1
SAND MOISTURE PREFERENCE,
DISTURBANCE EFFECTS AND INTRA- AND INTERSPECIFIC AGGRESSION IN
Microcerotermes crassus Snyder (BLATTODEA:
TERMITIDAE)
NELLIE WONG SU CHEE
UNIVERSITI SAINS MALAYSIA
2010
2
SAND MOISTURE PREFERENCE, DISTURBANCE EFFECTS AND INTRA- AND INTERSPECIFIC AGGRESSION IN Microcerotermes crassus Snyder
(BLATTODEA: TERMITIDAE)
by
NELLIE WONG SU CHEE
Thesis submitted in fulfilment of the requirements for the degree
of Master of Science
2010
3
ACKNOWLEDGEMENTS
I would like to record my express to my supervisor, Professor Lee Chow Yang for his supervision, advice and guidance. Thank you for giving me the opportunity to experience and learn so much throughout my Master Degree candidature.
Sincere thanks to all the staff of School of Biological Sciences, especially to Mr. Somasundram and Kak Sabariah for their technical assistance and equipment support. My project would not have been able to be carried out smoothly if the necessary materials were not available.
My thanks to Dr. Michael Lenz, Janette and Dr. Xing-Ping Hu for your constructive criticisms on my thesis. My thanks also to Dr. Zairi Jaal and Dr. Lee Yean Wang for your advices and also Mr. Lim Kay Min for letting me participate in field observations. Thanks for the experience and share of knowledge.
I would like to take this opportunity also to thank my friends in Urban Entomology Laboratory, Yee Fatt, Kok Boon, Sam, Hui Siang, Tomoki, Ru Yuan, Beng Keok, Evan, Rivo, who not only helped me whenever they could but taught me the value of friendship.
Special thanks to my friends, Diana, Sheena Tiong, Boon Hoi, Ling Eng, Kim Fung, and Ah Bong, who were by me throughout the entire period, cheering me up, keeping me company, sharing stories and laughs.
This dissertation could also not have been written without the support of my loved ones; mum, dad, Alan, and Christopher. Their presence gave me the strength and discipline to continue trying and succeeding.
Most importantly, I give thanks to the Lord for giving me the wisdom and directions in life always.
4
TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS
ii
TABLE OF CONTENTS iii
LIST OF TABLES vi
LIST OF FIGURES vii
LIST OF PLATES ix
LIST OF ABBREVIATION xii
LIST OF PUBLICATIONS & SEMINARS xiii
ABSTRAK xvi
ABSTRACT xviii
CHAPTER ONE: INTRODUCTION 1
CHAPTER TWO: LITERATURE REVIEW
2.1 Termites in the Order Blattodea 4
2.2 General information on termites 5
2.3 Ecological importance of termites 6 2.4 Damages by termites
2.4.1 Termite as pests of growing trees and timber 8
2.4.2 Termite as an urban problem 10
2.5 Basic biology of termites
2.5.1 Identifying characters 11
2.5.2 Colony structure and life history 13
2.5.3 Nests 16
2.5.4 Food preference and feeding behaviour 17
2.6 Termite control 19
2.7 Effects of disturbances towards termites 20
CHAPTER THREE: EVALUATION OF SEVERAL SUBSTRATES AGAINST Microcerotermes crassus Snyder IN LABORATORY STUDIES
5
3.1 Introduction 21
3.2 Materials and methods
3.2.1 Termites 23
3.2.2 Preparation of sterilised sand, vermiculite, 5% agar and
sawdust 23
3.2.3 Assay 24
3.2.4 Data analysis 25
3.3 Results and discussion
3.3.1 General observation 25
3.3.2 Wood consumption study 28
3.3.3 Tunnel formations 31
3.3.3 Survival study 32
CHAPTER FOUR: INFLUENCE OF DIFFERENT SAND MOISTURE LEVELS ON CONSUMPTION AND MOVEMENT PATTERNS OF
Microcerotermes crassus Snyder (Termitidae) AND Coptotermes gestroi Wasmann
(Rhinotermitidae) IN LABORATORY ASSAYS
4.1 Introduction 35
4.2 Materials and methods
4.2.1 Termites 37
