Curculionid Beetles Research Articles

Worldwide distribution and phylogeography of the agave weevil Scyphophorus acupunctatus (Coleoptera, Dryophthoridae): the rise of an overlooked invasion

Global plant trade represents one of the main pathways of introduction for invertebrates, including insects, throughout the world. Non-native insects include some of the most important pests affecting cultivated and ornamental plants worldwide. Defining the origins and updating the distribution of non-native invasive species is pivotal to develop effective strategies to limit their spread. The agave weevil, Scyphophorus acupunctatus (Coleoptera, Dryophthoridae), is a curculionid beetle native to Central and North America, although it also occurs in Eurasia, Africa, Oceania and South America as a non-native species. Despite being widespread, the extent of occurrence and origins of European populations of the agave weevil have been overlooked. In the present study, the current and potential worldwide distribution of S. acupunctatus was assessed and an analysis of its genetic diversity in the native and non-native ranges was performed. By analysing occurrences from local phytosanitary bulletins and citizen-science platforms, the agave weevil was confirmed to be widely distributed and to occur on all continents, except Antarctica. Additionally, there is potential for expansion throughout the world, as estimated by species distribution models. Nucleotide and haplotype diversity of the COXI mitochondrial gene (about 650 bp) was lower in the non-native (n = 39 samples) than native populations (n = 26 samples). The majority of introduced individuals belonged to the same haplotype, suggesting that most introductions in Europe might have occurred from a small geographical area in Central America. Constant transboundary monitoring and national laws must be considered to reduce the spread of the agave weevil, given that a bridgehead effect may occur from non-native populations to new suitable areas.

Exploring the diversity and host association of tarsonemid mites in West Bengal, a highly biodiverse state of Eastern India

The family Tarsonemidae is an extremely diverse assemblage of heterostigmatid mites which include phytophagous, fungivorous, detriphagous, algivorous and insect parasitic species living in various terrestrial, arboreal, subcortical or nidicolous habitats. Many of these mites pose a serious threat to global agriculture due to their direct feeding on crop plants or indirect transmission of disease-causing bacterial or fungal spores to healthy plants. For instance, Polyphagotarsonemus latus may reproduce year-round in all tropical and subtropical habitats and feed on more than 60 different plant families. Steneotarsonemus species, such as S. spinki and S. subfurcatus, attack rice and can significantly reduce the harvest, S. ananas attacks pineapple, and S. laticeps targets lilies. In temperate forests of the Northern Hemisphere, several Tarsonemus species phoretic on curculionid beetles transfer lethal fungal spores on healthy pine trees, while some other species pose a real hazard to cultivated mushrooms and stored products.

A list of the Curculionoidea (Coleoptera) from Sikhote-Alin Nature Reserve (Russian Far East)

Currently, 192 species of Curculionid beetles (Anthribidae – 4, Rhynchitidae – 20, Attelabidae – 10, Brentidae – 15 and Curculionidae – 143) are found in the Sikhote-Alin Nature Reserve. In total, 179 species are first found in the reserve for the first time. It is the first record of Thryogenes nereis (Paykull, 1800) for Primorskii Krai.

Effects of spawning Pacific salmon on terrestrial invertebrates: Insects near spawning habitat are isotopically enriched with nitrogen-15 but display no differences in body size.

When Pacific salmon (Oncorhynchus spp.) spawn and die, they deliver marine‐derived nutrient subsidies to freshwater and riparian ecosystems. These subsidies can alter the behavior, productivity, and abundance of recipient species and their habitats. Isotopes, such as nitrogen‐15 (15N), are often used to trace the destination of marine‐derived nutrients in riparian habitats. However, few studies have tested for correlations between stable isotopes and physiological responses of riparian organisms. We examined whether increases in δ 15N in terrestrial insect bodies adjacent to salmon spawning habitat translate to changes in percent nitrogen content and body size. This involved comparisons between distance from a salmon‐bearing river, marine‐derived nutrients in soils and insects, soil moisture content, and body size and nitrogen content in two common beetle families (Coleoptera: Curculionidae, Carabidae). As predicted, δ15N in riparian soils attenuated with distance from the river but was unaffected by soil moisture. This gradient was mirrored by δ15N in the herbivorous curculionid beetles, whereas carabid beetles, which feed at a higher trophic level and are more mobile, did not show discernable patterns in their δ15N content. Additionally, neither distance from the river nor body δ15N content was related to beetle body size. We also found that nitrogen‐15 was not correlated with total percent nitrogen in insect bodies, meaning that the presence of spawning salmon did not increase the percent nitrogen content of these insects. We conclude that while salmon‐derived nutrients had entered terrestrial food webs, the presence of δ15N alone did not indicate meaningful physiological changes in these insects in terms of percent nitrogen nor body size. While stable isotopes may be useful tracers of marine‐derived nutrients, they cannot necessarily be used as a proxy for physiologically important response variables.

