Nitidulid Beetles Research Articles

The Male Produced Aggregation Pheromone of a Strawberry Sap Beetle, Lobiopa insularis (Coleoptera: Nitidulidae).

The nitidulid beetle Lobiopa insularis is an important pest of strawberry crops in the United States and Brazil. Both larvae and adults feed on ripe strawberries, causing 20-70% loss in production during serious infestations. Aiming at the development of efficient, clean, and highly specific pest management systems, semiochemicals, especially pheromones, are particularly useful. Analyses of the extracts of both males and females obtained from aeration of live beetles showed the presence of three male specific compounds, 2-nonanone, 2-undecanone, and 2-undecanol (in an enantiomeric ratio of S:R=3.5:1). This is the first record of ketones and an alcohol as pheromone components in Nitidulidae. These compounds were emitted by males in amounts of 0.3:6:1.5ng per insect within 24h (1:30:3), respectively, during the scotophase, indicating nocturnal sexual activity. Field tests with pitfall traps containing different mixtures of compounds and ripe strawberries as a co-attractant summed up to five treatments with 25 replications. As a result, 59% males and 41% females (1:0.7) were caught, indicating the L. insularis pheromone to cause aggregation of both sexes. Results of the field tests showed that the attractivity of the binary mixture of ketones (T3) differed from the control (T5), from traps with 2-undecanone alone (T4), and from the mixture of 2-undecanone and racemic 2-undecanol (T2). Moreover, the activity of the ternary mixture of compounds (T1) was not different from that of T3, indicating that the racemic alcohol did not positively influence trap catches. In future applications, a mixture of synthetic strawberry-derived compounds that are attractive to L. insularis may substitute rapidly decaying fruit in the field, maintaining catches for longer periods. Because of its efficiency and low cost, a mixture of 2-undecanone and 2-nonanone is recommended to catch adult L. insularis in the field.

Metacommunity analyses of Ceratocystidaceae fungi across heterogeneous African savanna landscapes

Metacommunity theory offers a powerful framework to investigate the structure and dynamics of ecological communities. We used Ceratocystidaceae fungi as an empirical system to explore the potential of metacommunity principles to explain the incidence of putative fungal tree pathogens in natural ecosystems. The diversity of Ceratocystidaceae fungi was evaluated on elephant-damaged trees across the Kruger National Park of South Africa. Multivariate statistics were then used to assess the influence of landscapes, tree hosts and nitidulid beetle associates as well as isolation by distance on fungal community structure. Eight fungal and six beetle species were recovered from trees representing several plant genera. The distribution of Ceratocystidaceae fungi was highly heterogeneous across landscapes. Both tree host and nitidulid vector emerged as key factors contributing to this heterogeneity, while isolation by distance showed little influence. Our results are consistent with a model of metacommunity dynamics combining species sorting and patch dynamics processes.

Pollination by nitidulid beetles in the hemi-epiphytic aroid Monstera lentii (Araceae: Monsteroideae)

Among aroids (Araceae family) with bisexual flowers, the reproductive biology of the neotropical genus Monstera (Subfamily Monsteroideae) is misunderstood. Nothing is known about the reproductive phenology and the sparse evidence on its pollination system is equivocal, suggesting both bees and beetles as pollinators. In order to elucidate the pollination system and reproductive behavior of Monstera, we documented the floral cycle, spathe movement, floral visitors, and heat production of the inflorescence, and the flowering and fruiting phenology of M. lentii in a montane forest in Costa Rica. We found that M. lentii was mainly visited and likely pollinated by nitidulid beetles (Cychrocephalus corvinus, Nitidulidae) from the Mystropini tribe, which were mainly known as palm pollinators so far. In this mutualism, the beetles use the floral chamber as shelter, mating place, and probably as brood site. Drosophilid flies also visited the inflorescences and might participate in a mixed-pollination system, while stingless bees are considered as pollen robbers. Flowering and fruiting peaks occurred during the rainy season. Floral development was protogynous, a mechanism likely to prevent self-pollination. We concluded that pollination in M. lentii represents a highly dependent system on biotic pollinators for successful fruit set which likely contributes to an out-crossed mating system. Our findings indicate that pollination systems of bisexual aroids are more diverse than previously suggested.

Arthropods associated with fungal galls: do large galls support more abundant and diverse inhabitants?

