Research on factors of affecting ecology butterflies fauna in bidoup – nui ba national park

MINISTRY OF EDUCATION AND TRAINING VIETNAM ACADEMY OF SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY LE HAI SON RESEARCH ON FACTORS OF AFFECTING ECOLOGY BUTTERFLIES FAUNA (LEPIDOPTERA : RHOPALOCERA) IN BIDOUP – NUI BA NATIONAL PARK Major: ECOLOGY Code: 9 42 01 20 SUMMARY OF BIOLOGYCAL PHD DISSERTATION Ho Chi Minh City - 2018 The dissertation completed at: Graduate University of Science and Technology - Vietnam Academy of Science and Technology. Academic Supervisor 1: Assoc. Prof. Dr. Hoang Duc Huy Academic Supervisor 2: Assoc. Prof. Dr. Nguyen Thi Phuong Thao Referee 1: Referee 2: Referee 3: The thesis will be examined by Examination Board of Graduate University, Meeting at Graduate University of Science and Technology - Vietnam Academy of Science and Technology at ............................ The thesis can be found at: - Graduate University of Science and Technology Library - National Library of Vietnam 1 INTRODUCTION 1. Significance of the research Insects are a part of invertebrates that are found in most ecosystems from land, aquatics to the underground. It has more than one million species of insects have been described, accounting for more than half of all known species on the Earth. Annually, the number of species reported has continually increased (Blair RB, 1999, Vu Van Lien, 2004, 2011). In the insect class, butterflies are well known for their color and morphology, and are familiar to humans. Butterflies are quite sensitive to habitat. The impact of environmental change on the vertebrate populations often took a long time to be recognized (Price P. W., 1975) and less noticeable than invertebrates, while butterflies have responded early to environmental change. When the natural forest is affected, the species and structure of the vegetation was changed, leading the butterfly communities were also changed (Blau W.S, 1980; Bobo K., 2006, Janzen, 1968). The change in status of butterflies over time is largely due to the human impacts on the communities of nature. From the early years of the 20th century, many researches on butterflies were published as a list of species in Vietnam and Indochinese (Corber A.S., 1992). Up to now, butterflies have been researched on many National Parks and Nature Reserves of Vietnam. However, the study mainly focused on the inventory of species composition. Recently, some researches on butterfly ecology in Vietnam have been reported in several PhDs and masters’ thesis such as the 2 researches in Tam Dao - Vinh Phuc National park (Vu Van Lien, 2008); in Ta Dung Nature Reserve (Le Hai Son, Hoang Duc Huy, 2011); in Ta Kou Nature Reserve (Dang Viet Dai, 2011); in Binh Chau - Phuoc Buu Nature Reserve (Bui Huu Manh, 1998) and so on... However, comprehensive statistics on species composition as well as ecological and biological research of butterfly species have not been investigated yet. Therefore, the PhD. dissertation: "Research on factors of affecting ecology butterflies fauna (Lepidoptera: Rhopalocera) in Bidoup – Nui Ba National park" focused on investigating a number of biological and ecological factors on butterfly populations in the desired area. 2. Research Objective 2.1. The purpose of dissertation Evaluate the impacts of some ecological factors on the movement of butterfly population, biological data and the status of some valuable, rare and near threatened butterfly species. Based on research results, propose the conservation solution of butterflies in Bidoup - Nui Ba National park. 2.2. The requirement of dissertation Identify the composition of species and analyze the diversity of butterflies in different habitats in Bidoup - Nui Ba National Park. Identify the biological data of some butterflies, and determine the impact of weather conditions and forest on the movement of population and the variation in the individual number of butterfly species in the community. 3 Propose the conservation solution of butterflies in Bidoup - Nui Ba National park. 3. The scientific significance of dissertation The dissertation reported an complete and comprehensive statistics on the composition of butterfly species in Bidoup - Nui Ba National Park, with a total of 173 species, of which 02 species listed in the Red List of Vietnam, and 108 species were implemented in the butterfly list of Bidoup - Nui Ba National Park. The dissetation also identified the biological data of 31 species, of which rare and precious species are listed in the Red List of Vietnam. In addition, 12 new foodplant species have been recorded for 13 butterfly species in Bidoup. The results have quite comprehensively assessed a number of ecological features such as different habitats, environmental humidity, temperature, rainfall ... to the movement of butterfly populations 4. Chapter Layout of Dissertation The dissertation consists of Introduction; Chapter 1: Literature review; Chapter 2: Materials and Methods; Chapter 3: Results and discussion; Conclusions and recommendations; List of peer review; References; 38 pictures and 21 tables.. 