A new species of the genus Dorytomus Germar, 1817 (Coleoptera, Curculionidae) from Rovno amber.

A new species, Dorytomus mikhailovi sp. n., from late Eocene Rovno amber is described and illustrated. The new species is similar to D. groehni Bukejs et Legalov, 2019 from Baltic amber but differs in the shorter rostrum, dorsum covered with denser decumbent hairs and erect to semierect scale-like setae, and smaller body sizes. It is distinguished from D. bukejsi Legalov, 2020 from Baltic amber by the densely punctate pronotum, longer rostrum and wide elytral interstriae. The new species differs from D. vlaskini Legalov et al., 2019 from Rovno amber by the elytral interstriae covered with decumbent hairs and erect to semierect scale-like setae, shorter rostrum and coarsely punctuate pronotum. It is the first named curculionid beetle from the Olevsk amber locality, and the eleventh amber species reported from the Zhitomyr region. The presence of seven species of Dorytomus suggests a rather high diversity of Salicaceae in the late Eocene amber forests of Europe. It corresponds well with other principal Holarctic species in European amber biotas.

Stem borer insects on Hopea odorata in Bogor, West Java, Indonesia

Abstract. Haneda NF, Furqan M, Suheri M. 2020. Stem borer insects on Hopea odorata in Bogor, West Java, Indonesia. Biodiversitas 21: 5308-5316. Hopea odorata Roxb. locally known as “merawan”, is a dipterocarp species that has the potentials to be developed for plantation forestry. Nonetheless, anecdotal evidence in Bogor, West Java, Indonesia, suggested that the trees suffered serious attacks caused by stem borer insects, causing defoliation of the crown and leading to stunted growth and death. This phenomenon suggests a more systematic investigation. The objectives of this research were: (i) to identify the species of stem borer which attacked H. odorata; (ii) to investigate the types and forms of the damage of H. odorata tree due to stem borer attack; and (iii) to study the effects of stem borer attack on the tree and wood of H. odorata. The results showed that all species of stem borer insects belong to Coleoptera, namely as Xyleborus perforans (Scolytidae), Xyleborinus perexiguus (Scolytidae), Platypus parallelus (Platypodidae), Belionota prasina (Buprestidae), Curculionid beetle, and Tenebrionid beetle. The number of boring holes on a single tree was 1932 holes, of which 98.6% caused by ambrosia beetles: Xyleborus perforans (1426 holes, 73.8%), Xyleborinus perexiguus (457 holes, 23.7%), and Platypus parallelus (21 holes, 1.1%). The length of boring tunnel at cross-section ranged between 2-35 cm and at longitudinal section ranged between 4-6 cm. The number of boring holes decreased along with the increasing height of tree stem. The patterns of boring tunnel at stem cross-section were branching (X. perforans, P. parallelus); encircled (X. perforans), black stains along their wall (X. perexiguus, X. perforans, P. parallelus).

Salix transect of Europe: records of willow-associated weevils (Coleoptera: Curculionoidea) from Greece to Arctic Norway, with insights from DNA barcoding.

BackgroundCurculionid beetles associated with willow (Salix spp.) were surveyed at 42 sites across Europe, from Greece (lat. 38.8 °N) to arctic Norway (lat. 69.7 °N). DNA sequence data provide additional verification of identifications and geographic clustering.New informationIn all, 73 curculionid species were collected from willows, of which seven were particularly abundant. The most widespread species were: Acalyptus carpini Fabricius, 1793 at 15 sites; Tachyerges stigma Germar, 1821 at 13 sites; Phyllobius oblongus (Linnaeus, 1758) at 11 sites; Phyllobius maculicornis Germar, 1824 at 10 sites; and Archarius salicivorus (Paykull, 1792), Melanapion minimum (Herbst, 1797), and Phyllobius cf. pyri (Linnaeus, 1758) all at nine sites. The mean number of curculionid species collected on willow at each site was 5.5 (range 0-14). Compared to chrysomelids, curculionids were richer in species but the species had relatively low average abundance. Widespread curculionid species appear to have scattered and patchy observed distributions with limited geographical structuring in our data. However, deeper sampling (e.g. over multiple seasons and years), would give a better indication of distribution, and may increase apparent geographical structuring. There is some site-to-site variation in colour in a few taxa, but little notable size variation. DNA barcoding, performed on some of the more common species, provides clear species clusters and definitive separation of the taxonomically more challenging species, as well as some interesting geographic insights. Our northernmost sample of Phyllobius oblongus is unique in clustering with Canadian samples of this species. On the other hand, our samples of Acalyptus carpini cluster with European samples and are distinct from a separate Canadian cluster of this species. We provide the first available DNA sequences for Phyllobius thalassinus Gyllenhal, 1834 (Hungary).

