Contents - LAC Biosafety

254 Insect pests in plantations: case studies
Among stem-boring insects, an unidentified cossid of the genus Prionoxystus is
common on saplings in Indonesia. In East Kalimantan, 5–70% of the saplings
were infested by Prionoxystus sp. (Ngatiman and Tangketasik, 1987). In a clonal
multiplication nursery at Sebulu in East Kalimantan about 80% of the saplings
that were stumped to produce multiple shoots were infested by this borer
(Nair, 2000). At the same site, an unidentified small borer was found to damage
shoot cuttings maintained in the nursery for rooting (Nair, 2000).
Pest profile
Craspedonta leayana (Coleoptera: Chrysomelidae)
Craspedonta leayana (Latreille) (Coleoptera, Chrysomelidae) (Fig. 10.19a,b),
known until recently by the synonym Calopepla leayana Latreille, has been
recognized since the 1920s as a serious pest of G. arborea in northern India,
Bangladesh and Myanmar. This chrysomelid beetle of the subfamily Cassidinae,
is 12–16 mm long and has a brilliant metallic colouration, with coarsely
wrinkled, bluish green to violet blue elytra and pale yellow to reddish brown
pronotum and legs. The larva has a characteristic appearance, with lateral
spines. As in other cassidines, the excrement, instead of being ejected is extruded
in fine, black filaments, longer than the body, and formed into bunches attached
to the anal end. The moulted exuviae are also carried attached to the last
abdominal segment. When disturbed, the larva flicks the anal filaments up and
down and assumes a defensive posture.
Fig. 10.19 Craspedonta leayana. (a) Adult (length 12 mm), (b) larva. After Ahmad and
Sen-Sarma (1990).