Longhorn beetle assemblage composition
A total of 4090 individuals, 56 species, and 6 subfamilies of longhorn beetles were collected in the natural Mongolian oak forest. There were 2199 individuals belonging to 22 species of Cerambycinae, 1154 individuals belonging to 20 species of Lamiinae, 41 individuals belonging to 11 species of Lepturinae, only one species belonging to Aseminae, Prioninae, and Disteniinae, and 689 individuals belonging to Prioninae. Of the 56 species of longhorn beetles, only Massicus raddei (Blessig), Plagionotus pulcherpulcher (Blessig), Rhaphuma gracilipes (Faldermann), Mesosa myopsmyops (Dalman), Moechotypa diphysis (Pascoe), and Prionus insularis Motschulsky accounted for more than 1% of the total. There were 43 species and 2119 individuals in the canopy (H) and 40 species and 1914 individuals in the bottom (L). There were 39 species and 1782 individuals on the ridge (A), 34 species and 1370 individuals on the southern slope (B), and 29 species and 938 individuals on the northern slope (C) (Table 3).
Table 3 Longhorn beetles assemblage composition
Subfamilies/Species
|
Canopy
(H)
|
Bottom
(L)
|
Ridge
(A)
|
Southern slope(B)
|
Northern slope(C)
|
Total
|
%
|
Cerambycinae
|
|
|
|
|
|
|
|
Amarysius sanguinipennis (Blessig)
|
1
|
0
|
0
|
0
|
1
|
1
|
0.02
|
Anaglyptus colobotbeoides (Bates)
|
9
|
4
|
1
|
7
|
5
|
13
|
0.33
|
Chlorophorus motschulskyi (Ganglbauer)
|
1
|
0
|
0
|
1
|
0
|
1
|
0.02
|
Chlorophorus sexmaculatus (Motschulsky)
|
1
|
0
|
0
|
0
|
1
|
1
|
0.02
|
Chlorophorus sulcaticeps Pic
|
2
|
2
|
2
|
2
|
0
|
4
|
0.10
|
Chlorophorus tohokensis Hayash
|
1
|
0
|
0
|
1
|
0
|
1
|
0.02
|
Cyrtoclytus capracapra (Germar)
|
8
|
18
|
7
|
10
|
9
|
26
|
0.65
|
Massicus raddei (Blessig)
|
990
|
643
|
785
|
549
|
299
|
1633
|
39.93
|
Obrium obscuripenne Pic
|
0
|
1
|
0
|
0
|
1
|
1
|
0.02
|
Oupyrrhidium cinnabarium cinnabarium (Blessig)
|
0
|
1
|
0
|
1
|
0
|
1
|
0.02
|
Plagionotus pulcherpulcher (Blessig)
|
154
|
91
|
106
|
105
|
34
|
245
|
5.99
|
Purpuricenus sideriger Fairmaire
|
1
|
0
|
1
|
0
|
0
|
1
|
0.02
|
Rhaphuma acutivittis (Kraatz)
|
1
|
3
|
2
|
0
|
2
|
4
|
0.10
|
Rhaphuma gracilipes (Faldermann)
|
85
|
103
|
52
|
77
|
59
|
188
|
4.60
|
Rhopalopus speciosus Plavilstshikov
|
1
|
0
|
1
|
0
|
0
|
1
|
0.02
|
Trichoferus campestris (Faldermann)
|
7
|
4
|
2
|
8
|
1
|
11
|
0.28
|
Trichoferus guerryi (Pic)
|
5
|
1
|
2
|
4
|
0
|
6
|
0.15
|
Xylotrechus clarinus Bates
|
4
|
3
|
3
|
0
|
4
|
7
|
0.18
|
Xylotrechus cuneipennis cuneipennis (Kraatz)
|
27
|
13
|
11
|
13
|
16
|
40
|
0.98
|
Xylotrechus pyrrhoderus Bates
|
0
|
2
|
2
|
0
|
0
|
2
|
0.05
|
Xylotrechus rufilius Bates
|
8
|
3
|
3
|
6
|
2
|
11
|
0.28
|
Chloridolum sieversi (Ganglbauer)
|
1
|
0
|
1
|
0
|
0
|
1
|
0.02
|
Lamiinae
|
|
|
|
|
|
|
|
Acalolepta fraudatrix (Bates)
|
0
|
1
|
0
