BIODIVERSITY OF INSECTS ASSOCIATED WITH FRUITS OF Gymnacranthera paniculata WARB, Macaranga aleuritoides MUELL AND Mastixiodendron pachyclados MELCH IN NEW GUINEA FORESTS

By

Kari Sogera Iamba (150320132501)

Research Supervisors:1. Dr. Ir. Danar Dono, M.Si2. Yusup Hidayat, SP., M.Phil., Ph.D

Universitas PadjadjaranJatinangor

2015

1.1 Background of Research

• Three fruit-bearing tree species, Gymnacranthera paniculata (MYRISTICACEAE), Macaranga aleuritoides (EUPHORBIACEAE) and Mastixiodendron pachyclados (RUBIACEAE) were investigated for fruit-eating insect communities.

• These trees are predominant in Wanang Conservation Area, used as building material for their houses, firewood for cooking food, garden tools, for growing mushrooms (protein source of diet) and their roots prevents soil erosion.

• There has not been a detailed study into the frugivorous insect composition on these 3 tree species

• The findings from this study is important for formulation of environment and conservation policies.

1. INTRODUCTION

1.2 Problem Identification

• Firstly fruit-eating insect biodiversity has not been documented in New Guinea Forests in regard to their communities and composition on Gymnacranthera paniculata, Macaranga aleuritoides and Mastixiodendron pachyclados.

• Secondly, their role in maintaining high plant diversity in New Guinea Forests has not been tested on these three woody plants as pertaining to Connell-Janzen Hypothesis (Connell, 1971; Janzen, 1980).

1.3 Research Objectives

• This study; (i) examine the composition of fruit-feeding insects (beetles,

moths, flies, parasitoids) for three locally abundant species, Gymnacranthera paniculata (Myristicaceae), Macaranga aleuritoides (Euphorbiaceae) and Mastixiodendron pachyclados (Rubiaceae)

(ii) study the response of fruit-feeding insects to different local abundance of each tree species (i.e. testing the

Connell-Janzen Hypothesis on density-dependent attack of fruits).

1.4 Benefits of Research

• The findings will contribute to the ecology of tropical forests, particularly the biodiversity of fruit-eating insects and dynamics of tree species, including species important for human usage.

• The three host tree species are beneficial to the local communities living in the vicinity of the study area

1.5 Frame Work of Research

• These trees are native and are predominant mostly in the New Guinea lowland tropical rainforests

• Forms an important part of people’s livelihood, therefore the roles of frugivorous insects and their roles in maintaining high plant diversity in New Guinea Forests must be investigated for better conservation.

1.6 Hypothesis

• This study will test the following hypothesis;

(i) A high biodiversity of fruit-eating insects and their natural enemies (parasitoids) exist on these tree species Gymnacranthera paniculata (Myristicaceae), Macaranga aleuritoides (Euphorbiaceae) and Mastixiodendron pachyclados (Rubiaceae).

(ii) Fruit-eating insects act in a density-dependent manner, increasing the percentage of attack with increasing fruit density in the forest.

2.1 Field Fruit Sampling

• Location: Wanang Conservation Area (5o13 ʹS, 145o04 ʹE, 100 m asl), Madang, Papua New Guinea.

• Period: January to April, 2015• Vegetation: Mixed evergreen rain forest on Latosol with a humid

climate, mean annual rainfall of 3600 mm, a mild dry season from July to September, and mean annual temperature of 26 °C.

• Sampling method: Systemic sampling (row by row)• Collection: Fresh fallen undamaged fruits collected on the ground

under parent trees using 2x2 m quadrat.• Feeding guilds were based on the type of food resources associated

with fruits that the insects were feeding on and part of fruit that insects protrude (seed and/or flesh) (Ctvrtecka et al., 2014).

