Taxonomy of the Cecropia-inhabiting Azteca ants

Cecropia trees and several species of the ant genus Azteca form the most conspicuous ant-plant association in the Neotropics. The taxonomy and biology of the Cecropia-associated Azteca are reviewed. A key to queens is provided for the 13 species known to be obligate inhabitants of Cecropia trees, and a key to workers for the five species known from Costa Rica. Taxonomic changes include four new species and extensive synonymy. Individual species accounts contain taxonomic, behavioural, and ecological information. Evolutionary relationships among the species, and the community ecology of the Cecropia-Azteca association, are discussed.     

The parasitoid complex attacking coexisting Spanish populations of Euphydryas aurinia and Euphydryas desfontainii (Lepidoptera: Nymphalidae,Melitaeini)

We report on a five‐year investigation of the complex of parasitoids associated with coexisting populations of Euphydryas aurinia and Euphydryas desfontainii at a Spanish site. A sample of over 7000 eggs, 1000 larvae and 200 pupae (the last of these in part having been experimentally placed) revealed the existence of no egg parasitoids, of three primary larval parasitoids and of five primary pupal parasitoids, plus 13 secondary and facultatively tertiary parasitoids associated with the cocoons of the main larval parasitoid, the specialist Cotesia sp. D. The most abundant secondary parasitoid, Neochrysocharis albiscapus, entirely escaped tertiary parasitism by being gregarious. The mortality induced by parasitoids on the butterfly populations, although heavy, was clearly partially minimized by secondary parasitoids acting on Cotesia sp. D. The striking coincidence of the parasitoid complexes attacking the two Euphydryas species suggests a good system for investigating apparent competition between hosts sharing common natural enemies.     

Studies on Gasteroclisus rhomboidalis (Boheman.) (Coleoptera: Curculionidae)—a pest of the African ‘spinach’

Summary

Eggs of G. rhomboidalis are usually laid singly in separate excavations made with the snout of the beetle in either leaf petioles or tender portions of shoots of host plants, Amaranthus sp. At field temperatures fluctuating between 19°C and 30°C and in contact with water, eggs hatched in a mean of 2·8 days while unmoistened ones shrivelled up.

Beetle larvae bore and feed on the stele of host plants where development, up to adulthood, is completed in self-made larval galleries. On the average, the larvae are capable of consuming 40% and above of the cross-sectional areas of stems of infected host plants. In nature, multiple infection of host plants was quite common with 1–16 beetle larvae/plant rather usual. Consequently, the stem of virtually every healthy-looking host plant is internally traversed by larval galleries, at times even below ground level.

Adults bite their way out of the stem after a mean of 36·37 days from date of oviposition.

Larval damages to host plants are the gravest and bring about premature breakage and/or death of crops, stunted growth and reduced yield of the wanted leaf products.     

Weevil (Coleoptera: Curculionoidea) seed-predators of Syzygium and Eugenia spp. (Myrtaceae), with description of the Alcidodes expansitarsis species group (Coleoptera: Curculionidae: Molytinae: Mecysolobini)

The weevils known to develop in Syzygium and Eugenia (Myrtaceae) fruit are reviewed. These weevils belong to the genera Curculio, Alcidodes, Acythopeus, Apotomorhinus (Curculionidae: Curculioninae, Molytinae and (the last two) Baridinae respectively) and Sitophilus (Dryophthoridae) in the Old World, and Atractomerus (Curculionidae: Anthonominae) in the Neotropics; two undescribed baridine species (one in Australia and the other in the USA) are also known to feed on the fruits, and the Omophorine Teleuropus (Curculionidae: Molytinae) has been found associated with them. Particular attention is paid to species of Alcidodes from aseasonal dipterocarp-dominated forests in South-East Asia. Two Bornean species (Alcidodes janetae sp. n. and A. eugeniophilus sp. n.) are the first of their genus to be reared from the fruit of Syzygium or Eugenia. These species, plus two other (A. expansitarsis sp. n. from Assam, Myanmar, Cambodia and Laos, and A. gymnasticus sp. n. from Malaysia) belong to a previously undescribed species group of Alcidodes; all four species are described and keyed.     

Homichloda barkeri (Jacoby) (Coleoptera: Chrysomelidae: Alticinae), a candidate agent for the biocontrol of prickly acacia,Acacia nilotica (Mimosaceae) in Australia

The status of Homichloda barkeri (Jacoby) n. comb. is discussed. A key is presented to four Afrotropical Homichloda species, including fulva n. sp. The eggs, larvae and pupae of H. barkeri are described for the first time. Unusual adult and immature stage characters are discussed in relation to the placement of Homichloda in the Alticinae.     