4 CHAPTER 1. LITERATURE REVIEW 1.1. Butterfly researches in the world In the world, butterflies have been researched extensively, many of the research results on species composition have been published such as Butterflies in the world (Smart, 1989), Butterflies in China (Chou, 1994); Butterflies in Malaysia (Corbet and Pendlebury (1992), Butterflies in Indochina – Australia (D'Abrera, 1982 - 1986); Butterfies in Laos (Osada et al.,1999); Butterflies and Moths in Singapore (Carter, 2000); Butterflies in Thailand (Pinratana, 1974 – 1988; Pisuth Ek-Amnuay, 2012), and Butterflies in India (Wynter- Blyth, 1957). There are numerous studies of biology and ecology of butterfly published in Asia. Valuable scientific works included identification of host plants, life cycles, behavior and distribution of butterflies. Among butterflies, there are many rare and precious species listed in CITES and IUCN. These researches contribited to conservation and cultivation of butterflies (Igarashi S., 1997-2000, 2001). 1.2. Butterfly researches in Vietnam Butterflies in Vietnam have been studied since the early years of the 20th century. The first study was "Essai d’un traite d’entomologie indochinoise" with a list of 611 species (belonging to 7 families) by Dubois and Vitalis De Salvaza et al. (1919). It was the first list of butterflies of the nations of Indochina (Vietnam, Laos, Cambodia). By 1957, Metaye had identified a list of 454 species of butterflies in Vietnam (Metaye R., 1957). 5 So far, studies of butterfly have primarily focused on investigating species composition. Recently, studies on butterfly ecology have been interested but still few and mainly focus on the topics of masters, PhD thesis, and ecology of butterflies. Particularly, study of butterfly biology, such as life cycle and host plant, which help to preserve and cultivate rare and precious gene sources have not been resonably interested yet. In this study we, therefore, conducted survey of both ecology and butterfly biology to find out the rules of movemently of butterfly population as well as to study the life cycle of butterfly (egg, larva , pupae, host plants) to serve conservation and ecotourism in Vietnam. 6 CHAPTER 2. CONTENT AND METHODOLOGY 2.1. Research content Butterflies (Lepidoptera: Rhopalocera) are studied in habitats from natural forest to residential areas and agricultural land. 2.2. Research methodology 2.2.1. General ecological research method The general method used in ecological surveys is the Pollard Walk method. 2.2.2. Research on diversity of species composition and frequencies 2.2.2.1. Occurrence frequency To assess the prevalence of butterfly populations in the study areas, the occurrence frequency was calculated by formular Frequency (%) = Numbers of occurrence Total numbers of surveys x 100 (1) 2.2.2.2. Estimation of species abundance From results of the surveys, the cumulative curve of the number of species was setted up. Based on end-stage curve data, species richness was estimated. 2.2.2.3. Bray-Curtis index For the comparison of butterfly species between diverse habitats or regions, similarity index (Bray-Curtis Similarity index 7 (S'jk) (Charles J. Krebs, 1999) of butterfly species composition of habitats or study areas is calculated by formular according to Clarke et Gorley, 2001. 2.2.3. Research on Biology of butterfly Collect samples of host plants (or part of host plants for larval feeding) and larvae of wild butterflies in the natural forest, residential area and agricultural land. Research focus on: monitoring female butterflies that lay their eggs in the forest, taking pictures of host plants, collecting sample of plant, eggs, larva and pupae (if any). 2.2.4. Research on Ecology of butterfly 2.2.4.1. Movement of butterfly populations during the day Period of assessment time on day was carried out from 9h00 to 16h00 by line. To compare the activity of butterflies at different periods of the day, period of assessment time were sometime conducted from 7:00 am to 5:00 pm (Vu Van Lien, 2008). 2.2.4.2. Movement of butterfly populations by habitat Survey of butterfly habitat was conducted at the habitats in the desired areas: RTN, RTĐ, TC and NN. 2.2.4.3. Effects of environmental factors on butterfly behavior Studies on the influence of environmental factors on butterfly behavior include: assess the activity period of butterfly during a day, assess movement of butterfly population in terms of rainfall over months and seasons, and assess effect of humidity to number of butterfly populations. 