Potential novel hosts for the lily leaf beetle Lilioceris lilii Scopoli (Coleoptera: Chrysomelidae) in eastern North America

Abstract.  1. Introduced insects often incorporate native plants into their diets and might be expected to show a predilection for novel hosts that are phylogenetically related to their normal hosts. The lily leaf beetle, Lilioceris lilii (Coleoptera: Chrysomelidae), is an introduced pest of cultivated lilies. Oviposition behaviour, larval behaviour, and development of L. lilii was examined on a range of potential host plants, as well as on the normal host, Asiatic hybrid lilies Lilium sp.
2. Neonate larval feeding behaviour was quantified on 15 food plant species: 10 from the Liliales, three from the Asparagales and two eudicots. Larvae fed plants closely related to the genus Lilium were more likely to initiate feeding, less likely to abandon their food leaf, and consumed more leaf area.
3. In no-choice tests, females oviposited on the novel hosts Lilium philadelphicum , Medeola virginiana , Clintonia borealis , Streptopus amplexifolius , and Polygonatum biflorum ; however, all but L. philadelphicum received very few eggs. Non- Lilium novel hosts were not used for oviposition when presented along with Asiatic lilies in choice tests.
4. A single individual was reared to the adult stage on the novel host S. amplexifolius . Several larvae survived to the pupal stage on M. virginiana , although no adults emerged from those pupae. Larvae reared on the native wood lily L. philadelphicum performed equally well or better than on the Asiatic cultivar.
5. Our results indicate that the lily leaf beetle poses a threat to native Liliaceae. Several native Lilium species, including L. philadelphicum , are threatened or endangered in certain jurisdictions throughout their range; these species should be monitored closely for colonisation by the beetle.     

FLAGELLAR MOTILITY IS NOT INVOLVED IN THE INCORPORATION OF THE SPERM INTO THE EGG AT FERTILIZATION*

Cinemicrography of sea urchin fertilization reveals that the fertilizing sperm is one of the first sperm to attach to the egg. Just before the cortical reaction the fertilizing sperm ceases motility and then is incorporated into the egg without flagellar beating. The rate of incorporation is 5–11 μm/sec and is constant. Lytechinus pictus sperm rendered immotile by azide treatment can bind to and fertilize eggs but binding, and therefore fertilization, is blocked by azide treatment of Strongylocentrotus purpuratus gametes.     

Factors Controlling the Abundance and Size Distribution of the Phototrophic Ciliate Myrionecta rubra in Open Waters of the North Atlantic

ABSTRACT. Myrionecta rubra, a ubiquitous planktonic ciliate, has received much attention due to its wide distribution, occurrence as a red tide organism, and unusual cryptophyte endosymbiont. Although well studied in coastal waters, M. rubra is poorly examined in the open ocean. In the Irminger Basin, North Atlantic, the abundance of M. rubra was 0–5 cells/ml, which is low compared with that found in coastal areas. Distinct patchiness (100 km) was revealed by geostatistical analysis. Multiple regression indicated there was little relationship between M. rubra abundance and a number of environmental factors, with the exception of temperature and phytoplankton biomass, which influenced abundance in the spring. We also improve on studies that indicate distinct size classes of M. rubra; we statistically recognise four significantly distinct width classes (5–16, 12–23, 18–27, 21–33 μm), which decrease in abundance with increasing size. A multinomial logistic regression revealed the main variable correlated with this size distribution was ambient nitrate concentration. Finally, we propose a hypothesis for the distribution of sizes, involving nutrients, feeding, and dividing of the endosymbiont.     

Systematics, biogeography and diversification of the Indo-Australian genus Delias Hübner (Lepidoptera: Pieridae): phylogenetic evidence supports an 'out-of-Australia' origin

Abstract Two alternative hypotheses for the origin of butterflies in the Australian Region, that elements dispersed relatively recently from the Oriental Region into Australia (northern dispersal hypothesis) or descended from ancient stocks in Gondwana (southern vicariance hypothesis), were tested using methods of cladistic vicariance biogeography for the Delias group, a diverse and widespread clade in the Indo‐Australian Region. A phylogenetic hypothesis of the twenty‐four species‐groups recognized currently in Delias and its sister genus Leuciacria is inferred from molecular characters generated from the nuclear gene elongation factor‐1 alpha (EF‐1α) and the mitochondrial genes cytochrome oxidase subunits I and II (COI/COII) and NADH dehydrogenase 5 (ND5). Phylogenetic analyses based on maximum parsimony, maximum likelihood and Bayesian inference of the combined dataset (3888 bp, 1014 parsimony informative characters) confirmed the monophyly of Delias and recovered eight major lineages within the genus, informally designated the singhapura, belladonna, hyparete, chrysomelaena, eichhorni, cuningputi, belisama and nigrina clades. Species‐group relationships within these clades are, in general, concordant with current systematic arrangements based on morphology. The major discrepancies concern the placement of the aganippe, belisama and chrysomelaena groups, as well as several species‐groups endemic to mainland New Guinea. Two species (D. harpalyce (Donovan), D. messalina Arora) of uncertain group status are currently misplaced based on strong evidence of paraphyly, and are accordingly transferred to the nigrina and kummeri groups, respectively. Based on this phylogeny, a revised systematic classification is presented at the species‐group level. An historical biogeographical analysis of the Delias group revealed that the most parsimonious reconstruction is an origin in the Australian Region, with at least seven dispersal events across Wallacea to the Oriental Region. The eight major clades of Delias appear to have diverged rapidly following complete separation of the Australian plate from Gondwana and its collision with the Asian plate in the late Oligocene. Further diversification and dispersal of Delias in the Miocene–Pliocene are associated with major geological and climatic changes that occurred in Australia–New Guinea during the late Tertiary. The ‘out‐of‐Australia’ hypothesis for the Delias group supports an origin of the Aporiina in southern Gondwana (southern vicariance hypothesis), which proposes that the ancestor of Delias + Leuciacria differentiated vicariantly on the Australian plate.     

