-
THE HOST SPECIFICITY AND THEBARK BEETLES
Introduction:Knowing the host specificity and the community
structure of a group is important in understanding its biology.
This study examined host associations and community structure of
bark beetles by rearing them from artificially killed trees.
(2) Selected trees
Eight species of trees were selected for this study
1. Ficus nodosa2. Ficus pachystemon3. Artocarpus communis4.
Pterocymbium beccarii5. Litsea timoriana6. Myristica sp.7. Alstonia
brassii8. Pouteria sp.
(3), Killing target trees,Trees were killed by removing the bark
in a ring at breast height then let standing in the bush about a
month to dry and get infested.
Methods:(1) Study area
Our research took place in the lowland rainforests near
Madang.
4, Tree parts,
Twigs
Branches
Trunk
Roots
Timber samples were separated into different parts of tree.
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(5) Extractor
Extractors are used to collect bark beetlesemerging from the
timber samples.
(6) Sorting samples
The emerged beetles from the timber samples were sorted into
species and labeled.
(7) Databasing
All the data were added to the insect host specificity
database.
Results(8) Samples obtained
More than 30,000 individuals were obtained from 77 species.
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COMMUNITY STRUCTURE OF PNG
(9)
Species richness
0
4000
8000
12000
Ficus
nodo
sa
Ptero
cymb
ium
Litse
a
Myris
tica
F. pa
chys
temon
Alston
ia
Artoc
arpus
Poute
ria
Indi
vidu
als
0
15
30
45
Spec
ies
SpeciesIndividuals
Species abundance for all trees
0
1000
2000
3000
4000
5000
6000
1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64
67 70 73 76
Species
Indi
vidu
als
Host range
0 2 4 6 8
12345678
No.
of h
ost u
sed
No. of bark beetle species
A few species dominate the bark beetle community.while most of
the others are very rare.
(10)
Ficus nodosa had the greatest number of individuals and species
while Pouteria sp. had the poorest community.
(11) (12)
0%
20%
40%
60%
80%
100%
Ficus nodosa &F.pachystemon
Ficus & Artocarpus Moraceae &Sterculiaceae
% o
f spe
cies
Shared speciesNot shared
Overlap in bark beetle species between different hosts
The bark beetle community exhibited low host specificity.Only
18% of the species were reared from just one tree.
Many bark beetle species are shared between different Many bark
beetle species are shared between different host plant species,
genera and familieshost plant species, genera and families..
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(13)
Host part preference
0
5
10
15
20
25
Trunk Branches Twigs Roots
No.
of s
peci
esHost part specificity
0 2 4 6 8 10 12
1
2
3
4
No.
of p
arts
use
d
No. of species
Bark beetles were most commonly found on the trunk and only few
species used roots.
(14)
Bark beetles were generally not specific to any one part of the
tree and were most often found on three parts of the host tree:
trunk, branches and twigs
The bark beetle communities are dominated by a few very abundant
species, and most of the other species are rare. Bark beetles are
not very host specific, and not limited to only one part of the
tree.
Prepared by Martin Mogia in collaboration with Mark Andreas,
Mark Andreas, JiJiřřii HulcrHulcr & Gregory Setliff&
Gregory SetliffParataxonomist Training Center, PO Box 604, Madang,
Papua New Guinea, [email protected]
•• ParataxonomistParataxonomist Training CenterTraining Center••
The The OhuOhu communitycommunity•• BrusBrus IsuaIsua, Steven ,
Steven SauSau and Erik and Erik BrusBrus & the & the
staff of the staff of the OhuOhu Bush labBush lab••
VojtechVojtech NovotnyNovotny•• National Research Institute of
Papua New GuineaNational Research Institute of Papua New Guinea••
National Science Foundation & Darwin InitiativeNational Science
Foundation & Darwin Initiative
AcknowledgementsAcknowledgements
