MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAM ACADEMY OF AGRICULTURAL SCIENCES ****** NGUYEN THI THANH HIEN STUDY ON MAJOR BIOLOGICAL AND ECOLOGICAL CHARACTERISTICS OF FRUIT FLY Bactrocera dorsalis Hendel ON FRUIT TREES AND CONTROL METHOD IN INTEGRATED PEST MANAGEMENT APPROACHES IN MOC CHAU, SON LA PROVINCE Major: Plant Protection Code: 62.62.01.12 SUMMARY OF AGRICULTURAL DOCTORATE THESIS HANOI, 2014 The thesis was completed at: Vietnam Academy of Agricultural Sciences Supervisor: Dr Le Duc Khanh Prof Dr Pham Van Lam Peer reviewer 1: Peer reviewer 2: Peer reviewer 3: This thesis will be defended at Thesis evaluation committee in Vetnam Academy of Agricultural Sciences At hour, date month year The thesis can be accessed at: Vietnam national library Library at Vietnam Academy of Agricutural Science Library at Plant Protection Research Institute INTRODUCTION Rationale Oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae), is an important pest on fruit trees since larvae feed on and cause direct damage to fruits Furthermore, the oriental fruit fly is also in a list of quarantine pest for fruits imported from Vietnam for many countries Presently, control of fruit fly in general and Oriental fruit fly in particular is based on bait traps to lure and kill adult males and chemical pesticides, however these methods did not provide an effective control Current researches on biology and control of oriental fruit fly are limited and not provide effective tools for control of fruit fly in fruit tree production Management of fruit fly is an urgent need in agricultural production as it challenges fruit production and export of Vietnam Hence this study has been conducted to “Study on major biological and ecological characteristics of fruit fly Bactrocera dorsalis Hendel on fruit trees and control method in integrated pest management approaches in Moc Chau, Son La province” Objective To study biology, ecology of fruit fly and other factors affecting occurrence and abundance of fruit fly B dorsalis in order to develop an effective and sustainable integrated pest management (IPM) program to control B dorsalis on local H’Mong peach in Moc Chau, Son La province and other fruit trees in Vietnam Scientific and practical importance - Comprehensive understanding biological, ecological characteristics and other factors affecting the occurrence and development of B dorsalis in Moc Chau, Son La province at pre-harvesting stage of H’Mong peach - Successful development of IPM control program for oriental fruit fly B dorsalis based on its biological and ecological characteristics Results from this study provide effective tools for control of B dorsalis on fruit trees in Vietnam and particularly in Moc Chau, Son La province Scopes of study 4.1 Target insect pest Oriental fruit fly B dorsalis Hendel 4.2 Scopes of study Comprehensive study on biological, ecological characteristics of oriental fruit fly B dorsalis Develop and implement IPM program for control of this fruit fly species taken to a case study in Moc Chau, Son la province Novel aspects of the study - Determined and classified 21 fruit fly species on 31 host fruit trees in Hanoi, Hoa Binh, Son La and Lao Cai provinces A list of 21 fruit fly species on 20 different host fruit trees was also determined for Moc Chau, Son La province for the first time - Provided a systematic literature reviews on biological and ecological characteristics of oriental fruit fly B dorsalis - Recommended an IPM program for control of oriental fruit fly B dorsalis in large fruit plantation area in Moc Chau, Son La province Structure of the thesis This thesis consists of 119 pages including introduction; material, method; results (containing chapters); and discussion and recommendation The thesis also contains 19 Tables and 29 Figures Ninety seven literatures have been reviewed and cited in the thesis including 31 Vietnamese studies and 66 English publications CHAPTER LITURATURE REVIEW 1.1 The basic scientific of project Fruit flies (Diptera: Tephritidae) are diversity in species composition and broad host range of fruits (Ian and Marlence, 1992) However, the species composition of fruit flies is differences in each ecological zones and the change is mainly dependent on the structure of their host fruits Larvae (maggots) of fruit flies lives and damages inside of fruits Therefore, the study of population dynamic of fruit flies can only observation through the activities of fruit fly matures into traps Habitat of fruit fly larvae are inside fruits therefore the control methods (including chemical