4.2.2 Assay
4.2.2.1 Sand moisture preference 38
4.2.2.2 Tunnelling behaviour and pattern 40 4.2.3 Data analysis
4.2.3.1 Sand moisture preference 40
4.2.3.2 Tunnelling behaviour and pattern 42 4.3 Results and discussion
4.3.1 Sand moisture preference 42
4.3.2 Tunnelling behaviour and pattern 54
6
CHAPTER FIVE: INTRA- AND INTER-SPECIFIC AGONISTIC BEHAVIOURS OF SUBTERRANEAN TERMITES, Microcerotermes crassus Snyder (Termitidae)
5.1 Introduction 60
5.2 Materials and methods 5.2.1 Termites
5.2.1.1 Intraspecific study 61
5.2.1.2 Interspecific study 61
5.2.2 Assay
5.2.2.1 Intraspecific aggression 62
5.2.2.2 Interspecific aggression 64
5.2.3 Data analysis 64
5.3 Results and discussion
5.3.1 Intraspecific aggression 67
5.3.2 Interspecific aggression 68
CHAPTER SIX: EFFECTS OF DISTURBANCE AND THE PRESENCE OF TERMITES AND OTHER INVERTEBRATE CARCASSES AT THE FEEDING SITES ON THE BEHAVIOUR OF Microcerotermes crassus Snyder (Termitidae) IN THE LABORATORY
6.1 Introduction 81
6.2 Materials and methods
6.2.1 Termites 83
6.2.2 Assay 83
6.2.3 Data analysis 86
6.3 Results and discussion 86
SUMMARY AND CONCLUSION 104
REFERENCES 108
VITA 124
7
LIST OF TABLES
Page Table 3.1: Wood consumed (gm) (mean ± S. E. M.), tunnelling
distance (cm) (mean ± S.E.M) and number of tunnel branches (mean ± S.E.M) by M. crassus in dishes with and without presence of nest materials after 14 days.
30
Table 4.1: Tunnelling distance (mean ± S. E. M.) of M. crassus and C. gestroi in sand at different moisture levels at day 7.
48
Table 4.2: Wood consumption (mean ± S. E. M.) by M. crassus and C. gestroi in sand at different moisture levels at day 7.
50
Table 4.3: Comparison on mean tunnel lengths (± S. E. M.) and mean number of tunnel branches (± S. E. M.) between M.
crassus from two different locations and C. gestroi after 14 days experimental period.
56
Table 4.4: Wood consumption (mean ± S. E. M.) and survival (%) (mean ± S. E. M.) of M. crassus from two different locations and C. gestroi after 14 days experimental period.
57
Table 5.1: Colony combination of M. crassus. 64 Table 5.2: List of different interaction behaviours (modified
after Jmhasly and Leuthold 1999 and Adams 1991)
66
Table 5.3: Mean behavioural scores (± S. E. M.) between different termite species and caste composition within a 5 minutes interaction.
69
Table 5.4: Termite survival (%) (mean ± S. E. M.) for different pairings after 24 hours.
71
Table 6.1: Factors evaluated on week 2, 3 and 4. 85 Table 6.2: Wood consumption (mean ± S. E. M.) of M. crassus
in treated and untreated dishes.
101
8
LIST OF FIGURES
Page Figure 2.1: Caste pattern in the genus Microcerotermes
(Termitidae).
15
Figure 3.1: Survival (%) (mean ± S. E. M.) of M. crassus between various substrates - with and without presence of nest material (Tukey HSD, p<0.05).
33
Figure 4.1: Distribution of M. crassus from colony A, B and C (mean ± S. E. M) across dishes with different sand moisture levels on the 7th day at α=0.05 (Kruskal-Wallis).
52
Figure 4.2: Distribution of C. gestroi (mean ± S. E. M) across dishes with different sand moisture levels on the 7th day at α=0.05 (Kruskal-Wallis).
53
Figure 5.1: Frequency of different behaviours (mean ± S. E.
M.) exhibited by M. crassus (workers vs. workers) towards different termite species over a period of 5 minutes (Tukey HSD, p<0.05).
74
Figure 5.2: Frequency of different behaviours (mean ± S. E.
M.) exhibited by M. crassus (workers vs. soldiers) towards different termite species over a period of 5 minutes (Tukey HSD, p<0.05).
