Second Half Of March Research Articles

Is the butterfly Tomares ballus (Lepidoptera: Lycaenidae) a potential pest of Lens culinaris (Leguminosae)?

The lentil (Lens culinaris) is identified as a new host plant of the lepidopteran Tomares ballus. Five larvae of T. ballus were found on 19 May, 2007 in a crop of "castellana" lentils in Toledo Province, Spain and reared in the laboratory. The larval brown spiracles are slightly darker than the rest of the pupa. Traditional cultural practices reduce the insect's probability of completing its life-cycle. We present flight phenology data for T. ballus from the unedited Atlamar database (1,073 records from 1887 to 2003), based on the 438 records for which the year, month and day are known. This period coincides with the flowering and formation of the legumes of various species of leguminosae, such as lentils. The peak activity of the imagos occurs in the second half of March and the first half of April, and the last larvae must be present in the field until the beginning of June.

Capturing vertical profiles of aerosols and black carbon over the Indian Ocean using autonomous unmanned aerial vehicles

Abstract. Measurements of the vertical distribution of aerosol properties provide essential information for generating more accurate model estimates of radiative forcing and atmospheric heating rates compared with employing remotely sensed column averaged properties. A month long campaign over the Indian Ocean during March 2006 investigated the interaction of aerosol, clouds, and radiative effects. Routine vertical profiles of aerosol and water vapor were determined using autonomous unmanned aerial vehicles equipped with miniaturized instruments. Comparisons of these airborne instruments with established ground-based instruments and in aircraft-to-aircraft comparisons demonstrated an agreement within 10%. Aerosol absorption optical depths measured directly using the unmanned aircraft differed from columnar AERONET sun-photometer results by only 20%. Measurements of total particle concentration, particle size distributions, aerosol absorption and black carbon concentrations are presented along with the trade wind thermodynamic structure from the surface to 3000 m above sea level. Early March revealed a well-mixed layer up to the cloud base at 500 m above mean sea level (m a.s.l.), followed by a decrease of aerosol concentrations with altitude. The second half of March saw the arrival of a high altitude plume existing above the mixed layer that originated from a continental source and increased aerosol concentrations by more than tenfold, yet the surface air mass showed little change in aerosol concentrations and was still predominantly influenced by marine sources. Black carbon concentrations at 1500 m above sea level increased from 70 ng/m3 to more than 800 ng/m3 with the arrival of this polluted plume. The absorption aerosol optical depth increased from as low as 0.005 to as much as 0.035 over the same period. The spectral dependence of the aerosol absorption revealed an absorption Angstrom exponent of 1.0, which is typical of an aerosol with most of its absorption attributed to black carbon and generally indicates the absorbing component originated from fossil fuel sources and other high-temperature combustion sources. The results indicate that surface measurements do not represent the aerosol properties within the elevated layers, especially if these layers are influenced by long range transport.

133Xe in Surface Air of St. Petersburg

In the course of testing new devices for measuring atmospheric concentrations of radioactive noble gases and also of the monitoring techniques, large number (116) of determinations of Xe in surface air of St. Petersburg was made (100 in the period from December 1997 to December 1998 and 16 in the second half of March 2000). In 1998, samples were taken at 6-h to 7-day intervals with documentation of data on the wind direction, and in 2000, at 1-day intervals, but without fixing the wind direction. Statistical treatment of data obtained in 1998 gives the mean volume activity of 2.3 ± 0.6 mBq m−3. In 1998, this value was exceeded in three cases by a factor of 2–3 and in six cases by a factor of 5–16. In March 2000, even higher values were observed, exceeding by a factor of up to 43, which was caused essentially by releases from the Leningrad NPP. Data obtained in 1998 also show that the specific activity of 133Xe depends on the wind direction.

Double-diffusive convection in Lake Nyos, Cameroon

Since the catastrophic CO 2 eruption in 1986, Lake Nyos has been investigated in detail by several research groups. However, no signs of double-diffusive convection were observed before December 2002, when a set of 26 well-mixed layers with thicknesses of 0.2–2.1 m and sharp interfaces in between were discovered at 53–74 m depth. Such pronounced steps are a characteristic feature of double-diffusive convection of the diffusive regime. A temperature time series measured at 62 m depth indicates that the double-diffusive convection started in the second half of March 2002. The trigger was most probably the cooling at the top of this layer caused by relatively strong seasonal convective mixing down to 52.5 m depth during the dry season in February 2002. The heat fluxes calculated by the heat budget method and the thicknesses of the layers agree within the uncertainties with the values expected from the double-diffusive flux laws. The heat fluxes increased by an order of magnitude since the establishment of the double-diffusive convection and reached values comparable to the heat input by a source of warm and CO 2-enriched water to the deepest zone of the water column. In contrast, the CO 2 fluxes caused by double diffusion are negligible compared to the input by this source. Because the double-diffusive heat fluxes were higher in the upper layers of the staircase compared to the lower ones, the temperature gradient between 60 and 75 m depth approximately doubled from March 2002 to December 2002, whereas the total dissolved solids gradient remained almost constant during this period. Consequently, this process is reducing the stability of the staircase and could potentially lead to a complete homogenization of this zone within a few years. It cannot be excluded that a similar double-diffusive event could have been the trigger of the CO 2 eruption in 1986.