methods) are usually ineffective The scientific data on the change of mature population dynamic are important for propose of the suitable time to control of fruit flies Population variation of fruit flies in specific conditions will be important scientific information for construction a suitable, sustainable and effective method to control of fruit flies 1.2 International studies on fruit fly 1.2.1 Species composition, distribution and economic importance of fruit fly Oriental fruit fly B dorsalis was first recorded in Taiwan in 1912 Since then it was found in many other regions in Asia and Pacific including India, Pakistan, Nepal, Vietnam, Laos, Thailand and others (Wan et al., 2011) Oriental fruit fly is among the most important fruit fly species in Southeast Asia 1.2.2 Biological characteristics of Oriental fruit fly B dorsalis 1.2.2.1 Living behavior: Matured females and males oriental fruit fly and other fruit fly species in general look for preferred host plants for their nutrient food sources, particularly protein source to mate and lay eggs on Fruit fly species living in different climate conditions prefer different host plants as place for mating Oriental fruit flies are attracted to yellow color Tropical fruit flies usually choose ripen fruits with soft peel to lay eggs on (Allwood and Ema, 2003) Developmental periods for egg, larval and pupal stages are 1-20 days, 9-35 days and 10-30 days, respectively Adults live for 1-3 months (Ian and Marlene, 1992) A female adult can lay average 1,236.2 eggs or 10.2 eggs per day in laboratory rearing conditions Naturally developmental factor for Oriental fruit flies is 0.14; population multiple factor for a generation is 712; a life cycle for a generation is 50 days; and time period to double a population is approximate 4.3 days (Pablo Liedo and James Carey, 1996) Vargas et al (1997) also studied biology of Oriental fruit flies and reported these factors for 560,2 for multiple factor; 0.14 for developmental factor; 77,4 days for a life cycle; and 4,9 days for double a population Host range includes plant species in family Euphorbiaceae, species in family Rhamnaceae and species in family Rosaceae (Ian and Marlene, 1992) Hui and Jian (2005) reported 100 different fruits as food source for oriental fruit fly larvae 1.2.3 Ecological characteristics of oriental fruit flies 1.2.3.1 Impact of temperature on growth and development of Oriental fruit flies: Temperature has strong impact on the growth and development of Oriental fruit flies Time period for egg, larval, and pupal stages developed at 30°C is as short as half of their developmental time at 20°C (Liu et al., 1985) Likewise, it takes females B dorsalis 30.4 days pro-oviposition at 19°C, however this period is just 17.4 days at 36°C (Yang et al., 1994) Hence, the total life cycle is also temperature dependent The life cycle of Oriental fruit flies varies from 102 days, to 77 days and 38 days at 20°C, 25°C and 30°C, respectively (Liu et al., 1985) Similarly, other study also shows a strong reversible correlation between life cycle of B dorsalis and temperature, i.e life cycle of B dorsalis varies from 133,2; 77,4; 45,1; 33,4 to 28 days at 16°C, 18°C, 24°C, 29°C and 32°C, respectively The number of eggs laid by a female increases as temperature increases from 16°C to 24°C, i.e 40.8 eggs per female at 16°C, 690.6 eggs per female at 18°C; and 1,512 eggs per female at 24°C; thereafter, females lay less eggs as temperature increases, i.e 602.8 eggs per female at 29°C; and 77.9 eggs per female at 32°C Furthermore, temperature is also known to have impact on survival of B dorsalis at different developmental stages (Vargas et al., 1997) 1.2.3.2 Effect of nutrition on growth and development of oriental fruit flies : Food source and nutrition cause difference in the maturity of larvae oriental fruit flies Developmental time for larval stages of B dorsalis is 19; 23; 18.5; and 26 days as feeding on Robuta and Elakki banana, guava, papaya and mango, respectively (Liu et al., 1985) Nutrition and diet also affect on sex ratio of B dorsalis Sex ratio for B dorsalis feeding on mango is 1:1.7 for male: female This ratio varies on different food source, i.e 1.09:1; 1.0:1.0; 1.0:0.92; and 1:1.09 when fed on guava, papaya, Robuta banana and Elakki banana, respectively Feeding on diet containing protein, soya flour and soybean protein results in the sex ratio of 50.5% male: 49.5 % femal (Khan et al., 2011) 1.2.3.3 Occurrence and factors affecting occurrence of B dorsalis Occurrence, development and population abundance of B