Contents - LAC Biosafety

where the outbreak was observed. The level of damage was lower in stands where
the host trees were less dense. Two waves of outbreaks occurred in the first year
of observation, but none in the following year.
Ophiusa spp. (Noctuidae) on Palaquium and mangrove in Indonesia
Kalshoven (1953) reported that outbreaks of the caterpillar Ophiusa serva
occurred on Palaquium sp. which often constitutes 50% or more of the crop in
some primary forests in South Sumatra, Indonesia. Another species, O. melicerta
(syn. Achaea janata) is reported to have caused near total defoliation of a
mangrove species Excoecaria agallocha over a stretch of 500–1000 ha of forest
south of Belawan in North Sumatra, where the tree occurs essentially as single
species stands (Whitten and Damanik, 1986).
Cleora injectaria (Geometridae) on the mangrove Avicennia alba in Thailand
Piyakarnchana (1981) reported that on one occasion a vast area of the
mangrove species Avicennia alba in the Gulf of Thailand was defoliated by the
larvae of Cleora injectaria (Lepidoptera: Geometridae). Although this insect is
known to feed also on Rhizhophora mucronata, during the outbreak R. mucronata,
as well as R. apiculata, which were mixed within the avicennia forest were not
attacked.
Teak pests (Hyblaeidae and Pyralidae) in India and Myanmar
4.2 Empirical findings 85
Hyblaea puera is a well-known defoliator of teak in plantations in many
countries in Asia, but outbreaks are known to occur in natural forests as well.
Nair and Sudheendrakumar (1986) reported heavy defoliation of isolated teak
trees or small groups of trees in natural forests in the Kerala and Karnataka
States in India. Fairly high-density infestations over larger patches of
teak-bearing natural forests have also been observed in Myanmar, in Nagalaik
Reserve Forest where teak trees occur at greater densities (Nair, 2001a).
Outbreaks of H. puera have also been reported in natural stands of the mangrove
Avicennia marina, an alternative host, on the Bombay coast of India (Chaturvedi,
1995). The biology and dynamics of defoliation of this insect are discussed in
detail in Chapter 10.
Outbreaks of another caterpillar Eutectona machaeralis (Pyralidae) periodically
occur on teak in India. Extensive outbreaks of this insect in natural teak areas in
central India were reported as early as 1892–98 (Thompson, 1897; Fernandez,
1898). Thompson wrote that the whole forest where teak predominates had a
sombre brown appearance due to skeletonization of leaves caused by the insect.
He added ‘‘on 27th July, I traversed 32 miles, principally through teak forest and