Molecular Phylogeny of theCeratosolenSpecies PollinatingFicusof the SubgenusSycomorus sensu stricto:Biogeographical History and Origins of the Species-Specificity Breakdown Cases

The 14 species ofFicusof the subgenusSycomorus(Moraceae) are invariably pollinated byCeratosolenspecies (Hym. Chalcidoidea), which in turn reproduce in the fig florets. They are distributed mostly in continental Africa, Madagascar, and the Mascarene and Comoro Islands, but 1 species extends its geographical range all over the Oriental region. Fig–pollinator relationships are usually strictly species specific, but exceptions to the ‘one-to-one’ rule occur within the group we studied. In order to understand both the biogeographical history of theCeratosolenspecies associated withFicusof the subgenusSycomorusand the origins of the specificity breakdown cases, we have used cytochromebsequences to reconstruct a phylogeny of the fig wasps. The results show that the pollinators from the Malagasy region and those from continental Africa form two distinct clades, which probably diverged after the crossing of the Mozambique Channel by an ancestral population. The Oriental wasp species show strong affinities with the African species. The two species-specificity exceptions are due to different evolutionary events. The occurrence of the two West African pollinators associated withF. surcan be explained by successive speciation events of the mutualistic partner without plant radiation. In contrast, we hypothesize thatC. galilishifted by horizontal transfer from an unknown, presumably extinct,Ficusspecies toF. sycomorusafter this native Malagasy fig species colonized Africa.     

Adaptive radiation in the Afrotropical region of the Paleotropical genus Lissocephala (Drosophilidae) on the pantropical genus Ficus (Moraceae)

Abstract. Of sixty-three extant genera of Drosophilidae, the genus Lissocephala is unique in having produced a diverse radiation superimposed on a plant-insect mutualism. Lissocephala is basically Paleotropical, with twenty-three Afrotropical and eight Oriental and Australasian species, and seemingly the adaptive radiation occurred on a taxonomically restricted group of host-plants, species of Ficus (Moraceae), solely in the African floristic region. A paradox results from the consideration that only the African radiation is linked with a strict diversification on Ficus species, even though this host plant genus is more diverse in the Oriental region. The focus of the present work is to document the diversity of host-figs exploited by Lissocephala in the African mainland (twenty-two fig species have yielded twenty-three Lissocephala species, but similarities in numbers between insects and plants does not seemingly result from species specificity), and to show that the clear-cut divide between the two African strictly fig-breeding Lissocephala lineages (the juncta and sanu groups) observed from male terminalia is further supported on the basis of 28S nuclear DNA divergence. Evolutionary scenarios are discussed whereby the two African Lissocephala lineages might have diverged on the African mainland or arisen independently from Oriental ancestors. Although the possibility remains that the juncta and sanu lineages set foot independently on the African mainland, it is more likely that there was a single colonization event for a common juncta—sanu ancestor. A stepwise host-fig transfer would then have occurred on the African mainland. The African Lissocephala ancestor would have first spread among the Sycomorus figs and only secondarily among the Galoglychia figs.     

Complementary fruiting phenologies facilitate sharing of one pollinator fig wasp by two fig trees

Aims Most pollinator fig wasps are host plant specific, with each species only breeding in the figs of one fig tree species, but increasing numbers of species are known to be pollinated by more than one fig wasp, and in rare instances host switching can result in Ficus species sharing pollinators. In this study, we examined factors facilitating observed host switching at Xishuangbanna in Southwestern (SW) China, where Ficus squamosa is at the northern edge of its range and lacks the fig wasps that pollinate it elsewhere, and its figs are colonized by a Ceratosolen pollinator that routinely breeds in figs of F. heterostyla .Methods We recorded the habitat preferences of F. squamosa and F. heterostyla at Xishuangbanna, and compared characteristics such as fig size, location and colour at receptive phase. Furthermore, the vegetative and reproductive phenologies in the populations of F. squamosa and F. heterostyla were recorded weekly at Xishuangbanna Tropical Botanical Garden for 1 year.Important findings Ficus squamosa is a shrub found near fast-flowing rivers, F. heterostyla is a small tree of disturbed forest edges. Although preferring different habitats, they can be found growing close together. Both species have figs located at or near ground level, but they differ in size when pollinated. Fig production in F. squamosa was concentrated in the colder months. F. heterostyla produced more figs in summer but had some throughout the year. The absence of its normal pollinators, in combination with similarly located figs and partially complementary fruiting patterns appear to have facilitated colonization of F. squamosa by the routine pollinator of F. heterostyla. The figs probably also share similar attractant volatiles. This host switching suggests one mechanism whereby fig trees can acquire new pollinators and emphasizes the likely significance of edges of ranges in the genesis of novel fig tree–fig wasp relationships.     

