ICIMOD PROJECT PUBLICATIONS Exploration of Genetic Diversity in Himalayan Honeybee, Apis cerana Submitted to the Office of the Science Advisor U.S.Agencyfor InternationalDevelopment Grant Number: 367-5600-G-,S-1147-00 Beekeeping Research and Development Programme INTERNATIONAL CENTRE FOR INTEGRATED MOUNTAIN DEVELOPMENT MS#1 Himalayan Biodiversity: Conservation Strategies ed. U. Dhar. Gyanodaya Prakashan, Nainital, India, 1993 pp. 415-428. 32 CURRENT STATE OF HIMALAYAN HONEYBEE (APIS CERANA) BIODIVERSITY AND STRATEGIES FOR ITS CONSERVATION L. R.Verma ABSTRACT Himalayan region is rich in honeybee species and genetic diversity. Amongst the different native honeybee species, Apis ceranais equivalentof European honeybee, Apis mellifera because both can be domesticated and build parallel combs. Our research group in ICIMOD has successfully identified genetic variance in morphological characters of Apis ceranaand these results reveal the occurrence of three sub species in the Himalayan region named as Apis ceranacerana,Apis cerana himalayas and Apis cerana indica. Each sub species has further locally adapted geographic ecotypes which differ from each other in several biological and economic characters. For.example, sub-species Apis cerana himalaya can be further identified into three ecotypes that correspond to geographic distribution in (1) the Naga and Mizo hills, (2) Brahmaputra valley and Khasi hills, and (3) the foothills of north-east Himalayas. Despite its economic usefulness, beekeeping %uifhAn; rprann ic eiiffefrinc nrerinitnii 1frrline anti ithrpewopnod with 'mtl;nrlnn throughout its range. The major threat comes from its replacement with exotic and more prolific Apis mellifera, habitat alteration, pesticide poisoning, diseases and cnemies particularly the recurrence ofsacbrood virus diseaseand human predations especially through honey hunting methods. Such decline is undesirable in terms of LR.Vcrma, Intemadonal Centre for Inicgratcd Mountain Devlopmcnt. (ICIMOD), P.O. Box. 3226, Kathmandu:Ncpal. 416 liialayanBiod'vrsily: Conwervation Strategies commercial use value, maintenance of biodiversity in natural ecosystems and productivity of farming systems. In order to reverse the above trends, there isa need to adopt strategies for conservation of Apis ceranathrough development and promotion of beekeeping with nativec bee species. Such development strategies should include studies on biology, behavior and management of Apis cerana in different eco- geographic zones. Major thrust should be , further genetic improvement through classical breeding and molecular techniques and evolving the appropriate apiary management technology based on the ecological and socio-economic conditions of the region. Zonation of beekeeping areas for Apis cerana and Apis mellifera ippears to be the only logical solution for those species where latter species has already been introduced. INTRODUCTION Beekeeping is becoming an import.ant component of present strategies for sustainable mountain agriculture and integrated rural development programmes. The role of beekeeping in providing food, nutritional, economic and ecological security to rural communities, especially those living in the developing countries of Asia, cannot be overlooked as it has always been linked with the cultural and natural heritage of rural communities. This, being a non-land based activity, does not compete with other resource demanding components of farming systems. At micro level, beekeeping is an additional income-generating activity and at macro-level, investment may be quite high but there is greater use of temporal and spatial diversity of natural resources such as pollen and nectar that otherwise go unutilised. The pollination activities of honeybees are an important integration function, as they contribute to the sustainability and divrsity of agricultural and botanical resources in general, and thereby contribute to increased productivity and maintenance of biodiversity (Verma 1990 a). The south and south-east Asian region is rich in honeybee species and genetic diversity. Amongst the different honeybee species, the Asian hive bee Apis ceranais equivalent to the European honeybee, Apis mellifera because both can be domesticated and build parallel combs. Great strides inmodernizing beekeeping with the native and exotic honeybee species are being made in different eco-geographic zones (temperate, sub-temperate and sub-tropical) of the region. China at present isone of th6 major prodvcer and exporter of honey and other hive products inthe world. Similarly, India has taken the lead in south and south-east Asia utilizing honeybees for pollination purposes to boost