Molecular Prevalence of Acarapis Mite Infestations in Honey Bees in Korea

Acarapis mites, including Acarapis woodi, Acarapis externus, and Acarapis dorsalis, are parasites of bees which can cause severe damage to the bee industry by destroying colonies and decreasing honey production. All 3 species are prevalent throughout many countries including UK, USA, Iran, Turkey, China, and Japan. Based on previous reports of Acarapis mites occurring in northeast Asia, including China and Japan, we investigated a survey of Acarapis mite infestations in honey bees in Korean apiaries. A total of 99 colonies of Apis mellifera were sampled from 5 provinces. The head and thorax of 20 bees from each colony were removed for DNA extraction. PCR assays were performed with 3 primer sets, including T, A, and K primers. Results indicated that 42.4% (42/99) of samples were Acarapis-positive by PCR assay which were sequenced to identify species. Each sequence showed 92.6-99.3% homology with reference sequences. Based on the homology, the number of colonies infected with A. dorsalis was 32 which showed the highest infection rate among the 3 species, while the number of colonies infected with A. externus and A. woodi was 9 and 1, respectively. However, none of the Acarapis mites were morphologically detected. This result could be explained that all apiaries in the survey used acaricides against bee mites such as Varroa destructor and Tropilaelaps clareae which also affect against Acarapis mites. Based on this study, it is highly probable that Acarapis mites as well as Varroa and Tropilaelaps could be prevalent in Korean apiaries.     

Acarapis mites of honey-bee,Apis mellifera in Iran

An extensive survey of colonies of the honey-bee, Apis mellifera, was conducted from December 1991 to February 1993 for the presence of both internal and external Acarapis mites in 21 provinces of Iran. Ten apiaries from each province and 5 hives/apiary were randomly selected for examination. A. woodi (R.) was found in 19 of the 139 apiaries sampled. The infested colonies were found in 7 of 21 provinces surveyed. Two external mites, A. dorsalis M. and A. externus M. were also found in honey-bee colonies in 8 provinces.     

Infestation of Japanese Native Honey Bees by Tracheal Mite and Virus from Non-native European Honey Bees in Japan

Invasion of alien species has been shown to cause detrimental effects on habitats of native species. Insect pollinators represent such examples; the introduction of commercial bumble bee species for crop pollination has resulted in competition for an ecological niche with native species, genetic disturbance caused by mating with native species, and pathogen spillover to native species. The European honey bee, Apis mellifera, was first introduced into Japan for apiculture in 1877, and queen bees have been imported from several countries for many years. However, its effects on Japanese native honey bee, Apis cerana japonica, have never been addressed. We thus conducted the survey of honey bee viruses and Acarapis mites using both A. mellifera and A. c. japonica colonies to examine their infestation in native and non-native honey bee species in Japan. Honey bee viruses, Deformed wing virus (DWV), Black queen cell virus (BQCV), Israeli acute paralysis virus (IAPV), and Sacbrood virus (SBV), were found in both A. mellifera and A. c. japonica colonies; however, the infection frequency of viruses in A. c. japonica was lower than that in A. mellifera colonies. Based on the phylogenies of DWV, BQCV, and SBV isolates from A. mellifera and A. c. japonica, DWV and BQCV may infect both honey bee species; meanwhile, SBV has a clear species barrier. For the first time in Japan, tracheal mite (Acarapis woodi) was specifically found in the dead honey bees from collapsing A. c. japonica colonies. This paper thus provides further evidence that tracheal-mite-infested honey bee colonies can die during cool winters with no other disease present. These results demonstrate the infestation of native honey bees by parasite and pathogens of non-native honey bees that are traded globally.     

A comparative study of the physiological condition of native and invasive crayfish in Croatian rivers

The physiological condition of two invasive crayfish species identified in Croatian rivers (Orconectes limosus and Pacifastacus leniusculus) was compared with that of native crayfish populations (Astacus astacus and A. leptodactylus). Hepatosomatic, gonadosomatic and abdominal muscle indices were examined for all four species and within a specific invadernative pair. The results demonstrate that invasive crayfish had better overall physiological condition when compared to native species, with a higher energy content of the hepatopancreas, abdominal muscle and gonads in invasive than in native species, with the exception of A. leptodactylus females which demonstrated an increased ability to allocate energy to reproduction in comparison with other species. These results also indicate that A. astacus is physiologically more unstable than A. leptodactylus and thus more likely to be outcompeted and replaced by non-indigenous crayfish species.     