Contrasting floral biology of Artabotrys species (Annonaceae): Implications for the evolution of pollinator trapping

AbstractArtabotrys comprises a species‐poor early divergent grade (EDG) and a main species‐rich clade (“main Artabotrys clade,” MAC). All members of the MAC exhibit a remarkably well‐conserved floral Bauplan characterized by a tightly enclosed floral chamber with an elaborate rim between the inner petal blade and claw. Conversely, EDG resembles the sister genus Xylopia in lacking the inner petal rim, with one species (Artabotrys brachypetalus) bearing petals that lack the distinction between blade and claw altogether. The floral phenology and pollination ecology of two exemplar species—Artabotrys brachypetalus from the EDG and Artabotrys blumei from the MAC—are compared, including assessment of effective pollinators and their activity patterns, scent chemistry and thermogenesis. Our study revealed that Artabotrys blumei exhibits abbreviated anthesis (c. 27 hr), with a floral phenology and morphology that are clearly consistent with pollinator trapping, and may be pollinated by small beetles. Artabotrys brachypetalus has a typical anthetic duration (c. 45 hr), lacks a pollinator trapping mechanism, and is pollinated by honey bees and curculionid beetles. The “xylopioid” traits of the EDG are likely to be plesiomorphic, whereas the tightly enclosed floral chamber is likely to be apomorphic for the MAC and functionally significant in trapping pollinators.

Nesting biology and distribution of Stenancistrocerus (Paratropancistrocerus) obstrictus (Morawitz, 1895) (Hymenoptera: Vespidae: Eumeninae).

Nesting of Stenancistrocerus obstrictus was studied in the Republic of Dagestan, Russia. Ten nests were observed, six of them were dissected and their structure was studied. The nests were located in preexisting holes in a clayey cliff. Females searched for a place for the nest during more than a day. The holes with nests were 2.5-10.5 cm in length and 3-4 mm in diameter. Nest entrances were surmounted by laced earthen turrets curved downwards. The maximum length of a turret was 2 cm; the turrets had more laced structure at their distal ends while they became more solid towards the base. Nests consisted of a row of 3-10 cells separated by thin mud partitions. The cells were 5-9 mm in length. All lateral walls of the cells, as well as the vestibular cell were lined with a thin layer of mud. Females collected the building material outside the nests; they mixed clayey earth with regurgitated liquid and formed mud pellets used for the nest construction. Complete nests were sealed by final plugs; their turrets were dismantled by the females. The provision was tiny larvae of an unidentified curculionid beetle; several dozens of them were stored per cell. No parasites and associates were found in the nests. Reproductive success amounted to 92%. Adult feeding was recorded on flowers of Tamarix hohenackeri. The species is univoltine; hibernation occurs at the prepupa stage. Adult wasps are active from the end of May to the end of July. Nesting biology of the genus Stenancistrocerus and its phylogenetic position are discussed. Such a type of the nesting could be regarded as intermediate between nesting in various preexisting cavities and the excavation of burrows in an earthen substrate. The distribution of S. obstrictus is summarized; it includes Russia (Astrakhan Prov., Kalmykia, Stavropol Terr., Dagestan), Armenia, and Azerbaijan; the presence of the species in Eastern Europe is confirmed. The lectotype of Odynerus obstrictus Morawitz, 1895 is designated.

Three new species of the New Zealand endemic, Neptihormius van Achterberg & Berry (Hymenoptera: Braconidae), with diverse host records

AbstractThree new species of the New Zealand endemic braconid genus Neptihormius van Achterberg & Berry (Mesostoinae) are described. One of these species was reared from dipteran hosts on Coprosma (Rubiaceae): N. dipterophagus Quicke, Ward & van Achterberg sp. nov. from an agromyzid and unidentified gall‐forming cecidomyiid hosts. Neptihormius whakapapa Quicke & Ward sp. nov. was reared from a gall, thought to have been caused by a curculionid beetle. The third new species, N. herbaspicatum Quicke & Ward sp. nov., was reared from the New Zealand endemic moth Glyphipterix iocheaera Meyrick, 1880. A key to the species of Neptihormius is provided. Host records show Neptihormius attack galls and concealed leaf‐miner hosts indicating evolutionary plasticity in host utilisation.