8 CHAPTER 3. RESULTS AND DISCUSSION 3.1. Research on species diversity in Bidoup – Nui Ba National park 3.1.1. Species composition and occurrence frequency In Bidoup - Nui Ba National Park, there are 173 species of butterflies in 10 families were identified. These included: 22 species of Papilionidae, 52 species of Nymphalidae, 31 species of Pieridae, 15 species of Danaidae, 21 species of Satyridae, 01 species of Libytheidae, 2 species of Riodinidae, 1 species of Amathusiidae, 25 species of Lycaenidae and 09 species of Hesperiidae. The most diverse of species in Bidoup – Nui Ba and Ma Da is Nymphalidae family with 52/173 species (Bidoup) and 50/137 species (Ma Da), accounting for over 30% of the total species studied in each areas. In addition, the number of single species of the Nymphalidae family is also highest, indicating that they are the largest and most abundant species in both study areas. In this research, we haven’t found 3 butterfly families of Amathusiidae, Libytheidae and Riodinidae in Ma Da. Research results in Bidoup discovered 108 added species of butterflies to this area compared with those of Bui Xuan Phuong (2002) and Nguyen Dang Hoi and Kuznetsov (2012). This result has raised the total number of butterfly species present in Bidoup upto 264 species. 9 3.1.2. Typical species 3.1.2.1. The rare and precious species in the red list of Vietnam According to the Vietnam Red List (2000), four species recorded in Bidoup, include: Lamproptera curius curius (Fabricius, 1787) (T: Threatened level), Troides aeacus aeacus (C. & R. Felder 1860), T. helena cerberus (C. & R. Felder, 1865) (EN: Endangered) and Graphium antiphates pompilius (Fabricius, 1787) are all members of the Papilionidae family. According to the Vietnam Red List 2007, there are two species of Troides aeacus aeacus (C. & R. Felder, 1860), T. helena cerberus (C. & R. Felder, 1865) (Papilionidae) (Vulerable: Endangered) in Bidoup needs to be preserved. 3.1.2.2. Endemic species and common species a. Endemic species to survey lines There are 31 species of solitary, single species that show species endemism specific to each study site, which also suggests habitat preferences for butterflies. In addition, the identification of single species in the survey trails helped to estimate species richness in the study area. b. The commen and less common species Through the occurrence frequency of species, most of the species surveyed are rare species. In Bidoup, common species was no present, only five species was less common. However, according to each study site, there are two popular species at the grasslands habitat in Bidoup: 10 Ypthima baldus and Neptis hylas. There are 03 common and 11 less common in Ma Da. Seven species occured in all habitats from natural forest to agricultural land in both Bidoup and Ma Da areas, indicating that these species are popular and widely distributed in all habitats from the delta to the highland. 3.1.3. Estimation of jackknife abundance of species Based on the results of the survey in Bidoup, the relationship of number of species according to study time was establish to generate the cumulative curve for species discovert in Bidoup. Estimated species in Bidoup (�̂�NB) = 203,87  204 species. An estimation of the species size in Bidoup with 95% confidence has been obtained: Bidoup  12 species So, the species abundance estimated in Bidoup is: SNB = 204 ± 12 species. It means that the species abundance limit in Bidoup according Jackknife abundance varies from 192 to 216 species. 3.1.4. Bray-Curtis similarity index 3.1.4.1. Bray-Curtis index between Bidoup and other areas The results of the similarity of species composition between Bidoup and other areas were shown in Table 3.7 and Figure 3.6. The species composition in Bidoup was closer to Ta Dung Nature Reserve (Le Hai Son, Hoang Duc Huy, 2011) (65,34%) than other regions. Geographically, Ta Dung Nature Reserve (belong to Daknong province) locate in the south of Bidoup, and is characterized by highand medium mountainous terrain. Thus, the similarities of species 11 composition of Bidoup and Ta Dung Nature Reserve was highest compared to other areas. Although Bidoup and Ma Da (Le Hai Son et al., 2017) have different geographic locations, terrain and elevation, the similarity is only lower than that of Ta Dung (56,77%) since species composition of the common family Nymphalidae, Papilionidae, Pieridae and Danaidae have many similar species. 