Screening of Mulberry varieties for early sprouting

The sprouting behaviour of different 35 Mulberry varieties were taken during autumn 1999 and spring 2000 to screen out early sprouting varieties for introduction in the field for commercial exploitation. It was observed that Mandalya T-R8, TR10 and S146 are early sprouting varieties. These varieties take 13 to 14 days in spring and 7 to 10 days in autumn for sprouting. All exotic varieties were found exhibiting late sprouting characters. The sprouting in these varieties occurred only towards the second half of March and early April when temperature is comparatively higher for bivoltine rearing. The early sprouting varieties are more suitable for bivoltine rearing than the late sprouting varieties. Hence Mandalaya TR-8, TR-10 and S146 can safely be recommended for bivoltine rearing in subtropical area due to coincidence of their sprouting with bivoltine rearing schedule.

Timing and seasonal changes in Eider Somateria mollissima spring migration in the northern Öresund, south Sweden, 1975–2001

This paper describes the spring migration of Eiders Somateria mollissima through the Öresund, south Sweden, during the years 1975 to 2001. The birds are leaving their wintering grounds in the Kattegat to breed in the Baltic. The passage takes place in the second half of March and the first half of April with the major migration period between 22 March and 13 April (median date 4 April). Over the study years, there is a significant trend that the migration takes place earlier in the season. This is both in terms of median date and onset of the migration period. The change in the timing of the migration appears to be related to milder winter weather and earlier springs during the end of the 20th century. It is shown that the spring passage of Eiders for individual years is significantly correlated with the ice indices for Swedish seas the preceding winter.

Diapause induction and termination in the predatory mite Euseius finlandicus in peach orchards in northern Greece.

The course of diapause induction as well as of diapause termination in females of the predatory mite Euseius (Amblyseius) finlandicus Oudemans (Acari: Phytoseiidae) in Northern Greece was determined by transferring females during winter and early spring from peach trees to a short day (LD 8:16) or a long day (LD 16:8) photoperiod both at 20 degrees C. The first diapause females were found in mid September and by the first week of October all the females were in diapause. The mean number of days required for diapause termination under the short day photoperiod LD 8:16 was gradually reduced from 93.7 days in the beginning of October to less than 20 days in mid February and early March. Under the long day photoperiod of LD 16:8 diapause was terminated in less than 20 days irrespective of the date of collection. These results indicate that by mid February photoperiodic sensitivity of females was lost and diapause was terminated. However, females were found in their overwintering sites until the second half of March, probably because of the prevailing relatively low temperatures and lack of adequate food.

Reproduction of Faroe Plateau Cod: Spawning Grounds, Egg Advection and Larval Feeding

Faroe Plateau cod spawn mainly in two areas that lie close inside the tidal front that surrounds the Faroe Shelf. Eggs and larvae are advected in an anticyclonic direction around the Islands. Peak spawning is in the second half of March, and, thus, the majority of cod larvae start feeding in April. At this time, secondary production on the central shelf is still at a low level. However, over-wintered Calanus finmarchicus, which are advected from offshore onto the northern and western slope and shelf regions may spawn by April. Observations from April 1995 and 1999 showed that the firstfeeding cod larvae fed mainly on copepod eggs, which, based on their sizes, are presumed to be mainly C. finmarchicus eggs. Copepod nauplii were only of minor importance. The spawning areas of Faroe Plateau cod are close to the areas with the highest average egg productionof C. fmmarchicus during early spring. This results in a coherent advection of cod eggs, larvae, and food from the spawning ground. They are advected clockwise, in an easterly direction, onto the northern shelf region and are then dispersed throughout the central shelf area. As the cod larvae grow, they switch over to larger prey. Food observations in late May 1995showed mainly a mixture of copepod nauplii, young copepodites of C. finmarchicus, and various neritic copepod species (mainly Acartia and Temora), which were produced on the shelf during spring.