Fungus-induced galls can attract spore-feeding arthropods as well as gall-feeding ones, resulting in diverse communities. Do large fungal galls support more abundant and diverse arthropod communities than small fungal galls? To address this question, we investigated the structure of the arthropod community associated with bud galls induced by the fungus Melanopsichium onumae on the tree species Cinnamomum yabunikkei (Lauraceae) in central Japan. Thirteen species of arthropods were associated with M. onumae galls. Dominant arthropod species were represented by the larvae of a salpingid beetle (a spore feeder), a nitidulid beetle (a spore feeder), a cosmopterigid moth (a spore feeder), an unidentified moth (a gall tissue feeder), and a drosophilid species (a gall tissue feeder). Arthropod abundance and species richness were positively correlated with gall diameter. The majority of the most abundant species were more frequently found in large galls than in small ones, indicating that large fungal galls, which have more food and/or space for arthropods, could support a more abundant and diverse arthropod community.

Contrasting pollination ecology ofDisepalumspecies (Annonaceae): evolutionary loss of the floral chamber and partial breakdown of protogyny associated with a shift in pollination system

Disepalum comprises two monophyletic sister subgenera, Enicosanthellum and Disepalum, with strikingly different floral morphologies: the former has two whorls of unfused sepals, forming a partially enclosed floral chamber, whereas the latter possesses a single whorl of congenitally fused petals and lacks a floral chamber. The pollination ecologies of representative species are reported, including assessments of floral phenology, pollinators and floral thermogenesis. Disepalum pulchrum (subgenus Enicosanthellum) has hermaphroditic flowers with a pollination chamber and is protogynous with prolonged anthesis; it is pollinated by nitidulid beetles and drosophilid flies. Disepalum anomalum (subgenus Disepalum) is also hermaphroditic with prolonged anthesis, but has incomplete protogyny due to overlapping pistillate and staminate phases; it is pollinated by meliponine bees, which are attracted by the pollen, but which are only able to transfer pollen to receptive stigmas during the overlap phase. Alternative evolutionary hypotheses are evaluated, including the possibility that the ancestor of the subgenus Disepalum lineage may have experienced a profound genetic mutation, possibly involving genes responsible for organ merism and fusion, resulting in the loss of the pollination chamber and hence favouring different floral visitors. The breakdown in protogyny required for effective pollination is likely to have had significant ramifications on population genetic diversity.

The expanding large-spored Metschnikowia clade: Metschnikowia matae sp. nov., a yeast species with two varieties from the Brazilian Atlantic Forest.

Fifty-two yeast isolates from flowers and associated nitidulid beetles of the Brazilian Atlantic Forest (Mata Atlântica) region were found to represent a new species in the large-spored Metschnikowia clade. The species is heterothallic, haploid, and allogamous, and produces asci with two aciculate ascospores that can reach 80 μm in length, as is typical in the clade. Analysis of sequences of the ribosomal RNA gene cluster indicates that the new species is closely related to Metschnikowia lochheadii, which ranges across Central America to northern Brazil, occurs as an adventive species in Hawaii, but is rarely found in central Brazil. The species is not readily distinguishable from relatives based on morphology or growth responses, but is well delineated from M. lochheadii on reproductive isolation. Based on an intron splice site PCR screen, we selected 26 isolates for further study. The sequence of the region that includes the complete internal transcribed spacer/5.8S rRNA gene segment as well as the D1/D2 domains of the large subunit rRNA gene contained three polymorphic segments and 14 haplotypes were identified. Of these, a single divergent isolate from the southernmost of four sampled localities exhibited diminished mating success when crossed with others. We describe two varieties, Metschnikowia matae var. matae sp. nov. var. nov. (type UFMG-CM-Y395(T), CBS 13986(T), NRRL Y-63736(T); allotype UFMG-CM-Y391(A), CBS 13987(A), NRRL Y-63735(A)) and Metschnikowia matae var. maris sp. nov. var. nov. (type UFMG-CM-Y397(T), CBS 13985(T), NRRL Y-63737(T)). We also report on the discovery of the h (+) mating type of Candida ipomoeae and transfer of the species to Metschnikowia ipomoeae comb. nov. (allotype UWOPS 12-660.1(A), CBS 13988(A), NRRL Y-63738(A)).

