Anisoloboides joliveti n. g., n. sp. (Apicomplexa,Eugregarina, Gregarinidae), parasite of Brachyomus histrio Faust (Coleoptera,Curculionidae), with remarks on the other gregarines from the Curculionidae

The creation of a new genus of Eugregarina, Anisoloboides n. g., is proposed to accommodate the gregarines from the Curculionidae (Coleoptera) belonging to the subfamily Brachycerinae and the tribe Entimini and formerly described as Anisolobus (A. bulliardi, A. gymnopholi, A. desportis). A fourth species, A. joliveti n. sp. is described from another curculionid, Brachyomus histrio Faust, from Venezuela, and a list is presented of the other gregarines (Gregarina, Hirmocystis, Steinina) recorded from the Curculionidae.     

Phylogeny of the tribe Naupactini (Coleoptera: Curculionidae) based on morphological characters

Naupactini (Curculionidae: Entiminae) is a primarily Neotropical tribe of broad‐nosed weevils with its highest genus and species diversity in South America. Despite several taxonomic contributions published during the last decades, the evolutionary history of Naupactini remains poorly understood. We present the first comprehensive phylogenetic analysis for this tribe based on a data matrix of 100 adult morphological characters scored for 70 species, representing 55 genera of Naupactini (ingroup) and four outgroups belonging to the entimine tribes Otiorhynchini, Entimini, Eustylini and Tanymecini. According to the most parsimonious tree Artipus does not belong to Naupactini; the genera with flat and broad antennae, formerly assigned to other entimine tribes, form a monophyletic group (Saurops (Curiades (Aptolemus (Platyomus)))) related to the clade (Megalostylus (Megalostylodes (Chamaelops Wagneriella))); and the genera distributed along the high Andes, Paramos and Puna form a natural group (Asymmathetes (Amphideritus (Leschenius (Amitrus (Obrieniolus (Melanocyphus Trichocyphus)))))), nested within a larger clade that includes Pantomorus, Naupactus and allied genera. Atrichonotus, Hoplopactus, Mimographus and Naupactus are not recovered as monophyletic. In order to address the taxonomic implications of our phylogenetic analysis, we propose the following nomenclatural changes: to transfer Artipus from Naupactini to Geonemini, to revalidate the genera Mimographopsis (type species M. viridicans), and to revalidate the genus Floresianus (type species F. sordidus). The evolution of selected characters is discussed. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:C8AA4388‐A2F0‐4E2D‐889A‐500BEA5A9DE1 .     

Phenology of native weevils (Coleoptera: Curculionidae) in New Zealand pastures and parasitism by the introduced braconid,Microctonus aethiopoides Loan (Hymenoptera: Braconidae)

Abstract

The phenology of native brachycerine weevil species at seven pasture sites in Otago, Canterbury and Waikato was studied by regular quantitative sampling of adults. Weevils were identified to species, and dissected to record reproductive status and parasitism by introduced braconid parasitoids in the genus Microctonus. Climatic data assisted in the interpretation of some population density patterns. Weevil population density was estimated for periods of two to five years at the selected sites. Species in the Entimini (species of Irenimus and Nicaeana) were generally univoltine, with adults emerging in winter‐spring. The main period of reproductive activity was spring, and parasitism by Microctonus aethiopoides reached its highest incidence in January. Low level parasitism of native weevil species by M. aethiopoides was detected at all sites, and by M. hyperodae at two sites. At one site in Otago, parasitism by M. aethiopoides was higher and could have affected the population density of Irenimus aemulator (Broun) and Nicaeana sp. Most parasitism occurred after the main reproductive period of weevils in spring, but a putative second generation in some species might be more affected by parasitoid attack. A native rhytirhinine species, Steriphus variabilis, differed from the entimines because adults emerged in autumn and spring, and may be bivoltine. Mechanisms of M. aethiopoides parasitism of non‐target species in the field are discussed.     