Social organization in a primitive ponerine ant: queenless reproduction,dominance hierarchy and functional polygyny in Amblyopone sp. (reclinata group) (Hymenoptera: Formicidae: Ponerinae)

Social organization of colonies in the primitive ponerine ant Amblyopone sp. (reclinata group) was studied in Bogor, West Java, Indonesia. The colonies consisted of 97 workers on average, and there were no morphologically distinct queens; between one and 18 workers were inseminated and produced eggs, instead. Virgin workers developed their oocytes, but most of them degenerated before maturation. Experimental removal of mated laying workers (gamergates) from colonies resulted in oviposition by some virgin workers, suggesting that gamergates inhibit ovarian development of virgin workers. Degree of ovarian development of gamergates was not so different among gamergates within each colony; however, great variation was observed among colonies. This was correlated with number of virgin workers per gamergate. Among gamergates, aggressive antennation was frequently observed. The frequency of antennation increased with colony growth. A linear order was constructed by the antennation among gamergates, although there were many reversal interactions. Higher-ranked gamergates had 1–3 developed oocytes while three low-ranked gamergates had no developed oocytes. Since such sterile gamergates were rarely found in the field, low-ranked gamergates may be expelled from their colonies. Colonies of Amblyopone sp. were principally organized through physical and pheromonal interactions among individual workers. This paper provides the first demonstration of a dominance structure among gamergates and inhibitory effects of gamergates on reproductive activity of virgin workers in a functionally polygynous ant colony without queens.     

Description of the biology and immature stages of Pagyris ulla (Hewitson) (Lepidoptera: Nymphalidae: Ithomiini) in the Colombian Andes

The biology and immature stages of Pagyris ulla (Hewitson, [1857]) (Lepidoptera: Nymphalidae: Ithomiini) are described for the first time. The species’ host plant is established to be Brugmansia candida Pers. (Solanaceae). The life cycle from eggs to adult under laboratory conditions and ambient temperature took approximately 47 days, and the larvae passed through five instars. The larvae are gregarious, feed at night, and rest during the day in nests made by joining leaves near the apex of the plant stem.     

The first instar larva of Aulacoscelis appendiculata n. sp. (Coleoptera: Chrysomelidae: Aulacoscelinae) and its value in the placement of the Aulacoscelinae

Of all of the chrysomelid subfamilies, only the larvae of the Aulacoscelinae remain undescribed. The adults and first instar larva of Aulacoscelis appendiculata sp. n., from Panama are described, as well as the eggs. Larval characters, eggs, and oviposition behaviour are used to relatethe Aulacoscelinae with other chrysomelid subfamilies, in support of what is known to date concerning adult morphology.     

Observations on mermithid parasitism (Nematoda: Mermithidae) in two species of Lasius ants (Hymenoptera: Formicidae)

The morphological effects of nematode parasitism by Pheromermis myrmecophila were investigated in two species of ants, Lasius flavus and Lasius niger, collected on Clare Island, Ireland. Infected males and queens were found for L. flavus but only infected queens in L. niger. The numbers of nematodes present in each infected specimen were counted and their lengths were measured. Head width, femur length and wing measurements were made for infected and non-infected individuals of both species. In queens, the length of the nematodes decreased as the number per ant increased. When single nematodes were present their mean lengths were significantly greater in L. flavus than in L. niger. In addition to the reduction in wing size for all parasitized specimens, head widths and femur lengths of the queens were significantly different in both species. A log–log graph of radial cell length versus width suggested a linear reduction of wing size.     

A new stylochid flatworm (Platyhelminthes,Polycladida) from Victoria,Australia and observations on its biology

There are only four polyclad flatworms currently known from temperate waters of Victoria, Australia, although these turbellarians are common inhabitants of rocky shores. A new stylochid flatworm, Stylochus pygmaeus sp. nov. (Platyhelminthes, Polycladida) or oyster leech is described here from Port Philip Bay, Victoria. This flatworm was observed feeding on three species of barnacles by extending its pharynx over its prey and extruding copious amounts of mucus. Worms also preferred to prey on larger‐sized barnacles regardless of the species. Further observations indicated that these worms deposited eggs at night inside empty barnacle shells. Each eggmass was brooded for several days with the worms only moving off to feed. Each egg capsule contained multiple embryos and after 5 or 6 days, positively photo‐tactic, four‐lobed Götte's larvae emerged. Larvae metamorphosed to juvenile flatworms 1–2 weeks post‐hatching but failed to settle and survive.     