猕猴桃属十个种的染色体倍性鉴定

猕猴桃属(Actinidia)植物全世界有66种,约有118个种下分类单位(也有新的划分方法将其划分为54种21变种),其中大部分为中国特有。在猕猴桃杂交育种中,不同倍性之间选配不当会出现杂交失败、后代不育等现象,因此倍性鉴定是猕猴桃常规育种亲本选择的前提条件之一。但到目前为止,不少猕猴桃种或亚种的染色体倍性研究并不十分清楚,因而限制了这些资源的进一步开发利用。该研究针对广西植物研究所猕猴桃种质资源圃收集的目前倍性尚不明确的白萼、白花柱果、二色花、临桂、卵圆叶、桃花、宛田、长果、融水和五瓣猕猴桃等10个种类的猕猴桃,使用酸解法制备染色体标本,通过显微镜观察确定其倍性。这10个种类大多为广西特有,其中蕴藏着独特的优良园艺性状,具有很高的生产和开发价值。该研究结果表明这10个种类猕猴桃的染色体倍性均为二倍体(2n=2x=58)。该研究结果进一步丰富了猕猴桃种质资源多样性数据库,为这些猕猴桃资源的合理开发利用奠定了基础。     

Rhizosphere and rhizoplane fungi of Triticum vulgare cultivated in Saudi Arabia

131 species in addition to 7 varieties which belong to 40 genera were collected from the rhizosphere (36 genera and 120 species + 7 varieties) and rhizoplane (27 genera and 56 species + 2 varieties) of Triticum vulgare. More than 22 species and 3 varieties were not encountered previously from soils or other sources in Saudi Arabia.In the rhizosphere, Aspergillus and Penicillium contributed the broadest spectrum of species (26 species + 5 varieties; and 24 species, respectively). The most frequent fungi were Aspergillus niger, A. clavatus, A. flavus, A. terreus, A. carneus, Penicillium citrinum, P. notatum, P. chrysogenum and Fusarium solani. In the rhizoplane which is a more selective substratum for fungi than the rhizosphere, the picture of dominance became different and the most common fungi were Fusarium solani, F. oxysporum, F. moniliforme, Drechslera spicifera, Cephalosporium roseo-griseum, Stemphylium botryosum, Acremonium strictum and Rhizoctonia solani.     

Relation of water transport to leaf gas exchange properties in three mangrove species

Mangrove species more tolerant to salinity may function with less efficient water transport, which may be related to more conservative water use. To test the hypothesis, we investigate the gas exchange and hydraulic properties of three mangrove species: Rhizophora mangle L., Laguncularia racemosa Gaert and Avicennia germinans (L.)L. Experiments were performed with adult plants growing naturally in the field under a salinity of 35‰. Gas exchange parameters showed that A. germinans had significantly higher photosynthetic rates, and lower stomatal conductance and transpiration rates, compared to the other two mangroves. In concert with this, instantaneous water use efficiency was significantly high in A. germinans, intermediate in L. racemosa and lowest in R. mangle. The hydraulic parameters of the three mangrove species were in the lowest end of the range reported for tropical trees. However, the three mangrove species exhibited measurable differences in hydraulic parameters related to the control of water requirements for maintenance of carbon gain. L. racemosa and A. germinans showed less efficient water transport at shoot level but were the more efficient species in water use at the leaf level in comparison to R. mangle. Received: 7 April 1999 / Accepted: 25 July 1999     

Two alien invasive acacias in Italy: Differences and similarities in their flowering and insect visitors