Diversity and pathogenicity of the Ceratocystidaceae associated with cacao agroforests in Cameroon

Knowledge of the diversity and ecology of plant pathogenic fungi in cacao agroforests and surrounding natural ecosystems can inform the development of sustainable management strategies for new cacao disease outbreaks. This study investigated the occurrence of fungi related to the Ceratocystidaceae and their nitidulid beetle vectors in cacao agroforests in Cameroon, under diverse agroecological conditions. The fungi and their vectors were collected from artificially induced stem wounds on cacao and associated shade trees. Collections were also made from abandoned cacao pod husks and other tree wounds within and around plantations. Fungal isolates were identified using DNA sequence‐based phylogenies and morphological comparisons, and two representatives of each species were evaluated for pathogenicity on cacao. Five species of Ceratocystidaceae were recovered, including Huntiella chlamydoformis sp. nov., H. pycnanthi sp. nov. and H. moniliformis, as well as Thielaviopsis cerberus and T. ethacetica. The incidence of these fungi appeared to be influenced by the prevailing agroecological conditions. Nitidulid beetles in the genus Brachypeplus were found to be their most common insect associates on cacao. Both T. ethacetica and H. pycnanthi produced extensive lesions after inoculation on branches of mature cacao trees, while T. ethacetica also caused pod rot. Although their impact remains unknown, fungi in the Ceratocystidaceae and their nitidulid beetle vectors are common and probably contribute to the parasitic pressure in Cameroonian cacao agrosystems.

Beetles (Coleoptera) of Peru: A Survey of the Families. Nitidulidae

Diversity in Peru: 4 subfamilies, 22 genera, 63 species. Recognition: This family may be recognized by the following combination of adult characters: maxilla lacking galea; antennae typically 11-segmented, with terminal three antennomeres forming a club; antennal insertions moderately to broadly separated; subocular antennal grooves on ventral surface of head present; procoxae transverse with exposed trochantins; prosternum transverse with intercoxal process extending between procoxal cavities, procoxae always separated; mesoventral procoxal rests present; typically five visible abdominal ventrites present; metendosternite stalk present; metasternum with discrimen present; and tarsal formula 5-5-5. Habitat: Several recent comprehensive reviews of Nitidulidae biology are available (Jelinek et al., 2010; Cline, 2005; Audisio et al., 2000; Audisio, 1993). Overall, nitidulid beetles exhibit a diverse set of life history strategies, including: fungivory, saprophagy, phytophagy, pollination activities, facultative predation, necrophagy, frugivory, and inquilinism with social insects. Nitidulids may be collected using a variety of directed (sweeping and beating vegetation/inflorescences, sifting leaf litter, searching under bark and various fungal substrates, as well as in nests of social Hymenoptera) and passive techniques (flight intercept traps, pitfall traps, malaise traps, and mercury vapor or black lights at night). Large numbers of nitidulids can typically be found in palm inflorescences (e.g., Mytrops and related genera); baited fruit or molasses traps (Carpophilus, Colopterus, Brachypeplus, Amphicrossus, Lobiopa, and Cryptarcha), and sifting leaf litter (Stelidota). Notes: Nitidulidae have long been confused with numerous other families of Cucujoidea. In particular, members of Cybocephalidae, Kateretidae, Monotomidae, Cryptophagidae, Biphyllidae, Smicripidae, and Erotylidae have been attributed to Nitidulidae. Recent and upcoming work on the New World Kateretidae (Cline and Audisio, 2010, and unpubl. data) will help improve the diagnostic capabilities for Nitidulidae. A recent treatment of Nitidulidae higher level phylogenetics formally elevated Cybocephalidae to family status and provided an extensive list of adult and larval characters to differentiate this group from Nitidulidae (Cline et al., 2014). Invasive species such as Urophorus humeralis (F.), Epuraea luteola Erichson, and Carpophilus hemipterus (L.) likely occur in the country as they have been transported around the world in various agricultural commodities, in conjunction with several other alien species more or less recently introduced into Peru (Carrasco, 1986; Leschen and Marris, 2005; EPPO, 2010). However, there are no existing records for

A scientific note on the association of Haptoncus luteolus (Coleoptera: Nitidulidae) with colonies of multiple stingless bee species