Phylogenetic relationships of functionally dioecious FICUS (Moraceae) based on ribosomal DNA sequences and morphology

Figs (Ficus, Moraceae) are either monoecious or gynodioecious depending on the arrangement of unisexual florets within the specialized inflorescence or syconium. The gynodioecious species are functionally dioecious due to the impact of pollinating fig wasps (Hymenoptera: Agaonidae) on the maturation of fig seeds. The evolutionary relationships of functionally dioecious figs (Ficus subg. Ficus) were examined through phylogenetic analyses based on the internal transcribed spacer (ITS) region of nuclear ribosomal DNA and morphology. Forty-six species representing each monoecious subgenus and each section of functionally dioecious subg. Ficus were included in parsimony analyses based on 180 molecular characters and 61 morphological characters that were potentially informative. Separate and combined analyses of molecular and morphological data sets suggested that functionally dioecious figs are not monophyletic and that monoecious subg. Sycomorus is derived within a dioecious clade. The combined analysis indicated one or two origins of functional dioecy in the genus and at least two reversals to monoecy within a functionally dioecious lineage. The exclusion of breeding system and related characters from the analysis also indicated two shifts from monoecy to functional dioecy and two reversals. The associations of pollinating fig wasps were congruent with host fig phylogeny and further supported a revised classification of Ficus.     

Floral volatiles, pollinator sharing and diversification in the fig-wasp mutualism: insights from Ficus natalensis, and its two wasp pollinators (South Africa)

Combining biogeographic, ecological, morphological, molecular and chemical data, we document departure from strict specialization in the fig-pollinating wasp mutualism. We show that the pollinating wasps Elisabethiella stuckenbergi and Elisabethiella socotrensis form a species complex of five lineages in East and Southern Africa. Up to two morphologically distinct lineages were found to co-occur locally in the southern African region. Wasps belonging to a single lineage were frequently the main regional pollinators of several Ficus species. In South Africa, two sister lineages, E. stuckenbergi and E. socotrensis, pollinate Ficus natalensis but only E. stuckenbergi also regularly pollinates Ficus burkei. The two wasp species co-occur in individual trees of F. natalensis throughout KwaZulu-Natal. Floral volatile blends emitted by F. natalensis in KwaZulu-Natal were similar to those emitted by F. burkei and different from those produced by other African Ficus species. The fig odour similarity suggests evolutionary convergence to attract particular wasp species. The observed pattern may result from selection for pollinator sharing among Ficus species. Such a process, with one wasp species regionally pollinating several hosts, but several wasp species pollinating a given Ficus species across its geographical range could play an important role in the evolutionary dynamics of the Ficus-pollinating wasp association.     