Épocas de plantio da lentilha precoce em quatro regiões de Minas Gerais

Foram conduzidos cinco ensaios, todos irrigados, em quatro regiões de Minas Gerais: Viçosa, Leopoldina (Zona da Mata), Patos de Minas (Alto Paranaíba), Uberaba (Triângulo) e Janaúba (Norte), com o objetivo de determinar a melhor época de plantio da lentilha precoce. Em Viçosa, foram estudadas seis datas de plantio, de 15/3 a 30/5; em Leopoldina, quatro, de 7/4 a 10/6; em Uberaba e Patos de Minas, seis, de 17/2 a 2/6; e em Janaúba, cinco, de 16/5 a 3/8. O intervalo entre datas de plantio foi de, aproximadamente, 20 dias. No ensaio de Viçosa, foi utilizada a cultivar Precoz, plantada no espaçamento entre fileiras de 40 cm, com 30 sementes/m; nos outros ensaios, a Silvina, no espaçamento entre fileiras de 30 cm, com 50 sementes/m. Em geral, os maiores rendimentos foram alcançados quando o plantio foi feito em maio, principalmente na segunda quinzena. Em Viçosa, a lentilha também teve bom desempenho quando plantada na segunda quinzena de março. Em Leopoldina e Janaúba, os dois locais de temperaturas mais altas, o plantio no início de junho não prejudicou o rendimento, se comparado com o da segunda quinzena de maio. Nas épocas de plantio em que foram obtidos os maiores rendimentos, a lentilha precoce, após a emergência, levou entre 28 e 60 dias para iniciar o florescimento; e da emergência até a colheita, entre 92 e 112 dias. O maior rendimento médio foi alcançado em Leopoldina, quando o plantio foi realizado em 27/5: 1.644 kg/ha. O peso de 100 sementes da 'Silvina'variou de 5,5 a 6,3 gramas, quando o plantio foi feito em maio.

Biology of pike, Esox lucius (Esocidae), in the lower plain of Friuli‐Venezia Giulia (north‐eastern Italy)

This study investigates the biology of Esox lucius in an irrigation ditch, Storta Roggia (Torviscosa, Udine), in the lower plain of Friuli‐Venezia Giulia (north‐eastern Italy). About twenty fish were captured monthly from May 1996 to May 1997. Variables such as age (as determined from reading scales) and stomach contents were recorded from these fishes. Additionally, the gonads were excised and fixed to assess the reproductive stage. These fishes were from eight age‐classes (0–7 years). Age classes 6 and 7 were chiefly females. Their diet was chiefly fish and benthic macroin‐vertebrates. Their reproductive period was from the second half of March to May. Several female specimens collected within the second half of April and May were in a spent‐spawning condition or with degenerative oocytes. Some male pike from age‐class 1 attained maturity, while females did not attain sexual maturity until age‐class 2 or later.

On Prelarvae and Early Postlarvae of the Rockfish Helicolenus dactylopterus (Delaroche, 1809)'un From the Sea of Marmara

Little is known about the early life history of H. dactylopterus, and the prelarval stage has been described, in accordance with one single sample reared under laboratory conditions. In this study, morphological characteristics of prelarvae and postlarvae up to 9.27 mm lenght of H. dactylopterus were described and illustrated in detail, using material obtained from the plankton samples collected during the years 1953, 1955, 1956, 1966 and 1967 in the Sea of Marmara, in the context of the working program of the Hydrobiological Research Institute, istanbul. The distribution of the larvae of this species in the Sea of Marmara was shown by a map; and on the basis of early and late occurrence of the larvae, it was concluded that their seasonal occurrence in the sea extends from the second half of March to the beginning of July. Thus prelarvae of H. dactylopterus from their natural habitat and the pre- and postlarvae, from our waters were described, for the first time, and information concerning their distribution and seasonal occurrence in the Sea of Marmara was given.

Further ozone decline during the northern hemisphere winter‐spring of 1994–1995 and the new record low ozone over Siberia

Ground‐based total ozone observations show that during the second half of January 1995 through February, most of March, and the first week of April very low ozone values, again were observed in northern middle and high latitudes. Over Eastern and Southern Europe and North America the deficiency was 10–12% with a few periods down to 15–20%. Since mid January the ozone values fall 25% below the long‐term mean over Siberia and Yakutia. This anomaly lasted on the average for twelve consecutive weeks. For a number of days in early February and in the second half of March, the deficiency exceeded 35–40%. The monthly mean lower stratosphere temperatures over Siberia, where the polar vortex was displaced were 10°C below the normal for January and February falling down below −75°C to −80°C during the time of lowest ozone.