Thermal orientation of Anthonomus pomorum (Coleoptera: Curculionidae) in early spring

Abstract. The selection of habitats with favourable temperature by the apple blossom weevil Anthonomus pomorum (L.) is investigated in a temperature gradient arena with a range of approximately 0–15 °C. Single female and male weevils are tested in the arena 2, 4 and 6 days after termination of diapause, during photophase and during scotophase. During photophase, weevils of both sexes choose the warmest part of the temperature gradient arena, irrespective of the time elapsed after diapause. During scotophase, high temperature is favoured by male weevils, as well as by females 2 and 4 days after diapause. However, 6 days after termination of diapause, females show no thermal preference in the temperature gradient arena during scotophase, indicating that thermal choice of female A. pomorum in the scotophase changes with time after the termination of diapause. The results suggest that both sexes benefit from thermoregulation by habitat choice during photophase when the weevils are flight active and colonize apple trees.     

Life history of the Onopordum capitulum weevil Larinus latus (Coleoptera: Curculionidae)

The population structure and stage-specific survival of the capitulum weevil, Larinus latus, a potential control agent for weedy Onopordum thistles in Australia, was studied in its native range in Greece. Although fecundity of this univoltine insect was low (35.4 eggs/female), survival was relatively high, with 45% of eggs reaching adulthood when protected from predators and parasitoids, and 23% surviving when exposed to these natural enemies. Other mortality factors of importance for immature stages were a failure to establish, due largely to oviposition by females on inappropriate sites on the thistle capitula, and inter- and intraspecific competition for larval resources. Once emerged, adult losses due to overwintering mortality and net migration were estimated at a further 48%. Despite these losses there was a net doubling of the population at the study site between Onopordum flowering seasons. The data suggest that movement of adults occurs both within and between patches and that variability in population size relative to the resource base is low. Overall, L. latus may be considered a K-strategist which forms relatively stable populations over a fragmented habitat and which maintains its population integrity through a certain degree of annual redistribution. The implications of these data for the potential effectiveness of L. latus as a biological control agent of weedy Onopordum spp. are discussed.     

Higher Level Phylogeny of Curculionidae (Coleoptera: Curculionoidea) based mainly on Larval Characters, with Special Reference to Broad-Nosed Weevils

A cladistic analysis of Curculionidae was performed using 49 characters (41 from larvae, three from pupae, and five from adults). Illustrations of characters of immatures are provided. The analysis involved 19 terminal units and a hypothetical ancestor determined by the outgroup comparison method used to root the tree. One most parsimonious cladogram was obtained based on the complete data set and the following phylogenetic hypothesis is proposed: Ithycerinae, Microcerinae, and Brachycrinae sensu stricto are broad-nosed weevils placed sequentially at the base of the cladogram. The remaining weevil subfamilies form two major natural groups: one constituted by the sister taxa Rhynchophorinae—Platypodinae; the other with Erirhininae at the base, as sister taxon of the "Curculionidae sensu stricto " which show an unresolved trichotomy involving Curculioninae, Cossoninae—Scolytinae, and the clade including the Entiminae and allied subfamilies. This latter clade of broad-nosed weevils has Thecesterninae at the base; the next branch is Amycterinae, the sister taxon of the clade comprising two groups: one constituted by Aterpinae, Rhytirrhininae, and Gonipterinae; the other is Entiminae whose units form two main clades: one constituted by the sister tribes Pachyrhynchini—Ectemnorhinini, and the other by Alophini, Sitonini, and Entimini. When the analysis was done using only immature characters, results congruent with those based on the complete data set were obtained, except for the placement of Erirhininae. According to the results the hypothesis of monophyly of broad-nosed weevils is not accepted; the Entiminae are justified as monophyletic and their natural classification into tribes is proposed and the phylogenetic position and relationships of higher taxa of Curculionidae are discussed. This paper shows the importance of immature characters in recognition of natural groups and relationships in Curculionidae.     

Areography of the genus Dendroctonus (Coleoptera: Curculionidae: Scolytinae) in Mexico

