Colony stage and not facultative policing explains pattern of worker reproduction in the Saxon wasp

Inclusive fitness theory predicts that in colonies of social Hymenoptera headed by a multiple‐mated queen, workers should benefit from policing eggs laid by other workers. Foster & Ratnieks provided evidence that in the vespine wasp Dolichovespula saxonica, workers police other workers’ eggs only in colonies headed by a multiple‐mated queen, but not in those headed by a single‐mated one. This conclusion, however, was based on a relatively small sample size, and the original study did not control for possible confounding variables such as the seasonal colony progression of the nests. Our aim, therefore, was to reinvestigate whether or not facultative worker policing occurs in D. saxonica. Remarkably, our data show that in the studied Danish population, there was no correlation between worker–worker relatedness and the percentage of worker‐derived males. In addition, we show that variability in cuticular hydrocarbon profiles among the workers did not significantly correlate with relatedness and that workers therefore probably did not have sufficient information on queen mating frequency from the workers’ cuticular hydrocarbon profiles. Hence, there was no evidence that workers facultatively policed other workers’ eggs in response to queen mating frequency. Nevertheless, our data do show that the seasonal progression of the nest and the location in which the males were reared both explain the patterns of worker reproduction found. Overall, our results suggest that the earlier evidence for facultative worker policing in D. saxonica may have been caused by accidental correlations with certain confounding variables, or, alternatively, that there are large interpopulation differences in the expression of worker policing.     

Use of terrestrial chemical trails for nest orientation in an open nesting wasp, <Emphasis Type="Italic">Dolichovespula saxonica</Emphasis> F.

Summary The long-cheeked wasp Dolichovespula saxonica typically constructs exposed nests which can be reached by flying. Usually foragers do not walk on substrates in the close vicinity of the nests as cavity breeding wasps do (Steinmetz et al., 2002). Unexpectedly, when forced to walk outside the nest instead of flying in an artificial tunnel system, D. saxonica foragers lay a terrestrial trail and use it for orientation in the nest area in our experiments. 41% of the foragers followed the trail in a direction they were not accustomed to. We suggest that the foragers have employed the same orientation cues normally used for orientation in the close vicinity of the nest when approaching a free-hanging nest by flying, for example nest odour. Nest odour substances may have been transferred to the substrate as a trail as a consequence of foragers walking through the tunnels.Received 23 August 2002; revised 27 January 2003; accepted 30 April 2003.     

Influence of Illuminance and Forager Experience on Use of Orientation Cues in Social Wasps (Vespinae)

We tested the influence of illuminance and level of forager experience on nest orientation behavior of the social wasps Vespula vulgaris, Vespa crabro, and Dolichovespula saxonica in an artificial laboratory tunnel system. The number of wasps which oriented themselves chemically via a terrestrial trail or used visual orientation were determined at different illuminance levels for foragers which were naïve or experienced with the tunnel system. In V. vulgaris and D. saxonica, mainly the young and naïve foragers used the chemical trail for orientation in brightness. Experienced foragers used visual cues for nest orientation. In V. crabro, naïve and experienced foragers followed the chemical trail in a similar intensity. In darkness, when visual orientation was limited, the relative importance of the chemical trail increased dramatically in all species and all experience classes.     

Description of a new diatom genus Dorofeyukea gen. nov. with remarks on phylogeny of the family Stauroneidaceae

Type material of Navicula kotschyi was studied, and this species was transferred to Dorofeyukea gen. nov. as D. kotschyi comb. nov. Dorofeyukea was described on the basis of DNA sequence and morphological data. Additional species assigned to this genus that were previously included in Navicula include: D. ancisa comb. nov., D. grimmei comb. nov., D. ivatoensis comb. nov., D. orangiana comb. nov., D. rostellata comb. nov. & stat. nov., D. savannahiana comb. nov., D. tenuipunctata comb. nov., and D. texana comb. nov. All Dorofeyukea species share the same morphological features, including having a narrow stauroid fascia surrounded by 1–3 irregularly shortened striae, uniseriate, and weakly radiate striae, circular, or rectangular puncta in the striae that are covered internally by dome‐shaped hymenes, presence of a pseudoseptum at each apex and absence of septa. Partial DNA sequences of SSU and rbcL loci show Dorofeuykae belongs to the clade of stauroneioid diatoms together with Stauroneis, Prestauroneis, Craticula, Karayevia, Madinithidium, Fistulifera, Parlibellus, and, possibly, Schizostauron. A new species from the monoraphid genus Madinithidium, M. vietnamica sp. nov., was described based on valve and chloroplast morphology as well as DNA sequence data.     