Molecular phylogeny of fig wasp pollinators (Agaonidae, Hymenoptera) of Ficus section Galoglychia

The obligate mutualism between fig trees and their fig wasp pollinators, together with the general tendency for each host species to be pollinated by one fig wasp species, led to the hypothesis that these two lineages have cospeciated. The pollinators of African figs of section Galoglychia form a diverse group of genera whose species seem to be less constrained to a specific host than other pollinating fig wasp genera. Various authors have suggested remarkably different phylogenetic relationships between the seven genera associated with section Galoglychia. These uncertainties concerning the classification make it difficult to understand the historical patterns of association between these wasps and their hosts. The phylogenetic tree for the pollinators was reconstructed with 28S, COI and ITS2 DNA sequence data and compared with morphological classification of the hosts. Pollinator genera were monophyletic in all analyses. However, the relative position of some genera remains unresolved. Investigation of host−fig association suggests that there have been frequent host jumps between host subsections. This indicates that cospeciation between fig trees and fig wasps is not as stringent as previously assumed. In addition, pollinators of the genus Alfonsiella associated with three host figs (Ficus craterostoma, F. stuhlmannii and F. petersii) are morphologically very similar in South Africa. We investigated the possibility that these pollinators form a complex of species with host‐based genetic differentiation. Molecular analyses supported the distinction of the pollinator of F. craterostoma as a good species, but the pollinators of F. stuhlmannii and F. petersii clustered within the same clade, suggesting that these two host species share a single pollinator, Alfonsiella binghami. Based on both molecular data and morphological re‐evaluation, a new Alfonsiella species is described, Alfonsiella pipithiensis sp. nov., which is the pollinator of F. craterostoma in southern Africa. A key to both females and males of all described species of Alfonsiella is provided.     

Consequences of protecting flowers in a fig: a one-way trip for pollinators?

Abstract. Fig trees ( Ficus ) have closed inflorescences. Closure is an efficient protection of flowers against non-specialist predators and harsh external environmental conditions. Each Ficus species is pollinated by a single insect species, an agaonid wasp, capable of forcing its way through a bract-covered pore, the ostiole, to gain access to the flowers. Figs also provide oviposition sites for the wasps. The fig/pollinator interaction is a classic example of mutualism. It has been widely assumed that, once pollinators have entered a fig, oviposited and pollinated, they die trapped within the fig. In this paper, we present observations under natural conditions and results of field experiments on three very different fig species ( Ficus aurea Nutt., F. carica L. and F. microcarpa L.) showing that some pollinators do exit or try to exit from the fig after pollination and oviposition. Moreover, experimental results demonstrate that in at least one species ( F. carica ), the pollinator is able to oviposit successively in two different figs.
The frequency of re-emergences from figs after pollination varies among species and this may be related to variations in pollination dynamics depending on environmental constraints such as the abundance of trees and tree phenology. Several factors that may favour pollinators that leave figs after pollination and oviposition are discussed. They include competition between pollinators for oviposition sites, and minimising of the risk of vertical transmission of parasites and pathogens.     

Revision of the Malagasy species of the genus Tricalysia (Rubiaceae)

The Malagasy representatives of the large African genus Tricalysia (tribe Coffeeae s.l.) are revised. Three Malagasy species were hitherto recognized in the genus, namely T. cryptocalyx , T. madagascariensis , and T. ovalifolia . In this study, two species, T. boiviniana and T. leucocarpa , are transferred from the genus Hypobathrum and seven new species and two new subspecies are described, raising the species number for Tricalysia to a total of 12. This marked increase in species number is a recurring pattern for many Malagasy genera in systematically poorly known families such as Rubiaceae. All the species are described in detail and illustrated, and a list of exsiccatae and a distribution map are provided. Furthermore, the characters of the Malagasy taxa are compared with those of the continental African species, and their infrageneric status is discussed. With the exception of T. ovalifolia , a member of subgenus Empogona , all Malagasy species belong to subgenus Tricalysia . Because of their unisexual flowers, these species cannot be accommodated within one of the four existing sections in subgenus Tricalysia . A new section, Androgyne , is therefore recognized.  © 2007 National Botanic Garden of Belgium. Journal compilation © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 83–126.     