75
Figure 5.3: Frequency of different behaviours (mean ± S. E.
M.) exhibited by M. crassus (soldiers vs. workers) towards different termite species over a period of 5 minutes (Tukey HSD, p<0.05).
76
Figure 5.4: Frequency of different behaviours (mean ± S. E.
M.) exhibited by M. crassus (soldiers vs. soldiers) towards different termite species over a period of 5 minutes (Tukey HSD, p<0.05).
77
Figure 6.1: Termite number in dishes containing ‘treated’ and
‘untreated’ woods of day 1 and day 6 of week 2.
97
Figure 6.2: Termite number in dishes containing ‘treated’ and
‘untreated’ woods of day 1 and day 6 of week 3.
98
Figure 6.3: Termite number (distribution) ‘treated’ and
‘untreated’ dishes of day 1 and day 6 at week 4.
99
9
Figure 6.4: Survival (%) of M. crassus subjected to various treatments (disturbances) at the end of the experimental period (Tukey HSD, p<0.05)
102
10
LIST OF PLATES
Page Plate 2.1: Microcerotermes crassus soldier caste 12 Plate 3.1: Tunnel formations of M. crassus in Petri dishes
containing sand (a), sand with nest materials (b), vermiculate (c), vermiculate with nest materials (d), sand and vermiculate (e), and sand and vermiculate with nest material (f) at day 14.
27
Plate 3.2: Tunnel formations of M. crassus in Petri dishes containing 5% agar (a), 5% agar with nest materials (b), sawdust (c), and sawdust with nest materials (d) at day 14.
29
Plate 4.1: Experimental set-up for effects of various sand moisture levels against M. crassus and C. gestroi.
39
Plate 4.2: Experimental set-up for difference in tunnelling behaviour between M. crassus and C. gestroi.
41
Plate 4.3: Shelter tubes constructed by M. crassus in the release dishes opposing the treatment dishes at respective moisture levels (0, 5, 10, 15, 20 and 25% moisture)
40
Plate 4.4: Shelter tubes constructed by M. crassus in the release dishes at respective moisture levels (0, 5, 10, 15, 20 and 25%
moisture)
43
Plate 4.5: Shelter tubes constructed by C. gestroi in the release dishes opposing the treatment dishes at respective moisture levels (0, 5, 10, 15, 20 and 25% moisture)
45
Plate 4.6: Shelter tubes constructed by C. gestroi in the release dishes at respective moisture levels (0, 5, 10, 15, 20 and 25%
moisture)
45
Plate 4.7: Tunnelling activity of M. crassus at 0, 5, 10, 15, 20 and 25% moisture level.
46
Plate 4.8: Tunnelling activity of C. gestroi at 0, 5, 10, 15, 20 and 25% moisture level.
46
Plate 4.9: Termite tunnelling patterns of (a) M. crassus (site A) and (b) M. crassus (site B) and (c) C. gestroi.
55
Plate 5.1: Intra- and interspecific aggression test arena. 63
11
Plate 6.1: Experimental set-up for the study on the effects of disturbance and the presence of termite and other invertebrate carcasses at feeding sites of M. crassus.
84
Plate 6.2: Crushed carcasses of Asian subterranean termite, C.
gestroi on wood blocks covered with sand by M. crassus.
88
Plate 6.3: Crushed carcasses of Ghost Ants, Tapinoma indicum covered within shelter tubes built with sand by M. crassus.
88
Plate 6.4 (a): Distribution of M. crassus in each interconnected Petri dish in the control dish at the end of week 4.
90
Plate 6.4 (b): Distribution of M. crassus subjected to disturbance of the wood block in the treated dish at the end of week 4.
90
Plate 6.4 (c): Distribution of M. crassus subjected to crushed nestmate workers of the wood block in the treated dish at the end of week 4.
91
Plate 6.4 (d): Distribution of M. crassus subjected to crushed nestmate soldiers of the wood block in the treatment dish at the end of week 4.
91
Plate 6.4 (e): Distribution of M. crassus subjected to crushed Coptotermes gestroi of the wood block in the treatment dish at the end of week 4.
92
Plate 6.4 (f): Distribution of M. crassus subjected to crushed non-nestmate workers of the wood block in the treated dish at the end of week 4.
