Hypsipyla Shoot Borers of Meliaceae in Sri Lanka - Australian ...

Hypsipyla Shoot Borers of Meliaceae in Solomon Islands
M.L. Ngoro 1
Abstract
Hypsipyla robusta (Moore) is a major pest in the tropics including Solomon Islands. In 1996,
there was about 3545 ha of Swietenia macrophylla Jacq. plantation and the status of the pest needs
to be seriously considered. There are a number of experimental trials of S. macrophylla in which
H. robusta is being studied. It is necessary to research potential biological control of this pest, as
chemical control measures are highly uneconomical to implement in plantations. Treating
H. robusta in the nursery using a systemic insecticide, Orthene, is currently an accepted treatment
in Solomon Islands. Cedrela odorata, another of the Meliaceae, is also planted and is only
minimally attacked by H. robusta.
SOLOMON ISLANDS lies in the Southwest Pacific
between latitude 5° and 12°S and longitude 155°
and170°E and has a total land area of 28 300 km with
a population of 412 902 in 1996. The economy of
Solomon Islands relies heavily upon fishing, agriculture
and forestry. The cultural heritage and economic
development of Solomon Islands is dependent on
forests. Benefits from the forest include poles, fuelwood,
medicinal plants and a range of customary uses.
Overview of Forestry Industry
Solomon Islands is an independent state and relies
mostly on its natural resources for its revenue. The
forest and its people are almost inseparable and thus
the forest is highly valued. Some of the fundamentally
important aspects of forests in Solomon Islands are:
• part of the nation’s cultural heritage and future
economic development;
• environmental and the ecological stability of the
islands is conditioned by the protective covering
of the forest;
• forests cover more than 80% of the land area and
supports the timber industry;
• generate significant amounts of government
revenue;
1 Forestry Research Centre, Forestry Division, PO Box 79,
Munda, Western Province, Solomon Islands
37
• provide employment for 4% of the national workforce;
• earnings from log royalties by resource owners;
and,
• provide fuelwood, poles, food and a variety of
customary uses including medicinal herbs.
Revenue earned from log exports in the late 1990s
has been the largest for any industry in the country.
Estimates of production and revenue earned are
shown in Table 1. However, the sustainability of
these logging practices is currently a controversial
issue.
Table 1. Volume of timber and revenue earnt from
logging in Solomon Islands.
Year Volume (m 3 ) Revenue ($ million)
1993 591 100 73.9
1994 627 952 76.6
1995 733 817 79.3
1996 431 755 (Jan-June) 48.9
The national inventory carried out in 1995 by the
Solomon Island Forest Resources Inventory Project,
funded by AusAID, found that only 8 million ha of
forest remains and is likely to be exhausted in four to
five years. There are many foreign logging companies
operating in Solomon Island with a combined
annual quota of 642 000 m 3 (Table 2).