Different Nitidulid beetles can be found in social bee colonies (Ellis et al. 2008) andmay range from harmless associates (e.g.,Cychramus luteus , Neumann andRitter 2004) to damaging parasites (e.g., Aethina tumida , Neumann and Elzen 2004). Haptoncus luteolus (Coleoptera: Nitidulidae, Figure 1a, b) is a fruit pest (Yunus andHo 1980; Audisio et al. 1990) and has been reported as an associate of honeybee, Apis mellifera , colonies (Atkinson and Ellis 2011a, b). Here, we report for the first time its association with colonies of multiple stingless bee species. In July 2013, beetle larvae (N =6) were manually collected using entomological forceps from a thriving colony of the local stingless bee Trigona thoracica in Kelantan, Malaysia. The larvae were only found near and in multiple-punctured pollen pots in a bottom corner (Figure 1c). The pollen pots looked distorted oval and collapsed, which contrasts to the normal elongated oval shape in this stingless bee species (Michener 2013). No adult beetles were observed. In December 2013, adult beetles (N =21) were manually collected using entomological forceps from a thriving Heterotrigona itama , another local stingless bee. These beetles were hiding in the corners or under the brood comb of the colony. No beetle larvae was found. In January 2014, adult beetles (N >100), larvae (>100), and pupae (N >100) were manually collected using entomological forceps from the colony of a different local stingless bee, Tetragonula laeviceps . Several brood, honey, and pollen pots were infested by the larvae and adults (see Michener 2013 for respective details on the nesting biology of stingless bees). Interestingly, we observed distinct bulges on the surface of the nesting material. Careful dissections revealed that those apparently served as pupation sites (Figure 1d). This heavily infested T. laeviceps colony collapsed. All beetle samples were transported to the Biology Laboratory, Universiti Malaysia Kelantan. The adults were identified as H. luteolus (Coleoptera: Nitidulidae) [synonym—Epuraea luteola ] based on definitive morphological characteristics (see Gillogly 1982; Figure 1a). Then, a successful standard laboratoryrearing program for small hive beetles was established using plastic containers [18×12×6 cm, with a pin-holed lid (O=~1 mm), allowing for sufficient air circulation] and a diet consisting of pollen/honey/protein powder (Nutrilite®, Amway) in a 1:1:2 volume ratio (Neumann et al. 2013), thereby confirming that H. luteolus is able to successfully reproduce on bee products. Our observations show that H. luteolus can be associated with colonies of at least three different species of stingless bees. Taken together with earlier reports in honeybee, A. mellifera , colonies (Atkinson and Ellis 2011a, b), this suggests that this beetle species can exploit a variety of different social bee species. This is similar to the small hive beetle, which can infest colonies of honeybees (Neumann and Elzen 2004), bumblebees Bombus impatiens (Spiewok and Neumann 2006), Corresponding author: K. Krishnan, kumara_k2001@yahoo.com Manuscript editor: James Nieh Apidologie (2015) 46:262–264 Scientific note

Experimental Evaluation of Insect Pollination versus Wind Pollination in Leucadendron (Proteaceae)

Premise of research. Evolutionary transitions from insect to wind pollination are thought to have occurred many times during the angiosperm radiation. On the basis of floral features, several such transitions have been postulated for Leucadendron (Proteaceae), a dioecious genus of 96 taxa confined almost entirely to the Cape Floristic Region. To confirm whether these transitions took place, we carried out experimental tests for wind pollination and sampled insect flower visitors in 15 Leucadendron species, representing six clades in the genus. Methodology. In three clades in which an insect-wind shift has been inferred, we sampled species with traits suggestive of either wind or insect pollination. Plants were bagged with fine-mesh exclusion bags that excluded insects but allowed the passage of airborne pollen. Insects visiting female inflorescences were collected for identification and analysis of their pollen loads. Pivotal results. We found that insect exclusion had little effect on seed set of five species conforming to the wind pollination syndrome (L. rubrum, L. salicifolium, L. dubium, L. coniferum, and L. teretifolium), while seed set was strongly reduced by insect exclusion in the remaining 10 species conforming to an insect pollination syndrome. The most common pollinator of the insect-pollinated species was the nitidulid beetle Pria cinerascens. Conclusions. This study provides experimental verification of contrasting insect and wind pollination systems in Leucadendron and will thus enable formal phylogenetic tests of adaptive changes in floral traits, such as color and scent, that may be associated with pollination system transitions in this diverse lineage.