|
0
|
1
|
1
|
0.02
|
Acanthocinus griseus (Fabricius)
|
1
|
0
|
1
|
0
|
0
|
1
|
0.02
|
Anoplophora glabripennis Breuning
|
0
|
1
|
0
|
1
|
0
|
1
|
0.02
|
Eumecocera impustulata (Motschulsky)
|
1
|
3
|
2
|
1
|
1
|
4
|
0.10
|
Eutetrapha metallescens (Motschulsky)
|
0
|
5
|
4
|
0
|
1
|
5
|
0.12
|
Exocentrus fisheri Gressitt
|
6
|
0
|
1
|
4
|
1
|
6
|
0.15
|
Lamiomimus gottschei Kolbe
|
3
|
10
|
7
|
6
|
0
|
13
|
0.33
|
Leiopus stillatus (Bates)
|
2
|
1
|
3
|
0
|
0
|
3
|
0.07
|
Menesia sulphuratasulphurata (Gebler)
|
1
|
0
|
0
|
0
|
1
|
1
|
0.02
|
Mesosa hirsute Bates
|
4
|
0
|
0
|
4
|
0
|
4
|
0.10
|
Mesosa myopsmyops (Dalman)
|
264
|
110
|
135
|
173
|
66
|
374
|
9.14
|
Moechotypa diphysis (Pascoe)
|
456
|
241
|
258
|
323
|
116
|
697
|
17.04
|
Monochamus guttulatus (Gressitt)
|
5
|
1
|
5
|
0
|
1
|
6
|
0.15
|
Neacanista tuberculipennis Gressitt
|
31
|
1
|
16
|
11
|
5
|
32
|
0.79
|
Oplosia suvorovi (Pic)
|
1
|
0
|
0
|
0
|
1
|
1
|
0.02
|
Pterolophia angusta (Bates)
|
1
|
0
|
0
|
1
|
0
|
1
|
0.02
|
Pterolophia rigida (Bates)
|
0
|
1
|
1
|
0
|
0
|
1
|
0.02
|
Rhopa loscelisunifasciatus Blessig
|
0
|
1
|
1
|
0
|
0
|
1
|
0.02
|
Ropica dorsalis Schwarzer
|
1
|
0
|
1
|
0
|
0
|
1
|
0.02
|
Egesina bifasciana Matsushita
|
1
|
0
|
0
|
1
|
0
|
1
|
0.02
|
Lepturinae
|
|
|
|
|
|
|
|
Anastrangalia sequensi (Reitter)
|
2
|
8
|
7
|
3
|
0
|
10
|
0.24
|
Anoplodera cyanea (Gebler)
|
3
|
2
|
4
|
0
|
1
|
5
|
0.12
|
Gaurotes ussuriensis Blessig
|
1
|
2
|
1
|
2
|
0
|
3
|
0.07
|
Leptura arcuata Panzer
|
2
|
7
|
3
|
2
|
4
|
9
|
0.23
|
Macroleptura thoracica (Creutzer)
|
1
|
3
|
1
|
2
|
1
|
4
|
0.10
|
Macropidonia ruficollis (Pic)
|
0
|
1
|
0
|
1
|
0
|
1
|
0.02
|
Pedostrangalia femoralis (Motschulsky)
|
2
|
0
|
1
|
1
|
0
|
2
|
0.05
|
Pidonia gibbicollis (Blessig)
|
2
|
2
|
0
|
2
|
2
|
4
|
0.10
|
Rhagium inquisitor japonicum (Bates)
|
0
|
1
|
0
|
1
|
0
|
1
|
0.02
|
Stictoleptura succedanea (Lewis)
|
0
|
1
|
0
|
1
|
0
|
1
|
0.02
|
Stictoleptura variicomis (Dalman)
|
0
|
1
|
1
|
0
|
0
|
1
|
0.02
|
Aseminae
|
|
|
|
|
|
|
|
Arhopalus rusticus (Linnaeus)
|
0
|
2
|
2
|
0
|
0
|
2
|
0.05
|
Prioninae
|
|
|
|
|
|
|
|
Prionus insularis Motschulsky
|
75
|
614
|
344
|
44
|
301
|
689
|
16.85
|
Disteniinae
|
|
|
|
|
|
|
|
Distenia gracilis (Blessig)
|
3
|
2
|
2
|
2
|
1
|
5
|
0.12
|
Total
|
2176
|
1914
|
1782
|
1370
|
938
|
4090
|
100
|
Among the 56 species, 16 species were distributed only in the canopy (H), 13 species were distributed only in the bottom (L), and 27 species were distributed in both positions, as shown in Figure 1a. Among the 17 species distributed on the ridge, the southern slope, and the northern slope, 11 species were distributed only on the ridge, 10 species were distributed only on the southern slope, and 6 species were distributed only on the northern slope, as shown in Figure 1b.