The tortoise caterpillar: carnivory and armoured larval morphology of the metalmark butterfly Pachythone xanthe (Lepidoptera: Riodinidae)

ABSTRACT

The natural history and morphology of the later instars and pupa of the metalmark butterfly Pachythone xanthe H. Bates are described and illustrated for the first time. The caterpillars are myrmecophilous and carnivorous, feeding on scale insects (Hemiptera: Coccoidea) tended by Azteca cf. chartifex Forel (Formicidae: Dolichoderinae) ants and appear to be physically shielded from potential ant attacks by a carapace-like body that protects the head and appendages. In addition, the larvae present several types of specialised setae and ant-organs such as perforated cupola organs, glandular openings and functional tentacle nectary organs that may be related to appeasement of aggressive ant behaviour. Our results reveal the first detailed life cycle data for the Pachythonina subtribe and record a new independent origin of carnivory in Riodinidae.     

Synonymy of Rhynchophorus ferrugineus (Olivier), 1790 and R. vulneratus (Panzer), 1798 (Coleoptera,Curculionidae, Rhynchophorinae)

Morphological, molecular-genetic and breeding data were collected to investigate the species status of the Asian palm weevils, Rhynchophorus ferrugineus (Olivier) and R. vulneratus (Panzer) (Coleoptera: Curculionidae). These weevils are distinguished by characteristic colouring of the pronota and elytra, but naturally occurring colour intermorphs were observed. Contrary to the literature, quantitative measurements of the concavity of subgenal sutures and of pronotal shape indicated no differences between the two species. Larvae did not differ significantly in labral characteristics. Random amplified polymorphic DNA (RAPD) banding patterns were identical for nine of 14 primers, indicating that these weevils are very closely related. Sequences of the cytochrome oxidase gene for 201 base pairs read were identical for R. ferrugineus and R. vulneratus, but the congener R. bilineatus differed from them by 10%, suggesting divergence of these lineages about 5?million years ago. Hybrid F1s were obtained from all heterospecific crosses, and one surviving hybrid F1 female produced viable eggs. Previous studies have revealed no pheromonal differences. On the basis of this evidence, R. ferrugineus and R. vulneratus should be considered colour morphs of the same species and be synonymized under the name Rhynchophorus ferrugineus (Olivier), with the common name Asian palm weevil.     

Comparative investigation of the late embryogenesis of Leptodora kindtii (Focke, 1844) (Crustacea: Branchiopoda), with notes on types of embryonic development and larvae in Cladocera

The embryonic development of the parthenogenetic eggs of Leptodora kindtii has been investigated by observing living embryos removed from the female brood pouch. The sequence of morphological changes was analysed, as was the time at which the activity of certain organs began. The timing of these events at 20–22°C is documented. These data were compared with similar information obtained for some representatives of Ctenopoda and Anomopoda. The sequence of appearance of rudiments of organs on the ventral side of the embryos is similar in all these groups but the timing of shedding of the embryonic membranes differs. Hatching from the inner egg membranes takes place at the late metanauplius stage in Leptodora as in Ctenopoda and Cyclestherida, while in Anomopoda this stage is embryonized. The development of Leptodora is more like that of Ctenopoda than of Anomopoda. The embryos of all the above‐mentioned groups begin to grow at approximately the same morphological stage. A new scheme for the periodization of the embryogenesis of L. kindtii is proposed, which includes four well‐separated stages. Previously, the same number of developmental stages has been reported for Ctenopoda and Anomopoda. In Leptodora, as well as in Ctenopoda, the first two of these occur within the egg membranes. Cyclestheria has at least one embryonic moult and one embryonic stage more than Leptodora and other cladocerans. Embryonic stages 3 and 4 of the parthenogenetic eggs of L. kindtii represent a peculiar type of secondary larvae developing inside the female's brood pouch. The appearance of a free‐living nauplius in L. kindtii arises from its mode of hatching from the gamogenetic egg.     

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.     

Alipumilio (Diptera: Syrphidae) fly association with Burseraceae tree resins in the eastern Brazilian Amazon

Numerous fly (Diptera) larvae develop in plant saps or rotting exudates, but few have adapted to resin flows of trees. Among these are some primitive syrphid genera (Syrphidae), Cheilosia in the temperate region and Alipumilio in the neotropics. A recent study of resin harvest in the eastern Brazilian Amazon has revealed a potentially new species of Alipumilio that develops in resin lumps on some species of Burseraceae trees. These resin flows are primarily stimulated by larvae of a bark-boring Sternocoelus weevil (Coleoptera: Curculionidae). This fly larva's morphology, movement in the resin and unsuccessful rearing apart from fresh resin indicate it may be consuming microbial spores or sap materials coming out of tree wounds. While Sternocoelus weevils are found in resin lumps in a range of Protium and other Burseraceae species in the region, Alipumilio larvae were only found in the resin of some of these species. The study speculates that some trees do not support Alipumilio because their resin's chemical properties are inhospitable to these larvae or inhibit the micro-organisms that they feed on.     