92
Plate 6.4 (g): Distribution of M. crassus subjected to crushed non-nestmate soldiers of the wood block in the treatment dish at the end of week 4.
93
Plate 6.4 (h): Distribution of M. crassus subjected to crushed Anoplolepis gracilipes of the wood block in the treatment dish at the end of week 4.
93
Plate 6.4 (i): Distribution of M. crassus subjected to crushed Tapinoma indicum of the wood block in the treatment dish at the end of week 4.
94
Plate 6.4 (j): Distribution of M. crassus subjected to crushed Harphaphe sp. of the wood block in the treatment dish at the end of week 4.
94
After
12
Plate 6.4 (k): Distribution of M. crassus subjected to crushed Porcellionides sp. of the wood block in the treatment dish at the end of week 4.
95
13
LIST OF ABBREVIATION
gm grams
mm millimetres
cm centimetres
ml millilitres
◦C degrees Celsius
RH relative humidity
S.E.M Standard Error of the Mean
vs. versus
14
LIST OF PUBLICATIONS & SEMINARS
Papers presented
1. Wong, N. and CY Lee. Distribution and Abundance of Termite Mounds in Universiti Sains Malaysia, Minden Campus, Penang, Malaysia. In 11th Biological Sciences Graduate Congress (11th BSGC). Bangkok, Thailand. 15- 17 December 2007.
2. Wong, N. and CY Lee. Selection of substrates for Microcerotermes crassus and effects of two dyes, Nile Blue A and Neutral Red on Microcerotermes crassus. In the Regional Conference on Ecological and Environmental Modelling (ECOMOD), organised by School of Mathematical Sciences and School of Biological Sciences. Penang, Malaysia. 28-30 August 2007.
3. Wong, N. and CY Lee. Influence of different sand moisture level on consumption and movement patterns of Microcerotermes crassus Synder (Termitidae) and Coptotermes gestroi Wasmann (Rhinotermitidae). In 12th Biological Sciences Graduate Congress (12th BSGC). Kuala Lumpur, Malaysia. 17-19 December 2007.
4. Wong, N. and CY Lee. Effects of induced disturbances on the movement and feeding behaviour of Microcerotermes crassus Snyder (Blattodea:
Termitoidae: Termitidae). In 10th Symposium of the Malaysian Society of Applied Biology. Kuching , Sarawak, Malaysia. 6-8 November 2008.
5. Wong, N. and CY Lee. Intra- and Interspecific Agonistic Behaviour of Microcerotermes crassus Snyder (Blattodea:Termitoidea:Termitidae). In Sixth Conference of Pacific Rim Termite Research Group. Kyoto, Japan. 2-3 March 2009.
15 Publications
1. Wong, N. and CY Lee. Influence of Different Substrate Moistures on Wood Consumption and Movement Patterns of Microcerotermes crassus Snyder and Coptotermes gestroi Wasmann (Blattodea: Termitidae, Rhinotermitidae).
Submitted to Journal of Economic Entomology (Under review - as of 24/08/2009).
2. Wong, N. and CY Lee. Intra- and Interspecific Agonistic Behavior of the Subterranean Termite Microcerotermes crassus (Blattodea: Termitidae) Submitted to Journal of Insect Behavior (Under review - as of 24/08/2009).
3. Wong, N. and CY Lee. Effects of Disturbance and the Presence of Termite and other Invertebrate Carcasses at Feeding Sites on the Behaviour of Microcerotermes crassus Snyder (Blattodea: Termitidae). Submitted to Sociobiology (Under review - as of 24/08/2009).
Seminars/ workshops
1. Workshop on Methodology and Statistical Technique, organized by /Institute of Graduate Studies, Universiti Sains Malaysia, Penang. 25 June – 6 July 2007.
2. Occupational Safety and Health Course for Post Graduate Students, organized by The Occupational Safety and Health Committee of USM, Penang. 28 June 2008.
3. Workshop on Scientific Writing, organized by Institute of Graduate Studies, Universiti Sains Malaysia, Penang. 27 June – 28 June 2007.
