Orientation of flight for physically disturbed spotted lanternflies,Lycorma delicatula, (Hemiptera,Fulgoridae)

The spotted lanternfly, Lycorma delicatula, (Hemiptera, Fulgoridae) is an invasive pest to Korea and the United States, originating from China or Southeast Asia. Immature L. delicatula feed on a wide range of plants, but the adults are more host-selective, often preferring the tree of heaven, Ailanthus altissima. We performed field studies to evaluate adult movement in relation to A. altissima after disturbance. The Ailanthus trees were in a mixed suburban forested situated at the southern border of an open grassy field. Female adult lanternflies were manually disturbed from feeding on the trunks of large A. altissima trees. In the first experiment, insects were disturbed directly from the tree using a ballpoint pen to simulate a predatory attack. These insects usually flew initially southward away from the tree line toward a sunlit field, but turned northward back toward the tree line. In the second experiment, to simulate an initially successful predatory attack, they were manually taken from trees, and allowed to escape. The females immediately opened their wings in an apparent aposematic display. They then either immediately flew toward the sunlit open field, or remained with their wings splayed open for a prolonged period.     

Analysis of Anemotactic Flight Tendencies of the Spotted Lanternfly (Lycorma delicatula) during the 2017 Mass Dispersal Flights in Pennsylvania

Journal of Insect Behavior - Video-recordings were made of adult spotted lanternflies, Lycorma delicatula, taking flight from apple trees in an orchard in northeast Pennsylvania in September, 2017...     

Life history and seasonal occurrence of the spotted eagle ray,Aetobatus narinari,in the eastern Gulf of Mexico

The spotted eagle ray, Aetobatus narinari, is listed on the IUCN Red List of Threatened Species as Near Threatened with a decreasing population trend, but many aspects of this ray’s biology and population status are unknown. Aerial and on-water surveys were conducted in the eastern Gulf of Mexico off southwest Florida 2008–2013, to document seasonal occurrence and life history characteristics of this species. Aerial surveys documented spotted eagle rays mostly in spring, summer, and autumn months with larger aggregations observed near inlet passes. Boat-based surveys documented rays on 152 out of 176 survey days, mostly as solitary individuals but sometimes in aggregations of up to 60. More rays were observed when water temperatures were 23-31?ºC. A total of 393 rays (231 males, 161 females, 1 unrecorded sex) were captured, measured, sampled, tagged, and released. Sizes ranged 41.4–203.0 cm disc width (DW) and weight 1.1–105.5 kg. Male size at 50 % maturity was 127 cm DW. Five percent (19) of tagged rays were recaptured after 5–1,293 days at liberty and recaptured rays exhibited faster growth than previously estimated from vertebral readings. Based on observations of rays relative to survey effort, numbers of observed rays declined after 2009 for reasons not yet understood. This observation, together with concerns about sustainability of fisheries targeting these rays in nearby Mexico and Cuba, underscore the need for investigations into stock structure, population trends, growth, and critical habitat of spotted eagle rays throughout the Gulf of Mexico, Caribbean Sea, and elsewhere in their range.     

Diaspore dispersal season influences root growth and seed traits,but not germination responses,of sympatric Piper species in a seasonal forest

• Seeds may differ in terms of dormancy, longevity, sensitivity to desiccation and dry mass, according to the timing (dry season/rainy season) of diaspore dispersal. In addition, seasonal variations in temperature and water availability can act as signals of the season during seed development, influencing germination responses and root growth. We evaluated the effects of temperature variations and water availability on germination parameters, root growth and seed traits of four coexisting Piper species in seasonal vegetation that differed in diaspore dispersal timing.
• Eight temperature treatments (15, 20, 23, 25, 28, 30, 35 °C, and alternate 30 °C–20 °C) and four induced water potentials (0, −0.3, −0.6 and −1.2 MPa) were used. The parameters germination onset, germination percentage (G%), mean germination time (MGT), root elongation, seed longevity during ex situ storage and dry mass of seeds were evaluated.
• Germination responses observed were independent of the diaspore dispersal timing, such as variations in germination onset, G% and MGT, both in temperature and water availability treatments. In contrast, root elongation, longevity and dry mass of seeds varied according to the time of diaspore dispersal.
• Our results corroborate the hypothesis that the timing of diaspore dispersal is an important factor in controlling the initial development of seedlings in seasonal vegetation, but not in germination responses. The predominance of negative effects of temperature increases and water deficit on root growth shows that the initial stages of plant development can be strongly impacted by these environmental factors.