Life history of Paraselenis (Spaethiechoma) dichroa (Germar, 1824) (Coleoptera: Chrysomelidae: Cassidinae) in natural conditions of Atlantic Forest from Brazil

Cassidinae Gyllenhaal? is the second largest subfamily of Chrysomelidae (Coleoptera), which presents characteristic morphology, biology and behaviour. The current study describes the life cycle of Paraselenis(Spaetiechoma) dichroa (Germar), ?determining biological and behavioural aspects as well as the action of natural enemies on populations, when the species has maternal care. The study was conducted between February and April 2015 in the National Forest of Passa Quatro, municipality of Passa Quatro, Minas Gerais state, Brazil. Daily observations were made (morning and afternoon) to evaluate the offspring of females on Ipomoea sp. and Merremia macrocalyx (O’Donell?) (Convolvulaceae), as well as the actions of natural enemies on the young. The eggs are deposited on the midrib and abaxial surface of leaves (n = 25). Egg clusters are pedunculated, arranged in groups and devoid of any cover. On average, each female produced 27.3 ± 5.6 (n = 16) eggs, with a mean incubation period of 12.7 ± 2.9 days (n = 10 females with their young). The larvae remained grouped in the leaves throughout development, except when they fed. They retained faeces and exuviae as a stacked faecal structure on their mobile urogomphi (caudal process) like a faecal shield. The mean number of larvae per female was 12.7 ± 10.1 (n = 19) and the larval period lasted 24.9 ± 4.5 days (n = 12). Pupation occurred on the stem of the plant (n = 16). On average there were 8.1 ± 8.5 individuals for pupae progeny (n = 14). The mean duration of the pupal stage was 10.4 ± 3.3 days (n = 5). Overall, 3% of adults emerged (n = 13 individuals), with a total cycle time of 41.3 ± 8.4 days (n = 6). Adults are sexually dimorphic in the elytral shape. Females remain with the offspring throughout development. The natural enemies of immatures were Emersonella pubipennis Hansson? (Hymenoptera: Eulophidae), Tachinidae (Diptera) and Stiretrus decastigmus (Herrich-Schaeffer?) (Heteroptera: Pentatomidae), Conura sp. Spinola? (Hymenoptera: Chalcididae) and Brachymeria sp. Westwood? (Hymenoptera: Chalcididae). The information presented here on the natural history of P. dichroa are important as they may serve as a starting point to understand evolutionary questions and multispecies interactions.     

A troublesome sibling species complex of scuttle flies (Diptera: Phoridae) revisited

The complex of species resembling Megaselia pulicaria (Fallén) has proved to be one of the most troublesome challenges to attempts to resolve the recognition of species within the huge genus Megaselia Rondani. The new data presented allow more confident recognition of species and reveal that most published records represent misidentifications. The penis complex is discussed and its use in species identification demonstrated. All specimens currently assigned to M. pulicaria, other than the lectotype, are consequently reassigned to other species. These include the reinstatement of M. angusta (Wood) and its newly designated subspecies M. angusta angustina Schmitz, M. eupygis Schmitz, M. longifurca (Lundbeck) and M. monochaeta (Strobl) as valid species, and the recognition of M. buchsi sp. nov. from Germany, M. iberiensis sp. nov. from Spain, M. martensi sp. nov. from Nepal, M. nectergata sp. nov. from Britain, M. oviaraneae sp. nov. from Britain, and M. rotundapicis sp. nov. from Scotland. Five synonyms are proposed. The hitherto unknown male of M. petraea Schmitz is described. It and M. longifurca are reported from Britain and the latter from the Nearctic Region also. Natural history information is summarized for each species. In particular, it is reported that the species whose larvae prey upon spider eggs are M. angusta, M. longifurca and M. oviaraneae.     

Casinaria,a paraphyletic ichneumonid genus (Hymenoptera), and a revision of the Australian species

The Australian species of the campoplegine ichneumonid genus Casinaria are revised and an illustrated key is provided for their identification. Eleven species are recognized, but one is not formally named. The Australian species are referable to two morphologically and biologically distinct groups, the meridionalis species-group (containing amarilla sp. nov., hesperiophaga sp. nov. and meridionalis (Turner)) which are parasitoids of hesperiid larvae, and the siccata species-group (containing eremica sp. nov., micra sp. nov., mythologica sp. nov., pavlova sp. nov., siccata sp. nov., virgata sp. nov., woowonga sp. nov. and species A) which parasitize the larvae of a variety of smaller moths. The holophyly of each of the two species-groups is demonstrated, but characters supporting the holophyly of the genus could not be found, suggesting that Casinaria, as currently recognized, may either be paraphyletic or polyphyletic.