Objective To analyse whether the geographical ranges of Dendroctonus species are (1) associated with factors such as host species or elevation, and (2) in agreement with Halffter's Nearctic distribution pattern. (3) To identify and discuss the factors that are likely to act as barriers to the genus’ geographical distribution. (4) To explore whether there is an association between the size of the geographical ranges of Dendroctonus species and the number of Pinus host species used by each of them, and (5) to assess if these host species are most common at the elevations preferred by the individual Dendroctonus species. Site Mexico. Methods Records of 12 species of Dendroctonus were gathered from entomological collections in Mexico. Distribution ranges were defined by using the propinquity method ( Rapoport, 1975a ). Analysed parameters were: (1) geographical distribution of single species, (2) overlapping of species ranges, (3) disjunction patterns and barriers by means of isoprobabilistic lines, based on the morphotectonic subdivision of Mexico ( Ferrusquía‐Villafranca, 1998 ), (4) spatial variation in species richness with respect to latitude and altitude, (5) size of geographical ranges, and (6) host species for each Dendroctonus species. A correlation was determined between area size and number of pine host species. Results The species ranges varied in shape and size. Geographical ranges tend to be discontinuous in shape. Composite patterns showed that disjunctions among ranges do not closely follow Mexico's morphotectonic subdivision. There are repeated discontinuities among individual distributions, which define five areas: (1) Baja California Peninsula, (2) Sierra Madre Occidental (SMOC), (3) northern Sierra Madre Oriental (SMOR), (4) Sierra Madre de Chiapas, and (5) SMOR + Faja Volcanica Transmexicana (FVT) + Sierra Madre del Sur. The isoprobabilistic lines confirm that the inner part of SMOC provides an optimal environment for the genus, and the FVT province constitutes the broader corridor for it in the country. Richness does not directly decrease or increase with latitude. Richness behaviour of the insect is not associated with that of its host. Elevation distributions showed that most Dendroctonus species move within broad margins of tolerance and species richness is concentrated in the montane interval. Dendroctonus attack 24 of the 47 Pinus species distributed in Mexico. Preferred pine species belong predominantly to Leiophyllae, Ponderosae and Oocarpae subsections. The Spearman rank correlation between area size and number of pine host species was not significant. Dendroctonus clearly belongs to a Nearctic distribution pattern (sensu Halffter, 1987 ). Main conclusions Dendroctonus is present in all montane systems of Mexico and its species coexist within a high geographical sympatry. Overlapping of species distribution appears to be the result of two elements – generalized polyphagy inside Pinus and a wide elevation tolerance within mountainous environments. This behaviour, linked to a high vagility, has allowed the genus Dendroctonus to expand its distribution across Mexico and to employ mountainous systems as corridors separated by barriers that exert a low selective filter effect.     

Successful oviposition and reproductive biology of Aprostocetus vaquitarum (Hymenoptera: Eulophidae): A predator of Diaprepes abbreviatus (Coleoptera: Curculionidae)

Aprostocetus vaquitarum (Wolcott) causes 78–91 percent mortality to eggs of Diaprepes abbreviatus (L.), under field conditions in southern Florida. In the laboratory, A. vaquitarum was reared on D. abbreviatus eggs at 25 °C, a photoperiod of 12:12 (L:D) and with abundant hosts, A. vaquitarum adult females lived around 15 days. Oviposition was significantly affected by the age of the host egg mass. Egg masses aged 0- to 3-day-old were accepted significantly better than those aged 4–6 days. The mean number of eggs deposited per female was around 53, with extreme values of 124 and 19 eggs per female. Using these data in combination with the sex ratio observed in the field (0.16) and the duration of the preimaginal stages, r_m (0.168–0142 day⁻¹), T (22.39–22.89 days), and R₀ (43.03–25.81 females per female) were calculated.     

Energy use by the mountain pine beetle (Coleoptera: Curculionidae: Scolytinae) for dispersal by flight

The mountain pine beetle Dendroctonus ponderosae Hopkins is a major native pest of Pinus Linnaeus (Pinaceae) in western North America. Host colonization by the mountain pine beetle is associated with an obligatory dispersal phase, during which beetles fly in search of a suitable host. Mountain pine beetles use stored energy from feeding in the natal habitat to power flight before host colonization and brood production. Lipids fuel mountain pine beetle flight, although it is not known whether other energy sources are also used during flight. In the present study, we compare the level of energy substrates, proteins, carbohydrates and lipids of individual mountain pine beetles flown on flight mills with unflown control beetles. We use a colorimetric method to measure the entire metabolite content of each individual beetle. The present study reveals that mountain pine beetles are composed of more protein and lipid than carbohydrate. Both female and male mountain pine beetles use lipids and carbohydrates as energy sources during flight. There is variation between sexes, however, in the energy substrates used for flight. Male mountain pine beetles use protein, in addition to lipids and carbohydrates, to fuel flight, whereas protein content is not different between flown and control females.     