Testing common assumptions in studies of songbird nest success

We studied Ovenbird Seiurus aurocapilla and Golden‐winged Warbler Vermivora chrysoptera populations in northern Minnesota, USA, to test two common assumptions in studies of songbird nest success: (1) that the condition of an empty nest on or near its expected fledge date is an indicator of nest fate; and (2) that the presence of a fledgling or family group within a territory confirms a successful nest in that territory. We monitored the condition of nests and used radiotelemetry to monitor juveniles through the expected fledging date and early post‐fledging period. Of nests that contained nestlings 1–2 days before the expected fledge date, fates were misidentified using nest condition alone for 9.5% of Ovenbird nests, but those misidentifications were made in both directions (succeeded or failed), yielding only a small bias in estimated nest success. However, 20% of Golden‐winged Warbler nests were misidentified as successful using nest condition during the final visit interval, biasing the nest success estimate upward by 21–28% depending on the treatment of uncertain nest fates. Fledgling Ovenbirds from 58% of nests travelled beyond their natal territory within 24 h, rising to 98% after 5 days, and those fledglings travelled up to 390 m from nests within 10 days of fledging. Fledgling Golden‐winged Warblers from 13% of nests travelled beyond their natal territory within 24 h, rising to 85% after 5 days, and those fledglings travelled up to 510 m from nests within 10 days of fledging. We conclude that nest condition and fledgling presence can be misleading indicators of nest fate, probably commonly biasing nest success estimates upward, and we recommend that these assumptions should be tested in additional species.     

The Taxonomy and Phylogeny of the Poorly known Heterotrich Ciliate Ampullofolliculina lageniformis Hadži, 1951 (Ciliophora: Heterotrichea)

Ampullofolliculina Had?i, 1951 is a monotypic genus, the only species being A. lageniformis which was first discovered in estuarine habitats in the U.S. and has never been redescribed. In the present study, we investigated the taxonomy and phylogeny of A. lageniformis Had?i, 1951 based on analyses of a population collected from a brackish wetland in Ningbo, China. The main characteristics of this species are as follows: trophont about 450–700 μm long in vivo with two short, rounded peristomial lobes of equal size; lorica flask‐shaped, transparent and smooth with a short, wide neck at the base of which two transparent valves are asymmetrically inserted; cortex with brownish to reddish cortical granules and greenish pigment granules; about 80 somatic kineties evenly arranged; moniliform macronucleus with 4–8 ellipsoidal nodules; swarmer dark green, vermiform in shape, about 200–350 μm long in vivo, with about 60 adoral membranelles and 85 somatic kineties, no mouth nor paroral membrane. Phylogenetic analyses inferred from SSU rDNA sequences show that A. lageniformis is closely related to Folliculina and Eufolliculina which nest within a large clade that comprises five families, i.e. Stentoridae, Blepharismidae, Fabreidae, Maristentoridae, and Folliculinidae.     

Molecular Phylogeny of an Indian Population of Kleinstyla dorsicirrata (Foissner, 1982) Foissner et al., 2002. comb. nov. (Hypotrichia,Oxytrichidae): an Oxytrichid with Incomplete Dorsal Kinety Fragmentation

Kleinstyla dorsicirrata (Foissner, 1982) Foissner et al., 2002. comb. nov. (basionym: Gastrostyla dorsicirrata) is a slightly flexible oxytrichid, measuring about 88–115 × 27–46 μm in life and possesses cortical granules. Kleinstyla dorsicirrata is the only oxytrichid known so far with incompletely fragmented dorsal kinety. Morphological and morphogenetic data recognise K. dorsicirrata as nonstylonychine oxytrichid. Molecular phylogeny of an Indian population was inferred using 18S rRNA gene sequences and was examined with respect to oxytrichids exhibiting variation in dorsal kinety fragmentation. Kleinstyla dorsicirrata clusters with Oxytricha lanceolata; this proximity is quite significant as both show deviation from typical oxytrichid fragmentation of dorsal kinety. Molecular phylogeny of Indian population confirms its nonstylonychine oxytrichid status.     

Total Synthesis and Antibacterial Study of Cyclohexapeptides Desotamide B,Wollamide B and Their Analogs

As natural‐product‐derived antibiotics, desotamides A – D and wollamides exhibit growth inhibitory activity against Gram‐posivite bacteria (IC₅₀ 0.6 – 7 μm ) and are noncytotoxic to mammalian cells (IC₅₀ > 30 μm ). Herein we firstly report the total synthesis of above two cyclohexapeptides as well as a series of structural variants through solid phase peptide synthesis, of which 3 displayed a 2‐fold increase of antibacterial activity when compared with the original peptide 1 . This strategy may offer good improvements for the synthesis of other cyclic peptides.     