Population and activities of curculionids beetle in snake fruit (Salacca zalacca)

Snake fruit (Salacca zalacca), an Indonesian native palm, has high economic value. This plant has a dioecious inflorescence. At the present time, pollination of snake fruit plants was still conducted by a human. Until now, some insect visitors as a pollinator of the plants were reported, such as stingless bees (Apidae) and curculionid beetles (Curculionidae). In this study, we study the population and activities of curculionid beetles in snake fruit plantations. Three plantations of snake fruit in Sumatera were used to observe beetle populations, i.e., Gunung Leuser National Park (Aceh), Padang Sidempuan (Medan), and Riak Siabun (Bengkulu). The sampling method was used to measure beetle populations by observed directly beetle population on the panicle (flowers). Observation of beetle activities was done by purposive sampling method in 08.00-12.00 am. Results showed that the highest beetle population (23096 individuals) occurred in Riak Siabun, Bengkulu. The highest visiting activity of beetle occurred in the morning.

Keanekaragaman kumbang curculionid pada berbagai tipe penggunaan lahan di kawasan Hutan Harapan, Jambi

Famili Curculionidae termasuk kelompok kumbang (Ordo Coleoptera) yang memiliki peranan penting dalam berbagai ekosistem baik hutan, perkebunan, dan pertanian lainnya. Perubahan tipe penggunaan lahan dari hutan menjadi lahan pertanian dapat menyebabkan penurunan keanekaragaman kumbang curculionid. Penelitian ini bertujuan untuk memelajari kekayaan spesies dan kelimpahan kumbang curculionid berdasarkan musim dan tipe penggunaan lahan di kawasan Hutan Harapan, Jambi. Koleksi kumbang curculionid dilakukan dengan metode pengasapan (fogging) kanopi. Penelitian dilakukan pada empat tipe penggunaan lahan, yaitu hutan, hutan karet, perkebunan karet, dan perkebunan kelapa sawit pada musim kemarau (bulan Mei hingga September 2013) dan musim hujan (bulan November 2013 hingga Februari 2014). Total jumlah serangga curculionid yang ditemukan 1762 individu, 12 subfamili, dan 118 spesies kumbang curculionid. Spesies kumbang curculionid tertinggi ditemukan di hutan (81 spesies) dan terendah di perkebunan karet (20 spesies). Kumbang curculionid dominan yang ditemukan di setiap tipe penggunaan lahan, yaitu Curculioninae sp.21 (hutan), Entiminae sp.06 (hutan karet), Scolytinae sp.09 (perkebunan karet), dan Elaeidobius kamerunicus Faust (perkebunan kelapa sawit). Jumlah individu curculionid tertinggi ditemukan di perkebunan kelapa sawit (853 individu) dan terendah di perkebunan karet (33 individu). Tipe penggunaan lahan dan keanekaragaman vegetasi tumbuhan memengaruhi kekayaan spesies curculionid, tetapi tidak memengaruhi kelimpahan kumbang curculionid. Berdasarkan hasil analisis menunjukkan bahwa perbedaan musim memengaruhi komposisi spesies kumbang curculionid pada tipe penggunaan lahan hutan, sedangkan pada tipe penggunaan lahan hutan karet, perkebunan karet, dan perkebunan kelapa sawit tidak menunjukkan perbedaan.

Nesting and Biology of Alastor mocsaryi (Hymenoptera, Vespidae: Eumeninae)