yield and improve quality. In other countries of the region initiative efforts are being made to develop beekeeping on modern wientific lines. However, due to constraints such as lack of basic infrastructure, skilled manpower, training, extension facilities of basic and applied research programmes, the situation is far from satisfactory despite ideal climatic conditions and availability of diverse floral resources throughout the year. It is in the light of these observations, an attempt has been made inthe present paper to review the current stateApisceranadiversity and suggest a practical framework 32/Verma Statusof HinalayanHoneybee 417 for the improvement of Apis ceranabeekeeping in Asia (Verma 1992 a). THE AMOUNT OF APIS CERANA GENETIC DIVERSITY The genetic diversity of Apis nellfera has been organized into 24 sub-species having varied economic usefulness. These sub- species are adapted to a wide range of ecological condiions and at latitude ranging from 0' at equator to latitude as high as 50ON and 300S. So far only four sub-species of Apis ceranaare recognized, although there may be several more because of is wide range of geographic distribution (Ruttner 1S87). Our research group in ICIMOD has successfully identified genetic variance in morphological characters ofApis ceranaand confirmtd the accepted distribution of A. cerana sub- species in t-! Himalayan region. These sub-species have been named as Apis cerana ceran,;, Apis cerana himalaya and Apis cerana indica (Verma 1992 b). According to a survey canducted by bee scientists in China, five different sub-species ofApis ceranarepresenting different eco-geographic zones have been identified. These include Apis ceranacerana,Apis ceranaskorikovi,Apis cerana abaensis,Apis ceranahainanensisandApis ceranaindica.(Zhen-ming etal. 1992). Each sub-species has further locally adapted populations called ecotypes which differ from each other in several biological and economic characters. For example, we have succesfully identified three ecotypes of sub-speciesApiscerana himalayathat correspond to geographic distribution in (1) the Naga and Mizo hills, (2) Brahmaputra valley and Khasi hills, and (3) the foothills of the north-east Himalayas (Singh et al. 1990). On similar lines, Chinese bee scientists have also classified sub- species Apis ceranaceranainto 5 ecotypes namely, Guangdong- Guanxi type, Hunan type, Yunan type, North China type and Changbaishan type (Zhen-ming et al. 1992). In some parts of Hindu Kush Himalaya, A' is cerana cerana matches European hive bee, Apis mellifera in commercial use value and has spectacular potentials for further genetic improvement by selective breeding and molecular research. HOW MUCH GENETIC DIVERSITY ISBEING LOST Despite its economic usefulness, beekeeping with native Asian hive bee, Apis ceranais suffering precipitous decline and is threatened with extinction in its entire native habitat. For example, in Japan, beekeeping with Apis ceranahas been completely replaced by Europeat hive bee Apis mellifera and only a few beekeepers and research institutes are raising Apis ceranacolonies (Sakai 1992). In China, out of more than 8.5 millidn colonies of honeybees kept in modem hives, 70 per cent are European Apis melliferaand only 30 per cent are native Apis cerana (Zhen-ming et al. 1992). Similarly in south Korea, only 16 per cent beekeeping is with native Apis cerana and the remaining has been replaced by exotic Apis mellifera(Choi 1984). 418 Himalayan Bliodiversity Conseration Straiegies Recent survey conducted by author as a par, of USAID funded regional project in ICIMOD reveal that in Hindu Kush Himalayan region, beekeeping with native Apis cerana is being replaced by Apis mellifera at such a fast rate that populations of native Apis cerana is declining to a level that is no longer viable. These countries include Afghanistan, Bhutan, Burma, Nepal, India and Pakistan. In a small north Indian state of Himachal Pradesh, which has a centuries old tradition of beekeepig with Apis cerana, all the 43 beekeeping development and ex,ension centres have been replaced by Apis mellifera. Even in Kashmir region of north-wes Himalaya, where Apis cerana matches Ap.s mellifera in body size and honey production, only a few per cent of native Apis ceranacolonies are left which may soon be wiped ouL A visit to some mountain areas of north-west Frontier Province of Pakistan in May 1989, led Dr. Eva Crane to conclude thatApis ceranapopulations may soon become an endangered species (Crane 1992). Thus the existing long established craft of beekeeping with Apis cerana will soon get destroyed in the entire Hindu Kush Himalayan region. CAUSES AND CONSEQUENCES