     

Patterns of parasitism in monarch butterflies during the breeding season in eastern North America

1. Migratory behaviour can result in reduced prevalence of pathogens in host populations. Two hypotheses have been proposed to explain this relationship: (i) ‘migratory escape’, where migrants benefit from escaping pathogen accumulation in contaminated environments; and (ii) ‘migratory culling’, where the selective removal of infected individuals occurs during migration. 2. In the host–parasite system between the monarch butterfly (Danaus plexippus Linn.) and its obligate protozoan parasite Ophryocystis elektroscirrha (OE), there is evidence to support both hypotheses, particularly during the monarchs' autumn migration. However, these processes can operate simultaneously and could vary throughout the monarchs' annual migratory cycle. Assessing the relative strength for each hypothesis has not previously been done. 3. To evaluate both hypotheses, parasite infection prevalence was examined in monarchs sampled in eastern North America during April–September, and stable isotopes (δ²H, δ¹³C) were used to estimate natal origin and infer migration distance. There was stronger support for the migratory escape hypothesis, wherein infection prevalence increased over the breeding season and was higher at southern latitudes, where the breeding season tends to be longer compared with northern latitudes. Little support was found for the migratory culling hypothesis, as infection prevalence was similar whether monarchs travelled shorter or longer distances. 4. These results suggest that migration allows individuals to escape parasites not only during the autumn, as shown in previous work, but during the monarchs' spring and summer movements when they recolonise the breeding range. These results imply a potential fitness advantage to monarchs that migrate further north to exploit parasite‐free habitats.     

Roosting behavior of a Neotropical migrant songbird, the northern waterthrush Seiurus noveboracensis, during the non-breeding season

Several species of Nearctic-Neotropical migratory songbirds appear to form roosting aggregations while on their wintering grounds but little is understood about the ecology of this behavior. We studied roosting behavior and patterns of roost habitat selection in the northern waterthrush Seiurus noveboracensis , during three winter years (2002–2004) in Puerto Rico using radio telemetry. Overall, red mangrove was selected for roosting disproportionately to its availability. Regardless of diurnal habitat used, 87% (n=86) of northern waterthrush selected dense stands of coastal red mangrove for roost sites. Individuals traveled up to 2 km to access roost sites in this habitat on a daily basis. The majority (8 of 14) of individuals roosted alone, while others roosted in loose aggregations near communal roosts of gray kingbirds Tyrannus dominicensis . Patterns of roost site selection did not vary by sex. Individuals showing aggressive response to playback during the day, however, selected roost sites significantly closer to the coast. Several additional migratory and resident bird species also used red mangrove for night-time roosting habitat. Red mangrove may be a critical nocturnal roosting habitat for bird populations that live in proximity to coastal areas in the Neotropics. The benefits of nocturnal roosting behavior as well as why individuals appear to select red mangrove remain poorly understood.     

Regulation of substrate utilization in the flight muscle of the locust,Locusta migratoria,during flight

The concentrations of metabolites involved in carbohydrate metabolizing pathways, of amino acids and adenine nucleotides in the flight muscles of Locusta migratoria were determined during a fligt of 2 hr. During the first 15 min of flight, glycogen and glucose concentrations decreased to reach approximately constant levels. The concentration of glucose-6-phosphate increased rapidly. After an initial rise the concentration of fructose-1, 6-diphosphate, dihydroxyacetone phosphate and pyruvate reached constant levels within 1–5 min of flight. No changes were found in concentrations of other intermediates of the glycolytic pathway. The concentration of malate increased sharply, then decreased slightly, and then remained constant throughout the entire flight. Glycerol concentration increased about threefold.The concentrations of most amino acids were apparently not altered. Aspartate and alanine concentrations, however, showed a gradual increase during the first 10 min of flight, then decreased again to resting levels. The glutamate concentration decreased rapidly. The significance of this amino acid acting as a ‘sparker’ for citric acid cycle, is discussed along with the controlling sites of glycolytic flux.     

