Rapid shifting of foraging pattern by Yakushima macaques ( Macaca fuscata yakui ) in response to heavy fruiting of Myrica rubra

We describe short-term changes in foraging behavior by wild Yakushima macaques (Macaca fuscata yakui),which inhabit a warm-temperate broad—leaved forest on Yakushima Island (30°N, 131°E), Japan. Rapid changes of dietary composition, activity budget, and range use by the monkeys occurred from May to June, apparently associated with changes in the availability of the fruit of Myrica rubraBefore the fruit ripened, monkeys spent less time moving and more time feeding on many species of leaves, which accounted for 40% of feeding time. However, when M. rubrabegan to ripen, they fed intensively on the fruit, which accounted for three-fourths of feeding time,though the activity budget remained unaffected As fiuit of M. rubradecreased,the monkeys fed more on the fruit of other species and on insects, and spent more time moving at higher speeds. There marked shifts in foraging pattern occurred within only two months. In terms of moving cost and dietary quality,Yakushima macaques shifted their foraging pattern according to the availability of M. rubrafrom a “low-cost, low-yield” strategy to a “low-cost, high-yield” strategy, and then to a more costly strategy. The ability to make such rapid shifts in foraging pattern may allow the macaques to effectively use the highly variable food supply within their small range.     

Evidence for the involvement of ethylene in the expression of specific RNAs during maturation of the orange,a non-climacteric fruit

Twelve cDNAs corresponding to mRNAs inducible by ethylene were isolated by differential screening of a cDNA library from ethylene-treated Citrus sinensis fruits. Northern analysis of RNA extracted from flavedo of ethylene-treated fruits and from fruits at different maturation stages showed that some of the mRNAs corresponding to these cDNAs were regulated both by ethylene treatment and during fruit maturation. The effect of exogenous ethylene on leaves and of endogenous ethylene on flowers showed that gene induction was not restricted to the flavedo tissue. The possible role of ethylene during maturation of the non-climacteric Citrus fruit is discussed.     

Factors affecting in vitro shoot proliferation and ex vitro establishment of mangosteen

Shoot proliferation has been achieved in Garcinia mangostana L. using seed explants. Maximum mean number of shoots per explant (16.8) was obtained from cultures on Murashige and Skoog medium supplemented with 40 mM 6- benzyladenine, and 2.5 mM -naphthaleneacetic acid and kept at 30 °C under an 8 hour photoperiod. Cultures on the same medium but supplemented with 2 g l^-1 activated charcoal produced fewer shoots. However, growth of these shoots was more organized and 75% rooting was obtained. Woody Plant Medium was not a suitable medium for shoot proliferation. Ex vitro establishment was best obtained on planting medium consisting of sand, soil and organic material (3:2:1).Abbreviations BA 6-benzyladenine - IBA indole-3-butyric acid - NAA -naphthaleneacetic acid - MS Murashige & Skoog (1962) basal medium - WPM Woody Plant basal medium (Lloyd & Mc Cown 1980)     

A GENETIC PERSPECTIVE OF MAMMALIAN VARIATION AND EVOLUTION IN THE INDONESIAN ARCHIPELAGO: BIOGEOGRAPHIC CORRELATES IN THE FRUIT BAT GENUS CYNOPTERUS