OF DECLINING GENETIC DIVERSITY In seeking ways to conserve genetic diversity of Apis cerana,it is necessary to have a clear understanding of the major threats which this bee species is facing in its own native habitat.Like any other threatened biological resources, decline in Apis cerana populations is also being caused by human mismanagement, misguided economic, policies and faulky institutions. Major threats include the following. i) Impact of Exotic Apis mellifera Large scale importations and multiplication of exoticApismelliferainto the developing countries of south and south- east Asia for better economic returns in terms of higher honey production and efficient pollination services has become a controversial subject. On the one hand, some beekeeping experts and donor agencies are of the opinion that only exotic Apis mellifera can bring about the "Sweet Revolution" in this region in the same way as the high yielding exotic varieties of wheat are instrumental for the "Green Rev6lution". In parts of northern India and north-west Frontier Province of Pakistan, Apis meilifera has been the basis of a flourishing beekeeping industry and so much surplus honey is being produced that efficient marketing is becoming a major problem. Studies on the economics of beekeeping with native and exotic species of honeybees indicate such vast differences in the profit leveli that a farmer practicing beekeeping with exotic Apis melliferain north­ west Frontier Province of Pakistan can easily afford an imported car, whereas, the one continuing with native Apis ceranais still using bicycle (Verma 1990a). On the other hand, many importations of Apis mellifera in south-east Asia have proved disastrous. When l'ept sympatrically, Apis ceranaand Apis mellifera 32/Verma Status of Ilinialayan Honeybee 419 colonies frequently robbed each other (Koeniger 1982). Another cause of failing co- existence of the two species is attempted intermating which produces lethal off-spring (Ruttner and Maul 1983). A new problem is the transfer of parasites from one species to another. A parasitic mite of broad and adults, Varroajacobsonicar co-exist with Apis ceranaand causes no serious damage to their native bee species. In several countries of Asia, whce both these species are now kept together, the parasite has infested Apis mellifera colonies and became a serious pest to this unadapted host. There is now apprehension that through importations of Apis mellifera, Apis cerana populations in its native habitat will face serious risk of extinction. ii) Habitat Alteration In developing countries of south and south-east Asia, habitat a4jeration (especially due to deforestation) from a highly diverse natural ecosystems t-ni-r­ less diverse (often monocuhures) agro-ecosystems is adversely affecting native bee populations in the region. This is one of the most important threat often related to land-use changes on a regional scale that involve great reduction in the area of natural vegetation. Such habitat destruction could lead to loss of different l'yes of flowering plants and bee flora. Scarcity of bee flora due to environmental degrada­ tion not only leads to decline in colony numbers but also creates "stress conditions" for living bee colonies and increases their vulnerability to the pests and diseases, hunting and random population changes. Recent incidence of Thai sacbrood virus disease and European foul brood in Apis ceranamight have arisen due to the stress conditions created by environmental degradation (for details please see "Diseases and Enemies" section below). Destruction of forest habitat for growing agricultural and horticultural crops adversely affects the availability of floral resources because many of the staple crops such as rice, wheat, barley, poto etc. are of little or no value to honeybees. Due to increasing dearih of bee floral resources, colonies in the spring would not be able to build their owr. populations rapidly and this might force them to forego swarming or cause them cast smaller swarms that would reduce the probability of survival. In either case, the residt would be.an eventual decline in colony numbers. Habitat destruction greatly limit the choice of honeybees to carefully choose a particular micro-habitat in which to build nests and rear off-spring and thus protect itself from the attacks of predators. In their absence of dense vegetation, nest sites are often visible from a long distance and colonies are not able to defend themselves effectively from the predators and they became more Drone to absconding. iii) Pesticide Poisoning of Honeybees Beekeeping and pesticides both have become essential inputs of modem agricultural