Phylogenomics and biogeography of sawflies and woodwasps (Hymenoptera, Symphyta).

Phylogenomic approaches have recently helped elucidate various insect relationships, but large-scale comprehensive analyses on relationships within sawflies and woodwasps are still lacking. Here, we infer the relationships and long-term biogeographic history of these hymenopteran groups using a large dataset of 354 UCE loci collected from 385 species that represent all major lineages. Early Hymenoptera started diversifying during the Early Triassic âˆ¼249 Ma and spread all over the ancient supercontinent Pangaea. We recovered Xyeloidea as a monophyletic sister group to other Hymenoptera and Pamphilioidea as sister to Unicalcarida. Within the diverse family Tenthredinidae, our taxonomically and geographically expanded taxon sampling highlights the non-monophyly of several traditionally defined subfamilies. In addition, the recent removal of Athalia and related genera from the Tenthredinidae into the separate family Athaliidae is supported. The deep historical biogeography of the group is characterised by independent dispersals and re-colonisations between the northern (Laurasia) and southern (Gondwana) palaeocontinents. The breakup of these landmasses led to ancient vicariance in several Gondwanan lineages, while interchange across the Northern Hemisphere has continued until the Recent. The little-studied African sawfly fauna is likewise a diverse mixture of groups with varying routes of colonization. Our results reveal interesting parallels in the evolution and biogeography of early hymenopterans and other ancient insect groups.

Leaf acclimation to soil flooding and light availability underlies photosynthetic capacity of Lindera melissifolia, an endangered shrub of bottomland forests in the Mississippi Alluvial Valley, USA.

Lindera melissifolia is an endangered shrub indigenous to the broadleaf forest of the Mississippi Alluvial Valley (MAV). In this region, extant colonies of the species are found in periodically ponded habitats where a diversity of broadleaf trees can form well-developed overstory and sub-canopies-these habitat characteristics suggest that soil flooding and light availability are primary drivers of L. melissifolia ecophysiology. To understand how these two factors affect its photosynthetic capacity, we quantified leaf characteristics and photosynthetic response of plants grown in a large-scaled, field setting of three distinct soil flooding levels (no flood, 0 day; short-term flood, 45 days; and extended flood, 90 days) each containing three distinct light availability levels (high light, 30% shade cloth; intermediate light, 63% shade cloth; and low light, 95% shade cloth). Lindera melissifolia leaves showed marked plasticity to interacting effects of flooding and light with lamina mass per unit area (Lm/a) varying 78% and total nitrogen content per unit area (Na) varying 63% from the maximum. Photosynthetic capacity (A1800-a) ranged 123% increasing linearly with Na from low to high light. Extended flooding decreased the slope of this relationship 99% through a reduction in N availability and metabolic depression of A1800-a relative to Na. However, neither soil flooding nor light imposed an additive limitation on photosynthetic capacity when the other factor was at its most stressful level, and the A1800-a-Na relationship for plants that experienced short-term flooding suggested post-flood acclimation in photosynthetic capacity was approaching the maximal level under respective light environments. Our findings provide evidence for wide plasticity and acclimation potential of L. melissifolia photosynthetic capacity, which supports active habitat management, such as manipulation of stand structure for improved understory light environments, to benefit long-term conservation of the species in the MAV.

Intensity and mode of Lindera melissifolia reproduction are affected by flooding and light availability.

We studied the impact of flooding and light availability gradients on sexual and asexual reproduction in Lindera melissifolia (Walt.) Blume, an endangered shrub found in floodplain forests of the Mississippi Alluvial Valley (MAV), USA. A water impoundment facility was used to control the duration of soil flooding (0, 45, or 90 days), and shade houses were used to control light availability (high = 72%, intermediate = 33%, or low = 2% of ambient light) received by L. melissifolia established on native soil of the MAV. Sexual reproductive intensity, as measured by inflorescence bud count, fruit set, and drupe production, was greatest in the absence of soil flooding. Ninety days of soil flooding in the year prior to anthesis decreased inflorescence bud counts, and 45 days of soil flooding in the year of anthesis lessened fruit set and drupe production. Inflorescence bud development was the greatest in environments of intermediate light, decreased in high-light environments, and was absent in low light environments. But low fruit set diminished drupe production in intermediate light environments as compared to high light environments. Asexual reproduction, as measured by development of new ramets, was greatest in the absence of soil flooding and where plants were grown in high or intermediate light. Plants exhibited plasticity in reproductive mode such that soil flooding increased the relative importance of asexual reproduction. The high light environment was most favorable to sexual reproduction, and reproductive mode transitioned to exclusively asexual in the low light environment. Our results raise several implications important to active management for the conservation of this imperiled plant.