The nest structure of Alastor mocsaryi in trap nests was studied in Crimea. Fifteen nests were examined, located inside hollow reed stems 3.0–4.8 mm in inner diameter. The nests contained 1–9 cells separated by partitions. These were made of gravel cemented with soil mastic or sand. The bottom partitions (present in 14 nests) and final plugs (present in 2 nests) also contained loose gravel particles. The mean cell length was greater in the nests made in narrow cavities than in those made in broad cavities. The mean length of a cell with a female exceeded that of a cell with a male. Females provisioned the nest cells with weakly paralyzed larvae of curculionid beetles. The cocoon looked as whitish cobweb-like film and could be detached from the cell walls. The prepupae retained a high level of mobility during winter hibernation. Adult feeding was recorded on flowers of 12 plant species belonging to 9 families. Only 3 of them had nectar accessible to A. mocsaryi while 9 species were specialized melittophilous (7 species) or psychophilous plants (2 species). The wasps obtained nectar from flowers of the latter plants through holes in the perianth which they gnawed out with their mandibles. The nest partitions were found to contain monosaccharides; this indicates that wasp females use nectar as building material, to moisten and bond dry soil and sand particles. Water collection by female A. mocsaryi was recorded only once. The species is univoltine. The sex ratio is female-biased. Attachment behavior of the females to the point of their emergence from mother nests (philopatry) was recorded. The nests were infested with the parasitoid wasps Melittobia acasta and Hoplocryptus coxator, a larva of the beetle Trichodes apiarius, and a puparium of an unidentified tachinid fly. The progeny mortality was 38.8%. Nesting of A. mocsaryi is discussed in relation to the phylogenetic position of the genus Alastor. The use of nectar as building material may be related to nectar robbing from the flowers of many plant species; this feature may also be characteristic of some other members of the subfamily Eumeninae.

The role of beetles in the pollination of the mangrove palm Nypa fruticans

The flowers of the mangrove palm Nypa fruticans attracts a diverse array of potential pollinators. However, little is known about the pollination mechanism and which functional groups are the key pollinators. Inflorescences of nine nipa palms of different flowering stages were observed three times a day between sunrise and sunset in Thailand. The apparent entomofauna activity was recorded and all inflorescences were collected for extraction and identification of the beetle fauna. Beetles extracted from female inflorescences were measured for pollen load. In addition, thermogenesis was recorded over two days on two separate inflorescences. The most frequent visitors were species of nitidulid (genus Epuraea and the subfamily Cillaeinae) and curculionid beetles. Although they only carried small amounts of pollen grains, these groups of beetles were omnipresent. Thermogenesis peaked around 6.30 am with temperature elevations reaching 6° above ambient. The result obtained in this study are compared with those of previous studies conducted elsewhere in Thailand and in the Philippinies. The combined evidence strongly suggests a pivotal role in pollination of beetle visitors to the inflorescences of Nypa fruticans.

First Report ofHeilus freyreissi(Coleoptera: Curculionidae) Attacking Avocado and Associated withColletotricumsp. in Brazil

Curculionid beetles are significant pests of avocado trees (Persea americana [Lauraceae]). Adults of Heilus freyreissi (Coleoptera: Curculionidae) are reported for the first time on avocado trees, feeding on the tender lateral branches, the central leaf vein, inflorescences, peduncles, and fruits at the beginning of development. These injuries were consistently associated with symptoms of anthracnose disease caused by the fungus Colletotrichum sp. Thus, infestation of this insect may be of great economic significance in avocado production, because of its ability to attack various plant organs as well as it being a vector of the pathogen Colletotrichum sp.

Anthropogenic disturbance of tropical forests threatens pollination services to açaí palm in the Amazon river delta

Abstract The açaí palm Euterpe oleracea Mart. in the Amazon river delta has seen rapid expansion to meet increased demand for its fruit. This has been achieved by transforming lowland forest habitats (floodplains) into simplified agroforests and intensive plantation in upland areas. As açaí palm makes an important contribution to the economy and food security of local communities, identifying management approaches that support biodiversity and ecosystem processes that underpin fruit production on açaí farms is essential. We compared flower‐visitor communities and açaí fruit production in floodplain forests and upland plantations, across gradients of local management intensity (i.e. açaí density per ha) and surrounding forest cover. The relative contribution of biotic pollination and degree of pollen limitation were assessed using insect exclusion and hand‐pollination experiments. We found that açaí flower visitors are highly diverse (c. 200 distinct taxa) and had variable responses to disturbance. Bee visitation was higher in floodplains and positively related to surrounding forest cover, but other flower visitors, including specialised curculionid beetles, were unresponsive to changes in surrounding forest cover. However, intensive management practices (i.e. high açaí palm densities) in floodplains and uplands had contrasting effects on flower‐visitor communities, with flower‐visitor richness being lower on intensively managed floodplain farms and ant densities being higher on intensive upland farms. Pollination experiments revealed açaí palm to be highly dependent on biotic pollination. Fruit set in open‐pollinated inflorescences was positively related to flower‐visitor richness and specialised curculionid beetle visitation, whereas the presence of ants on inflorescences had a negative effect. Synthesis and applications. Our study shows that pollinators are essential for açaí fruit production, but that intensive farming practices have eroded the relationship between surrounding forest cover and ecosystem function in floodplains (i.e. conversion of native forest into simplified agroforests) and increased the frequency of antagonistic interactions in uplands (e.g. high ant densities). These findings underline the value of extensive management practices, such as the maintenance of other tree species within farms and adjacent unmanaged forest patches, to ensure the long‐term sustainability of açaí fruit production in the Amazon river delta.