Sitting ducklings: Timing of hatch,nest departure,and predation risk for dabbling duck broods

For ground‐nesting waterfowl, the timing of egg hatch and duckling departure from the nest may be influenced by the risk of predation at the nest and en route to wetlands and constrained by the time required for ducklings to imprint on the hen and be physically able to leave the nest. We determined the timing of hatch, nest departure, and predation on dabbling duck broods using small video cameras placed at the nests of mallard (Anas platyrhynchos; n = 26), gadwall (Mareca strepera; n = 24), and cinnamon teal (Anas cyanoptera; n = 5). Mallard eggs began to hatch throughout the day and night, whereas gadwall eggs generally started to hatch during daylight hours (mean 7.5 hr after dawn). Among all species, duckling departure from the nest occurred during daylight (98%), and 53% of hens typically left the nest with their broods 1–4 hr after dawn. For mallard and gadwall, we identified three strategies for the timing of nest departure: (a) 9% of broods left the nest the same day that eggs began to hatch (6–12 hr later), (b) 81% of broods left the nest the day after eggs began to hatch, and (c) 10% of broods waited 2 days to depart the nest after eggs began to hatch, leaving the nest just after the second dawn (27–42 hr later). Overall, eggs were depredated at 10% of nests with cameras in the 2 days prior to hatch and ducklings were depredated at 15% of nests with cameras before leaving the nest. Our results suggest that broods prefer to depart the nest early in the morning, which may best balance developmental constraints with predation risk both at the nest and en route to wetlands.     

Fine Structure of the Plasmodia and Myxospore of Ellipsomyxa gobioides n. sp. (Myxozoa) Found in the Gallbladder of Gobioides broussonnetii (Teleostei: Gobiidae) from the Lower Amazon River

A fish infecting myxosporean Ellipsomyxa gobioides n. sp. is described in the gallbladder of the Amazonian dragon fish Gobioides broussonnetii. Irregular disporous plasmodia (up to ~30 μm in diameter) with long branched and anastomosed pseudopodia were found attached to the gallbladder wall. Mature ellipsoid myxospores occurring floating in the bile measured 6.8 (6.5–7.0) μm (n = 30) long, 7.2 (6.9–7.5) μm (n = 15) wide, and 13.1 (12.8–13.5) (n = 25) thick. They had smooth thin valves elongated in the direction perpendicular to the plane of the straight central transverse sutural line. The two ellipsoidal polar capsules (PC) opened some distance from the sutural line on opposite sides, each measuring 4.6 (4.3–4.8) μm (n = 15) long and 2.5 (2.1–2.7) μm (n = 20) wide. Distance between PC 3.5 (3.1–3.8) μm (n = 15) in apical view. The polar filament was isofilar and consisted of a single coil with five or six turns. The objective of this study was to characterize this new species based on its morphological differences from the three previously described species. This is the first reported species of genus Ellipsomyxa from among the South American fauna.     

Factors that influence vital rates of Seaside and Saltmarsh sparrows in coastal New Jersey,USA

As saltmarsh habitat continues to disappear, understanding the factors that influence the population dynamics of saltmarsh breeding birds is an important step in the conservation of these declining species. Using 5 yrs (2011–2015) of demographic data, we evaluated and compared apparent adult survival and nest survival of Seaside (Ammodramus maritimus) and Saltmarsh (A. caudacutus) sparrows at the Edwin B. Forsythe National Wildlife Refuge in New Jersey, USA. We determined the effect of site management history (unditched vs. ditched marshes) on adult and nest survival to aid in prioritizing future management or restoration actions. Apparent adult survival (61.6%, 95% CI: 52.5–70.0%) of Seaside Sparrows averaged > 1.5 times greater than that of Saltmarsh Sparrows (39.9%, 95% CI: 34.0–46.2%). Nest survival and predation and flooding rates did not differ between species, and predation was the primary cause of nest failure for both species. Apparent adult survival and nest survival did not differ between unditched and ditched marshes for either species, indicating that marsh ditching history may not affect the quality of breeding habitat for these species. Because predation was the primary cause of nest failure for both species in New Jersey, we suggest that future studies should focus on identifying predator communities in salt marshes and the potential for implementing predator‐control programs to limit population declines.     

