Insect-pests - Biology East Borneo

24 Insect Pests and Diseases of Major Plantation Species
dipterocarps have been planted for a longer period. An
exception is Shorea robusta (sal) in India, where
devastating outbreaks of a borer, Hoplocerambyx
spinicornis (Coleoptera, Cerambycidae) have
occurred periodically in northern latitudes (Roonwal
1978). There was a large outbreak of a hairy
caterpillar in over 12 000 ha of natural peat swamp
forest of Shorea albida in Sarawak and Brunei during
the 1950s (Anderson 1961). This may be an
exceptional situation but details are sketchy. While
there is no indication of any serious emerging pest
problem in dipterocarps, the situation needs
monitoring. In general, the resin present in
dipterocarps may afford protection against insects.
Diseases do not seem to be a major threat.
4.8. Dyera spp.
Indonesian common name: Jelutung
At least three species of Dyera (Apocynaceae):
D. costulata, D. polyphylla and D. lowii occur in
Indonesia (Whitten et al. 1987; Kessler and Sidiyasa
1994). In Kalimantan, D. costulata and D. polyphylla
occur in lowland swamp forests and they have been
tapped for latex and their soft timber used for
manufacturing plywood, toys, boards, etc.
Plantations of Dyera spp. are being established South
Kalimantan and Jambi provinces.
Insect pests
No information is available.
Diseases
No information is available except for the occurrence
of sapstain fungi on freshly cut logs (Martono 1989).
Threat assessment
Little information is available from other countries.
In Malaysia, where there are trial plantations of
D. costulata (Appanah and Weinland 1993), seeds
were damaged by ants (Duncan 1977) but no major
pests recorded. The timber is susceptible to damage
by powder-post beetles. It appears that there is no
major threat of pests and diseases for plantations of
Dyera spp. Perhaps the latex affords protection as it
does in most other Apocyanaceae.
4.9. Eucalyptus spp.
Indonesian common names: Empupu, Leda,
Ekaliptus
As in many tropical countries, Eucalyptus spp.
(Myrtaceae) have been planted over large areas in
Indonesia for pulpwood production. The main species
planted are E. deglupta and E. urophylla, which are
native to Indonesia although their natural distribution
is in the eastern islands. Many other species have been
tried in small-scale experimental plantations, notably,
E. camaldulensis, E. grandis, E. pellita, E. tereticornis
and E. torelliana. Most plantations are in Sumatra
(Aceh, North Sumatra, Jambi) and Kalimantan (West,
East and South Kalimantan).
Insect pests
In the nursery, eucalypt seedlings may be attacked by
several insects, including a pyralid leaf roller (probably
Archips micaceana), the jassid bug, Kolla bataviae, the
curculionid shoot borer, Alcides sp. and the teamosquito
bug, Helopeltis spp. (Table 4.5) (Hardi 1993;
Rachmatsyah and Haneda 1998). Generally, they have
not posed a major threat, and chemical control methods
have been tested (Hardi 1993). Transplanted saplings
are attacked, particularly during the field establishment
phase, by species of subterranean termites that often
cause substantial mortality unless prophylactic chemical
protection is given (Intari and Natawiria 1976; Selander
1990; Santoso and Hardi 1991). Older plants are
attacked by Helopeltis spp., which cause dieback of
young shoots and are a serious pest in North Sumatra
where up to 57% of trees may be infested (Hardi and
Intari 1990). Saplings are attacked by Zeuzera coffeae
(Lepidoptera, Cossidae), which bore into the stem and
often cause it to break; Suratmo (1996) reported that
12-30% of saplings might be infested in Sumatra and
Kalimantan. Recently, an unidentified borer killed 1000
ha of 2-3-year-old E. deglupta plantation of PT. Hutan
Kusuma (Soepangkat 1998). Most probably, this
damage was caused by the varicose borer, Agrilus
sexsignatus (Coleoptera, Buprestidae) which devastated
some plantations in the Philippines in the 1970s.
Eucalyptus deglupta trees weakened by other
causes and the Papua New Guinea provenances
are very susceptible to this borer whose density in
attacked plants has reached 37 larvae m -2 of wood
surface in the Philippines (Braza 1988, 1992).