Determination of effective light pulse and classical Bünsow experiment in the larval diapause of the Indian meal moth Plodia interpunctella

Plodia interpunctella Hübner (Lepidoptera: Pyralidae) comprises a model insect to analyse the photoperiodic time‐measuring system controlling its larval diapause. In the present study, the effective length of light pulse in night interruption experiments is determined at 25 °C. Various lengths of light pulse are tested by inserting them at the midnight of an LD 12 : 12 h photoperiod. When the light pulse is 15 or 30 min, the incidence of diapause is 86%. To inhibit the induction of diapause effectively, a light pulse of 1.75–2 h is needed. The incidence of diapause is 12% under an LD 12 : 5 : 2 : 5 h photoperiod. To determine the precise role of the light pulse, 2‐h light pulses placed at the midnight of an LD 12 : 12 h photoperiod are disrupted systematically by darkness. When a 2‐h light pulse is disrupted by 15 min of darkness, diapause is generally prevented (< 29%) regardless of the temporal position of darkness. Longer disruption by darkness induces diapause moderately (37–67%). A Bünsow experiment is also conducted at 25 and 20 °C, in which the main photophase of 12 h of light is combined with 24–72‐h scotophases scanned by a 2‐h light pulse. The photoperiodic cycle length tested, therefore, varies in the range 36–84 h. In each cycle length, the incidence of diapause fluctuates as the light pulse moves toward dawn. However, no regular and circadian changes in the percentage diapause are observed in relation to diapause determination.     

Does the disturbance hypothesis explain the biomass increase in basin‐wide Amazon forest plot data?

Positive aboveground biomass trends have been reported from old-growth forests across the Amazon basin and hypothesized to reflect a large-scale response to exterior forcing. The result could, however, be an artefact due to a sampling bias induced by the nature of forest growth dynamics. Here, we characterize statistically the disturbance process in Amazon old-growth forests as recorded in 135 forest plots of the RAINFOR network up to 2006, and other independent research programmes, and explore the consequences of sampling artefacts using a data-based stochastic simulator. Over the observed range of annual aboveground biomass losses, standard statistical tests show that the distribution of biomass losses through mortality follow an exponential or near-identical Weibull probability distribution and not a power law as assumed by others. The simulator was parameterized using both an exponential disturbance probability distribution as well as a mixed exponential–power law distribution to account for potential large-scale blowdown events. In both cases, sampling biases turn out to be too small to explain the gains detected by the extended RAINFOR plot network. This result lends further support to the notion that currently observed biomass gains for intact forests across the Amazon are actually occurring over large scales at the current time, presumably as a response to climate change.     

Isolation and characterization of polymorphic microsatellite DNA markers in the Omono type of ninespine stickleback,genus Pungitius

We isolated and characterized 25 polymorphic microsatellite loci for the Omono type of ninespine stickleback, genus Pungitius, an endangered species in streams including agricultural canals in Japan. The number of observed alleles per locus ranged from two to 15 within 32 individuals each collected from three populations in the Omono River, and the values of observed and expected heterozygosities ranged from 0.031 to 0.906 and from 0.031 to 0.856, respectively. All loci conformed to the Hardy–Weinberg equilibrium. Genetic linkage disequilibrium analysis between all pairs of the loci showed no significant departure from the null hypothesis between any of the loci.     

FORMATION OF LIGNIN IN TISSUE CULTURE OF PINUS STROBUS

The formation of shikimic acid and lignin from glucose in thecambium tissue was investigated. Glucose-1-¹⁴C, shikimic acid-G-¹⁴C, sodium acetate-1-¹⁴C and sodium acetate-2-¹⁴C were administeredto the tissue culture of strob pine. Glucose was well incorporatedinto shikimic acid, but acetic acid was less effective. Shikimicacid was very efficient as a precursor of aromatic nucleus andglucose was also converted efficiently to lignin. The extentof incorporation of acetic acid, however, was considerably low.A possibility was discussed that in the cultured tissue ligninand its precursor were synthesized from glucose via the shikimicacid pathway. (Received May 14, 1960; )     

Satellite‐tracking of Northern Pintail Anas acuta during outbreaks of the H5N1 virus in Japan: implications for virus spread

We fitted Northern Pintail Anas acuta in Japan with satellite transmitters and monitored their spring migration movements relative to locations where the highly pathogenic H5N1 avian influenza virus was detected in Whooper Swans Cygnus cygnus in 2008. Pintails were assumed not to be infected with the H5N1 virus at the time they were marked because capture occurred between 2 and 5 months before reported outbreaks of the virus in Japan. We assessed spatial and temporal overlap between marked birds and occurrence of the virus and tracked Pintails after they departed outbreak locations. Eight of 66 (12.1%) Northern Pintails marked with satellite transmitters used wetlands in Japan where the H5N1 virus was detected in Whooper Swans. Apparent survival did not differ between Pintails that used H5N1 sites and those that did not. However, the proportion of Pintails that migrated from Japan was significantly lower among birds that used H5N1 sites compared with those that did not (0.50 vs. 0.79). Northern Pintails were present at the H5N1 sites from 1 to 88 days, with five birds present at the sites from 0 to 7 days prior to detection of the virus in Swans. The six Pintails observed to depart H5N1 sites did so within 2–77 days of the reported outbreaks and moved between 6 and 1200 km within 4 days of departure. Four Pintails migrated to eastern Russia. After their departure from outbreak sites, Northern Pintails made long‐distance migrations within the period when newly infected ducks would shed the H5N1 virus. This supports a hypothesized mechanism by which a highly pathogenic avian influenza virus could be spread by migratory birds.