Alphonsea glandulosa (Annonaceae), a New Species from Yunnan, China.

Alphonsea glandulosa sp. nov. is described from Yunnan Province in south-west China. It is easily distinguished from all previously described Alphonsea species by the possession of glandular tissue at the base of the adaxial surface of the inner petals. Nectar was observed throughout the flowering period, including the pistillate phase and subsequent staminate phase. Small curculionid beetles were observed as floral visitors and are inferred to be effective pollinators since they carry pollen grains. A phylogenetic analysis was conducted to confirm the placement of this new species within Alphonsea and the evolution of the inner petal glands and specialized pollinator reward tissues throughout the family.

Comparison of full mitochondrial genomes for the rice weevil, Sitophilus oryzae and the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae)

Complete mitochondrial genome sequences were assembled for the rice weevil, Sitophilus oryzae (17,602bp) and the maize weevil, S. zeamais (18,105bp; Coleoptera: Curculionidae: Dryophthorinae), which encode 13 protein coding genes (PCGs), 22 transfer RNAs, and 2 ribosomal RNAs that is typical among Animalia. The A+T-rich control regions of S. oryzae (2818bp) and S. zeamais (2832bp) are the longest described to date among curculionoidea (weevils). Additionally, non-coding intergenic regions have increased in size due to expansion of tandem repeat arrays, but is more pronounced in S. zeamais (606bp) compared to S. oryzae (109bp). A total of 69 and 22 substitution mutations were found among reads from S. oryzae and S. zeamais, out of which 68 and 2 were predicted in the PCGs respectively, with a majority in NADH Dehydrogenase subunit I. Phylogenetic analyses of coleopteran insects based upon full mitogenomes PCG sequence supported the existence of Curculionoidea and Tenebrionoidea as a monophyletic group, whereas the Cucujoidea and Elateroidea remain paraphyletic. The mitogenomes of these two Sitophilus species provide insight into short-term evolutionary relationships among curculionid beetles, and provide resources for the potential deciphering of more broad systematic questions in the Order Coleoptera.

The floral biology and reproductive system of Mauritia flexuosa (Arecaceae) in a restinga environment in northeastern Brazil

Studies of the floral biology of the buriti palm, Mauritia flexuosa, have presented conflicting results with respect to the mechanism of pollination, indicating either cantharophily or anemophily. To resolve this question, the floral biology of M. flexuosa was studied in a coastal restinga environment in northeastern Brazil. The reproductive system was studied experimentally, and floral visitors were collected by bagging inflorescences. In this environment, M. flexuosa, a dioecious species, has several gender-specific floral features that function to attract pollinators, especially beetles. The male flowers produce large amounts of pollen as a reward, and male and female inflorescences produce similar odors that attract pollinators to female flowers, which offer only a nectar secretion as a reward. When feeding on the female flowers, the visitors frequently come into contact with the stigmata. To increase the chances of pollination, the female flowers persist longer than the male ones, and the viability of the pollen grain is very high. A curculionid beetle species of the genus Grasidius was found to be an effective pollinator. We suspect that wind also contributes to the pollination of M. flexuosa in the study area, but in a relatively minor way.

Ant–herbivore interactions in an extrafloral nectaried plant: are ants good plant guards against curculionid beetles?

Extrafloral nectary drinking ants are known as effective plant guards, but some herbivores may circumvent ant attacks by foraging on different plant parts or presenting adaptations to avoid ant predation. Here we experimentally investigated the effect of Camponotus blandus on the florivory of the extrafloral nectaried shrub Banisteriopsis malifolia; and a possible spatial segregation between ants and herbivores (leaves and flowers). Flower buds are attacked by Anthonomus weevils. Results revealed no significant influence of C. blandus on the reduction of florivory. Adult Anthonomus are hard-bodied and were immune to ant bites; larvae are endophytic, so protected from ants. Ants and adult beetles were concentrated in different plant parts (leaves and flowers, respectively) so restraining the probability of encounters. Our results indicate that the system C. blandus–Anthonomus–B. malifolia is not stable, as ants receive extrafloral nectar, but are unable to protect the plant against weevils.