A contribution to the biology ofBangasternus fausti [Col.: Curculionidae], a potential biological control agent of diffuse knapweed,Centaurea diffusa,and its effect on the host plant

The biology of the weevilBangasternus fausti (Reitter), the larvae of which live in the flowerheads ofCentaurea diffusa (De Lamarck) and some relatedCentaurea spp., was studied in the field and in the laboratory in northern Greece and in the laboratory in Rome, Italy. The species is univoltine and overwinters as adults. Under laboratory conditions adults lived up to 90 days and up to 359 eggs were deposited by a single female (n=18). The maximum number of eggs laid by a female per day was 12 and the maximum number of days a female laid eggs was 73. Generally, there is only one larva per seedhead. One-hundred percent seed destruction was recorded in 18.7% of 502 field collected seedheads, each with oneB. fausti egg. The average mortality of the species, from egg to adult, was 94.4% in the field during 1988 (n=200) and 95.8% during 1987 (n=502).      

External microstructure of the ambrosia beetle Platypus koryoensis (Coleoptera: Curculionidae: Platypodinae)

Platypus koryoensis is a minute ambrosia beetle found in forests. It can cause significant economic damage to oak trees. Recently in Korea, it has been reported as a major pest of oak trees, because it causes sooty mold of oak by introducing the pathogenic fungus Raffaelea sp. In this paper, we demonstrate the fine structural aspects of the external body of the ambrosia beetle using field emission scanning electron microscopy, as a part of basic research into this pest so that strategies for its control might be developed. This beetle has a sensory system well developed to respond to both visual and chemical stimuli. Both sexes have a pair of faceted compound eyes and a pair of knobbed antennae, but simple eyes are absent. The mouthparts on its distinct snouts are effective devices for penetration and for boring holes. The mouthparts consist of the labrum, a pair of mandibles, a pair of maxillae and the labium. Both the maxillary and the labial palpi have the function of directing the food to the mouth and holding it while the mandibles chew the food. The distal ends of these palpi are flattened and have shovel‐like setae. The thorax has a particularly hard exoskeleton and hard elytra, including powerful muscles that operate both the wings and the legs. The legs are multi‐segmented and have a strong femur and tibia, including one pair of claws on the end of each tarsal segment. Characteristically, both male and female beetles have mycangial cavities for storing spores and other microorganisms, but only females have three pairs of large depressions on their dorsal thorax.     

Fine-tuning the composition of the cranberry weevil (Coleoptera: Curculionidae) aggregation pheromone

The cranberry weevil Anthonomus musculus Say is a key pest of highbush blueberries (Vaccinium corymbosum L.) and cranberries (Vaccinium macrocarpon Aiton) in the northeastern United States. Previous studies have reported A. musculus adult attraction to traps baited with the aggregation pheromone of the pepper weevil Anthonomus eugenii Cano, likely because these two weevils share similar pheromone blends that differ only in two components. The A. musculus aggregation pheromone contains (Z)-2-(3,3-dimethylcyclohexylidene) ethanol (Z grandlure II), (Z)-(3,3-dimethylcyclohexylidene) acetaldehyde (grandlure III), (E)-(3,3-dimethylcyclohexylidene) acetaldehyde (grandlure IV) and (E)-3,7-dimethyl-2,6-octadien-1-ol (geraniol); whereas A. eugenii produces a pheromone blend that includes (E)-2-(3,3-dimethylcyclohexylidene) ethanol (E grandlure II) and (E)-3,7-dimethyl-2,6-octadienoic acid (geranic acid) in addition to the four A. musculus pheromone components. Here, we hypothesized that differences in pheromone composition between these two species influence A. musculus adult attraction to its aggregation pheromone. To test this, we studied the response of A. musculus to its pheromone blend with and without E grandlure II and geranic acid, a commercial A. eugenii pheromone lure and a no-lure control in highbush blueberry and cranberry fields in New Jersey and Massachusetts, respectively. Regardless of crop type, A. musculus adults were more attracted to their four-component pheromone blend and the blend plus geranic acid than the commercial A. eugenii pheromone and the no-lure controls. The A. musculus pheromone blend plus E grandlure II and the A. eugenii pheromone blend also captured more A. musculus adults than the no-lure control but not compared to the commercial A. eugenii pheromone. Further analysis showed that A. musculus adults are significantly (~27%) less attracted to their pheromone blend if it contains E grandlure II, although the addition of geranic acid did not affect their response. These findings may help guide future efforts towards the development of behaviour-based tools to monitor and manage A. musculus.     