Evolutionary steps in the reproductive biology of Annonaceae

Flowers of Annonaceae are characterized by fleshy petals, many stamens with hard connective shields and numerous carpels with sessile stigmas often covered by sticky secretions. The petals of many representatives during anthesis form a closed pollination chamber. Protogynous dichogamy with strong scent emissions especially during the pistillate stage is a character of nearly all species. Scent emissions can be enhanced by thermogenesis. The prevailing reproductive system in the family seems to be self-compatibility. The basal genus Anaxagorea besides exhibiting several ancestral morphological characters has also many characters which reappear in other genera. Strong fruit-like scents consisting of fruit-esters and alcohols mainly attract small fruit-beetles (genus Colopterus, Nitidulidae) as pollinators, as well as several other beetles (Curculionidae, Chrysomelidae) and fruit-flies (Drosophilidae), which themselves gnaw on the thick petals or their larvae are petal or ovule predators. The flowers and the thick petals are thus a floral brood substrate for the visitors and the thick petals of Anaxagorea have to be interpreted as an antipredator structure. Another function of the closed thick petals is the production of heat by accumulated starch, which enhances scent emission and provides a warm shelter for the attracted beetles. Insight into floral characters and floral ecology of Anaxagorea, the sister group of the rest of the Annonaceae, is particularly important for understanding functional evolution and diversification of the family as a whole. As beetle pollination (cantharophily) is plesiomorphic in Anaxagorea and in Annonaceae, characters associated with beetle pollination appear imprinted in members of the whole family. Pollination by beetles (cantharophily) is the predominant mode of the majority of species worldwide. Examples are given of diurnal representatives (e.g., Guatteria, Duguetia, Annona) which function on the basis of fruit-imitating flowers attracting mainly fruit-inhabiting nitidulid beetles, as well as nocturnal species (e.g., large-flowered Annona and Duguetia species), which additionally to most of the diurnal species exhibit strong flower warming and provide very thick petal tissues for the voracious dynastid scarab beetles (Dynastinae, Scarabaeidae). Further examples will show that a few Annonaceae have adapted in their pollination also to thrips, flies, cockroaches and even bees. Although this non-beetle pollinated species have adapted in flower structure and scent compounds to their respective insects, they still retain some of the specialized cantharophilous characters of their ancestors.

Catching speciation in the act: Metschnikowia bowlesiae sp. nov., a yeast species found in nitidulid beetles of Hawaii and Belize

We describe the species Metschnikowia bowlesiae sp. nov. based on the recovery of six isolates from Hawaii and Belize. The species belongs to the Metschnikowia arizonensis subclade of the large-spored Metschnikowia clade. The isolates are haploid and heterothallic. Both Hawaiian strains had the mating type h(+) and the Belizean strains were h(-). Paraphyletic species structures observed in some ribosomal DNA sequence analyses suggest that M. bowlesiae sp. nov. might represent an intermediate stage in a succession of peripatric speciation events from Metschnikowia dekortorum to Metschnikowia similis and might even hybridize with these species. The type of M. bowlesiae sp. nov. is strain UWOPS 04-243x5 (CBS 12940(T), NRRL Y-63671) and the allotype is strain UWOPS 12-619.1 (CBS 12939(A), NRRL Y-63670).

Genetic structure ofKurtzmaniella cleridarum, a cactus flower beetle yeast of the Sonoran and Mojave Deserts: speciation by distance?

We studied 95 isolates of the yeast species Kurtzmaniella cleridarum recovered from nitidulid beetles collected in flowers of cacti of the Sonoran Desert of southern Arizona and the Mojave Desert of California. They were characterized on the basis of mating type and ten polymorphic DNA markers in relation to their geographic distribution. Although all loci appeared to be free of strong linkage, the recovered haplotypes represented but a small fraction of possible combinations, indicating that abundant asexual reproduction of local genotypes accounts for much of population growth, even though the yeast is capable of sexual recombination in nature. Much of the genetic differentiation took place at the local level, indicating that gene flow across the various localities is limited. However, a relationship exists between overall genetic differentiation and geography over long distances. We estimated that populations separated by c.1300km would share no alleles in common and that such a separation might be enough to favor the onset of speciation.