In Italy, alien acacias have been introduced for ornamental and reforestation purposes, and some species became invasive occupying patches of the Mediterranean landscape. On the Island of Elba (Central Italy), Acacia dealbata and A. pycnantha form dense stands at short distance, showing an impressive massive flowering at the end of the winter/early spring. Our aim was to investigate the behaviour of the two species in relation to the flowering features, from phenology to floral characteristics, and their replay to the observed flower visitors. Differences between the two species emerged on all the parameters considered. A. pycnantha peak of flowering occurred later than A. dealbata and showed larger flower heads (FHs), more flowers/head, stamens/flower and polyads. On A. dealbata, we recorded longer racemes and more FHs/raceme, determining a more flower-dense crown. Even if contacts with flower visitors were generally low on both species, A. dealbata showed a more heterogeneous visitor assemblage. Both acacias species interacted with local generalist pollinators, as bumblebees and honey bees. Flower handling and resource collection strategy by the honey bee indicate a long-term relationship between the bee and the acacias, with bees investing longer time on the larger A. pycnantha flower heads.     

Invasive <Emphasis Type="Italic">Alternanthera philoxeroides</Emphasis> (alligator weed) associated with increased fungivore dominance in Coleoptera on decomposing leaf litter

Invasive Alternanthera philoxeroides (alligator weed), when controlled by biocontrol agent Agasicles hygrophila, is known to differ from native vegetation in its decomposition dynamics. This study investigated whether this difference would have indirect effects for fungal-feeding Coleoptera. The study tested the hypothesis that fungivores would be more abundant and species rich on A. philoxeroides than on native vegetation. The study also tested the hypothesis that fungivores would be more affected than other functional groups. The study was conducted in a northern New Zealand lake. Litterbags were placed beneath A. philoxeroides and two native sedge species (Schoenoplectus tabernaemontani and Isolepis prolifer). Coleoptera communities were examined from the litterbags. Fungivorous Coleoptera were more abundant and species rich beneath A. philoxeroides than beneath either sedge species. No other functional groups differed between cover types. Fungivorous Coleoptera also comprised a greater proportion of total Coleoptera catch from litterbags beneath A. philoxeroides cover than from beneath native sedge cover. Four of the six fungivorous Coleoptera species collected in the study were present beneath A. philoxeroides cover. Of these, the two most abundant species (on native, one exotic) were both from the family Corylophidae. Alternanthera philoxeroides invasion is thus associated with altered Coleoptera communities in this ecosystem.     

Cellulose-decomposing fungi of barley grains in Egypt

100 species and 2 varieties of A. nidulans which belong to 35 genera were identified from 40 samples of barley collected from different places in Upper Egypt. Two methods of isolation were used: the grain-and the dilution plate. The spectrum of fungal genera and species collected by the former (35 genera, 96 species+1 variety) was broader than by the latter method (28 genera, 76 species+1 variety). Nine genera were of high occurrence (represented in more than 50% of the samples) namely, Aspergillus, Penicillium, Fusarium, Alternaria, Chaetomium, Cladosporium, Humicola, Drechslera and Myrothecium. The most frequent species were A. fumigatus, A. niger, A. flavus, A. sydowii, F. oxysporum, F. moniliforme, A. alternata, M. verrucaria, P. funiculosum, P. corylophilum, P. duclauxi, C. herbarum, C. globosum, D. spicifera and H. grisea. Several fungi such as Chaetomium, Humicola, Altemaria, Drechslera, Stachybotrys, Myrothecium, Pénicillium corylophilum and P. funiculosum were far more frequently recovered on cellulose than on glucose agar.     

新疆地图衣属地衣分类学研究

该研究以新疆的地图衣科(Rhizocarpaceae)地图衣属(Rhizocarpon)100余份地衣标本为材料,通过形态解剖学观察、化学成分分析及分子学鉴定的方法了解新疆地图衣属地衣的物种多样性。结果表明:(1)鉴定出7种地图衣属地衣,包括1个中国新记录种,命名为淡黄色地图衣(R.atroflavescens),6个常见种分别是黑红地图衣(R.badioatrum)、灰地图衣(R.disporum)、双孢地图衣(R.geminatum)、地图衣(R.geographicum)、巨地图衣(R.grande)和岩表地图衣(R.superficiale)。(2)编制了新疆22种地图衣属地衣的分种检索表。(3)系统发育分析结果表明,新疆地图衣属地衣的分子鉴定与形态解剖特征结果一致,更准确地证明淡黄色地图衣为中国新记录种。(4)对已报道的新疆22种地图衣属地衣的地区分布及海拔分布统计显示,新疆22种地图衣属地衣在世界各地均有分布,其中亚洲分布最丰富;该22种地图衣属地衣从低海拔到高海拔都有分布,且各海拔高度物种分布不均匀,总体在高海拔地区分布的物种较多。     