Sex differences in the play behavior of immature spotted hyenas, Crocuta crocuta

Social, locomotor, and object play were studied in a colony of five male and five female peer-reared spotted hyenas during 12 1-hr tests while the animals were 13-19 months of age. Animals were tested in both same-sex and mixed-sex groups and were stimulated to play by the introduction of fresh straw and sawdust bedding. Each test was videotaped and the frequency of each type of play was determined by a time sampling procedure. Females played more frequently than males, however, the category of play which was elevated depended upon the social context during testing. In same-sex tests the frequency of vigorous social play displayed by females markedly exceeded that by males, but no comparable sex difference appeared in mixed-sex tests. Females engaged in locomotor play more frequently than males in mixed-sex tests, but no comparable sex difference appeared in same-sex tests. No sex difference in object play was observed. Two male and two female hyenas were gonadectomized prior to the initiation of the present sequence of tests. The results suggest that gonadectomy during the prepubertal period does not affect the frequency of play behavior. However, the small sample sizes preclude any conclusive determination of the effects of these gonadectomies on play.     

Geographic, seasonal and bathymetric distribution of demersal fish species in the eastern Mediterranean

The distributional abundance of three demersal fish species, Merluccius merluccius, Mullus barbatus and Lophius budegassa, was studied as a function of sampling season, bathymetry and geographic area. Data were collected during research trawl surveys in the Aegean and Ionian seas under the same sampling scheme, thereby allowing comparisons to be made on the mean regional densities in numbers and biomass of these three commercially important species in Greek waters. Results indicated that European hake, M. merluccius, demonstrated a wide bathymetric and geographic distribution, with specimens encountered in all regions between 20 and 500 m depth, although density was found to be highest usually between 101 and 200 m. The mean regional density of hake was observed to vary seasonally, being higher mainly in winter. Red mullet, M. barbatus, was distributed in shallow water depths (<100 m) throughout the Greek seas, particularly in the northern part of the Aegean Sea. Abundance of this species steadily decreased with increasing depth. The geographic distribution of anglerfish, L. budegassa, was found to be restricted to the central and northern part of the Aegean Sea, with the highest mean densities encountered in the Thermaikos Gulf and in intermediate water depths between 101 and 200 m. Spatial patterns of observed density are assumed to be attributed mainly to prevailing topographic and hydrographic conditions and related biological productivity levels.     

Migratory and targeted flight in seasonal forms of the black bean aphid, Aphis fabae

ABSTRACT. Adult winged forms of Aphis fabae Scop., the spring migrants (fundatrigeniae; alate virginoparae), the summer migrants (alate virginoparae) and the autumn migrants (gynoparae), were flown in an automated vertical wind tunnel, with a small green target presented every 60 s. On average, targeted flight developed in the spring and summer migrants after 19 and 15 min, respectively. However, in autumn migrants targeted flight occurred after 184 min of flight. No evidence of target approach was found up to 30 min prior to this time, although some movement towards the target was observed in the 30 min before the first response of autumn migrants, suggesting that a gradual change from migratory to targeted flight occurred. No correlation was found between aphid weight and the time to first response for spring or summer migrants, but a positive correlation was found for autumn migrants. Flight patterns of autumn migrants, in the absence of a target, are described and compared with flight patterns previously reported for summer migrants.     

Polymorphism and modulation of cell wall esterase enzyme activities in the chicory root during the growing season

Pectins are major components of the primary plant cell wall. They can be both methylesterified and acetylesterified and de-esterification occurs by specific esterases. Proteins extracted by NaCl treatment from root cell walls of two chicory varieties (Cichorium intybus L. cv. Nausica and Arancha) sampled in an experimental field every 2 weeks between July 2002 and January 2003 were analysed by isoelectrofocalization, semi-denaturing SDS-PAGE, and quantitative assays for their esterase activity. Zymograms showed that chicory root pectin methylesterases belong to a multigene family. The isoelectric points of the pectin methylesterase isoforms ranged from pI 3.8 to pI 9.0. Concerning acetylesterases, only acidic isoforms between pI 4.1 and pI 5.2 were observed, but a large polymorphism of this class of enzymes could be identified in one variety. The results indicate that the root pectin methylesterase activity of the Nausica variety was correlated with ambient temperature, while no significant effect of temperature could be detected on any acetylesterase isoform.     