New species of Cerambycidae from Panama, with new distribution records (Coleoptera: Cerambycidae).

Two new species of Cerambycidae, Tessaropa elizabeth Bezark, sp. nov. (subfamily Cerambycinae, tribe Methiini ) and Anelaphus cordiforme Tyson, sp. nov. (subfamily Cerambycinae, tribe Elaphidiini), are described from the western part of the Darien, Panama. Nine new country records for Panama are reported for the following species: Adetus linsleyi Mar-tins & Galileo, Estola strandiella Breuning, Nubosoplatus inbio Swift, Paranisopodus heterotarsus Monné & Martins, Pempteurys sericans Bates, Rosalba costaricensis (Melzer), Tomopterus brevicornis Giesbert, Psapharochrus nigricans (Lameere), and Oedudes bifasciata (Bates).

First contact pheromone identified for a longhorned beetle (Coleoptera: Cerambycidae) in the subfamily Prioninae.

Little is known of the reproductive behavior of longhorned beetles (Coleoptera: Cerambycidae) in the subfamily Prioninae. Mallodon dasystomus (Say), the hardwood stump borer, is a widely distributed prionine that is native to the southern U.S. Here, we explored the chemically-mediated mating behavior of M. dasystomus, and tested the hypothesis that males recognize females by a contact pheromone. In mating bioassays, all males tested attempted to mate with females only after contacting females with their antennae. Moreover, all males attempted to mate with solvent-washed dead females treated with as little as 0.15 ± 0.03 female equivalents of conspecific cuticular extracts, confirming that compounds on the cuticle of females are essential for mate recognition. Cuticular hydrocarbon profiles of females contained 13 compounds that were not present in profiles of males. Among the female-specific compounds, two co-dominant methyl-branched alkanes, 2-methylhexacosane (2Me-C(26)) and 2-methyloctacosane (2Me-C(28)), accounted for 17% of the total hydrocarbons. Our strategy for identifying the contact pheromone was to synthesize and test the bioactivity of female specific compounds, starting with the most abundant. In bioassays, males displayed mating behavior in response to synthetic 2Me-C(26) and 2Me-C(28) when tested individually. Furthermore, when these compounds were tested in combination, they elicited the full progression of mating behaviors, suggesting that 2Me-C(26) and 2Me-C(28) make up the contact pheromone. These findings are further evidence of the critical role of contact pheromones in mating systems of longhorned beetles.

Trapping Phyllophaga spp. (Coleoptera: Scarabaeidae: Melolonthinae) in the United States and Canada using sex attractants.

The sex pheromone of the scarab beetle, Phyllophaga anxia, is a blend of the methyl esters of two amino acids, L-valine and L-isoleucine. A field trapping study was conducted, deploying different blends of the two compounds at 59 locations in the United States and Canada. More than 57,000 males of 61 Phyllophaga species (Coleoptera: Scarabaeidae: Melolonthinae) were captured and identified. Three major findings included: (1) widespread use of the two compounds [of the 147 Phyllophaga (sensu stricto) species found in the United States and Canada, males of nearly 40% were captured]; (2) in most species intraspecific male response to the pheromone blends was stable between years and over geography; and (3) an unusual pheromone polymorphism was described from P. anxia. Populations at some locations were captured with L-valine methyl ester alone, whereas populations at other locations were captured with L-isoleucine methyl ester alone. At additional locations, the L-valine methyl ester-responding populations and the L-isoleucine methyl ester-responding populations were both present, producing a bimodal capture curve. In southeastern Massachusetts and in Rhode Island, in the United States, P. anxia males were captured with blends of L-valine methyl ester and L-isoleucine methyl ester.