Seasonal availability of Fasciola hepatica metacercariae in a temperate Mediterranean area (Madrid, Spain).

In this experiment, conducted over a 3-year period (1988-1990), the seasonal availability of Fasciola hepatica metacercariae in a temperate Mediterranean area (Madrid, central Spain) was analysed according to the rhythms of snail infection, the periods of cercarial emission, and the resistance of metacercariae. In this area, snails could be infected from late April to early November. Cercarial emission by spring infection started at the beginning of summer and terminated 3-4 weeks later. Mid-summer temperatures led to the extinction of shedding populations and of the metacercariae emitted by them, but were well tolerated by the snails with undeveloped infections. No aestivation was observed and summer infection led to a progressive shedding wave from August to late December, when it was interrupted. These populations became extinguished in the colder winter of 1988, but overwintered in the mild and belated winter of 1989. Only the snails infected from late summer onwards resumed activity and shed cercariae in spring, from the second half of March to late June. Risk of infection for grazing animals during winter will depend on survival of metacercariae. With a mean mortality of 23% during December and January, and of 38% during the following 2 months, no more than 30% of metacercariae reach the spring alive. Accordingly, risk of infection for grazing animals in spring will depend on overwintering infection of snails. These results indicate that temperature more than humidity could be responsible for different transmission patterns from year to year as winter thermic profiles could be the key for the transmission of fasciolosis during spring.

Reproductive biology of the parsley frog, Pelodytes punctatus, at the northernmost part of its range

Abstract The reproductive biology and population dynamics of Pelodytes punctatus were studied at the breeding season over a three year period in a coastal dune system located at the extreme northwestern border of the species' range. Adult population size estimates ranged from about 100 in the first year to 60 in the third year. Males were remarkably sedentary near the pond under artificially provided shelters. Many were observed during the most of the breeding season which lasted from mid-March or the end of March to the end of April or mid-May. Most spawning took place in the second half of March or early April. In two years out of three a second period of spawning involving fewer animals was observed in the first half of May. Both periods of spawning coincided with, or shortly followed, periods of rising median air temperature. Egg-clutches were deposited in the deepest parts of pond, mainly on submerged vegetation not reaching the surface. An average sized clutch contained approximately 360 eggs. Development of the embryos until hatching took from 4 to 14 days, depending on the ambient temperature. Larval development and growth were fast. Recently metamorphosed froglets at a size of around 18 mm were found from the end of May onwards. Juveniles may reach adult size in the autumn of the year that they were born. Adult frogs did not show a strong fidelity to the breeding pond between years. In the study area the population structure of Pelodytes punctatus seems to be best described by a source - sink model in which flourishing populations in the dunes give rise to short lived satellite populations outside the dunes.

Seasonal variations in mineral concentrations in the trunk xylem sap of beech (Fagus sylvatica L.) in a 42‐year‐old beech forest stand

SUMMARYIn a 42‐yr‐old beech forest stand, growing on acid brown earth, five trees were felled every 2 wk. From their lowest trunk segments, each 100 cm in length, tracheal sap was collected by water displacement. The investigation was performed from mid‐October 1988 to mid‐October 1989, comprising a total of 130 sample trees. Xylem sap concentrations of calcium, magnesium, potassium, and manganese of 26 sampling series were analysed by atomic absorption spectrophotometry, and the pH values of fresh sap samples were determined. The seasonal variation in xylem sap concentrations of Ca, Mg and Mn in the lowest trunk sections showed a strong increase in the second half of March and in April, a decrease in May, after the leaves had expanded, a low level in summer, and a new increase in late autumn and winter. Potassium showed a different pattern with maximal xylem sap concentrations in autumn. Additionally, at four sampling dates (mid‐March, beginning of May, mid‐August and mid‐November), four trees, one at each date were cut into sections for the determination of the mineral concentrations in the xylem sap along the stem.

Maturation of male and female North Sea plaice (Pleuronectes platessa L.)

The maturation of North Sea plaice is studied on the basis of two research-vessel surveys and market-sampling data from the commercial fisheries. In female plaice the juvenile-adult transition occurred between May and September. Development of the female gonad took place between July and December, although the gonad did not gain weight before October. Gonad weight reached a maximum of circa 17% of the gutted body weight between January and March. The average female plaice was in spawning condition for about five weeks from late January to early March. Male plaice were in spawning condition for at least 11 weeks from the second half of December to the second half of March. In females the start of spawning was earlier in older fish, but the end of spawning did not differ between age groups. In males spawning ended later in older fish. The time that mature plaice were in spawning condition increased with the age of the fish in males and females. During the spawning season mature plaice hardly fed. Spent fish resumed feeding in January. The cessation of feeding in mature plaice was not related to the absence of food. Male plaice became sexually mature as II- and Ill-group, females as IV- and V-group. Length at 50% maturity (L 50 ) was 22 cm and 34 cm for males and females respectively. L 50 and age at 50% maturity (A 50 ) differed between geographical areas, increasing from south to north. Annual differences were observed in L 50 and A 50 which were related to annual differences in growth rate. Slower-growing plaice reached maturity at a smaller length but higher age than faster-growing plaice. Comparison with published data shows that at present both male and female plaice mature at a younger age and at a smaller size than at the beginning of this century.