Foraging behavior of adult female Steller sea lions during the breeding season in Southeast Alaska

During the 1990s, the Steller sea lion ( Eumetopias jubatus Schreber) Western Alaska stock (WS) suffered steep population decline while the Eastern Alaska stock (ES) steadily increased. One bottom-up forcing hypothesis explaining this decline predicted lactating adult female foraging behavior would be different between stocks. To investigate this effect, we monitored 11 ES females at two breeding rookeries using satellite dive recorders (SDR) during the early breeding seasons of 1992–1993, examined their behavior with respect to prey, physiological limitations, and habitat, and made limited comparisons to observations of WS female behavior reported in the literature. ES females were not operating at the extremes of ability, with most diving within the limits of aerobic metabolism, less than one-quarter of possible foraging time during trips spent submerged and most foraging trips requiring less than one-half the lipid store fasting ability of dependent pups. Thus, females may have some capacity to alter behavior to accommodate future changes in foraging conditions, but the extent of this plasticity is unknown. Because recent work suggests WS recovery is impeded by low natality, future studies should test differences between reproductive and non-reproductive mature females in order to properly assess the contribution of foraging ecology to SSL population dynamics.     

Changes in fish bycatch during the shrimp fishing season along the eastern coast of the mouth of the Gulf of California

One of the main concerns of shrimp fisheries is the associated impact on ecosystem biodiversity, particularly on fish assemblages that are poorly characterized yet likely very relevant to the health of the ecosystem. The continental shelf along the eastern coast of the mouth of the Gulf of California is a region of high biodiversity that harbors highly productive fisheries. This study aimed to analyze the changes in the soft bottom fish assemblages caught as bycatch in the shrimp fishery located in this region. Sampling was conducted with commercial trawls at 16 fixed stations during the 2006–2007 shrimp‐fishing season. A total of 103 fish species from 80 genera and 47 families were collected. The ecological and taxonomic diversity as well as the composition and abundance of the fish community caught as bycatch in the shrimp trawl fishery were found to be significantly different in the autumn and winter. Ordination and similarity analyses also revealed differing patterns. Species abundance was strongly associated with sea bottom temperature, depth and latitude. The effects of these abiotic variables on the observed diversity patterns and the possible influences of the fishery are discussed.     

Hepatic mixed function oxidase (MFO) activities during the seasonal life cycle of the frog,Rana temporaria

1. A single dose of DDT (5 mg/kg) did not affect the activities of hepatic mixed function oxidase (MFO) components in fed summer frogs, Rana temporaria.2. The activity of MFO system showed remarkable seasonal variation with its higher activity level during the summer period.The MFO activity tended to be lower in the females than in the males at the beginning of spawning time while at the end of the spawning the reverse tendency was observable.4. In frogs overwintered in laboratory the activity levels of MFOs were lower than in the frogs undergone a natural wintering. The activity levels in an immature female resembled those observable in mature males.     

Age-related changes in flight muscle mass, lipid reserves and flight capacity during adult maturation in males of the territorial damselfly Calopteryx atrata (Odonata: Calopterygidae)

In the territorial damselfly Calopteryx atrata Selys, length of the hindwing, the wing areas and the aspect ratio did not differ significantly among age classes during the pre-reproductive period, while the body mass of males increased about 2.5 times. This is due primarily to increase in mass of thorax and abdomen. The flight muscle mass accounted for the great part of the thorax mass, and began to increase from early in the pre-reproductive period and continued increasing until sexual maturation. The average flight muscle mass of sexually matured males was about 2.4 times of that of the youngest immature ones. On the other hand, the abdomen mass and total lipids increased remarkably in the latter half of the pre-reproductive period. The average total lipid content of mature males was about tenfold of that of the youngest immature ones. The maximum lift production per flesh body mass was positively correlated with the flight muscle mass and total lipid content. Such an increase in flight muscle mass and lipid reserves resulted in the increase of maximum lift force, and probably enhanced flight performance.     