Biological Activities of Triterpenoids and Phenolic Compounds from Myrica cerifera Bark

Seven triterpenoids, 1  –  7 , two diarylheptanoids, 8 and 9 , four phenolic compounds, 10  –  13 , and three other compounds, 14  –  16 , were isolated from the hexane and MeOH extracts of the bark of Myrica cerifera L. (Myricaceae). Among these compounds, betulin ( 1 ), ursolic acid ( 3 ), and myricanol ( 8 ) exhibited cytotoxic activities against HL60 (leukemia), A549 (lung), and SK‐BR‐3 (breast) human cancer cell lines (IC₅₀ 3.1 – 24.2 μm ). Compound 8 induced apoptotic cell death in HL60 cells (IC₅₀ 5.3 μm ) upon evaluation of the apoptosis‐inducing activity by flow cytometric analysis and by Hoechst 33342 staining method. Western blot analysis on HL60 cells revealed that 8 activated caspases‐3, ‐8, and ‐9 suggesting that 8 induced apoptosis via both mitochondrial and death receptor pathways in HL60. Upon evaluation of the melanogenesis‐inhibitory activity in B16 melanoma cells induced with α‐melanocyte‐stimulating hormone (α‐MSH), erythrodiol ( 7 ), 4‐hydroxy‐2‐methoxyphenyl β‐d ‐glucopyranoside ( 13 ), and butyl quinate ( 15 ) exhibited inhibitory effects (65.4 – 86.0% melanin content) with no, or almost no, toxicity to the cells (85.9 – 107.4% cell viability) at 100 μm concentration. In addition, 8 , myricanone ( 9 ), myricitrin ( 10 ), protocatechuic acid ( 11 ), and gallic acid ( 12 ) revealed potent DPPH radical‐scavenging activities (IC₅₀ 6.9 – 20.5 μm ).     

No evidence that cameras affect shorebird nest survival on the coastal plain of Arctic National Wildlife Refuge,AK

Cameras are important tools used to determine nest fate, identify predators and evaluate behaviour; however, they may impact the parameters they are used to measure, thereby biasing results. We evaluated the impact of cameras ? 10 m from the nest on shorebird nest survival at the Canning River Delta, Alaska, 2017–2018 (n_control = 122, n_camera = 109) using a much larger sample size than in previous studies conducted in the Arctic and random assignments at nest discovery. We found no effect of camera presence at the nest on daily nest survival (model-averaged daily survival rate (DSR) 85% confidence interval (CI); control: 0.971–0.983, camera: 0.969–0.982). We suggest that nest survival studies of tundra-nesting birds should consider the use of cameras to minimize researcher disturbance, increase the accuracy of fate assignments, and broaden the ecological data collected (e.g. incubation behaviour, predator identification and non-anthropogenic non-predation disruption such as by caribou).     

Movements and Resource Selection of Fledgling Goshawks in Montane Forests of Southeastern British Columbia

ABSTRACT The northern goshawk (Accipiter gentilis) has been the subject of considerable interest because of the impact of logging on this species' nesting habitat. However, few studies have examined movements of fledgling birds around the nest prior to independence, and even fewer have described resource requirements of young birds during their postfledging period. Over 3 years, we followed 31 radiotagged goshawk fledglings from 15 nests in southeastern British Columbia, Canada. Of these birds, 26 survived to disperse. Between fledging and dispersal 95% of fledgling relocations (n = 1, 148) were within 450 m of the nest. Fledglings primarily remained within 298 m of the nest during the first 21 days postfledging and within 525 m of the nest between 21 days postfledging and dispersal. Fledglings' movements were highly directional, with individual and sibling movements away from any particular nest tending out in one direction. Postfledging areas averaged 36.7 ha in size (median = 23.1, inter-quartile range = 20.8–39.7 ha). Fledglings strongly avoided forest <40 years old and weakly selected young forests (40–80 yr), mature forests (>80 yr), and stands with >40% canopy cover during the first 21 days and after. We suggest forest managers wishing to conserve goshawk postfledging areas in the interior montane forests of British Columbia maintain forests >40 years old with high crown closure covering an area ≥21 ha and preferably >40 ha. This area should contain all identified occupied and alternative nest trees in a nest area. At least half this area should be forest >80 years old and contain existing nests and potential for future nest trees.     

