larva will see red -brown wood
mulch extruding. At first, the body is soft and light brown in color, after
about 6 to 12 days of supplementing, the body begins to mature. Adult
longhorn beetle lay eggs most concentrated in 2 hours is from 8 to 10 pm
and 10 to12 pm and an adult individual can lay 1 - 3 eggs each time, they
take from 6 to 11 minutes to lay 1 egg. Eggs: when newly laid are pale
white, then turn yellowish. The larvae of ages of 1th, 2th only feed on the
bark of the tree, at the age of 3th, they begin to attack the core and make
holes in the trunk. Pupa: It is a naked pupa, when it first enters it is milky
white and then gradually turns yellowish white. Longhorn beetle species
appeared with a litter, 1 to 2 generations a year, from the second half of
April to the beginning of October all four stages of development were
recorded. The adult and egg stages are active for 8 months of the year and
the larvae are reported to appear in most months of the year.