• Data: Entry in data sheet

2. METHODOLOGY

Materials Fruit collection Field data record

SamplesInsect rearingInsect collection

Specimen Moth mounting Data entry datasheet

2.2 Laboratory Insect Sorting and Identification

• Location: New Guinea Binatang Research Center (NGBRC), Madang, Papua New Guinea

• Period: May to June, 2015• Aids of Identification: reference text books, online insect

databases (www.buglife.com), NGBRC insect database and reference collections of NGBRC.

• Identification: Insect specimens were sorted initially into morpho-species and given codes based on their distinct morphological features. Then identified to genus and species level.

• Data: Recored in data sheet then transfered to MS Excel to detect density-dependent patterns of attack.

• Host specificity: monophagous (M) for species feeding on a single plant species, congeneric (CG) for species feeding on > 1 congeneric species, confamilial (CF) for species feeding on > 1 confamilial genus, and allofamilial (AF) for species feeding on > 1 family (Ctvrtecka et al. 2014) .

• The infestation rates were analysed using general linear modelling Y = b0 + b1X + ε in Minitab 17.

• Insect composition analyzed by Pearson Correlation test and ANOVA.

• Species diversity: • Species richness:

• Species evenness: (E) = H/Hmax

2.3 Data Analysis

3. RESULTS3.1 Diversity of Frugivorous Insects Table 1. Gymnacranthera paniculata (Myristicaceae)

Species No. of Individuals

P1 |In P1| (P1) |In P1|

ANIS001 (Anisopodidae) 1 0.0054348 5.214935758 0.028342042 COCCXXX (Mimemodes sp.) 1 0.0054348 5.214935758 0.028342042 DROS001 (Drosophilidae) 74 0.4021739 0.910870664 0.366328419 LONC001 (Lonchaeidae) 8 0.0434783 3.135494216 0.136325835 LYGA001 (Lygaeidae) 1 0.0054348 5.214935758 0.028342042 MYCE001 (Mycetophilidae) 1 0.0054348 5.214935758 0.028342042 NITI002 (Phenolia sp.2) 5 0.0271739 3.605497845 0.097975485 NITI003 (Cillaeus sp.) 6 0.0326087 3.423176288 0.111625314 PERIS001 (Periscelididae) 5 0.0271739 3.605497845 0.097975485 PSYC001 (Psychodidae) 20 0.1086957 2.219203484 0.24121777 SCOL164 (Coccotrypes dactyliperda) 29 0.1576087 1.847639928 0.291204119 SCOL174 (Xyleborus metacuneolus) 8 0.0434783 3.135494216 0.136325835 SCOL194 (Xyleborinus saxeseni) 2 0.0108696 4.521788577 0.049149876 TIPU001 (Tipulidae) 15 0.0815217 2.506885557 0.20436567 XXXX358 (Blastobasis sp.) 6 0.0326087 3.423176288 0.111625314 ZZZZ000 (Non-ID moth family) 2 0.0108696 4.521788577 0.049149876 Total 184 1.00 2.006637167 Spp. Diversity index: 2.006637167 Spp. Richness index: 1.179535649 Spp. Evenness index: 0.723741373