Management of Carpophilus spp. beetles (Nitidulidae) in stone fruit orchards by reducing the number of attract-and-kill traps in neighbouring areas

Owing to variation in susceptibility of different stone fruit varieties to nitidulid beetles (Carpophilus spp.), growers generally use attract-and-kill traps to treat only the most susceptible fruit tree varieties. Carpophilus populations often tend to build up in the untreated, less-susceptible varieties and then migrate to ripening, more-susceptible varieties in neighbouring areas. This compromises the ability of attract-and-kill traps to control the pest in the treated orchards. The use of attract-and-kill traps at the standard rate of 3 traps/ha in less-susceptible varieties is also expensive. Field experiments were conducted over two consecutive growing seasons in stone fruit orchards to test whether treating neighbouring less-susceptible varieties with a reduced number of attract-and-kill traps (2 traps/ha) would compromise control of the pest in susceptible target plots (treated with 3 attract-and-kill traps/ha). Each of the target plots with susceptible varieties had a history of high levels of damage caused by Carpophilus spp. Both treatments resulted in low levels of damage and there were no significant differences in the number of beetles killed, or the amount of fruit damage caused in the susceptible target plots. These results suggest that deployment of 2 attract-and-kill traps per hectare in the neighbouring areas is adequate to protect the susceptible target orchards from migrating Carpophilus beetles.

Functional Monoecy Due to Delayed Anther Dehiscence: A Novel Mechanism in Pseuduvaria mulgraveana (Annonaceae)

Unlike most genera in the early-divergent angiosperm family Annonaceae, Pseuduvaria exhibits a diversity of floral sex expression. Most species are structurally andromonoecious (or possibly androdioecious), although the hermaphroditic flowers have been inferred to be functionally pistillate, with sterile staminodes. Pseuduvaria presents an ideal model for investigating the evolution of floral sex in early-divergent angiosperms, although detailed empirical studies are currently lacking. The phenology and pollination ecology of the Australian endemic species Pseuduvaria mulgraveana are studied in detail, including evaluations of floral scent chemistry, pollen viability, and floral visitors. Results showed that the flowers are pollinated by small diurnal nitidulid beetles and are protogynous. Pollen from both hermaphroditic and staminate flowers are shown to be equally viable. The structurally hermaphroditic flowers are nevertheless functionally pistillate as anther dehiscence is delayed until after petal abscission and hence after the departure of pollinators. This mechanism to achieve functional unisexuality of flowers has not previously been reported in angiosperms. It is known that protogyny is widespread amongst early-divergent angiosperms, including the Annonaceae, and is effective in preventing autogamy. Delayed anther dehiscence represents a further elaboration of this, and is effective in preventing geitonogamy since very few sexually mature flowers occur simultaneously in an individual. We highlight the necessity for field-based empirical interpretations of functional floral sex expression prior to evaluations of evolutionary processes.

Ceratocystis species, including two new taxa, from Eucalyptus trees in South Africa

The ascomycete genus Ceratocystis (Microascales, Ceratocystidaceae) includes important fungal pathogens of trees, including Eucalyptus species. Ceratocystis species and their Thielaviopsis asexual states are typically associated with insects, such as nitidulid beetles, that spread them over long distances. Eucalyptus trees comprise a substantial component of the forestry industry in South Africa, however, limited information is available regarding Ceratocystis species that infect these trees. In this study, Ceratocystis species were collected from wounds on Eucalyptus trees in all the major plantation regions of South Africa, as well as from insects associated with these wounds. Both morphology and multigene DNA sequence analyses, using three nuclear loci, were used to identify the Ceratocystis species. Of the 260 isolates collected, nine Ceratocystis species, of which two were represented only by their Thielaviopsis anamorph states were identified. These species were C. eucalypticola, C. pirilliformis, C. savannae, C. oblonga, C. moniliformis, T. basicola, T. thielavioides and two Ceratocystis species that are described here as C. salinaria sp. nov. and C. decipiens sp. nov. Insects associated with these Ceratocystis species were Brachypeplus depressus (Nitidulidae), Carpophylus bisignatus, C. dimidiatus (Nitidulidae), Xyleborus affinis (Scolytidae), Litargus sp. (Mycetophagidae) and a Staphylinid (Staphylinidae) species.

