THE ECOLOGY AND BIOLOGY OF Aedes aegypti (L.) AND Aedes albopictus (Skuse) (DIPTERA: CULICIDAE) AND THE RESISTANCE STATUS OF Aedes albopictus (FIELD STRAIN) AGAINST ORGANOPHOSPHATES IN PENANG, MALAYSIA by MANORENJITHA MALAR A/P SIVANATHAN Thesis submitted in fulfillment of the requirements for the Degree of Masters of Science JUNE 2006 EKOLOGI DAN BIOLOGI Aedes aegypti (L.) DAN Aedes albopictus (Skuse) (DIPTERA: CULICIDAE) DAN STATUS KERINTANGAN Aedes albopictus (STRAIN LAPANGAN) TERHADAP ORGANOFOSFAT DI PULAU PINANG, MALAYSIA oleh MANORENJITHA MALAR A/P SIVANATHAN Tesis yang diserahkan untuk memenuhi keperluan bagi Ijazah Sarjana Sains JUN 2006 ACKNOWLEDGEMENT AMASIVAYA, all praise to the god. After years of hardworking N this thesis is finally completed. First of all, I would like to extend my sincere appreciation to my project supervisor Prof. Madya Dr. Zairi Jaal. Thank you for your endless guidance, assistance and advice throughout this project. My sincere appreciation also goes to Dr. Latiffah Ibrahim (Pengarah Kesihatan Cawangan Rancangan Kawalan Penyakit Bawaan Vektor, Pulau Pinang), Inspector Kesihatan Heng (Pusat Kesihatan Daerah Seberang Perai Utara) and Inspector Kesihatan Hj Shaari (Pusat Kesihatan Daerah Timur Laut) for their invaluable time, my labmates (Vino, Wati, Chia Shian, Chooi Kim, Fatma, Alicia, Firdaus), seniors (Adanan and Lee Yean Wang) staff (Pak Hamid and Encik Nasir) and friends for their endless moral supports and assistance. Finally I would like to extend my thanks to my parents and brother for their patience and for being understanding. ii TABLE OFCONTENTS Contents Page Acknowledgements ii Table of contents iii List of Tables ix List of Figures xi List of Plates xiii List of Abbreviations and symbols xv Abstrak xvi Abstract xviii CHAPTER 1: GENERAL INTRODUCTION 1.1 Introduction 1 1.2 Objective 3 CHAPTER 2: LITERATURE RIEW 2.1 History of Aedes in relation to dengue in Malaysia 5 2.2 Mosquito 6 2.2.1 Classification of mosquitoes 6 2.2.2 Classification of Aedes mosquito 8 2.2.3 Indentification of adult Aedes aegypti and 8 Aedes albopictus 2.2.4 Indentification at the larval stage 10 2.2.5 Aedes aegypti (Linnaeus) 10 iii Contents Page 2.2.6 Aedes albopictus (Skuse) 13 2.3 Ovitrap 15 2.4 Biology of Aedes aegypti and Aedes albopictus 17 2.4.1 Egg biology 17 2.4.2 Larval biology 19 2.4.3 Pupal biology 22 2.4.4 Adult biology 24 2.4.4.1 Resting 24 2.4.4.2 Survival and longevity 24 2.4.4.3 Flight and dispersal 25 2.4.4.4 Biting activity 25 2.4.4.5 Host preferences 26 2.4.4.6 Feeding behaviour 27 2.4.4.7 Oviposition 28 2.5 Mosquito control 29 2.5.1 Biological control 30 2.5.2 Source reduction 30 2.5.3 Physical barrier and personal protection 31 2.5.4 Chemical control 31 2.5.4.1 Adulticides 32 2.5.4.2 Larvicides 32 2.6 Organophosphates Insecticides (OP) 33 2.6.1 Malathion 34 iv Contents Page 2.6.2 Temephos 35 2.6.3 Fenitrothion 35 2.6.4 Fenthion 35 2.6.5 Chlorpyrifos 36 2.7 Resistance 36 CHAPTER 3: THE SEASONAL ABUNDANCE AND POPULATION DENSITIES OF Aedes aegypti (L.) AND Aedes albopictus (Skuse) 3.1 Introduction 37 3.2 Material and methods 38 3.2.1 Site selection 38 3.2.2 Ovitrap 47 3.2.3 Ovitrap setting 47 3.2.4 Rearing and identification 50 3.2.5 Meteorological data 50 3.2.6 Statistical