Species-abundance distribution with different vertical heights and slope directions
When the number of traps was low, there was no significant difference in the number of species between the canopy and the bottom. When the number of traps exceeded 10, the number of species in the canopy (H) was higher than that in the bottom (L). Under different topographic conditions, longhorn beetles collected by the same number of traps had higher number of species on the ridge (A), followed by the southern slope (B) and the northern slope (C), as shown in Figure 2 (a, b).
The richness and abundance in the canopy and bottom
Two-factor ANOVA was carried out for species number and individual number of longhorn beetles between topographic conditions (A, B, C) and vertical heights (H, L). The results showed that the interaction between topographic conditions and vertical height had no significant influence on the richness and abundance of the longhorn beetles, but the topographic conditions had a significant influence on the richness and abundance, while vertical height had a significant influence on the number of species (Table 4).
Table 4 Repeated-measures MANOVA for topographic conditions and vertical height, and the interactive effects of number of species and number of individuals
Factors
|
d.f.
|
Individuals (N)
|
Species (S)
|
F
|
P
|
F
|
P
|
HL
|
1,94
|
0.46
|
0.499
|
5.069
|
0.027*
|
ABC
|
2,45
|
4.486
|
0.014*
|
3.962
|
0.022*
|
HL×ABC
|
2,45
|
0.865
|
0.424
|
0.246
|
0.782
|
With respect to the spatial vertical distribution, the richness and abundance of longhorn beetles in the canopy (H) were significantly higher than those in the canopy (L) (Q1,94 = 6.737; p = 0.009; Q1,94 = 7.681; p = 0.006). Among all the subfamilies, the numbers of species and individuals of Cerambycinae were the highest, and the richness and abundance in the canopy (H) were significantly higher than those in the bottom (L) (Q1,94 =11.308; p = 0.001; Q1,94 =8.696; p = 0.003). The numbers of species and individuals of Lamiinae were the highest, and the richness and abundance in the canopy (H) were significantly higher than those in the bottom (L) (Q1,94 =11.765; p=0.01; Q1,94 =16.200; p=0.000). There was no significant difference in the richness and abundance of Lepturinae in the canopy (H) and the bottom (L) (Q1,94 =1.800; p=0.180; Q1,94 =1.800; p=0.180) (Figure 3).