An analysis of inter‐ and intraspecific aggregations in two sympatric species of hermit crab (Decapoda,Anomura, Paguridae)

A series of experiments was conducted on the relationship between population density and spacing out in two sympatric species of crab, Pagurus bernhardus (L.) and Pagurus prideauxi Leach. A second series of experiments investigated the two species’ aggressiveness and activity by observing the behaviour of pairs of animals.

In the first series of experiments, animals became more aggregated (Clarke and Evans’ R) as the population density (p) was increased. The rate of aggregation (dR/dp) was greater when the species were mixed than when they were separate.

In the second series of experiments, activity, total encounters, and resolved encounters, were highest in paired P. bernhardus, lower in mixed pairs of the two species, and lowest in pairs of P. prideauxi. Larger individuals were more active than smaller ones in P. bernhardus and P. prideauxi pairs. In the mixed pairs, P. bernhardus were more active. Paired P. bernhardus were slightly more active than isolated P. bernhardus but this difference was not statistically significant. The activities of paired and isolated P. prideauxi were not significantly different. The distances between individuals in pairs were similar for all combinations.

The results are discussed in relation to the distribution of sympatric species.     

Occurrence and colonization of nematophagous fungi in different substrates,agricultural soils and root galls

Seventeen species of nematophagous fungi were recorded, three species were endoparasitic and fourteen species were predacious fungi. Among the predacious fungi Arthrobotrys oligospora, Dactylaria brochopaga and Monacrosporium eudermatum were very frequent, whereas others were recorded at lower frequency. Twelve species of nematophagous fungi from compost as well as cow dung manure, 15 species from leaf litter and only eight species from agricultural soils were recorded. In general, substrate colonization by nematophagous fungi was higher in leaf litter, compost and cow dung manure. The agricultural soil amended with FYM (farm yard manure) recorded nine species of nematophagous fungi while unamended soil recorded only seven species. Thirteen species of nematophagous fungi were recorded from soils under banyan tree. Of all these fungi unidentified net-forming fungus, M. eudermatum, A. cladodes, D. brochopaga, S. hadra, A. oligospora and A. dactyloides had higher percentage of soil colonization. In soil collected under pipal tree only eight species were recorded, of which A. oligospora, A. cladode and an unidentified fungus were more predominant as their percentage colonized in soil samples was higher. Few studies have examined root galls as a substratum for colonization of nematophagous fungi. Of all the root gall samples, okra root galls recorded maximum colonization by predacious fungi. Maximum percentage of root gall colonization was recorded for M. eudermatum followed by A. oligospora and M. ellipsosporum. M. eudermatum was also most predominant colonizer of balsam, brinjal and rice root galls.     

Seasonal and interannual variation in waterbird abundance and species composition in the Melincué saline lake, Argentina

We conducted 14 bird surveys in the Melincué saline lake from 1992 to 2002 (7 in winter and 7 in summer), and we detected 223,643 individuals belonging to 71 species from 17 families. The more abundant species were Fulica leucoptera, Larus maculipennis, Phoenicopterus chilensis, Plegadis chihi, Anas platalea, Himantopus mexicanus, and Rollandia rolland. Bird abundance was similar in winter and summer, whereas species composition differed between seasons. We recorded 65 species in summer and 59 in winter. P. chilensis and A. sibilatrix were more abundant in winter, whereas Ajaia ajaja, Phalacrocorax olivaceus, Ardea ibis, Sterna nilotica, Egretta thula, Mycteria americana, Charadrius collaris, A. versicolor, Calidris fuscicollis, and Ciconia maguari were more abundant in summer. Bird abundance in each survey was positively associated with the lake level. In summer surveys, the highest variation in species composition through the years was associated with water level fluctuations. Shorebirds predominated in those years with lower level, whereas the species that fed mainly on plants or vertebrates predominated in years with higher levels. Those species that fed on invertebrates (not shorebirds) and those that fed on invertebrates and plants predominated in years with intermediate level. The omnivorous species predominated in years of lower level. There were differences among transects in the proportion of different trophic groups. Short-term studies that do not take into account the particular dynamic of these systems may lead to erroneous generalisations. Thus, the long-term information of this study may be useful for management and conservation of species and system.     