4. Pest Summit 2006: Targeting Zero Pest Infestation, organized by Pest Control Association of Malaysia & Singapore Pest Management Association, co-
16
organised by Ikatan Perusahaan Pengendalian Hama Indonesia & Thailand Pest Management Association. Bangkok, Thailand. 13-15 August 2008.
17
KELEMBAPAN TANAH, KESAN GANGGUAN DAN KEAGRESIFAN INTRA- DAN INTERSPESIFIK DALAM Microcerotermes crassus SNYDER
(BLATTODEA: TERMITIDAE)
ABSTRAK
Tesis in bertumpu pada aspek ekologi dan perilaku anai-anai Microcerotermes crassus Snyder. Pelbagai substrat telah diuji untuk memastikan kemandirian yang tertinggi bagi anai-anai ini di dalam makmal dan pasir terbukti sebagai substrat yang sangat sesuai. Di dalam pasir, kemandirian anai-anai adalah tinggi dan aktiviti menerowong boleh dilihat dengan jelas. Aktiviti pemakanan secara relatifnya adalah serupa bagi semua substrat yang diuji. Kesan beberapa tahap kelembapan (0, 5, 10, 15, 20 dan 25%) pada pasir diuji terhadap M. crassus dan dibandingkan dengan C. gestroi dalam suatu eksperimen makmal. Kandungan kelembapan pasir mempengaruhi kadar pemakanan kayu dan mempengaruhi taburan M. crassus merentasi suatu gradien kelembapan. Perubahan terhadap parameter kelembapan juga mempengaruhi lokasi C. gestroi tetapi kesan kelembapan terhadap kadar pemakanan kayu adalah tidak signifikan. Walau bagaimanapun, M. crassus dan C. gestroi menunjukkan satu taburan yang berpola serupa berhubung dengan tahap kelembapan tertentu. Kajian perbandingan menunjukkan bahawa M. crassus adalah kurang agresif kerana sedikit akitiviti menerowong telah direkodkan.
Terowong-terowong yang dibina C. gestroi adalah amat bercabang dan luas, manakala M. crassus membina terowong-terowong yang lebih sempit dan kurang bercabang. Apabila koloni-koloni anai-anai daripada spesies yang sama atau berbeza berinteraksi, pelbagai kelakuan agonistik boleh terjadi. Dengan menakjubkan, M.
crassus tidak mempamerkan sebarang kelakuan agresif apabila diletakkan bersama
18
koloni yang bersamaan spesiesnya dan tiada kematian atau hanya kadar kematian yang rendah dicatatkan. Secara kontras, pelbagai kelakuan agresif telah dipamerkan di dalam kajian interspesifik, mengakibatkan kadar kematian yang tinggi bagi kebanyakan pertemuan yang berlaku. Pertemuan antara M. crassus dengan anai-anai spesies yang sama atau berbeza dan dengan serangga-serangga lain seperti semut juga boleh mengakibatkan pertempuran yang kemudiannya mungkin meninggalkan bangkai-bangkai di kawasan bekalan makanan berada. Tambahan pula, M. crassus mungkin bertemu dengan bangkai invertebrata yang lain seperti gonggok dan kutu kayu yang boleh ditemui di dalam sarang mereka, di tempat bekalan makanan berada seperti di sekitar bangunan, dan sebagainya. Sepuluh faktor telah diuji ke atas kelakuan M. crassus. Taburan M. crassus dicatatkan pada hari pertama dan keenam selepas rawatan di antara kawasan yang tidak dirawat dengan kawasan yang dirawat.
Pemerhatian menunjukkan bahawa gangguan atau kehadiran bangkai hanya mencegah anai-anai untuk sementara waktu. Walau bagaimanapun, rawatan berterusan dengan C. gestroi yang dihancurkan menunjukkan bahawa anai-anai itu juga mengelak daripada kawasan yang dirawat pada hari keenam selepas rawatan.
Kemandirian juga adalah terendah dalam piring-piring yang telah dirawat dengan C.
gestroi. Didapati bahawa kurang kayu telah dimakan anai-anai di kawasan yang mengandungi atau dirawati dengan konspesies yang telah dihancurkan (pekerja atau askar ahli sesarang dan bukan ahli sesarang), atau dengan C. gestroi yang telah dihancurkan.