Taxonomic revision of Melanocyphus Jekel (Coleoptera: Curculionidae)

Cornops aquaticum (Bruner) is host specific on Eichhornia spp. and Pontederia spp. (Pontederiacae). Its present distribution ranges from Mexico to Argentina. The number of juvenile instars (5-7) apparently mirrors the photoperiod and temperature pulses of different climatical conditions in the respective geographical regions. Based on life-history data, three working hypotheses are proposed for forthcoming studies. These will test whether the varying number of juvenile instars represents a phenotypic plasticity of a single genotype or an adaptation that is genetically fixed, due to an evolutionary relationship of the host with its host-plant.     

The effect of cold temperature exposure and long-day photoperiod on the termination of the reproductive diapause of newly emerged female Pissodes strobi (Coleoptera: Curculionidae)

Abstract

• 1 There is confusion in the literature concerning a possible reproductive diapause in the adult white pine weevil Pissodes strobi.
• 2 We evaluated the effects of temperature, photoperiod, feeding substrate and mating status on the sexual maturation and oviposition of female white pine weevils.
• 3 Less than 30% of female P. strobi became sexually mature and laid eggs without experiencing dormancy under a temperature regime of 2 °C for 4 weeks.
• 4 Among the females that experienced a cold temperature treatment after emergence, 80% laid eggs after dormancy when exposed to a long‐day (LD 16 : 8 h) photoperiod and 17.6% laid eggs when exposed to a short‐day (LD 8 : 16 h) photoperiod.
• 5 Significantly more eggs were laid by all the females (with and without a cold treatment) when subjected to a long‐day photoperiod compared with a short‐day photoperiod.
• 6 A period of cold temperature followed by exposure to a long‐day photoperiod with warmer temperatures is required to break reproductive diapause and to obtain a good oviposition response in female P. strobi.
• 7 This study reveals the existence of much intraspecific variation in the response of the white pine weevil to temperature and photoperiod with respect to the induction and termination of reproductive diapause.

     

Phylogenetic reassessment of the Exophthalmus genus complex (Curculionidae: Entiminae: Eustylini,Geonemini)