Seasonal variations of LH, prolactin, androstenedione, testosterone and testicular FSH binding in the male blue fox (Alopex lagopus).

The seasonal changes in testicular weight in the blue fox were associated with considerable variations in plasma concentrations of LH, prolactin, androstenedione and testosterone and in FSH-binding capacity of the testis. An increase in LH secretion and a 5-fold increase in FSH-binding capacity were observed during December and January, as testis weight increased rapidly. LH levels fell during March when testicular weight was maximal. Plasma androgen concentrations reached their peak values in the second half of March (androstenedione: 0.9 +/- 0.1 ng/ml: testosterone: 3.6 +/- 0.6 ng/ml). A small temporary increase in LH was seen in May and June after the breeding season as testicular weight declined rapidly before levels returned to the basal state (0.5-7 ng/ml) that lasted until December. There were clear seasonal variations in the androgenic response of the testis to LH challenge. Plasma prolactin concentrations (2-3 ng/ml) were basal from August until the end of March when levels rose steadily to reach peak values (up to 13 ng/ml) in May and June just before maximum daylength and temperature. The circannual variations in plasma prolactin after castration were indistinguishable from those in intact animals, but LH concentrations were higher than normal for at least 1 year after castration.

Gill (Na +K +)-ATPase activity and smolting in Atlantic salmon ( Salmo salar L.) in France

A survey of the gill (Na +K +)-ATPase activity in yearling Atlantic salmon reared in a hatchery in Brittany was conducted during 3 years. In 1982, in a French strain, the gill enzymatic activity increase occurred in the second half of March, after the equinox. The growth rate was variable in the population and two clear length modes appeared during the fall and winter, the larger fish presenting obvious smolt characteristics. There is a clear relationship between the limiting size found only from the intensity of the level of the gill enzyme activity and the size separating the two length modes. The large fish mode corresponds to the smolts. In 1983, in a Norwegian strain, ATPase activity began to increase earlier, and in 1984, in the same strain, increased even earlier, well before the equinox. Temperature, rather mild in Brittany in winter, remained at the same value and cannot be involved in the enzyme activation. Growth rates and absolute size are probably able to modify the receptivity of the fish to environmental parameters, and subsequently to modify the date of smoltification.

A water-borne hepatitis A outbreak in Rio de Janeiro.

An excess of hepatitis cases, in the research center of Petrobrás located in the Fundaão Island, within the city of Rio de Janeiro, was notified during the second half of March 1980. In recent years this center has had an average of four cases per year, but between March 5th and April 25th, sixteen cases were reported. The cause and possible source of infection were investigated. A serologic diagnosis of hepatitis A was made by showing IgG serum antibodies against this virus in patients. No subclinical cases among a group of 60 healthy employees could be identified. A questionnaire was circulated to investigate a possible commom source of infection. Evaluation of the water supply system indicated that it had recently been contaminated. Information obtained from other medical services in the island failed to reveal that the episode was part of a larger outbreak.

Geophysical events

Mount St. Helens Volcano, Cascade Range, southern Washington, USA (46.20°N, 122.18° W). All times are local (GMT‐8 h). March eruptive activity from Mt. St. Helens was limited to occasional emission of small steam clouds, at least one of which contained ash. However, significant deformation was measured within the crater, and there was a slight increase in volcanic seismicity during the second half of March. Geologists announced that another eruptive episode was likely if the deformation and seismic trends continued, but none had occurred by SEAN's April 8 press time.The U.S. Geological Survey‐University of Washington seismic net recorded 15 bursts of seismicity in March and five more bursts during the first 6 days of April. In the past, similar signals have often been correlated with episodes of steam emission, but because of poor weather, correlations with only two such episodes could be confirmed in March: a minor puff on March 9 at 1549, and a steam cloud containing some ash on March 27 at 1441. Newly fallen ash (made up of reworked dome material) observed NE of the volcano March 25 may have been ejected during a burst of seismicity the previous day.