management technology. By ignoring either of two, global food production would be seriously impaired. Since the advent of synthetic pesticides several decades ago, the beekeeping industry, both in the developed and developing cointries, have been incurring heavy losses. In developed countries, large scale 420 Himalayan Biodyersiy: Co, ervation Strae its monoculture cultivation of crops and a high degree of mechanization had greatly amplified the problem of honeybee poisoning by pesticides. However, in recent years, education and public relations have achieved much in reducing tee losses due to pesticide poisoning in the developed world. Indeveloping countries, all species of honeybee still face very risk because agricultural practices often include insecticide application carried out in ignorance of indifference to the indispensability of b-es. Inall the developing countries of south and south-east Asia, alarge area of land isbeing brought under the cultivation of high yielding exotic cultivars of crops and alongwith them their pests have also become introduced either through human error, accidentally or lack of proper quantitative fac~lities. For the control of these pests, a large.number of biocides are coming into use. Because of the lack of information, faners in the region use blanket application without caring as to what and how much to use and when. Unlike developed countries, there isalso lack of legislation to prohibit the use of pesticides to the extent that kill bees. Integrated pest management technologies for protection of honeybees from harmful effects of broad-spectrum biocides are lacking. Such over reliance on chemical methods is adversely affecting environmental health including health hazards to humn beings and decline inother ion-target animal populations. Amongst the latter, honeybees because of their social behavior run the highest risk of pesticide poisoning. iv) Diseases and Enemies There are frequent reports of Apis cerana colonies being affected by nosema, virus cluster and sacbrood diseases inthe Hindu Kush Himalayan region. Recently, the European foul brood disease has badly affected Apis ceranacolonies in Kathmandu valley of Nepal. Amongst the mites, Acarapis woodi, Varroajacobsonii. Neocyphalaeps, Tropilaelapssp and Pymotes naferihave been reported on Apis cerana.Amongst these, acarine diseasc poses a serious problem (Verma 1987). Amongst the predators, five different species of wasps pose a serious threat to beekeeping industry in this region. However, because of its shimmering and evasive behavior, Apis cerana can resist the attacks of wasps beuer than Apis mellifera.Two species of waxmoths, Gallariamellonellaand Archoriagrisellaare serious pests inApis cerana colonies as this native species of honeybee do not coillect propolis to guard against the attack of moths. In recent years, Thai sacbrood virus disease has been reported from all countries where Apis ceranaisfound, in early eighties, the incidence and severity of this disease increased at such an alarming rate that more than 95 per ccnt of colonies infected in different countries were killed by this disease (Rana etal. 1986, 1987). This resulted ingreat economic loss to beekeeping with Apis cerana inAsia not only in terms of honey and beewax production but also through adversely affected pollination services. The problem was particularly severe in the temperate region of the country where disease was more widespread than in tropical and sub-tropical region. 32/Verma Status ofHimalayan Honeybee 421 The presence of Thai sacbrood virus in the diseased colonies of Apis cerana in northern India was confirmed by conducting electron microscopic and serologi­ cal studies (Rana et al. 1986, 87). Different control measures recommended earlier to control the spread of sacbrood disease in Apis mellifera were unsuccessful in Apis cerana (Rana et al. 1986). However, about 5 percent of colonies in the affected areas were resistant and escaped the attack of this disease. Detailed investigations on such colonies indicate that some mechanism of resistance to the sacbrood virus disease exists in Apis cerana. In nature, this disease has a five years cycle, arid after this period, about 5 per cent of the surviving colonies start multiplying in a normal way and normal population is then restored. Due to the incidence to Thai sacbrood virus disease in Apis ceranain recent years, the beekeepers inthe region had no choice but to adopt beekeeping with Apis melliferawhich is not only free from this disease but is also giving higher economic returns to the farmers. Consequently, Apis ceranahas been completely abandoned by the farmers in the region and