The richness and abundance of longhorn beetles on the ridge, southern slope, and northern slope
The richness of longhorn beetles on the ridge (A) and southern slope (B) was significantly higher than that on the northern slope (C) (Q2, 93 =9.453, p=0.009), and the abundance on the ridge (A) was significantly higher than that on the northern slope (C) (Q2, 93 =12.438, p=0.002) (Figure 2a). Among the major subfamilies, there was no significant difference in the richness of Cerambycinae on the ridge (A), southern slope (B), and northern slope (C) (Q2, 93 =1.528, p=0.446), but the abundance was significantly higher on the ridge (A) and southern slope (B) than on the northern slope (C) (Q2, 93 =9.276, p=0.01) (Figure 2b). The richness and abundance of Lamiinae on the ridge (A) and southern slope (B) were significantly higher than those on the northern slope (C) (Q2, 93 =14.000, p=0.001; Q2, 93 =6.397, p=0.041) (Figure 2c). The richness and abundance of Lepturinae were not significantly different among the ridge (A), southern slope (B), and northern slope (C) (Q2, 93 =1.104, p=0.576; Q2, 93 =1.114, p=0.564) (Figure 2d).
Indicator species
With respect to vertical height, three longhorn beetles were significantly associated with traps placed in the canopy (H), and one species was significantly associated with the bottom (L). Among the three directions, Massicus raddei (Blessig) was significantly associated with the ridge (A), and Mesosa myopsmyops (Dalman) was significantly associated with the ridge and the southern slope (B). On the ridge (A), Mesosa myopsmyops (Dalman), Moechotypa diphysis (Pascoe), and Neacanista tuberculipennis Gressitt were significantly associated with the ridge canopy (AH), and Prionus insularis Motschulsky and Lamiomimus gottschei Kolbe were significantly associated with the ridge bottom (AL). On the southern slope (B), Mesosa myopsmyops (Dalman) and Neacanista tuberculipennis Gressitt were significantly associated with the southern canopy (BH), and Prionus insularis Motschulsky was significantly associated with the southern bottom (BL). Only Mesosa myopsmyops (Dalman) was significantly associated with the northern canopy (CH) on the northern slope (Table 5).
Table 5 Significant trap height associations based on indicator species analysis
Location combination
|
Spatial position
|
Species
|
IV
|
p
|
Number of individuals
|
H×L
|
H
|
Mesosa myopsmyops (Dalman)
|
66.2
|
0.0001
|
374
|
|
H
|
Neacanista tuberculipennis Gressitt
|
32.3
|
0.0001
|
32
|
|
H
|
Plagionotus pulcherpulcher (Blessig)
|
48.5
|
0.0187
|
245
|
|
L
|
Prionus insularis Motschulsky
|
70.5
|
0.0002
|
689
|
A×B×C
|
A
|
Massicus raddei (Blessig)
|
48.1
|
0.0038
|
1633
|
|
B
|
Mesosa myopsmyops (Dalman)
|
41.9
|
0.0265
|
374
|
A
|
AH
|
Mesosa myopsmyops (Dalman)
|
75.6
|
0.0002
|
374
|
|
AH
|
Moechotypa diphysis (Pascoe)
|
77.5
|
0.0152
|
697
|
|
AH
|
Neacanista tuberculipennis Gressitt
|
41.0
|
0.0170
|
32
|
|
AL
|
Prionus insularis Motschulsky
|
76.3
|
0.0068
|
689
|
|
AL
|
Lamiomimus gottschei Kolbe
|
37.5
|
0.0184
|
13
|
B
|
BH
|
Mesosa myopsmyops (Dalman)
|
66.5
|
0.0398
|
374
|
|
BH
|
Neacanista tuberculipennis Gressitt
|
37.5
|
0.0193
|
32
|
|
BL
|
Prionus insularis Motschulsky
|
55.4
|
0.0497
|
689
|
C
|
CH
|
Mesosa myopsmyops (Dalman)
|
57.9
|
0.0485
|
374
|
Community composition
Non-metric multidimensional scaling yielded a two-dimensional solution with a final stress of 22.88. The R2 values were 0.45 (axis 1) and 0.31 (axis 2). It was clear from the two-dimensional depiction of these results (based on axes 1 and 2) that the longhorn beetle assemblage sampled in the canopy (H) was compositionally distinct from that sampled at the bottom (L), and the beetle assemblage in the canopy (H) and at the bottom (L) of the three positions (A, B, C) differed (Figure 5).