analysis 52 3.3 Results and discussion 53 3.3.1 The seasonal abundance of Aedes eggs in an outdoor 53 environment in Bagan Dalam and Paya Terubong 3.3.2 The distribution of Aedes aegypti and Aedes albopictus 64 in an outdoor environment in Bagan Dalam and Paya Terubong v Contents Page 3.4 Summary and conclusion 70 CHAPTER 4: THE BIOLOGY OF Aedes aegypti (L.) AND Aedes albopictus (Skuse) OF FIELD COLLECTED EGGS UNDER LABORATORY CONDITIONS 4.1 Introduction 71 4.2 Material and Methods 72 4.2 Mass culture of Aedes mosquitoes in the laboratory 72 4.2.1 The hatching rate of field strain Aedes aegypti and Aedes 75 albopictus 4.2.2 The development rate of field strain and laboratory strain 77 Aedes aegypti and Aedes albopictus 4.2.3 Survival and longevity of field and laboratory strain Aedes 79 aegypti and Aedes albopictus fed on different diets 4.2.4 The length of gonotrophic cycle and the number of eggs laid 79 by field strain Aedes aegypti and Aedes albopictus 4.2.5 The effect of overcrowding and starvation on length of 80 pupation and mortality rate of field strain Aedes aegypti and Aedes albopictus 4.2.6 The effect of larval diet on the fecundity of field strain Aedes 81 aegypti and Aedes albopictus vi Contents Page 4.2.7 Substrates preference for oviposition of field strain 81 Aedes aegypti and Aedes albopictus 4.2.8 Data analysis 82 4.3 Results and discussion 83 4.3.1 The hatching rate of field strain Aedes aegypti and 83 Aedes albopictus 4.3.2 The development rate of field strain and laboratory strain 87 Aedes aegypti and Aedes albopictus 4.3.3 Survival and longevity of field strain and laboratory strain of 90 Aedes aegypti and Aedes albopictus fed on different diets 4.3.4 The length of gonotrophic cycle and the number of eggs laid 93 by field strain Aedes aegypti and Aedes albopictus 4.3.5 The effect of overcrowding and starvation on length of 95 pupation and mortality rate of field strain Aedes aegypti and Aedes albopictus 4.3.6 The effect of larval diet on the fecundity of Aedes aegypti 99 and Aedes albopictus 4.3.7 Substrate preference for oviposition of field strain 102 Aedes aegypti and Aedes albopictus 4.4 Summary and conclusion 105 vii Contents Page CHAPTER 5: RESISTANCE STATUS OF Aedes albopictus (Skuse) (FIELD STRAIN) AGAINST ORGANOPHOSPHATES 5.1 Introduction 106 5.2 Material and method 107 5.2.1 Mosquito strains 107 5.2.2 Chemicals 107 5.2.3 Larval bio-assay 108 5.2.4 Statistical analysis 111 5.3 Result and discussion 112 5.4 Summary and conclusion 121 CHAPTER 5: SUMMARY AND CONCLUSION 122 REFERENCES 124 APPENDICES VITAE viii LIST OF TABLES Page Table 3.1 Spearman’s correlation (r) for egg populations in relation 61 to environmental factors (total rainfall, mean relative humidity and mean temperature) Table 3.2 Population densities of Aedes aegypti and Aedes albopictus 65 that emerge in laboratory from total collection that was made in Bagan Dalam and Paya Terubong between November 2002 until December 2003 Table 4.1 The hatching rate of field strain Aedes aegypti and 84 Aedes albopictus Table 4.2 The development rate of field strains and laboratory strains 88 Aedes aegypti and Aedes albopictus Table 4.3 Survival and longevity of field strain and laboratory strain 91 Aedes aegypti and Aedes