Comparative flight performance of the seasonal morphs of the cabbage whitefly, Aleyrodes brassicae (Wlk.), in the laboratory

Abstract. 1. The flight capacity of the summer (non-diapausing) and the winter (diapausing) females of A.brassicae was assessed in terms of the climbing flight directed phototactically toward an overhead source of light in a laboratory flight chamber.
2. The summer morph took off only when prodded and its flight bouts were much briefer than those of the winter morph.
3. Immediately on take-off, the summer morph sank in flight and was negatively phototactic in the horizontal plane whereas the winter morph climbed on take-off, being positively phototactic both vertically and horizontally.
4. Three phases of behaviour during flight were observed in the winter morph: a short period of widely fluctuating rate of climb, a long 'cruising' phase of steady climbing, and a final erratic phase when the rate of climb had fallen to and below zero.
5. In general, the mean rate of climb was significantly higher on re-take-off after a landing than immediately before the landing.     

Food consumption, body mass and fat deposition in captive regent honeyeaters, Xanthomyza phrygia (Meliphagidae), during the non-breeding season

The regent honeyeater (Xanthomyza phrygia) is a large endangered honeyeater from eastern and south-eastern Australia. Little is known about the ecology of this bird during the autumn-winter period, when it is absent from its breeding areas. In this study, food consumption and body condition of captive regent honeyeaters were studied during this period. Nectar was the dominant component of the regent honeyeaters diet and varied significantly throughout the study, peaking in early July. Fruit and mealworm consumption also showed significant seasonal shifts with maxima in late June and early March, respectively. In general, immature birds consumed significantly more protein-rich food than adults. The average body mass of the male birds varied significantly with season. Female birds did not show a significant seasonal change in body mass but, similarly to males, attained their highest mass in late April. Fat deposition changed significantly over months, with highest levels of fat recorded from late April until late June. These seasonal trends, independent of food abundance, may suggest that body condition within this species is controlled endogenously.Communicated by F. Bairlein     

Dispersal traits and dispersal patterns in an oro-Mediterranean thorn cushion plant formation of the eastern High Atlas, Morocco

This study describes the dispersal traits and dispersal patterns of 51 perennial plant species belonging to 19 families in an oro-Mediterranean thorn cushion plant formation on the High Atlas, Morocco. Diaspore type, mass, number, antitelechoric mechanisms and dispersal time were studied with respect to growth forms, dispersal modes and spatial dispersal. Species spanned 10⁵ range of diaspore mass, which coincided with those found in other high mountain regions. Diaspore mass was significantly higher in trees and shrubs than in semi-shrubs and perennial herbs. Barochorous and zoochorous species are more likely to have heavy diaspores, whereas anemochorous and ballistic species have a medium diaspore mass and semachorous and ombro-hydrochorous species have low diaspore mass. Diaspore number was significantly higher in trees and shrubs than in semi-shrubs and perennial herbs. The barochorous, ombro-hydrochorous and zoochorous species tended to produce higher diaspore numbers than species with other dispersal modes. Bradyspory was well-developed by trees and large shrubs dispersed by biotic vectors. Synaptospermy was represented by its long dispersal component. Myxospermy was significantly associated with semi-shrubs and perennial herbs with restricted spatial dispersal. It seems that ombro-hydrochory combined with myxospermy and a high number of light seeds is an efficient mechanism that ensures successful establishment of the most typical and endemic thorn cushion plant species, such as Alyssum, Vella and Ormenis. In our study area, the highest dispersal availability was synchronized with the dry summer season (July–August) and the beginning of the rainy months (September). The dispersal peak for the wind-dispersed species, which is the most effective primary dispersal mode, occurs during the dry season, while dispersal for the biotic-dispersed species takes place throughout the year.