The PerMANOVA results indicated that the longhorn beetle assemblage sampled in the canopy (H) was compositionally distinct from that at the lower level (L) (t = 2.54, p = 0.0018). There was a significant difference in the assemblage composition on the three positions (t = 2.47, p = 0.0014); the ridge (A) was compositionally distinct from the southern slope B (t = 1.810, p = 0.003) and the northern slope (C) (t = 1.723, p = 0.004). There was a significant difference between the assemblage composition of traps placed in the ridge canopy (AH) and on the southern slope canopy (BH) (t = 1.902, p = 0.003), and on the southern slope canopy (BH) and on the northern slope canopy (CH) (t = 1.426, p = 0.048). Only on the ridge (A), beetle assemblages composition were different on the canopy (AH) from those on the bottom (AL) (t = 2.157, p = 0.0006) (Table 6).
Table 6 The PerMANOVA results of the beetle assemblage sampled at different positions
Sampling position
|
df
|
t
|
p
|
HL
|
1, 94
|
3.538
|
0.0018*
|
ABC
|
2, 93
|
2.468
|
0.0014*
|
A-B
|
|
1.810
|
0.003*
|
B-C
|
|
0.937
|
0.516
|
A-C
|
|
1.723
|
0.004*
|
ABCHL
|
5, 90
|
2.173
|
0.001*
|
AH-BH
|
|
1.902
|
0.003*
|
AH-CH
|
|
0.911
|
0.531
|
BH-CH
|
|
1.426
|
0.048*
|
AL-BL
|
|
1.031
|
0.378
|
AL-CL
|
|
0.938
|
0.836
|
BL-CL
|
|
1.291
|
0.091
|
AH-AL
|
|
2.157
|
0.0006*
|
BH-BL
|
|
0.906
|
0.602
|
CH-CL
|
|
1.178
|
0.203
|
Correspondence analysis of longhorn beetles and different positions
The individual number of 56 species of longhorn beetles from 6 subfamilies was square root transformed. Correspondence analysis was conducted between the canopy (H) and bottom (L) and the ridge (A), southern slope (B), and northern slope (C) for 6 subfamilies and 56 species of longhorn beetles, and the results are shown in Figure 6(a, b). In Figure 6 (a), the contribution rate of the first axis was 60.07%, and that of the second axis was 39.93%. The cumulative contribution rate was 100%, and the eigenvalue = 0.18. In Figure 6 (b), the contribution rate of the first axis was 39.08%, and that of the second axis was 17.36%. The cumulative contribution rate was 56.44%, and the eigenvalue = 0.36.
Among the six subfamilies, Lamiinae (n1), Lepturinae (n2), Disteniinae (n4), and Cerambycinae (n5) had a strong correlation with the slope direction of the ridge (A) and southern slope (B). Prioninae (n3) had a strong correlation with the ridge (A) and northern slope (C), while Aseminae (n6) had only one species collected from the ridge (A). In the bottom and canopy under different topographic conditions, only one species of Aseminae (N6) was collected from the bottom of the ridge (A), and only one species of Prioninae (N3) was closely related to the ridge bottom (AL) and northern slope bottom (CL). Lepturinae (n2) was closely related to the ridge bottom (AL), while Lamiinae (n1) and Cerambycinae (n5) were closely related to the ridge canopy (AH), southern slope canopy (BH), and northern slope (CH).
The majority of the 56 species of longhorn beetles were closely related to the ridge canopy (AH), southern slope canopy (BH), and northern slope (CH). Among the species with more individuals, Mesosa myopsmyops (Dalman) (11), Moechotypa diphysis (Pascoe) (12), Massicus raddei (Blessig) (41), and Plagionotus pulcherpulcher (Blessig) (44) were closely related to the ridge canopy (AH), southern slope canopy (BH), and northern slope (CH), while Rhaphuma gracilipes (Faldermann) (47) was closely related to the southern slope bottom (BL) and northern slope bottom (CL). Prionus insularis Motschulsky (32) was closely related to the ridge bottom (AL) and northern slope bottom (CL).