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61.
Nine (CT)n microsatellites were developed for tree of heaven, Ailanthus altissima, from invasive populations on the Mediterranean islands. These loci had seven to 12 alleles in 96 trees from five islands. Two loci had significant deficits of heterozygotes within islands while the other loci were in Hardy–Weinberg equilibrium, and four pairs of loci had significant linkage disequilibrium within a single island. These loci were also polymorphic in one to three individuals of the tree of heaven varieties, Ailanthus altissima erythrocarpa, Ailanthus altissima sutchuenensis and Ailanthus altissima tanakai, and the related species Ailanthus giraldii and Ailanthus vilmariniana. 相似文献
62.
A Suite of Adaptations for Intertidal Spawning 总被引:1,自引:0,他引:1
Salt marshes and similar tide-dominated habitats present anunusual challenge for reproduction of resident aquatic organisms.Strong currents, siltation and hypoxia can potentially contributeto reproductive failure through mortality of the eggs or flushingof the eggs and larvae from the habitat. Fundulus heteroclitus,a small brackish water killifish, is a common resident of tidalmarshes along the east coast of North America from Newfoundlandto Florida. The reproductive strategy of this and related speciesis based on aerial incubation of eggs in the high intertidalzone. The eggs are resistant to desiccation and, when fullydeveloped, hatch on immersion. Copulatory behavior and anatomyof accessory reproductive structures are adapted to placementof eggs in protected incubation sites. The gonads of both malesand females mature rhythmically with an endogenous circasemilunarperiod, which is synchronized with the "spring" tides of newand full moons. Spawning occurs on high tides. Embryos developin 915 days, and usually hatch on the succeeding springtide series. Reproductive cyclicity in F. heteroclitus and relatedfishes ensures that spawning fish will have access to the highintertidal zone, thereby permitting aerial incubation of eggs. 相似文献
63.
MALCOLM LUXTON 《Zoological Journal of the Linnean Society》1989,95(1):71-95
Keys are provided to families of Hyadesioidea, to genera of Hyadesiidae, and to all species of this family known from the New Zealand subregion. A new species of Amhyadesia , two new species of Hyadesia sensu stricto , and four new species of a newly defined subgenus of Hyadesia (Parahyadesia) are described. 相似文献
64.
MALCOLM J. SCOBLE F.L.S. 《Zoological Journal of the Linnean Society》1994,111(2):99-160
Phrygionis and Pityeja belong to the Palyadini, a tribe of neotropical Ennominae. The moths of both genera bear striking wing markings and mere variants were frequently described as species with the consequence that species diversity was overestimated. Numerous taxonomic changes are made in this work based on the study of primary types and much other material. Variation and distribution is recorded for each species and subspecies. Phylogenetic relationships within Phrygionis are examined, and comments are made on the evolution of wing pattern within this genus.
Fifteen full species are recognized in this study (13 in Phrygionis and two in Pityeja ), of which four (all in Phrygionis ) are described as new; 19 species-group (specific and subspecific) names refer to valid taxa. Twenty-four species-group names are synonymized (19 in Phrygionis and five in Pityeja ) and five are recombined with different genera (four with Phrygionis and one with Pityeja ). Three generic names are synonymized (one in Phrygionis and two in Pityeja ). 相似文献
Fifteen full species are recognized in this study (13 in Phrygionis and two in Pityeja ), of which four (all in Phrygionis ) are described as new; 19 species-group (specific and subspecific) names refer to valid taxa. Twenty-four species-group names are synonymized (19 in Phrygionis and five in Pityeja ) and five are recombined with different genera (four with Phrygionis and one with Pityeja ). Three generic names are synonymized (one in Phrygionis and two in Pityeja ). 相似文献
65.
Reduced susceptibility to permethrin and its relationship to DDT resistance in larvae of Anopheles stephensi 总被引:1,自引:0,他引:1
C. A. MALCOLM 《Medical and veterinary entomology》1988,2(1):37-46
Permethrin selection of DDT resistant Anopheles stephensi Liston mosquito larvae produced a reduction in susceptibility to knockdown (2 h exposure) of 17-fold, but only 1.6-fold to kill (24 h exposure). Genetic analysis, incorporating visible mutant markers, was interpreted as indicating that, through multigenic inheritance, several interacting genetic factors were collectively responsible for reduced larval susceptibility to knockdown. These were maintained together only under selection pressure, as the effect was lost quickly in the absence of selection or with outcrossing. The 30-40-fold DDT-resistance found in the parental strain was barely altered by permethrin selection, suggesting no relationship with the major source of DDT resistance. This was confirmed in single family studies. Some evidence for an additional tolerance to DDT was found to be associated with reduced larval susceptibility to permethrin. 相似文献
66.