19
SAND MOISTURE PREFERENCE, DISTURBANCE EFFECTS AND INTRA- AND INTERSPECIFIC AGGRESSION IN Microcerotermes crassus SNYDER
(BLATTODEA: TERMITIDAE)
ABSTRACT
This thesis focuses on the ecological and behavioural aspects of Microcerotermes crassus Snyder. Different substrates were tested to ensure the highest survival of these termites under laboratory conditions and sand proved to be very suitable. In sand, survival of termites was high and tunnelling activities can be observed clearly. Wood consumption for the termites was relatively the same for all substrates. The effects of different moisture levels (0, 5, 10, 15, 20 and 25%) of a sand substrate on the behaviour of M. crassus were evaluated and compared to C.
gestroi in a laboratory assay. Moisture content of sand affected wood consumption and influenced the distribution of M. crassus across a moisture gradient. Changing the moisture parameters also affected the location preference of C. gestroi but the effect on wood consumption was not significant. Nonetheless, M. crassus and C.
gestroi showed a similar distribution pattern of association with particular moisture levels. Comparative studies showed that M. crassus was less aggressive as less tunnelling activity was recorded. Tunnels built by C. gestroi were highly branched and wide, whereas M. crassus built tunnels that were more narrow and less branched.
When termite colonies from the same or different species interact, wide range of agonistic behaviours can occur. Remarkably, no aggressive behaviours were displayed by M. crassus when placed in different colonies of the same species and no or low mortality was recorded. In contrast, various aggressive behaviours were displayed in the interspecific study, resulting in a high mortality rate in most of the
20
encounters. Encounters between M. crassus with termites of the same or different species and with other insects such as ants may also result in fighting and subsequently carcasses may be left at feeding sites. Moreover, M. crassus may encounter other invertebrate carcasses such as millipedes and wood lice that can be found within their nests, at feeding sites around buildings, etc. Ten factors were evaluated on the behaviour of M. crassus. The distribution of M. crassus was recorded between treated and untreated areas on day 1 and day 6 post-treatment.
Observations show that disturbances or the presence of carcasses only deterred the termites temporarily. However, prolonged treatment particularly with crushed C.
gestroi showed that termites avoided the treated area even at 6 days post-treatment.
Survival was also lowest in dishes treated with crushed C. gestroi. Termites consumed less wood in the dishes containing or treated with crushed conspecifics (workers or soldiers of nestmates and non-nestmates), or with crushed C. gestroi.
21
CHAPTER ONE
GENERAL INTRODUCTION
In many parts of the world, termites are an important group of insect (Edward and Mill 1986). According to Wagner et al. (2008), the presence of termites can hardly go unnoticed to inhabitants and travellers in the tropics. These insects can cause a lot of problems to the users of wood since the termite food is mainly wood and woody tissues. Each year, a great deal of effort and money are spent on attempting to prevent termites from damaging houses, buildings, trees and crops (Edward and Mill 1986).
Around 2200-2700 termite species were identified, covering 7 families and 82 genera (Harris 1971, Edward and Mill 1986, Pearce 1997, Lee and Chung 2003).
Tho (1992) classified a total of 175 termite species in Peninsular Malaysia into 42 genera. However, it was reported that less than 10% of the total termite species are pest in the man environment (Lee and Chung 2003).
Termites can be classified into three main categories: drywood termites, dampwood termites and subterranean termites. Drywood termites can be found living entirely within dry wood and usually infesting structures above the soil surface. This group of termites is less dependent on moisture (Edward and Mill 1986). The damages caused by these termites usually go unnoticed as no mud tubes are constructed and their colony size is relatively small (Robinson 1996).
Dampwood termites can be found infesting wood with a high moisture content or has contact with moist soil. They are found to live in old tree stumps, they common in the northwestern United States of America (Edward and Mill 1986).
Subterranean termites build their nests in soil or above ground. This group of termite is prone to desiccation when they are exposed to the air in the open
22
environment. Therefore, mud tubes or covered runways are constructed when they search for food above ground. In urban and suburban environments, subterranean termites are the most destructive and the most frequently encountered structural pest (Lee 2002b, Kirton and Azmi 2005). Subterranean termites from the genus Coptotermes are the most destructive species in South East Asia (Kirton et al. 2000, Kirton and Wong 2001, Lee 2002a, 2002b, Lee and Chung 2003). In Malaysia, subterranean termites from the genera Coptotermes, Macrotermes, Microtermes, Globitermes, Odontotermes, Schedorhinotermes and Microcerotermes are found to infest perimeters of buildings and structures, in gardens and in parklands (Lee et al.