dorsalis have been intensively studied in Thailand, China and Hawaii (Frank and Henrry, 1970; Keawchoung et al., 2000; Yuan Meng et al., 2008, Zhou et al., 2008) Several abiotic factors greatly affect population abundance and occurrence of B dorsalis including moisture (Allwood and Ema, 2003; Amice and Sales, 1995; Nripendra and Hirak, 2010), temperature (Wu et al., 2000; Frank et al., 1970; He et al., 2002), and nutrition and diet (Amice and Sales, 1996; Leweniqila et al., 1996; Ye and Jian, 2005; Vargas et al., 1990) 1.2.4 Control of fruit flies Several control methods have been recommended for control of fruit flies as follow: - Plant quarantine: fumigation using fenthion, dimethoate, Methyl bromide, Ethylen dibromide; radiation treatment; cold and hot temperature treatment, hot water treatment, hot water vaporization treatment and hot vaporization treatment; - Cultivation method: change planting season, field sanitation, early harvesting (Allwood, 1996; Khandelwal and Nath, 1978; Susanto and Tati, 1971; Vijayseganran, 1996); - Physical method: fruit packaging, pheromone traps, food traps (Drew and Romig, 2010; Pinero et al., 2010; Vickers,1996); - Sterilization method: Pupa sterilization using Coban 60 and Cesium 137 implemented in Thailand, Japan and other countries (Obra and Resilva, 2011; Orankanok et al., 2011); - Biological control: use parasitoid wasp as implemented in Hawaii and Fiji; - Chemical control: application of chemical insecticide cover all plant canopy; - IPM program: successfully prevent the immigration of fruit flies from intercrop hosts and surroundings to commercial production fields 1.3 In country literature review 1.3.1 Species composition, distribution and economic importance of fruit flies B dorsalis has been reported damaging in all fruit production areas in Vietnam (Viện Bảo vệ thực vật, 1967-1968; 1997-1998; Drew et al., 2001; Le Duc Khanh et al., 2008; 2010; Dang Xuan Ky et al., 2008; Le Thi Dieu and Nguyen Van Huynh, 2009; Nguyen Thi Thanh Hien et al., 2011; 2012) Several studies on species composition of fruit flies have also been conducted in Long An province (Le Thi Dieu and Nguyen Van Huynh, 2009), Tien Giang province (Viện Nghiên cứu ăn miền Nam, 2011) and Binh Thuan province (Nguyen Thi Thanh Hien et al., 2011) 1.3.2 Biological characteristics Biological characteristics of B dorsalis have been published by several authors (Huynh Tri Duc et al., 2001; Duong Minh Tu et al., 2001; Nguyen Huu Dat, 2003; 2007; Nguyen Huu Dat and Bui Cong Hien, 2004, Vo Thi Bao Trang et al., 2012), however, life table of B dorsalis has not been studied in Vietnam 1.3.3 Ecological characteristics Population variation of B dorsalis has been studied from 2009 to 2011 in dragon fruit production area in Long An (Le Thi Dieu and Nguyen Van Huynh, 2009), Binh Thuan (Nguyen Thi Thanh Hien et al., 2011) and Tien Giang (Viện Nghiên cứu ăn miền Nam, 2011) Food, moisture and temperature were reported to impact on the capture of B dorsalis in pheromone traps in Tien Giang and Binh Thuan No result on population variation of B dorsalis is available for Northern part of Vietnam 1.3.4 Control methods Cultivation control method (field sanitary) and physical method (fruit packaging, pheromone traps) have been trialed and recommended (Le Duc Khanh et al., 2008; Nguyen Van Chi et al., 2010; Nguyen Minh Chau et al., 2010; Nguyen Thi Thanh Hien et al., 2012) IPM program for control of fruit flies has been successfully implemented in dragon fruit plantation in Binh Thuan and Tien Giang (Nguyen Minh Chau et al., 2010; Nguyen Thi Thanh Hien et al., 2012) 1.4 Conclusion and concerning issues Oriental fruit flies have been extensively and systemically studied worldwide However, such studies on biological and ecological characteristics of B dorsalis are still limited, especially in the field study in Vietnam Therefore, to meet the increasing requirement for fruit production in Vietnam, it is necessary to have more comprehensive studies on biology and ecology of B dorsalis in Vietnam field conditions CHAPTER MATERIAL, CONTENT AND METHOD 2.1 Study location: Study was conducted in Moc Chau district, Son La province 2.2 Study duration: Study was conducted between 2009 and 2013 2.3 Materials: Oriental fruit flies, common fruit trees and experimental materials for collecting and rearing of the fruit flies 2.4 Study content - To determine species composition and damage of fruit flies on fruit trees in some provinces in the North; - To study biological characteristics of Oriental fruit flies B dorsalis; - To study ecological