67.
ROBERT GODFREE BRUCE ROBERTSON MALCOLM CARNEGIE ANDREW YOUNG 《Global Change Biology》2011,17(1):439-451
The use of solar passive hexagonal open‐top chambers (POTCs) is a viable method for experimentally manipulating daytime air temperatures in low‐stature plant communities at high latitudes. Here we describe a new hexagon POTC‐based system that uses thermal inertia to increase overnight temperatures and variable chamber height to reduce overheating in summer. Field data collected in tall temperate grasslands show that the presence of thermal mass raised minimum and mean nighttime air temperatures by up to 1.5 °C while lowering chamber height, along with thermal mass, limited the development of extreme daytime chamber temperatures in summer. We also demonstrate that, by using a simple, inexpensive twin carbon dioxide (CO2) injection system regulated by an infrared gas monitor, it is possible to generate targeted and stable atmospheric CO2 enrichment within these chambers. These innovations significantly improve the conventional hexagon POTC design and represent a low‐cost method for assessing the effects of warming and CO2 enrichment on low‐stature vegetation in low latitude environments. 相似文献
68.
MALCOLM EDMUNDS 《Zoological Journal of the Linnean Society》1976,58(2):129-145
An ecological study was made of a population of caterpillars of the African queen butterfly (Danaus chrysippus) feeding on three species of asclepiad plants at Nungua, Ghana, over a nine month period in 1972-73. The principal sources of mortality of caterpillars are probably the parasitic hymenopterans Apanteles chrysippi and Charops sp. There is an inverse correlation between the population of caterpillars and incidence of parasitization. This, and other evidence, suggests that the two parasites are important in limiting the population of Danaus chrysippus below the level imposed by the available food supply. Early instar caterpillars are probably palatable to birds but later instars may be edible or emetic depending on the toxicity of their food plant. It is suggested that the early instar caterpillars are cryptic whilst late instars are cryptic from a distance but conspicuous from nearby, and these may be aposematic or mimetic according to the nature of the food plant. Caterpillars parasitized by Apanteles are paler and hence more cryptic than normal caterpillars. There is also a green, cryptic morph present in the population at low frequency. It is suggested that there is a correlation between colour of caterpillars and the principal source of mortality: i.e., cryptic caterpillars are palatable to birds, suffer heavy predation but a low incidence of parasitization, whilst conspicuous caterpillars are unpalatable to many birds, suffer little predation but have a high incidence of parasitization. 相似文献
69.
70.
GLENNA M. MALCOLM JUAN C. LÓPEZ-GUTIÉRREZ‡ ROGER T. KOIDE † DAVID M. EISSENSTAT † 《Global Change Biology》2008,14(5):1169-1180
Ectomycorrhizal (ECM) fungi contribute significantly to ecosystem respiration, but little research has addressed the effect of temperature on ECM fungal respiration. Some plants have the ability to acclimate to temperature such that long‐term exposure to warmer conditions slows respiration at a given measurement temperature and long‐term exposure to cooler conditions increases respiration at a given measurement temperature. We examined acclimation to temperature and temperature sensitivity (Q10) of respiration by ECM fungi by incubating them for a week at one of three temperatures and measuring respiration over a range of temperatures. Among the 12 ECM fungal isolates that were tested, Suillus intermedius, Cenococcum geophilum, and Lactarius cf. pubescens exhibited significant acclimation to temperature, exhibiting an average reduction in respiration of 20–45% when incubated at 23 °C compared with when incubated at 11 or 17 °C. The isolates differed significantly in their Q10 values, which ranged from 1.67 to 2.56. We also found that half of the isolates significantly increased Q10 with an increase in incubator temperature by an average of 15%. We conclude that substantial variation exists among ECM fungal isolates in their ability to acclimate to temperature and in their sensitivity to temperature. As soil temperatures increase, ECM fungi that acclimate may require less carbon from their host plants than fungi that do not acclimate. The ability of some ECM fungi to acclimate may partially ameliorate the anticipated positive feedback between soil respiration and temperature. 相似文献