Pollination biology of Annona squamosa L. (Annonaceae): Evidence for pollination syndrome

Pollination biology of Annona squamosa was investigated in the context of functional specialization and pollination syndrome. Hermaphroditic flower exhibited protogynous dichogamy as stigma became receptive a day before anther dehiscence. Flowers produce moderately high number (16,280±324) of spherical and medium size (98.6μm×87.3μm) pollen with pollen/ovule ratio of 120.6. Nitidulid beetles; Carpophilos domidiatus and Carpophilos hemipterous were identified as pollinators in terms of visitation frequency, pollination potential index score and pollination efficiency. However C. hemipterous was relatively effective pollinator than C. domidiatus. Floral traits and specific reward system of A. squamosa clearly exhibit obligate specialization by filtering only C. hemipterous and C. domidiatus as pollinators and thereby explicitly indicating canthrophilous pollination syndrome.

Saccharomycopsis fodiens sp. nov., a rare predacious yeast from three distant localities

Three strains representing a novel yeast species were recovered as part of independent collections from flower-associated nitidulid beetles in Australia, Costa Rica and the Galapagos Islands, Ecuador. Analysis of the D1/D2 domains of the large subunit rRNA gene indicated that the species belongs to the genus Saccharomycopsis, although the formation of ascospores was not observed. The yeast is capable of necrotrophic parasitism by means of infection pegs when mixed with other yeasts or filamentous fungi. Of particular interest is the fact that despite the large distances separating the isolation sites of the three strains, other strains of the species have not been recovered in other samples of flower-associated nitidulids even though these habitats have been sampled extensively. It is suggested that the dispersal of the yeast may be linked to human historical factors. The name Saccharomycopsis fodiens sp. nov. is proposed for the yeast. The type strain is UWOPS 95-697.4(T) (=CBS 8332(T)=NRRL Y-48786(T)).

Biology and Sources of Inoculum of Geotrichum candidum Causing Sour Rot of Peach and Nectarine Fruit in California.

Geotrichum candidum causes sour rot of fresh-market stone fruit such as peach and nectarine. Since 2001, the incidence of sour rot has increased in California, a semi-arid production area, which is considered atypical for the occurrence of the disease. In this study, sour rot developed at significantly higher incidence on wounded fruit compared with unwounded fruit, and disease severity increased as fruit matured. In packinghouse surveys, sour rot was found on up to 4% of non-fungicide- treated peach and nectarine fruit. In laboratory assays, sour rot developed when fruit were inoculated with a minimum of 20 conidia per inoculation site. Inoculum of G. candidum could be detected in California orchard soils at depths of up to 10 cm. The amount of inoculum in the soil was positively correlated with that on leaf and fruit surfaces of trees growing at a specific site. Moreover, inoculum of G. candidum was detected at different areas of packing lines in seven packinghouses. There were significant differences among the packinghouses evaluated, and these differences could be attributed, in part, to different sanitation practices used. Nitidulid beetles and fruit flies were found to play a role in disease transmission. These insects acquired sour rot inoculum in the orchard, and 25% of nitidulid beetles and 26% of fruit flies collected were positive for the pathogen. Spore survival in the soil over a 12-month period decreased significantly when soil depth increased from 10 to 20 cm. This study identified sources of inoculum of G. candidum in orchards and packinghouses, and provides information to guide development of disease management programs under the semi-arid conditions of California.

Ceratocystis species, including two new species associated with nitidulid beetles, on eucalypts in Australia

The genus Ceratocystis includes important fungal pathogens of trees, including Eucalyptus spp. Ironically, very little is known regarding the diversity or biology of Ceratocystis species on Eucalyptus species in Australia, where most of these trees are native. The aim of this study was to survey for Ceratocystis spp., and their possible insect associates, on eucalypts in Australia and thus to establish a foundation of knowledge regarding these fungi on the continent. Collections were made in three states of Australia from wounds on trees, as well as from nitidulid beetles associated with these wounds. Ceratocystis spp. were identified based on morphology and multigene sequence comparisons. Of the 54 isolates obtained, two previously unknown species of Ceratocystis were found and these are described here as Ceratocystis corymbiicola sp. nov. and Ceratocystis tyalla sp. nov. Furthermore, the distribution of Ceratocystis pirilliformis is expanded to include Eucalyptus spp. in Tasmania.