Phylogeny,diversification patterns and historical biogeography of euglossine orchid bees (Hymenoptera: Apidae)

The orchid bees constitute a clade of prominent insect pollinators distributed throughout the Neotropical region. Males of all species collect fragrances from natural sources, including flowers, decaying vegetation and fungi, and store them in specialized leg pockets to later expose during courtship display. In addition, orchid bees provide pollination services to a diverse array of Neotropical angiosperms when foraging for food and nesting materials. However, despite their ecological importance, little is known about the evolutionary history of orchid bees. Here, we present a comprehensive molecular phylogenetic analysis based on ～4.0 kb of DNA from four loci [cytochrome oxidase (CO1), elongation factor 1‐α (EF1‐α), arginine kinase (ArgK) and RNA polymerase II (Pol‐II)] across the entire tribe Euglossini, including all five genera, eight subgenera and 126 of the approximately 200 known species. We investigated lineage diversification using fossil‐calibrated molecular clocks and the evolution of morphological traits using disparity‐through‐time plots. In addition, we inferred past biogeographical events by implementing model‐based likelihood methods. Our dataset supports a new view on generic relationships and indicates that the cleptoparasitic genus Exaerete is sister to the remaining orchid bee genera. Our divergence time estimates indicate that extant orchid bee lineages shared a most recent common ancestor at 27–42 Mya. In addition, our analysis of morphology shows that tongue length and body size experienced rapid disparity bursts that coincide with the origin of diverse genera (Euglossa and Eufriesea). Finally, our analysis of historical biogeography indicates that early diversification episodes shared a history on both sides of Mesoamerica, where orchid bees dispersed across the Caribbean, and through a Panamanian connection, thus reinforcing the hypothesis that recent geological events (e.g. the formation of the isthmus of Panama) contributed to the diversification of the rich Neotropical biota. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 552–572.     

Molecular evolution of a long wavelength-sensitive opsin in mimetic Heliconius butterflies (Lepidoptera: Nymphalidae)

This study examines the pattern of opsin nucleotide and amino acid substitution among mimetic species 'rings' of Heliconius butterflies that are characterized by divergent wing colour patterns. A long wavelength opsin gene, OPS1 , was sequenced from each of seven species of Heliconius and one species of Dryas (Lepidoptera: Nymphalidae). A parsimony analysis of OPS1 nucleotide and amino acid sequences resulted in a phylogeny that was consistent with that presented by Brower & Egan in 1997, which was based on mitochondrial cytochrome oxidase I and II as well as nuclear wingless genes. Nodes in the OPS1 phylogeny were well supported by bootstrap analysis and decay indices. An analysis of specific sites within the gene indicates that the accumulation of amino acid substitutions has occurred independently of the morphological diversification of Heliconius wing colour patterns. Amino acid substitutions were examined with respect to their location within the opsin protein and their possible interactions with the chromophore and the G-protein. Of the 15 amino acid substitutions identified among the eight species, one nonconservative replacement (A226Q) was identified in a position that may be involved in binding with the G-protein.     

The double cloak of invisibility: phenotypic plasticity and larval decoration in a geometrid moth,Synchlora frondaria,across three diet treatments

Abstract 1. Crypsis is one of the main defences that insects use to avoid predators, and both the juveniles and adults of many geometrid moths are remarkable in their ability to blend into different host backgrounds. The larvae of Synchlora frondaria have two methods to achieve crypsis: phenotypic plasticity in colouration that enable them to hide more effectively on their host plants, and a self‐decorating behaviour whereby the larvae camouflage themselves with materials from their host plants. 2. Larvae of Synchlora frondaria reared on three different host plants showed systematic differences in relative growth rate, survivorship and larval colouration. 3. Larval colouration varied across diet treatments in a way that was consistent with diet‐induced phenotypic plasticity, and larvae also exhibited characteristic decorating behaviour on all three hosts. 4. Larvae showed highest survivorship on Heterotheca subaxillaris (Asteraceae), and had significantly higher relative growth rates on H. subaxillaris (Asteraceae) and Lantana camara (Verbenaceae) than on Bejaria racemosa (Ericaceae). 5. Synchlora frondaria provides an example of a species where both decorating behaviour and phenotypic plasticity in larval colouration produce a cryptic form that is remarkably responsive to its background.     

Performance of Symydobius americanus (Homoptera: Aphididae) on paper birch grazed by caterpillars

Abstract.

• 1 The potential for host plant-mediated interactions between leaf-chewers and the aphid Symydobius americanus on paper birch (Betula papyrifera) was investigated experimentally.
• 2 Datana ministra and Malacosoma disstria caterpillars were caged on randomly chosen, undamaged branches until they had eaten 30–50% of the leaf area. Control branches received cages but no larvae.
• 3 Alates of S.americanus were than caged on the experimental and control branches to assess the effect of chewing damage on colony performance.
• 4 Chewing damage had no detectable effect on initiation of alate reproduction, development time, mortality of nymphs or colony growth rate.