This study investigated allozyme and morphometric variability within the genus Cynopterus, with particular emphasis on C. nusatenggara, which is endemic to Wallacea, the area encompassing the Oriental-Australian biogeographic interface. The genetic distances between Cynopterus species are small by mammalian standards and suggest that this genus has undergone a recent series of speciation events. The genetic distance between populations of C. nusatenggara is strongly correlated with both the contemporary sea-crossing distance between islands and the estimated sea crossing at the time of the last Pleistocene glacial maximum, 18,000 b .p . This observation, together with low levels of population substructure within islands as shown by F-statistics, indicates that the sea is a primary and formidable barrier to gene exchange. The genetic distance and the great-circle geographical distance between the populations of C. nusatenggara are not correlated, although a principal-coordinates analysis of genetic distance reveals relationships between the populations that are similar to their geographical arrangement. A strong negative correlation exists between the level of heterozygosity within island populations of C. nusatenggara and the minimum sea-crossing distance to the nearest large source population. This is interpreted as reflecting an isolation effect of the sea, leading to reduced heterozygosity in populations that have larger sea barriers between them and the large source islands. Independently of this, heterozygosity is negatively associated with longitude, which in turn is associated with systematic changes in the environment such as a gradual decline in rainfall from west to east. The association between heterozygosity and longitude is interpreted as reflecting an association between genetic and environmental variance and supports the niche-width theory of genetic variance. Morphometric variability did not show any of the main effects demonstrated in the genetic data. Furthermore, there was no evidence that, at the level of individuals, genetic and morphometric variability were associated.     

银杏速生早实示范栽培试验

本研究是在我区银杏主产区兴安进行的８０多亩,３０００多株的示范栽培试验。其综合技术措施是选用良种嫁接苗、适当密植、配置雄株、整形修剪、合理施肥、防治病虫害及促花早实等。种后５—６年取得速生、早实、高产的良好效果。     

火棘属果实发育解剖学研究

火棘属植物的托附杯呈深杯状,具有５个分离心皮,子房半不位。托附杯发育成肉质果壁,主要藉细胞体积增大,子房壁全部石细胞化,发育成骨质瘦果状小果的果皮。火棘属的果实不是典型和梨果,是蔷薇科果实在演化过程中的一个过渡类型。火棘属肉质果壁的厚角组织经过角隅减薄后再转变成厚壁组织。     

Medfly eradication in California:

The impact of malathion-bait sprays (directed against medfly, Ceratitis capitata [Wiedemann]) on an endemic gall midge (Rhopalomyia californica Felt) and its parasitoids was investigated during 1982–83 in the south San Francisco Bay area of northern California. In a heavily sprayed area (Woodside), a population explosion of the midge was detected following 24 applications of malathion bait. The midge population reached levels ca. 90x greater than those observed in an adjacent unsprayed area (Jasper Ridge). In a moderately sprayed area (Portola Valley), the midge population increased as much as 5x that observed in the adjacent unsprayed area (Jasper Ridge), following 12 applications of malathion bait. In laboratory tests, the malathion bait was toxic to both the midge and its parasitoids. The major parasitoids were Torymus koebelei (Huber), Zatropis capitis Burks, Platygaster californica (Ashmead) and Mesopolobus sp. Population increases of the midge following malathion-bait sprays were attributed to destruction of parasitoids and other natural enemies of the midge. If the environmental impact of malathion-bait sprays is related to the number of applications (as suggested in this study), then it would be worthwhile to determine the appropriate bait-spray strategy for a given situation, so as to minimize adverse effects on nontarget species, yet insure suppression or eradication of medfly.

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Résumé L'impact des pièges tratiés au malathion (destinés à Ceratitis capitata Wiedem) sur Rhopalomyia californica Felt et ses parasitoïdes a été examiné en 1982–1983 dans le sud de la zone de la baie de San Francisco en Californie. Dans une zone fortement traitée (Woodside), une explosion de population a été décelée après 24 traitements. La population de R. californica a atteint des niveaux 90 fois supérieurs à ceux observés dans une zone contiguë non traitée (Jasper Ridge). Dans une zone modérément traitée (Portola Valley), avec 12 traitement, la population de R. californica a atteint jusqu'a 5 fois celle de Jasper Ridge. Au laboratoire, le piège à malathion a été toxique tant pour R. californica que pour ses parasitoïdes, dont les principaux étaient: Torymus koebelei (Huber), Zatropis capitis Burks, Platygaster californica(Ashmead) et Mesopolobus sp. L'accroissement de la population de C. capitata après traitement a été attribué à la destruction de parasitoïdes et d'autres ennemis naturels. Si l'effet su l'environnement du traitement est lié au nombre d'interventions (comme le suggère cette étude), alors cela vaudrait la peine de définir une stratégie de traitement appropriée à une situation donnée, de façon à minimiser les effets négatifs sur des espèces non visées, tout en assurant la suppression ou l'éradication de C. capitata.