it has now become endangered/threatened species of mere academic interest to the researchers in conservation biology. v) Human Predations Beekeeping in Hindu Kush Himalayan region is marked by a long history of honey hunting methods killed most of the bees, destroyed the brood and left no honey stores behind in the nest for consumption by bees during dearth periods. Such harmful exploitation by man resulted either in the loss of bee colonies or developmerit of undesirable traits like absconding and swarming during the course of evolution. Since many of these absconding or swarming colonies have the tendency to return to the same nesting site each year, they are thus subjected to further harmful exploitation as these locations are well known to people. The net result of such human predation is both termporal and spatial decline in bee populations in its native habitat (Bishop 1992). According to Gilpin and Soule (1986), loss of genetic diversity of species leading to its extinction is a systems phenomenon involving the interaction of processes and states. It is to be based on three interacting fields i.e. Population Phenotype (PP), Environment (E) and Population Structure and Fitness (PSF). When such model is applied in relation to loss of genetic diversity in Apis cerana, the first field (PP) includes behavioral and genetic components such as frequent swarming and robbing, production of large number of laying workers, inbreeding depression and drift inbreeding. A second field, the environment (E) is the context. It ipcludes all abiotic and biotic factors that influence the population. In case of Apis cerana,the loss of habilat quantity and quality as a result of rapid agricultural transformation and deforestation in the region and pesticide hazards due to their indiscriminate use are important abiotic components. The biotic components include introduction of exotic Apis mellifera, epidemic of sacbrood virus disease and human predations as a result of traditional honey hunting methods. Population Phenotype (PP) and Environment (E) together determine the third field, the 422 HmalayanDiodiversdy: CorervalionStrategies Population Structure and Fitness (PSF). This is the field in which dynamic ronsc­ quences of interactions of PP and E are manifested interns of patch dis'.ribufion, population fragmenation, demographic randomness, reduced effective population size, growth rate and distributic nleading to stochastic and deterministic extinction. The decay in one component can exacerbate not only itself but also the behavior of other components. Table I list the components of each of these fields and Figure I represents their overlaps and interactions schematically. Table 1 : Components of population vulnerability analysis inApis cerana Field Component Environmental Perturbations (E) Loss of habitat quantity and quality - Exotic species :Introduction of European honeybee, Apis mellifera . Pathogens and parasites especially sacbrood virus infection - Human prediaons Traditional honey hunting methods - Pesticide hazards Population Phenotype (PP) Frequent swarming behaviour - -Robbing behaviour - Large number of laying workers - Inbreeding depression - Drift inbreeding Population Structure and Fitness - Paich distribution (PSF) - Population fragmentation - Demographic randomness . Reduced effective population size. growth rate and distribution - Stochastic and deterministic extinction (Modified from Gilpin and Soule 1986) STRATEGIES FOR CONSERVATION OF APIS CERANA Stock Improvement of Apis cerana Many of the above mentioned sub-species/ecotypes of Apis ceranaare at present not economically viable. The.efore, selection and breedriUg programme of superior genotypes to produce n bee suitable for intensive management is required. To achieve stock improvement, different Apis cerana sub-species and ecotypes should be accumulated at a central location and superior genotypes be identified 321Verrm Status of Himalayan Honeybee 423 Environment.independent Environment Dependent pp E IInbreeding Depression Adaptation I Heterozygosity ~~PSF tIr, N,D Inbreeding Ne--- Randomness PP: Population Phenotype E: Environment .1 PSF: Population Structure and Fitness N : Population Size D : Population Distribution r: Population Growth Rate E)TINCTION Ne : Effective Population Size S: Decrease I : Increase Adopted from Gilpin and Soule, 1986 Fig. 1. Population Vulnerability Analysis (PVA). Case of APIS CERANA. by integrafing biometric and molecular data with behavioral and economic criteria. Another important pre-requisite for stock improvement is to evolve an efficient queen rearing for Apis ceranaand also establish isolated mating stations for pure