albopictus fed on different diets Table 4.4 The length of gonotrophic cycle and the number of eggs laid 94 by field strain Aedes aegypti and Aedes albopictus Table 4.5a Effect of overcrowding and starvation on length of pupation 96 and mortality rate of Aedes aegypti (BD-strain) Table 4.5b Effect of overcrowding and starvation on length of pupation 97 and mortality rate of Aedes albopictus (PT-strain) ix Page Table 4.6 Effect of larval diet on the fecundity of Aedes aegypti and 100 Aedes albopictus Table 4.7 Number of eggs laid by Aedes aegypti and Aedes 103 albopictus on two substrates (cone shaped filter paper versus flat surface) Table 5.1 Organophosphate resistance in Aedes albopictus 113 collected from Bagan Dalam and Paya Terubong, Penang. Table 5.2 Insecticides used in Bagan Dalam and Paya Terubong, 114 Penang and the duration of its application Table 5.3: Comparison of laboratory strain Aedes albopictus larvae to 116 insecticides and with field strain Aedes albopictus larvae x LIST OF FIGURES Page Figure 2.1 Thorax of adults 9 Figure 2.2 Terminal segments of larvae 11 Figure 3.1 Location of Bagan Dalam, Butterworth 39 Figure 3.2 Location of Paya Terubong, Air Itam 40 Figure 3.3 Total rainfall (mm), mean temperature (C) and mean 54 relative humidity (%) for Bagan Dalam, Butterworth from November 2002 until December 2003 Figure 3.4 Total rainfall (mm), mean temperature (C) and mean 55 relative humidity (%) for Paya Terubong, Penang from November 2002 until December 2003 Figure 3.5 Mean eggs per paddle and mean eggs per month 56 collected from outdoor ovitrap sampling in Bagan Dalam, Butterworth from November 2002 until December 2003. Figure 3.6 Mean eggs per paddle and mean eggs per month 57 collected from outdoor ovitrap sampling in Paya Terubong, Air Itam from November 2002 until December 2003. Figure 3.7 Average number of eggs collected in Bagan Dalam 58 (outdoor sampling) in relation to total rainfall (mm) from November 2002 until December 2003 xi Figure 3.8 Average number of eggs collected in PayaTerubong, 59 Air Itam (outdoor sampling) in relation to total rainfall (mm) from November 2002 until December 2003 Figure 3.9 Percentage of adult emergence in the laboratory and 66 the population densities of Aedes albopictus and Aedes aegypti from the paddles collected in an outdoor environment of Bagan Dalam, Butterworth from November 2002 until December 2003 Figure 3.10 Percentage of adult emergence in the laboratory and 67 the population densities of Aedes albopictus and Aedes aegypti from the paddles collected in an outdoor environment of Paya Terubong, Penang from November 2002 until December 2003 xii LIST OF PLATES Page Plat 2.1 Aedes aegypti 12 Plat 2.2 Thorax of Aedes aegypti 12 Plat 2.3 Aedes albopictus 14 Plat 2.4 Thorax of Aedes albopictus 14 Plat 2.5 Aedes eggs on filter paper 18 Plat 2.6 Aedes eggs (upclose) 18 Plat 2.7 A cluster of Aedes larvae 20 Plat 2.8 Aedes larva (upclose) 20 Plat 2.9 A cluster of Aedes pupae 23 Plat 2.10 An upclose view of Aedes pupae 23 Plat 3.1 Houses in Kampung Bagan Dalam 42 Plat 3.2 Poor drainage system in Bagan Dalam 42 Plat 3.3 A slaughter house in Bagan Dalam 43 Plat 3.4 A Bridge across Kuala Prai River, is one of the 43 dumping sites used by the residence.