Table 2. Macaranga aleuritoides (Euphorbiaceae)Species No. of

Individuals P1 |In P1| (P1) |In P1|

AGON001 (Agonoxenidae) 2 0.001031992 6.876264612 0.007096248 ANIS001 (Anisopodidae) 1 0.000515996 7.569411792 0.003905785 BRAC001 (Braconidae) 6 0.003095975 5.777652323 0.017887468 COCC004 (Spaerosoma sp.) 49 0.025283798 3.677591494 0.092983479 CURC433 (Haplonyx sp.) 13 0.006707946 5.004462435 0.033569665 DROS001 (Drosophilidae) 147 0.075851393 2.578979206 0.195619166 FORM001 (Formicidae) 1 0.000515996 7.569411792 0.003905785 LEWAN01 (Thiotricha sp.) 6 0.003095975 5.777652323 0.017887468 LYGA001 (Lygaeidae) 1 0.000515996 7.569411792 0.003905785 MUSC001 (Muscidae) 2 0.001031992 6.876264612 0.007096248 NITI001 (Phenolia sp.1) 2 0.001031992 6.876264612 0.007096248 NITI002 (Phenolia sp.2) 1 0.000515996 7.569411792 0.003905785 NITI003 (Cillaeus sp.) 7 0.003611971 5.623501643 0.020311925 PERIS001 (Periscelididae) 332 0.17131063 1.764276824 0.302239373 PHOR001 (Phoridae) 1 0.000515996 7.569411792 0.003905785 PSYC001 (Psychodidae) 156 0.080495356 2.519555785 0.20281254 SCOL164 (Coccotrypes dactyliperda) 1112 0.57378741 0.555496318 0.318736793 SCOL174 (Xyleborus metacuneolus) 24 0.012383901 4.391357962 0.054382142 SCOL194 (Xyleborinus saxeseni) 70 0.036119711 3.32091655 0.119950546 TIPU001 (Tipulidae) 5 0.002579979 5.95997388 0.01537661 TORY001 (Torymidae) 3 0.001547988 6.470799504 0.010016717 Total 1938 1.00 1.442591566 Spp. Diversity index: 1.442591566 Spp. Richness index: 0.477026393 Spp. Evenness index: 0.473831806

Table 3. Mastixiodendron pachyclados (Rubiaceae)

Species No. of Individuals

P1 |In P1| (P1) |In P1|

ANIS001 (Anisopodidae) 1 0.003460208 5.666426688 0.019607013 ANTH A1 (Araecerus sp.2) 9 0.031141869 3.469202111 0.108037436 ANTH A2 (Araecerus sp.3) 3 0.010380623 4.567814399 0.047416758 ANTH A3 (Araecerus sp.4) 1 0.003460208 5.666426688 0.019607013 ANTH A4 (Araecerus sp.5) 2 0.006920415 4.973279508 0.034417159 ANTH002 (Araecerus sp .1) 10 0.034602076 3.363841595 0.116395903 BRAC001 (Braconidae) 73 0.252595156 1.375967247 0.347562661 CURC141 (Baris sp.) 44 0.152249135 1.882237054 0.286568963 CURC321 (Conotrachelus sp.) 6 0.020761246 3.874667219 0.080442918 CURC433 (Haplonyx sp.) 1 0.003460208 5.666426688 0.019607013 DROS001 (Drosophilidae) 13 0.044982699 3.101477331 0.139512821 EUCO001 (Eucoilidae) 1 0.003460208 5.666426688 0.019607013 EULO001 (Eulophidae) 1 0.003460208 5.666426688 0.019607013 ICHN001 (Ichneumonoidea) 1 0.003460208 5.666426688 0.019607013 MUSC001 (Muscidae) 5 0.017301038 4.056988776 0.070190117 NITI002 (Phenolia sp.2) 4 0.01384083 4.280132327 0.059240586 PERIS001 (Periscelididae) 2 0.006920415 4.973279508 0.034417159 PHOR001 (Phoridae) 1 0.003460208 5.666426688 0.019607013 SCOL164 (Coccotrypes dactyliperda) 16 0.055363322 2.893837966 0.160212483 SCOL174 (Xyleborus metacuneolus) 2 0.006920415 4.973279508 0.034417159 SCOL194 (Xyleborinus saxeseni) 1 0.003460208 5.666426688 0.019607013 TIPU001 (Tipulidae) 14 0.048442907 3.027369358 0.146654571 XXXX324 (Mussidia pectinicornella) 72 0.249134948 1.389760569 0.346237927 XXXX358 (Blastobasis sp.) 1 0.003460208 5.666426688 0.019607013 ZZZZ000 (Non-ID moth family) 5 0.017301038 4.056988776 0.070190117 Total 289 1.00 2.258377854 Spp. Diversity index: 2.258377854 Spp. Richness index: 1.470588235 Spp. Evenness index: 0.701604528