     

Oviposition deterring pheromone influences dispersal distance in tephritid fruit flies

We tested the hypothesis that Rhagoletis pomonella females exhibit a greater propensity for engaging in long distance (i.e.1000 m) flight following encounters with egg-infested oviposition-deterring-pheromone (ODP) marked host fruit than similar females that encounter uninfested, clean (i.e. no ODP) fruit. Female flies which were first tethered to flight mills were presented with and permitted to explore (a) ODP-marked or (b) clean fruit and then stimulated to fly. Results showed that females that had encountered a high rate of infested, ODP-marked fruit displayed long distance flight more frequently and flew greater average distances than females that had searched uninfested fruit. We discuss there results in light of contemporary foraging theory.

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Résumé La réponse d'insectes à leurs phéromones de dissuasion (ODP) est examinée généralement à un seul niveau de prospection, c'est-à-dire celui de la ressource individuelle elle-même. Ces marqueurs chimiques peuvent, cependant, fournir aussi des informations au prospecteur sur la disponibilité en ressources, tant au niveau de l'inflorescence qu'au niveau de l'habitat. Une telle information influence vraisemblablement le comportement de prospection à différents niveaux.Dans cette note, nous vérifions l'hypothèse que la rencontre avec des hôtes marqués par ODP influence la tendance de Rhagoletis pomonella (Dipt: Tephrit) à entreprendre des vols importants (c'est-à-dire interhabitats). Nous avons montré dans des expériences de laboratoire que les femelles lors de trois rencontres consécutives avec des fruits marqués par ODP: 1) entreprenaient plus fréquemment (19 cas sur 81 contre 6 sur 81) un vol à longue distance (c'est-à-dire 1000 m) et 2) parcourient des distances moyennes supérieures à celles couvertes par des femelles ayant eu la possibilité de prospecter successivement trois fruits propres (sans ODP).Nous engageons le lecteur à examiner nos résultats d'un point de vue qualitatif. Nous ne pouvons nous attendre à ce qu'un vol à longue distance se produise aussi facilement dans la nature qu'au laboratoire, étant donné le plus grand nombre de variables (par exemple, la taille de l'arbre) qui peuvent y modifier le vol réel.Pour terminer, nous discutons les coûts et bénéfices potentiels qui peuvent résulter de ce comportement.

     

Water-relation parameters of giant and normal cells of Capsicum annuum pericarp

Abstract. Measurements of the water-relation parameters of the giant subepidermal cells (volume, V = 0.119 to 1.658 mm³; = 0.53±0.35 mm³, SD, n = 23) and the smaller mesocarp parenchyma cells ( V = 0.10 to 0.79×10⁻³ mm³; = 0.36±0.27×10⁻³ mm³, SD, n = 6) of the inner pericarp surface of Capsicum annuum L. were made using the Jülich pressure probe. The volumetric elastic modulus ɛ for the large cells was between 1.5 and 27 MPa for a pressure range of 0.09 to 0.41 MPa. For the small cells ɛ was 0.1 to 0.6 MPa for a pressure range of 0.22 to 0.39 MPa. The turgor pressure P , the half-time of water exchange T _1/2, and the hydraulic conductivity L _p were as follows, with SD and number of replicates: large cells, P = 0.27±0.06 MPa (23), T _1/2=2.7±2.2 s (46), L _p=5.8±3.7 pm s⁻¹ Pa⁻ (46); small cells, P = 0.33±0.07 MPa (6), T _1/2= 33±10s (12), L _p=0.21±0.07 pm s⁻¹ Pa⁻¹ (12). The determination of these basic water-relation parameters is considered as a prerequisite for future ecotoxicological and phytopathological studies. The differences between the large and the small cells are discussed in relation to a desirable biophysical definition of succulence. Further, for the large cells a pressure and volume dependence of ɛ was demonstrated.