The monophyly of the Neotropical entimine weevil genus Exophthalmus Schoenherr, 1823 (Curculionidae: Entiminae: Eustylini Lacordaire) is reassessed. Exophthalmus presently includes more than 80 species, approximately half of which are restricted to either the Caribbean archipelago or the continental Neotropics. The taxonomic composition and position of Exophthalmus have been subject to longstanding disagreements; in particular, authors have questioned the relationship of Exophthalmus to other Caribbean genera such as Diaprepes Schoenherr, 1834 (Eustylini) and Lachnopus Schoenherr, 1840 (Geonemini Gistel), as well as to the speciose Central and South American genera Compsus Schoenherr, 1823, Eustylus Schoenherr, 1842, and Exorides Pascoe, 1881 (all Eustylini), among others. The present study scrutinizes these traditional perspectives, based on a cladistic analysis of 143 adult morphological characters and 90 species, representing 30 genera and seven tribes of Neotropical entimine weevils. The character matrix yielded eight most‐parsimonious cladograms (length = 239 steps; consistency index = 66; retention index = 91), with mixed clade support that remains particularly wanting for some of the deeper in‐group divergences. The strict consensus supports the existence of a paraphyletic Geonemini ‘grade’ that includes Lachnopus and related Caribbean genera such as Apotomoderes Dejean, 1834, followed by a monophyletic Eustylini in‐group clade. Within the latter, a monophyletic South American Eustylini clade – including Compsus, Eustylus, Exorides, and related genera – is sister to a major clade that contains a ‘grade’ of heterogeneous and often misclassified Caribbean members of the Eustylini, Geonemini (Tetrabothynus Labram & Imhoff, 1852 and Tropirhinus Schoenherr, 1823), and Tanymecini Lacordaire (Pachnaeus Schoenherr, 1826), as well as two major clades: one with the majority of Central American Exophthalmus species, and the other with most Caribbean members of Exophthalmus. The Central American Exophthalmus clade is paraphyletic with respect to Chauliopleurus Champion, 1911 (Geonemini) and Rhinospathe Chevrolat, 1878 (Phyllobiini Schoenherr). The Caribbean clade, in turn, contains two subclades: i.e. (1) the Greater Antillean Exophthalmus s.s. clade, including the type species Exophthalmus quadrivittatus (Olivier, 1807); and (2) the primarily Lesser Antillean Diaprepes. The latter genus is therefore nested within Central American and Caribbean species of a highly paraphyletic Exophthalmus, yet may be rendered monophyletic if several Lesser Antillean Exophthalmus species are (re‐)assigned to Diaprepes. The results thus provide a suitable basis for a revision of all Exophthalmus species, and furthermore suggest that historical biographic factors, including colonization via temporary continental Neotropics‐to‐Caribbean land connections, were important in the evolution of major eustyline lineages. Based on these preliminary insights, the following taxonomic and nomenclatural adjustments are made. Compsoricus gen. nov. is erected to accommodate two Puerto Rican species erroneously assigned to Compsus: i.e. the herein designated type species Compsoricus maricao comb. nov. and Compsoricus luquillo comb. nov. Eustylus dentipes comb. nov. is transferred from Compsus. Diaprepes marginicollis Chevrolat, 1880 is reinstated from synonymy under Exophthalmus. Lastly, the following five transfers are proposed: (1) Chauliopleurus Champion, 1911, from Geonemini to Eustylini; (2) Tetrabothynus Labram & Imhoff, 1852, from Geonemini to Eustylini; (3) Tropirhinus Schoenherr, 1823, from Geonemini to Eustylini; (4) Rhinospathe Chevrolat, 1878, from Phyllobiini to Eustylini; and (5) Pachnaeus Schoenherr, 1826, from Tanymecini to Eustylini. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 510–557.     

Antennal sensilla of male and female of the nut weevil,Curculio nucum Linnaeus, 1758 (Coleoptera: Curculionidae)

The nut weevil, Curculio nucum (Linnaeus, 1758), is the main pest in hazelnut orchards (Corylus avellana L.). Semiochemicals are interesting bio control tools that could be used to manipulate the pest behaviour and to control pest populations. The study of the sensorial equipment of the insect antennae provides information on the importance of olfaction in the adult life for host plants and mate findings as well as on the putative other senses. Before electrophysiological investigation, the knowledge of antennae equipment is also necessary. The aim of this study is to determine the types, number and location of sensilla on the antennae of male and female adult C. nucum in order to determine their implication in seeking a sexual partner and a host plant. The 12-segmented antenna comprises a scape, a 7-segmented funicle and a 4-segmented club. Out of the nine sensillum types listed, three are present on the scape and the funicle and seven types on the club which gathers 71–73% of the total of sensilla. Tactile aporous sensilla chaetica C1, gustatory uniporous sensilla chaetica C2, olfactory multiporous sensilla basiconica B1 and B2 are found on both the dorsal and ventral surfaces of the club in both sexes. Thermo-hygroreceptive dome-shaped sensilla D, olfactory multiporous sensilla basiconica B3 and olfactory multiporous fluted sensilla basiconica F are found exclusively on the ventral surface of the club, suggesting that these sensilla are utilized in host plant acceptance during antennal tapping. The sexual dimorphism concerns only the numbers of sensilla chaetica C1 and sensilla basiconica B2.     

Interactions between Apion species (Coleoptera: Curculionidae) and Polygonaceae. I. Apion curtirostre Germ, and Rumex acetosa L.

Abstract.