characteristics of Oriental fruit flies B dorsalis; - To develop an effective IPM control method of B dorsalis in Moc Chau, Son La province 2.5 Methods Study species composition and damage of fruit flies followed method described by Drew et al (2001) Classification of fruit flies was based on literatures from White and Harris (1992) and Lawson et al (2003) Biological characteristics of fruit flies were studied following methods described by Walker et al (1996), Vargas et al (1997) and Nguyen Van Dinh (1994) Ecological characteristics, population dynamics and factors affecting population dynamics of fruit flies were based on methods described by Drew et al (2001), Walker et al (1996), Vargas et al (1997) and Nguyen Van Dinh (1994) Field experiments for control of Oriental fruit flies B dorsalis were conducted in a complete randomized design with 3-4 replications Large scale experiment implementing IPM control program for control of Oriental fruit fly B dorsalis on local H’Mong peach was conducted in farmer plantation with the control treatment as farmer’s practice 2.6 Data analysis: Data were statistical analyzed based on method described by Vo Huy Van et al (1997) and using IRRSTAT statistical analysis program (IRRSTAT 5.0) CHAPTER RESULTS AND DISCUSSION 3.1 Species composition and damage of fruit flies in some provinces in Northern Vienam 3.1.1 Species composition and distribution Survey using pheromone traps and collecting of damaged fruits from provinces in the North of Vietnam has revealed 21 fruit fly species including 19 Bactrocera species and Dacus species, Tephritidae family Among these determined fruit fly species, 11 Bactrocera species were common found in all investigated locations in Hanoi, Son La, Hoa Binh and Lao Cai provinces The other 10 species were distributed individually in particular provinces 3.1.2 Species composition and host plants Study has recorded 31 host fruit species for fruit flies in studied provinces including Hanoi, Son La, Hoa Binh and Lao Cai 22 fruit species out of 31 reported fruits were from fruit trees including 17 sub-tropical fruit tree species and temperate fruit tree species The rest was fruit vegetables and wild fruit trees B correcta, B carambolae, B dorsalis, B pyrifoliae and B verbacifoliae were found damaging fruit trees; B cucurbitae, B tau, B latifrons caused damage on both fruit vegetable and wild fruit trees Oriental fruit fly B dorsalis damaged on both cultivated fruit trees including subtropical and temperate fruit tree species and wild types 3.1.3 Fruit flies abundance and their host plants in Moc Chau, Son La 21 fruit fly species have been recorded in Moc Chau including 19 Bactrocera species and Dacus species, Tephritidae family Among these determined fruit fly species, B carambolae was also found on fruit trees in Moc Chau, Son La 31 fruit tree species were determined as host plants for fruit fly Oriental fruit fly has a most diverse host plants (20 species) 3.1.4 Feeding damage In the field, fruit flies were active and damaged their host fruits from March to November They attached their hosts at different developmental stages of the fruit depending on fruits tree species Fruit trees were usually infested at ripen stage, whereas fruit vegetables were infested starting at earlly fruit stage and all other later stages Fruit trees were more severe damaged than other host plants, i.e fruit vegetable and wild type For instance, damage severities of fruit flies were 63.2%, 44,1% and 36.8% on local H’Mong peach, rose apple and kaki, respectively Lower damage severity was found on bitter gourd, the most severe damage among fruit vegetables, accounting for 42% severity The hosts for Oriental fruit flies included fruits of Rosasae, Myrtaceae, Ebenaceae, Cucurbitaceae and Anacardiaceae families Among the host plants in Rosasae family, H’Mong peach was most severe damaged 3.2 Biological charateristics of Oriental fruit fly B dorsalis 3.2.1 Living behavior of B dorsalis Adult flies laied eggs deep into fruit flesh under the peel Larvae fed and developed inside fruit, caused fruit rotten and shed from tree Matured larvae left fruit and dropped into soil to pupate Pupae were made at 2-3 cm underground 3.2.2 Life cycle Under rearing conditions on H’Mong peach at 28°C and RH 75% it took 1,98 ± 0,04 days for B dorsalis eggs to hatch Time for larvae to complete their stage was 6,48 ± 0,04 days Pupae needed 9,28 ± 0,09 days before emerging to adults Pro-oviposition adults lived for 14,79 ± 0,04 days before being ready for laying eggs The average life cycle of B dorsalis was 32,53 ± 0,06 days Males can live for about 120 ± 3,8 days, while lifespan of females were about 140 ± 10,6 days (Table 3.4) Table 3.4 Developmental stages and life cycle of B dorsalis (Plant Protection Research Institute- PPRI, 2012-2013) Developmental stages Unit Time period n Egg (*) day 1.98 ± 0.04 30 Larva (*) day 6.48 ± 0.04 30 Pupa (*) day 9.28 ± 0.09 30 Pre-ovipostional periods (*) day 14.79 ± 0.04 30 Life cycle day 32.53 ± 0.06 30 Lifespan of male (**) day 120 ± 3.8 19 Lifespan of female (**) day 140 ± 10.6 19 Note: (*) At temperature 28°C and RH 75%; (**) At temperature 26-28°C and RH 6075%, reared on H’Mong peach; n: sample size 3.2.3 Reproductive behavior 3.2.3.1 Reproductive system: Oviduct of the female B dorsalis consists of movable segments Male’s testes are at seminal vesicles and in pale yellow color Testes turn darker as males close to mature 3.2.3.2 Sex ratio: Four out of six evaluations on sex ratio of B dorsalis resulted in higher ratio of females to males 3.2.3.3 Ratio of female oviposition: Results from laboratory experiments showed that ratio of female B dorsalis oviposition range from 91.7- 94.4 % 3.2.3.4 Day time preference for oviposition: Females prefered laying eggs from 13 to 16 p.m (Figure 3.6) Số trứng (quả) 120 100 80 60 40 20 9-12 13-16 16-19 Thời gian thu trứng ngày Figure 3.6 Eggs production collected at different time period within a day in laboratory conditions (PPRI, 2012) Note: at temperature 26-28°C and RH 60-75% n= 50 3.2.3.5 Female fecundity and frequency of oviposition: Oviposition behavior of B dorsalis was evaluated on 19 male and female couples in laboratory from July 2012 to January 2013 throughout their lifespan Male and female adults were separated and coupled right after emerging Results showed that a female laid average 6.68 eggs a day Total number of eggs laid by a female varied significantly from 574 to 1,298 eggs In average, a female laid 949.73 eggs during their lifespan (table 3.7) Egg production per female recorded in this study was higher than that published by Nguyen Huu Dat and Bui Cong Hien (2004) These authors reported an average egg production per female vary from 601-721 eggs Other authors reported more productive females laid 1,200-1,551 eggs in average in their lifespan (Ian and Marlene, 1992; Pablo and James, 1996) This variation in productivity of female Oriental fruit fly B dorsalis can be explained by different sources of B dorsalis used for studies Moreover, food sources also strongly affected productivity of female B dorsalis This study performed on the 8th generation of laboratory B dorsalis fed on H’Mong peach whereas Nguyen Huu Dat and Bui Cong Hien (2004) studied the 3rd-4th laboratory generations fed on carrot Ian and Marlene (1992) also fed B dorsalis with carrot, however the productivity test was conducted on 65th laboratory generation of B dorsalis Table 3.7 Average total oviposition time duration for a female and its fecundity( PPRI, 2012-2013) Observations Range Average Total oviposition time period for a female 57 – 96 81.32 ± 2.8 (day) Fecundity (Number of eggs/female/day 1- 46 6.68 ± 0.14 Total eggs laid/female 574-1298 949.7 ± 38,84 Note: Rearing condition at T=26-28°C and RH 60-75%, reared on H’Mong peach Frequency of B dorsalis female oviposition was also not continuously This study also observed “off-the job day” when female did not lay eggs (Figure 3.7) 35 30 25 20 15 10 13 19 25 31 37 43 49 55 61 67 73 79 85 91 Tuổi ruồi mẹ 97 103 109 115 121 127 133 139 145 151 157 Figure 3.7 Oviposition frequency of female B dorsalis (PPRI, 2012-2013) Note: Rearing condition at T=26-28°C and RH 60-75%, reared on H’Mong peach 3.2.4 Lower temperature threshold and generations in a year B dorsalis was reared at temperature regimes, i.e 23°C and 28°C, RH 75% and fed with H’Mong peach Lower temperature threshold was calculated 11 3.3.2 Impact of food source on developmental stages of B dorsalis 3.3.2.1 Impact of food on developmental stages of B dorsalis: In this study, larvae B dorsalis were fed with different fruits including H’Mong peach (Prunus persica L.), mango (Mangifera indica L.), guava (Psidium guajava L.), papaya (Carica papaya L.) and carrot (Daucus carota subsp sativus) to demonstrate the impact of different food sources on the developmental stages and lifecycle of B dorsalis Significant shorter in developmental time for egg stage of B dorsalis eggs manually placed on ground carrot, accounting for 1.8 days, compared to the eggs on H’Mong peach, papaya, mango and guava, accounting for 3.76, 2.38, 2.49 and 2.59 days, respectively (p