3.2 Density of Frugivorous Insects

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Total Insect density (Pearson Correlation = -0.254, P-Value < 0.001)

G. paniculata (Pearson Correlation = - 0.022, P-Value > 0.05)

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M. aleuritoides (Pearson Correlation = - 0.276, P-Value < 0.001)

M. pachyclados (Pearson Correlation = - 0.109, P-Value > 0.05

3.3 Host Specificity Table 4. Insect Host Specificity (> 10 individuals )

Host tree Insect Morpho-species Total abundance

Host Specificity

Gymnacranthera paniculata

DROS001 (Drosophilidae) 74 #Generalist PSYC001 (Psychodidae) 20 +Preference TIPU001 (Tipulidae) 15 +Preference SCOL164 (Coccotrypes dactyliperda) 29 Generalist

Macaranga aleuritoides

DROS001 (Drosophilidae) 148 Generalist PERIS001 (Periscelididae) 332 *Specialist PSYC001 (Psychodidae) 156 +Preference SCOL164 (Coccotrypes dactyliperda) 1112 #Generalist SCOL174 (Xyleborus metacuneolus) 24 *Specialist SCOL194 (Xyleborinus saxeseni) 70 *Specialist COCC004 (Spaerosoma sp.) 49 *Specialist CURC433 (Haplonyx sp.) 13 *Specialist

Mastixiodendron pachyclados

DROS001 (Drosophilidae) 13 #Generalist TIPU001 (Tipulidae) 14 +Preference SCOL164 (Coccotrypes dactyliperda) 15 #Generalist BRAC001 (Braconidae) 73 *Specialist CURC141 (Baris sp.) 44 *Specialist XXXX324 (Mussidia pectinicornella) 72 *Specialist ANTH002 (Araecerus sp .1) 10 *Specialist

(a)(b)

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G. paniculata M. aleuritoides

M. pachyclados

3.4 Feeding Guild of Frugivorous Insects

3.5 Reared Frugivorous Insects3.5.1 Diptera (flies) reared on G. paniculata

Figure 1. Families of Diptera; Anisopodidae (a), Drosophilidae (b), Lonchaeidae (c), Periscelididae

(d), Mycetophilidae (e), Psychodidae (f) and Tipulidae (g).

3.5.2 Coleoptera (beetles) reared on G. paniculata

Figure 2. Mimemodes sp. (Cucujoidea) (a), Phenolia sp.2 (Nitidulidae) (b), Cillaeus sp. (Nitidulidae) (c),

Coccotrypes dactyliperda (d), Xyleborus metacuneolus (e), and Xyleborinus saxeseni (f).

3.5.3 Lepidoptera (moths) reared on G. paniculata

3.5.4 Diptera (flies) reared on M. aleuritoides

Figure 3. Blastobasis sp. (Blastobasidae).

Figure 4. Phoridae (a) and Musicdae (b)

a

b

3.5.5 Coleoptera (beetles) reared on M. aleuritoides

Figure 5. Phenolia sp.1 (Nitidulidae) (a), Haplonyx sp. (Curculionidae) (b), and Spaerosoma sp. (Cucujoidea) (c).

3.5.6 Lepidoptera (moths) reared on M. aleuritoides

Figure 6. Thiotricha sp. (Gelechiidae)

3.5.7 Parasitoid: Hymenoptera (wasps) on M. aleuritoides

Figure 7. Braconid wasp

3.5.8 Coleoptera (beetles) reared on M. pachyclados

Figure 8. Baris sp. (Curculionidae) (a) and Conotrachelus sp. (Curculionidae)

a b

a bc

de

Figure 9. Araecerus Sp.1 (a), Araecerus Sp.2 (b), Araecerus Sp.3 (c), Araecerus Sp.4 (d), and Araecerus Sp.5 (e).