• 1 Apion curtirostre is the commonest weevil attacking Rumex acetosa in the Lancaster area.
• 2 The ovipositional behaviour, larval development, emergence and hibernation of A. curtirostre are described.
• 3 From dissection of samples of stems of R. acetosa, abundance curves for the stages of A. curtirostre and its chalcid parasitoids were constructed and the between-stage mortalities determined.
• 4 There is an exponential relationship between R. acetosa stem height and number of A. curtirostre eggs laid.
• 5 Male stems of R. acetosa appear earlier and are smaller than female stems. Taller stems, at least in female plants, live longer than shorter ones.
• 6 Apion survival is lower in male than in female stems.
• 7 Stem sex is the primary determinant of opposition choice with stem thickness a secondary determinant.
• 8 A. curtirostre eggs introduced experimentally into stems of four Rumex species survived significiantly better in R. acetosa than in any other species. Survival in R. acetosa female plants was twice that in males.
• 9 Survival of A. curtirostre eggs at densities of 4, 8 and 16 per R. acetosa stem was twice that at densities of 32 and 64 per stem.
• 10 The stem size of female R. acetosa was reduced as the number of attacking weevils increased. There was no significant effect in males. No adverse effect on seed production was detected.
• 11 The nature of the relationship between A. curtirostre and R. acetosa is discussed.

     

Towards a phylogenetic system of derelomine flower weevils (Coleoptera: Curculionidae)

Abstract. A revised phylogenetic classification for derelomine flower weevils (Coleoptera: Curculionidae: Curculioninae: Derelomini Lacordaire) is proposed, based on a cladistic analysis of 115 outgroup and ingroup taxa and 155 primarily morphological characters. The single most‐parsimonious cladogram (length = 271, consistency index = 65, retention index = 95) indicates that several genera must be excluded from the tribe, as they lack certain modifications of the mouthparts and a primary reproductive association with the inflorescences of palms. These include Araucarietus Kuschel, Eisingius Kuschel, and Planus Kuschel, new placements (now all Trypetidini); Euryscapoides Wibmer & O'Brien, new placement (Curculioninae incertae sedis); Neopsilorhinus Bovie, new placement (Erirhinidae: Erirhinini); and Pedetinus Faust, new placement (Eugnomini). Five subtribes are recognized within Derelomini. The oldest African and South American Derelomina have a carinate rostrum and lamellate dorsal scales. Grasidius Champion (previously Erirhinini) and Terires Champion (Storeini) are placed therein, new placements. Neoderelomus Hoffmann is nested within Derelomus Schoenherr, syn.n. , and its only species is therefore renamed as D. piriformis (Hoffmann), comb.n. The predominantly Asian Acalyptina are reduced from tribal status, stat.n. , to now be part of Derelomini, new placement. They are defined (inter alia) by truncate elytra. They also contain Eudela Pascoe and Eudelodes Zimmermann, new placements (previously Curculioninae incertae sedis). The New World Notolomina, subtr.n. , are distinguished by bifurcate maxillary lacinial teeth and other mouthpart characters. Andranthobius mariahelenae (Bondar) (formerly Derelomus), comb.n. , is added to this entity. Phyllotrogina, subtr.n. , are a very diverse and mostly Neotropical lineage. They have two‐segmented maxillary palps, a densely pubescent prosternum, and long macrosetae along the basal fifth of the posterior wing margin. Within the subtribe there are independent transitions to host plant associations with various dicots (Phyllotrox Schoenherr), Cyclanthaceae (e.g. Perelleschus Wibmer & O'Brien and Systenotelus Anderson & Gómez), and Araceae (Cyclanthura Franz). Their life history traits show related changes, including losses of the ability to pollinate, and more detrimental (herbivorous, seed‐predating) larval developments (e.g. Cotithene Voss). Phyllotrox tatianae (Bondar) (formerly Derelomus), comb.n. , is assigned to Phyllotrogina. Hypoleschus Fall is nested within Phyllotrox, syn.n. , and thereby the latter now contains P. atratus (Fall), comb.n. The Central American palm‐associated Androtrox Franz, gen.n. , is proposed to accommodate A. megalops (Champion) (formerly Phyllotrox), comb.n. , a species with large contiguous eyes and a set of mouthpart attributes convergently present in Andranthobius Kuschel (Notolomina) and Phyllotrox. The Neotropical Staminodeina, subtr.n. , with a labial prementum with two triangular projections and a large anal lobe on the wing, probably represent a young clade of weevils specialized to oviposit into the ephemeral staminodes of Cyclanthaceae inflorescences. The apparent phylogenetic sequence of the subtribes is (Derelomina ((Acalyptina, Staminodeina) (Notolomina, Phyllotrogina))), with a Juano‐ rhinini–Trypetidini clade as the most immediate outgroup, followed by various curculionine lineages. The revised system thus improves the taxonomy of derelomine weevils, and clarifies our understanding of their roles in the evolution of several tropical plant lineages – palms and cyclanths in particular.     