Can chemical signals,responsible for mutualistic partner encounter,promote the specific exploitation of nursery pollination mutualisms? – The case of figs and fig wasps

In nursery pollination mutualisms, where pollinators reproduce within the inflorescence they pollinate, floral scents often play a major role in advertizing host location and rewards for the pollinator. However, chemical messages emitted by the plant that are responsible for the encounter of mutualist partners can also be used by parasites of these mutualisms to locate their host. Each species of Ficus (Moraceae) is involved in an obligatory nursery pollination mutualism with usually one pollinating fig wasp (Hymenoptera: Chalcidoidea: Agaonidae). In this interaction, volatile compounds emitted by receptive figs are responsible for the attraction of their specific pollinator. However, a large and diverse community of non-pollinating chalcidoid wasps can also parasitize this mutualism. We investigated whether the chemical message emitted by figs to attract their pollinator can promote the host specificity of non-pollinating fig wasps. We analysed the volatile compounds emitted by receptive figs of three sympatric Ficus species, namely, Ficus hispida L., Ficus racemosa L., and Ficus tinctoria G. Forster, and tested the attraction of the pollinator of F. hispida ( Ceratosolen solmsi marchali Mayr), and of one species of non-pollinating fig wasp [ Philotrypesis pilosa Mayr (Hymenoptera: Chalcidoidea: Pteromalidae)] to scents emitted by receptive figs of these three Ficus species. Analysis of the volatile compounds emitted by receptive figs revealed that the three Ficus species could be clearly distinguished by their chemical composition. Behavioural bioassays performed in a Y-tube olfactometer showed that both pollinator and parasite were attracted only by the specific odour of F. hispida . These results suggest that the use by non-pollinating fig wasps of a specific chemical message produced by figs could limit host shifts by non-pollinating fig wasps.     

Permeability of receptive fig fruits and its effects on the re‐emergence behaviour of pollinators

1. Figs and pollinating fig wasps provide a model system for studying mutualism. The permeability of the syconium changes during receptivity or between seasons, which may affect the behaviour of pollinators. Fig fruits are permeable during receptivity, and in some species, pollinators can enter and re‐emerge after oviposition/pollination. We studied the relationship between fig permeability and pollinator re‐emergence behaviour with a functional dioecious fig, Ficus hispida and the obligate pollinator Ceratosolen solmsi marchali. 2. The relationship reflects the interaction of figs and pollinators in the mutualism and also the conflicts of interests between the two partners: figs benefit from the enclosed fig fruits which have low permeability, but pollinators benefit from their re‐emergence behaviour, which requires high fig permeability. 3. The results showed that at the end of receptivity, the permeability of fig fruits lowered rapidly with changes to the ostiole structures, and re‐emergence rate was low, with more re‐emerging pollinators trapped in the ostiolar bracts. Our results also showed that in the rainy season, the length of receptivity was shorter and fig permeability was lower. The re‐emergence rates were also lower than those in the dry season. The results elucidated that figs' interests dominated in the conflicts between fig and pollinating wasp. 4. Based on a new criteria which employed the classification of pollinators found dead in the ostiolar bracts and which involved a survey of 6 monoecious and 12 dioecious fig species, we found that re‐emergence behaviour was prevalent among fig species, and was more prevalent in functional dioecious figs than monoecious ones.     

鸡嗉果榕榕小蜂产卵时序与种群数量分析

榕树与传粉榕小蜂的互惠共生体系被多种非传粉榕小蜂利用。在同一个榕果中,具有较高种群密度的传粉榕小蜂和多种非传粉榕小蜂生存在一起并相互作用。通过野外观察和采样分析的方法,对鸡嗉果榕内5种榕小蜂（传粉榕小蜂Ceratosolen gravelyi;非传粉榕小蜂Apocrypta sp., Philotrypesis dunia, Platyneura cunia和Sycoscaptertr ifemmensis）的产卵行为进行了研究。结果证明,鸡嗉果榕内生活的各种榕小蜂通过比较严格的产卵时序在榕果内产卵以占领不同的生态位,这反映了这些榕小蜂各自的生物学特性。自然种群数量分析表明,单个非传粉榕小蜂物种的种群数量几乎不与传粉榕小蜂种群数量呈负相关,而所有非传粉榕小蜂物种的种群个体总量与传粉榕小蜂的种群个体数呈正相关,这可能是多个物种共存于单个榕果内的进化适应。     