3.5.9 Lepidoptera (moths) reared on M. pachyclados

Figure 10. Mussidia pectinicornella (Pyralidae)

4. DISCUSSION

4.1 Diversity of Frugivorous Insect Species• Each of the three host trees had different fruit-eating insect

diversity (H,) species richness (D) and species evenness (E). • The insect diversity associated with fruits was highest in M.

pachyclados since it possess larger seed size than other two plant species and has soft endocarp (seed) for ease of penetration by frugivorous insect larvae.

• G. paniculata (H= 2.007) with second highest insect diversity was attributed to its soft mesocarp and semi-soft endocarp (seed) that permits penetration by insect larvae.

• M. aleuritoides (H= 1.443) was least diverse probably due to its seeds being shielded with chemical defences and mechanical defences of mesocarp.

4.2 Density of Frugivorous Insects• Density of insects (number of insects per 1 kg fruits) generally

decreases with increasing fruit density. • Decreasing trend might be due to herbivore satiation (Burkey,

1994; Forget et al. 1999; Kelly et al. 2000). • Supported by low seed infestation of true seed feeders like

Scolytinae , Curculionidae, Anthribidae, Pyralidae, Blastobasidae, Gelechiidae and Agonoxenidae.

• Another factor in decrease of insect density maybe Host-parasitoid relationships since parasitoids may contribute to the decline of host frugivorous insects thus leading to lower insect densities.

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HostParasitoid

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y = 4.024 – 0.677x

Figure 11. Positive correlation between host and

parasitoid on Macaranga aleuritoides and statistically

significant (Pearson r = -0.443, P < 0.05).

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y = 3.449 – 0.3807x

Figure 12. Positive correlation between host and

parasitoid on Mastixiodendron pachyclados and

statistically significant (Pearson r = -0.222, P < 0.05).

4.3 Host Specificity of Frugivorous Insects• Monophagy was found to be rarer in frugivorous beetles in New

Guinea forest.• Species of Drosophilidae reproduce on a wide range of resources

such as fruits, sap, flowers, mushrooms and cacti where host chemistry may pose great challenges for Drosophila species .

• Psycodidae, Mycetophilidae, Periscelididae and Tipulidae are considered as decomposers and recyclers of decaying materials such as rotting logs, fruits and othe decaying matter .

• Coccotrypes dactyliperda (Scolytinae) was considered generalist • Varying abundances on each woody plant may be due to host

plant chemistry, morphology and food resources they offered

4.4 Feeding Guild of Frugivorous Insects• Feeding guilds were based on the food resources provided or

associated with fruits and part of fruit fed on. • Seeds are often shielded with chemical and mechanical defences • Specialists such as seed predators which possess detoxifying

mechanisms attack seeds which are mainly chemically protected• Mesocarp is thought to be less chemically defended than seeds • Specialists who will often be in low numbers than the mesocarp

feeders. • Drosophilidae is both frugivore and scavenger.• Tephritid flies were not reared mainly due to very thin fruit mesocarp.• Nitidulidae (Phenolia & Cillaeus sp.) are considered both scavengers

and as fungal-feeders (mycetophagous)• Feeding guilds varied according to resources insect prefer as provided

by fruits either for their reproduction, food resources or both.

5. Conclusion

• The biodiversity of fruit-eating insects in New Guinea Forests and their roles in maintaining high plant diversity in tropical forests is important.

• Communities of frugivorous insects feed on fruits of tropical forest trees and their host specificity and unique feeding guilds plays a very important role in the plant’s distribution.

• Other factors such as host-parasitoid relationships, herbivore satiation, distance-density fruit patterns and competition among frugivorous insects may have contrasting effect on the Janzen-Connell hypothesis.

• Contributes to better understanding of the ecology of tropical forests, particularly the dynamics of tree species, and potential role of frugivorous insects in it.

End of Presentation

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