Contents - LAC Biosafety

278 Insect pests in plantations: case studies
Rhyacionia (¼ Petrova) (Tortricidae) are involved. Speight and Speechly (1982 a,b)
have reviewed the biology, impact and control of pine shoot moths in Southeast
Asia. Dioryctria species tend to be predominantly cone borers while Rhyacionia
species are predominantly bud or shoot borers. Mixed infestation of the two
groups of moths may sometimes occur on the same tree. For example, in a
plantation of Pinus caribaea in the Philippines, out of about 400 infested shoots
examined, half were infested by both D. rubella and R. cristata and a quarter each
by D. rubella alone and R. cristata alone (Lucero, 1987).
Dioryctria species
Several species of Dioryctria occur on pines in different geographical
regions. Dioryctria abietella is the dominant species, present throughout the
Palaearctic region. Although it has been reported from North America and
Europe from a wide range of hosts including pines, firs, cedars, larches
and spruces, according to CABI (2005), it has formerly been misidentified
and confused with two very closely related species, D. abietivorella which occurs in
North and Central America and D. mutatella which occurs in northern Europe.
Dioryctria species recorded on pines in the tropics are listed in Table 10.11.
The biology and habits of Diocryctria species vary slightly; the details given
below are primarily applicable to D. abietella. The moth has a wingspan of
25–35 mm; its forewing is grey, mottled with black and contrasts markedly with
the lighter hindwing. The larva varies in colour from reddish to greenish, with a
black head, and is about 25 mm long when mature.
Table 10.11. Dioryctria species recorded on tropical pines
Species Country Pine hosts Refs
Dioryctria abietella India P. kesiya, P. roxburghii 1
Thailand P. kesiya, P. merkusii 2
D. rubella Philippines P. kesiya, P. merkusii, P. caribaea 3
Indonesia P. merkusii 4
D. sylvestrella Vietnam P. caribaea 5
Thailand P. kesiya, P. merkusii 2
D. assamensis India P. kesiya 1
D. castanea India P. kesiya 1
D. raoi India P. kesiya 1
D. horneana Cuba P. caribaea 6
D. clarioralis Cuba P. caribaea 6
1, Singh et al. (1982); 2, Hutacharern and Tubtim (1995); 3, Lapis (1987) and Lucero (1987);
4, Natawiria (1990); 5, Speight and Speechly (1982a); 6, Hochmut (1972b).