西双版纳聚果榕隐头果内小蜂群落结构及种间关系

聚果榕Ficus racemosa Linn.是雌雄同株榕树,它是西双版纳热带雨林生态系统中的一个常见种群。聚果榕必须依靠聚果榕小蜂Ceratosolen fusciceps Mayr传粉才能获得有性繁殖,而聚果榕小蜂又必须依靠聚果榕隐头果内短柱花繁衍后代,两者间形成了种间专一的互惠共生体系。同时,在其隐头果内还存在一个复杂的非传粉小蜂功能群,它们主要是榕树种子和传粉榕小蜂的寄生者。在云南省西双版纳自治州勐腊县勐仑镇选取了5个样地,对聚果榕单果内小蜂群落组成和种间相互关系进行研究。在不同时间段采集聚果榕单果242个,共收集小蜂366660头。聚果榕隐头果内有6种小蜂,隶属小蜂总科Chalcidoidae中的榕小蜂科Agaonidae、长尾小蜂科Caliimomidae、金小蜂科Pteromalidae,其中榕小蜂科中的C．fusciceps是聚果榕唯一的传粉者。金小蜂科中的Apocryta westwoodi Grandi和Apocryta sp.两个种是榕小蜂的寄生者,它们的寄生是传粉榕小蜂的种群数量减少因素之一。长尾小蜂科中Platyneura agraensis Joseph,Platyneura mayri Rasplus和Platyneura testacea Motschulsky3个种是寄生榕树种子或与榕小蜂争夺食物(瘿花)资源的小蜂类群,它们的出现与发生,致使聚果榕正在发育成种子的长柱小花形成瘿花,同时一部分种类把卵寄生在已被榕小蜂产卵的短柱小花子房中与榕小蜂争夺食物资源,致使榕小蜂食物资源的匮乏而死亡,对传粉小蜂种群有明显的影响。传粉小蜂从花托口钻入隐头果内,在隐头果内的长柱小花传粉和短柱小花子房中产卵,5种非传粉小蜂从隐头果外部把产卵器刺穿果肉把卵产在小花子房上。通过对5块样地隐头果内小蜂群落的综合分析发现,传粉榕小蜂为优势种群,而Apocryta sp.种的数量最少。在传粉及非传粉小蜂自然群体中各种类性比明显具有偏雌现象。小蜂群落表现异常的是聚果榕孤立株的样地,该样地传粉小蜂个体数量明显下降,非传粉小蜂个体数量则增加,各小蜂种群之间竞争激烈,出现C．fusciceps和P．mayri两个优势种。     

Ficus racemosa is pollinated by a single population of a single agaonid wasp species in continental South‐East Asia

High specificity in the Ficus‐agaonid wasp mutualism has lead to the assumption of a mostly ‘one‐to‐one’ relationship, albeit with some exceptions. This view has been challenged by new molecular data in recent years, but surprisingly little is known about local and spatial genetic structuring of agaonid wasp populations. Using microsatellite markers, we analysed genetic structuring of Ceratosolen fusciceps, the fig wasp pollinating Ficus racemosa, a fig tree species widely distributed from India to Australia. In sampling stretching from the south of China to the south of Thailand we found evidence for only a single pollinating wasp species in continental South‐East Asian mainland. We found no evidence for the co‐occurrence of cryptic species within our subcontinent sampling zone. We observed no spatial genetic structure within sites and only limited structuring over the whole sampling zone, suggesting that F. racemosa is pollinated by a single population of a single agaonid wasp species all over continental South‐East Asia. An additional sample of wasps collected on F. racemosa in Australia showed clear‐cut genetic differentiation from the Asian continent, suggesting allopatric divergence into subspecies or species. We propose that the frequent local co‐occurrence of sister species found in the literature mainly stems from contact zones between biogeographic regions, and that a single pollinator species over wide areas might be the more common situation everywhere else.     