(1R,2S,6R)-Papayanal: a new male-specific volatile compound released by the guava weevil Conotrachelus psidii (Coleoptera: Curculionidae)

The guava weevil, Conotrachelus psidii is an aggressive pest of guava (Psidium guajava L.) that causes irreparable damages inside the fruit. The volatile compounds of male and female insects were separately collected by headspace solid-phase microextraction or with dynamic headspace collection on a polymer sorbent, and comparatively analyzed by GC–MS. (1R,2S,6R)-2-Hydroxymethyl-2,6-dimethyl-3-oxabicyclo[4.2.0]octane (papayanol), and (1R,2S,6R)-2,6-dimethyl-3-oxabicyclo[4.2.0]octane-2-carbaldehyde (papayanal) were identified (ratio of 9:1, respectively) as male-specific guava weevil volatiles. Papayanal structure was confirmed by comparison of spectroscopic (EIMS) and chromatographic (retention time) data with those of the synthetic pure compound. The behavioral response of the above-mentioned compounds was studied in a Y-tube olfactometer bioassay, and their role as aggregation pheromone candidate components was suggested in this species.     

Description and phylogeny of a new Neotropical genus of Acalyptini (Coleoptera: Curculionidae: Curculioninae) associated with the staminodes of Cyclanthaceae

The weevil genus Azotoctla gen. nov. (Coleoptera: Curculionidae: Curculioninae: Acalyptini Thomson), is described to accommodate the following 15 new Neotropical species: Azotoctla aecuatorialis sp. nov. (Ecuador), Azotoctla anerunca sp. nov. (Ecuador), Azotoctla angustacra sp. nov. (Ecuador), Azotoctla curvirostra sp. nov. (Peru), Azotoctla dasygastra sp. nov. (Costa Rica and Honduras), Azotoctla femorata sp. nov. (Colombia, Costa Rica, Ecuador and Panama), Azotoctla gomezi sp. nov. (Colombia, Costa Rica and Panama), Azotoctla gottsbergeri sp. nov. (Brazil), Azotoctla clemmyssa sp. nov. (Colombia), Azotoctla melolauta sp. nov. (Colombia), Azotoctla migueli sp. nov. (Colombia), Azotoctla nana sp. nov. (Panama), Azotoctla punctata sp. nov. (Costa Rica), Azotoctla tibiatra sp. nov. (Belize), and Azotoctla tuberquiai sp. nov. (Colombia). Azotoctla is placed in the tribe Acalyptini, subtribe Staminodeina Franz, thus representing the sister taxon of Staminodeus Franz. The monophyly of Azotoctla is supported by the following inferred traits: a noncarinate rostrum that is tumescent above the antennal insertion in males; equilaterally subtriangular hemisternites of the male sternum 8; paired, longitudinal, laterally positioned sclerites of the aedeagus; and a bifurcate lamina of the female sternum 8, which bears explanate, diverging furcal arms. A key to the species of Azotoctla is provided; and the salient features of each species are illustrated and presented along with distributional and natural history data. A morphological cladistic analysis of 23 terminal species (eight outgroup, 15 ingroup) and 33 characters yielded a single most parsimonious cladogram (length = 75 steps, consistency index = 52, retention index = 77), with the ingroup topology ((A. aecuatorialis, (A. anerunca, A. gottsbergeri)), (A. punctata, ((A. angustacra, A. nana), (A. tibiatra, (A. clemmyssa, (A. curvirostra, A. femorata)), (A. melolauta, ((A. gomezi, A. migueli), (A. dasygastra, A. tuberquiai))))))). Species of Azotoctla are reproductively associated with the ephemeral staminodes of different members of the Neotropical monocot family Cyclanthaceae; most commonly with the widespread genus Carludovica Ruiz & Pavón. The interspecific homogeneity in external morphology, coupled with marked differences in genital traits and an apparent absence of narrow geographical ranges mediated by either host plants and/or biogeographical factors, jointly suggest that the diversification of Azotoctla is a relatively recent phenomenon and driven strongly by sexual selection. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 559–623.