Development of the embryo nest ofVespa affinis (Hymenoptera: Vespidae) in Southern Japan

Summary The aerial nests ofVespa affinis on Ishigaki Island, Japan, were found mainly within 1 m of the ground, attached to a twig roughly 4 mm in diameter. These are probably adaptations to survive adverse weather conditions. The favoured nesting habitat was in open farmland areas rather than in the natural forest. The entire envelope and more than half of the comb of the embryo nest is constructed during the first 10–12 days. The first workers emerge around 34 days after nest initiation. The duration of larval development was found to be linked to the number of larvae present in the nest, with the earlier progeny developing faster. The changes in the ovarian index of the mother queen during the early stages of nesting are described.     

First Report of Peronospora belbahrii on Sweet Basil in Baja California Sur,México

In Baja California Sur, Mexico, a foliar disease occurred on sweet basil which seriously affected its quality and yield. The most common symptoms were yellowing and necrosis on leaves, caused by a downy mycelium growth on the lower leaf surface. Symptomatic leaves from two sampling sites were collected for morphological studies and molecular analysis of pathogen DNA. Based on morphological characteristics (sporangiophore size of 240–530 × 7–11 μm, branches of 5–8 order and a sporangia size of 27–31 × 21–25 μm) and molecular analysis (the GenBank blast of the PCR assays showed unique rDNA sequence data with 99% similarity to P. belbahrii), the pathogen was identified as Peronospora belbahrii, the causal agent of basil downy mildew. This is the first report of P. belbahrii affecting sweet basil in Mexico.     

Superbanone,A New 2‐Aryl‐3‐benzofuranone and Other Bioactive Constituents from the Tube Roots of Butea superba

Phytochemical investigation from the tube roots of Butea superba, led to the isolation and identification of a new 2‐aryl‐3‐benzofuranone named superbanone ( 1 ), one benzoin, 2‐hydroxy‐1‐(2‐hydroxy‐4‐methoxyphenyl)‐2‐(4‐methoxyphenyl)ethanone ( 2 ), eight pterocarpans ( 3  –  10 ), and eleven isoflavonoids ( 11  –  21 ). Compound 2 was identified for the first time as a natural product. The structure of the isolated compounds was elucidated using spectroscopic methods, mainly 1D‐ and 2D‐NMR. The isolated compounds and their derivatives were evaluated for α‐glucosidase inhibitory and antimalarial activities. Compounds 3 , 7 , 8 , and 11 showed promising α‐glucosidase inhibitory activity (IC₅₀ = 13.71 ± 0.54, 23.54 ± 0.75, 28.83 ± 1.02, and 12.35 ± 0.36 μm , respectively). Compounds 3 and 11 were twofold less active than the standard drug acarbose (IC₅₀ = 6.54 ± 0.04 μm ). None of the tested compounds was found to be active against Plasmodium falciparum strain 94. On the basis of biological activity results, structure–activity relationships are discussed.     

Size‐structured vulnerability of the colonial cyanobacterium,Microcystis aeruginosa,to grazing by zebra mussels (Dreissena polymorpha)

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Nematicidal screening of essential oils and potent toxicity of Dysphania ambrosioides essential oil against Meloidogyne incognita in vitro and in vivo

It is known that some plant essential oils have pesticide activities. Among the 29 oils evaluated in this study, 14 showed nematicidal activities of 8 to 100% at the concentration of 1,000 μg/ml, compared with a control of 0.01 g/ml Tween 80^®. At a lower concentration of 500 μg/ml, only Dysphania ambrosioides oil caused >90% mortality of second‐stage juveniles (J2) of Meloidogyne incognita. The LC₅₀ and LC₉₅ values for D. ambrosioides oil were 307 μg/ml and 580 μg/ml, respectively. M. incognita eggs placed in D. ambrosioides oil solutions had a significant reduction in J2 hatching compared with controls. Therefore, the oil had a toxic effect on both eggs and J2 of M. incognita. This was in contrast to nematicides on the market that act efficiently only on J2. When J2 were placed in D. ambrosioides oil at its LC₅₀ concentration and inoculated onto tomato plants, the reduction in numbers of galls and eggs was 99.5% and 100%, respectively. Dysphania ambrosioides oil applied to the potting substrate of plants at a concentration of 1,100 μg/ml significantly reduced the number of galls and eggs of M. incognita, whereas a concentration of 800 μg/ml only reduced the number of eggs compared with the controls (Tween 80^® and water). The main components of the D. ambrosioides oil detected by gas chromatography–mass spectrometry were (Z)‐ascaridole (87.28%), E‐ascaridole (8.45%) and p‐cymene (3.35%), representing 99.08% of the total oil composition. Given its nematicidal activity, D. ambrosioides oil represents an exciting raw material in the search for new bioactive molecules for the pesticide industry.