Pollinating fig wasps: genetic consequences of island recolonization

The levels of genetic diversity and gene flow may influence the long-term persistence of populations. Using microsatellite markers, we investigated genetic diversity and genetic differentiation in island (Krakatau archipelago, Indonesia) and mainland (Java and Sumatra, Indonesia) populations of Liporrhopalum tentacularis and Ceratosolen bisulcatus, the fig wasp pollinators of two dioecious Ficus (fig tree) species. Genetic diversity in Krakatau archipelago populations was similar to that found on the mainland. Population differentiation between mainland coastal sites and the Krakatau islands was weak in both wasp species, indicating that the intervening 40 km across open sea may not be a barrier for wasp gene flow (dispersal) and colonization of the islands. Surprisingly, mainland populations of the fig waSPS may be more genetically isolated than the islands, as gene flow between populations on the Javan mainland differed between the two wasp species. Contrasting growth forms and relative 'immunity' to the effects of deforestation in their host fig trees may account for these differences.     

大果榕亚组三种榕树传粉榕小蜂核型研究

研究了木瓜榕(Ficus auriculata Loureiro)、苹果榕(F.oligodon Miquel)及未知榕(Ficus sp.)3种榕树传粉榕小蜂的核型。结果表明:3种榕树对应的传粉榕小蜂具有非常相似的核型,染色体数目相同为2n=10,染色体全部为中着丝粒染色体;核型公式2n=2X=10=10M,核型均为Stebbins-1A型。以臂比不对称性系数Dc和相对长度不对称性系数Dt作二维散点图,Ceratosolen emarginatus Mayr(木瓜榕传粉榕小蜂)和C.emarginatus Mayr(苹果榕传粉榕小蜂)具有非常相近的核型不对称系数,核型不对称性大于Ceratosolen sp.(未知榕传粉榕小蜂),显示出两者更近的亲缘关系,而Ceratosolen sp.(未知榕)与前两者亲缘关系较远。此外,比较了Ceratosolen属和Blastophaga属在核型方面的差异,认为染色体数目包括染色体形态能够作为准确区分Ceratosolen属和Blastophaga属的依据,并对Ceratosolen属的核型进化进行了初步探讨。     

New insights into the phylogeny of fig pollinators using Bayesian analyses

The interaction between figs and fig pollinators is one of the most species-specific mutualisms. Recently, phylogenies of both partners based on molecular data provided insights into a wide spectrum of co-evolutionary questions. However, for the phylogeny of fig pollinators, there are some discrepancies between different studies and left some relationships unresolved, especially for deep nodes. The phylogenetic uncertainties of pollinators prohibit our further understanding of the history of the mutualism. Here, we present phylogenetic analyses of a larger COI sequence dataset that includes previously published datasets and our sequences from 20 species using Bayesian method and maximum parsimony. The analyses using different methods share similar topologies. Bayesian analyses provide high level of confidence for most internal nodes in terms of posterior probability. This study also clarifies some discrepancies between previous studies. After rooting with Tetrapus, other pollinators split into two clades. Wiebesia and Blastophaga are at basal positions in respective clade. Ceratosolen is not monophyletic because Kradibia and Liporrhopalum fall inside this group. Three subgenera of Ceratosolen: subgen. Ceratosolen, subgen. Rothropus, and subgen. Strepitus are not supported. Therefore, Ceratosolen is suggested to be re-divided into three groups. Urostigma pollinators (including Dolichoris and Blastophaga psenes) are clustered together. The monophylies of Wiebesia, Blastophaga, Dolichoris are not supported in this analysis. This study also provides a new framework for re-evaluating character evolution and re-inspecting the definition of some genera.     