2007).
According to Lee et al. (2007), secondary pest termites are often encountered in homes in Malaysia. Among these pests includes Schedorhinotermes, Microcerotermes, Macrotermes, Nasutitermes, Globitermes (Ngee and Lee 2002, Lee et al. 2003) and Odontotermes. These termite genera have been clasified under the family of Termitidae and are referred to as the higher termites (Krishna 1969). It is the largest termite family containing three-fourths of the known termite species (Krishna 1969). Most of the species, especially from the family Termitidae do not respond well to bait with paper-based matrices. Thus, several months after the elimination of the principal pest species (Coptotermes spp.) with bait, other termite species such as Macrotermes and Schedorhinotermes were found infesting the same structure or building (Lee et al. 2007).
Pest control operators usually carry out chemical soil treatment when they encounter a structure infested with higher termites after previously eliminating Coptotermes through baiting. It was reported that Microcerotermes crassus Snyder would infest structures after the elimination of Coptotermes species. Lee et al. (2007)
23
reported that from 2001 until 2004, the succession rate of termites from the genera of Microcerotermes after the suppression/elimination of Coptotermes spp. is 2.4% in Malaysia. In Australia, localized nests of Microcerotermes were found in bait stations after Coptotermes is eliminated or suppressed (Lee et al. 2007). On the other hand, in Thailand, M. crassus has been identified as the predominant termite species that attacks houses in rural areas (Sornnuwat 1996). Therefore, Lee et al. (2007) suggested that mounds of higher termite species found along the perimeter of baited homes should be excavated. This approach can help reduce the chances of these species infesting premises upon suppression or elimination of Coptotermes species.
In general, efforts of managing multi-genera termite fauna are best done by taking into account the biology of different target species (Lee et al. 2007). Detailed studies of various aspects of the biology of only a few termite species have been carried out. Thus, the purpose of this study is to obtain more information on the behaviour of M. crassus.
The objectives of this study were;
1. To acquire the most suitable medium that promotes the highest survival and encourages tunnelling of M. crassus.
2. To determine and compare the effects of various soil moisture level on the tunnelling activity and wood consumption rates of M. crassus and Coptotermes gestroi Wasmann and also to compare the tunnelling pattern and feeding behaviour between the two different species.
3. To study the intra- and inter-colony agonistic behaviour of M. crassus.
4. To study the effects of various inflicted disturbances on M. crassus.
24
CHAPTER TWO LITERATURE REVIEW
2.1 Termites in the Order Blattodea
Inward et al. (2007) reported that in morphological and molecular phylogenetic analyses, termites are considered as social cockroaches and should no longer be classified under a separate order (Isoptera).
The woodroach Cryptocercus was found to share several groups of flagellates with early branching termites (Cleveland et al. 1934). In addition, McKitterick (1964) stated that there are morphological similarity between some termite nymphs and Cryptocercus nymphs, suggesting a close phylogenetic relationship between the two groups. Inward et al. (2007) described termite+Cryptocercus clade as sister to Blattidae. In turn, termite + Cryptocercus and Blattidae are sister to Blattellidae + Blaberidae (Blaberoidea). In Polyphagoidea, Nocticolidae+Polyphagidae are sister to all cockroaches as well as the termites and Mantodea are sister to the cockroaches (Blattodea). The relationships between the sisters groups were shown to have 100%
posterior probability. No other relationships were found from the 2501 sampled trees in the Bayesian analysis. Therefore, the odds of termites branching out of the cockroaches are very small. It was proposed that termites should instead be treated as a family (Termitidae) of cockroaches. Therefore, the existing termite taxa would have to be downgraded by one taxonomic rank, such as families become subfamilies, subfamilies become tribes and so on.
Lo et al. (2007) commented that ranking termites as a family will destabilize termite nomenclature and disrupt scientific communication. Family would not be an ideal rank for termites as it does not acknowledge the stability of present family