3.1.4.2. Bray-Curtis similarity index according to butterfly family The results of the similarity index (Appendix 12) of the Papilionidae, Nymphalidae, Pieridae and Danaidae families showed that there is a high correlation among regions (over 50%). It indicated that they are popular families with wide distribution on many habitats and elevations. The result is consistent with previous reports (Vu Van Lien, 2008; Le Hai Son, Hoang Duc Huy, 2011). For other butterfly families, there is a low similarity index among regions (the Libytheidae family have few species, so we cannot calculate similarity index). It suggested that the endemism of the species composition of the butterflies is relatively high. 3.2. Study of butterfly ecology 3.2.1. Fluctuation of butterfly populations by habitat Result in Table 3.8 showed the species composition decreased according to habitat. The highest number of species occurred in natural forest (RTN) with 138 species (79.8% of total species) and lowest in agriculture land habitat (NN). Result in Table 3.9 showed that the occurrence frequency of species in natural forest habitat is highest with 8.09 species / 1 h and 12 lowest in the agricultural area habitat. However, the frequencies of occurrence of species in grassland habitats (7.81 species/1 hour) and impact forest (7.56 species/1 hour) were almost same. However, during the survey in Bidoup - Nui Ba National Park, grassland habitats are often close to natural forests (Lang Tranh, Dung K'No, Giang Ly...) and the presence of beautiful flowers can be attracted many species of butterflies so that the occurrence frequencies of butterfly species in the impact forest and grassland habitats were quite similar. The similarity index of species composition of butterfly among the different habitats waa presented in Table 3.10 and Figure 3.7. It showed that the species composition in natural habitats was close to the impacted forest, and the second one is grassland habitats. Agriculture land had the most differrent species composition compared to natural forests. These results showed that the occurrence frequency of butterfly species in Bidoup-Nui Ba National Park was dependent on habitat. Occurrence frequency of species and number of species is highest in natural forest habitat and lowest in agriculture land. 3.2.2. Movement of butterflies populations by rainfall and seasons 3.2.2.1. Correlation of occurrence frequency of butterfly species with rainfall Results in Table 3.11 showed that the number of individuals appearing at the highest density (138.08 individuals/hour in 2014 and 206.29 individuals/hour in 2015) at the rainfall peak in the beginning of the rainy seasons. However, number of individuals at the rainfall 13 peak at the end of the rainy season the did not increase sharply as that at the beginning of the rainy season (Figure 3.8). The correlation of the total number of species, occurrence flequency and individual number of the species to rainfall in Bidoup- Nui Ba National Park was shown in Figure 3.8; 3.9 and 3.10. Increase in numbers of species at low rainfall in this study is contrary to previous reports. It is due to with high mountainous terrain and low average temperatures in Bidoup - Nui Ba National Park (Nguyen Dang Hoi, Kuznetsov AN, 2012). In addition, the annual average humidity in Bidoup is also quite high at the rainy season (General Statistics Office 2015, 2016). And there is often cloudy and low sunshine combined with low temperatures while the dry season is quite sunny and litte foggy. The butterflies often appeared with high density under the sunny and clear weather condition. Therefore, the number of species in the dry season was higher than that in the rainy season. In addition, data of other places in the dry season have the lowest rainfall and even zero (0). However, there is no zero value of rainfall in Bidoup in the period from 2014 to 2015, so the seasonal transition or high rainfall period leaded the increase in humidity but the decreases in the environment temperature. It is unfavorable conditions for increasing populations of butterflies. 3.2.2.2. Movement of butterfly populations by seasons The ANOVA results (Table 3.13) on the occurrence frequency of species by seasons showed a P-value of 0.01 which P- value <α = 0.05. Therefore, seasons in the year significantly affected the occurrence frequency of butterflies. During the dry season, the occurrence frequency of species was highest with 22 species / hour of 14 survey, the frequency of occurrence of species of the seasonal transition and rainy seasonis were similar (16-17 species). In the rainy season, there is high rainfall, low temperature and foggy condition covering the study areas in Bidoup - Nui Ba National Park. Meanwhile, the butterfl often appears under clear and sunny condition (Vu Van Lien, 2008). Therefore, the low rainfall and strong sunny conditions in the dry season facilitated the appearance of butterfly populations. In addition, during the dry season, the moisture content in Bidoup was always high, so the plant species including the host palnts of butterflies are still growing well. Thus, the occurrence frequency of species in the dry season