Chromosome numbers are not fixed in Agaonidae (Hymenoptera: Chalcidoidea)

Agaonidae (the pollinators of fig trees, Ficus spp., Moraceae) are a distinctive family of chalcid wasps with uncertain affinities within the Chalcidoidea. Chromosome numbers have only been described previously for one species (Blastophaga psenes, 2n = 12, the pollinator of F. carica, of subgenus Ficus). In this paper, we used a modified technique to analyze the karyology of three Ceratosolen species, Ceratosolen solmsi, C. graveli and C. emarginatus which are associated with figs of Ficus subgenus Sycomorus. Their karyotypes are 2n = 10. All the chromosomes are metacentric (NF = 20) with little difference in relative lengths, making them hard to distinguish. The variation in chromosome numbers that we have detected suggests that karyology can usefully complement molecular-based studies of the phylogeny of fig wasps.     

Development of 17 microsatellite markers for Ceratosolen constrictus, the pollinating fig wasp of Ficus fistulosa

The obligate mutualism between figs (Ficus) and fig pollinating wasps (Agaonidae) is regarded as a classic example of mutualism. Seventeen polymorphic microsatellite loci were developed for Ceratosolen constrictus, the pollinating wasp of the dioecious fig Ficus fistulosa. The number of alleles per locus ranged from two to 15 and the observed and expected heterozygosities ranged from 0.040 to 0.846 and from 0.040 to 0.916, respectively. These microsatellite loci offer a powerful tool for evolutionary and population genetic studies in C. constrictus, and gene flow of F. fistulosa.     

Finding hidden females in a crowd: Mate recognition in fig wasps

Multi-species mating aggregations are crowded environments within which mate recognition must occur. Mating aggregations of fig wasps can consist of thousands of individuals of many species that attain sexual maturity simultaneously and mate in the same microenvironment, i.e, in syntopy, within the close confines of an enclosed globular inflorescence called a syconium – a system that has many signalling constraints such as darkness and crowding. All wasps develop within individual galled flowers. Since mating mostly occurs when females are still confined within their galls, male wasps have the additional burden of detecting conspecific females that are “hidden” behind barriers consisting of gall walls. In Ficus racemosa, we investigated signals used by pollinating fig wasp males to differentiate conspecific females from females of other syntopic fig wasp species. Male Ceratosolen fusciceps could detect conspecific females using cues from galls containing females, empty galls, as well as cues from gall volatiles and gall surface hydrocarbons.In many figs, syconia are pollinated by single foundress wasps, leading to high levels of wasp inbreeding due to sibmating. In F. racemosa, as most syconia contain many foundresses, we expected male pollinators to prefer non-sib females to female siblings to reduce inbreeding. We used galls containing females from non-natal figs as a proxy for non-sibs and those from natal figs as a proxy for sibling females. We found that males preferred galls of female pollinators from natal figs. However, males were undecided when given a choice between galls containing non-pollinator females from natal syconia and pollinator females from non-natal syconia, suggesting olfactory imprinting by the natal syconial environment.     

榕树传粉昆虫榕小蜂染色体制备方法研究

榕树与其传粉昆虫榕小蜂之间具有高度专一的互惠共生关系,榕小蜂为榕树传粉的同时又在榕果内营寄生生活,直至完成其整个生活史,因此一直以来对榕小蜂的染色体研究存在很大困难。本文以对叶榕Ficus hispida传粉榕小蜂Ceratosolen solmsi和鸡嗉子榕F.semicordata传粉榕小蜂C.gravelyi为材料,摸索出一套适合于榕树传粉昆虫榕小蜂染色体研究的详细、有效的技术和方法。应用该法对对叶榕传粉榕小蜂C.solmsi和鸡嗉子榕传粉榕小蜂C.gravelyi的染色体核型进行了研究,结果表明两种榕小蜂的染色体核型特征非常相似,具有相同的染色体数目2n(♀)=10,染色体类型全部为中着丝粒染色体,臂数NF=20。此外,在相对长度方面两者也没有明显的差异。最后与Imai等1988年研究蚂蚁染色体时提出的方法进行了比较。利用本文介绍的方法进行榕小蜂染色体制备,操作过程简单、重复性强,不仅能够得到大量的染色体分裂相,而且染色体细胞界限明确、形态清晰、分散良好。