The role of flying aphid vectors in the transmission of cucumber mosaic virus and potato virus Y to peppers in Israel

More than 44 species of aphids were trapped by suction during the spring seasons of 1981, 1982 and 1983 over a pepper field at Bet Dagan, Israel. Nineteen species transmitted cucumber mosaic virus (CMV), while seven transmitted potato virus Y (PVY) at least once. Over 80% of the CMV and of the PVY infection among test plants (Capsicum annuum cv. Weindale) exposed to trapped aphids was caused by Aphis citricola and two or three other Aphis species, Myzus persicae and Macrosiphum euphorbiae. Landing rate was determined by comparing the proportion of each species found on green tiles or pepper plants with that found in suction traps. A. citricola was the most common but was found in a much lower proportion on plants than either in flight or on green tiles. Aphis spp. and M. persicae were more than 2–5 times more frequent (relative to other species) on green tiles than in flight. M. persicae and M. euphorbiae, which colonise peppers, were found on peppers at a proportion several times higher than either on green tiles or in the air. The relative importance of the different vector species was calculated by multiplying abundance by the proportion of transmitters and the landing rate. A. citricola and Aphis spp. were responsible for more than 50% of the total transmission of either CMV in 1981 and 1982 and of PVY in 1981. Peaks of CMV infection of bait plants coincided with peaks of transmitters of A. citricola and Aphis spp. caught in suction traps. The significance of these findings in primary infection of peppers with CMV and PVY is discussed.     

Host range in solitary versus gregarious parasitoids: a laboratory experiment

Behavioural interactions among relatives may have consequences for many other traits. We tested the hypothesis that solitary parasitoids (displaying siblicidal behaviour in their larvae) have narrower host ranges than gregarious parasitoids (with tolerant larvae). In laboratory experiments, we compared parasitization success in two sister species of braconid wasp [Aphaereta genevensis (Fischer), solitary, and Aphaereta pallipes (Say), gregarious (Hymenoptera: Braconidae: Alysiini)] on eight Drosophila species or strains. Host species or strain was the most important factor affecting parasitization success, and some of this variation was accountable to host physiological defences. Although two hosts were more suitable for the solitary species, and one more suitable for the gregarious species, these differences were small, and there was no consistent difference across all hosts. Wasp body size was positively correlated with parasitization success in both wasp species. This may be because body size increases oviposition success, or the motivation to oviposit. In A. pallipes parasitization success peaked after 3–4 days, but later in A. genevensis. This is likely due to low life expectancy and high egg loads increasing oviposition tendency in young A. pallipes, and egg limitation decreasing oviposition tendency in old A. pallipes. These data suggest that interactions among wasp larvae do not greatly affect the size of the fundamental niche examined here. However, they show the potential for life history traits, which differ between the species as a likely consequence of larval interactions, to affect the extent of the realized niche.     

Comparison of the attachment rates of males of the ticksAmblyomma hebraeum andA. variegatum to cattle,sheep and rabbits in the absence of aggregation-attachment pheromone

Losses in domestic ruminants caused by heartwater (Cowdria ruminantium infection) in Zimbabwe and Mozambique are greater when the vector isAmblyomma hebraeum than when the vector isA. variegatum. It has been suggested that the epidemiology of the disease may be influenced by the rates at which unfed adults of these two tick species attach to uninfested hosts (i.e. in the absence of the male-produced aggregation-attachment pheromone [AAP]). In this study we confined unfed males ofA. hebraeum andA. variegatum on uninfested cattle, sheep and rabbits and recorded their attachment rates. Males of both species attached more rapidly on cattle than on sheep or rabbits. Males ofA. hebraeum attached more rapidly than males ofA. variegatum on all three host species. The differences in the attachment rates between the two species were much greater on sheep and rabbits than on cattle. The findings suggest that in the absence of AAP, pioneer males of both tick species may attach to cattle, and pioneer males ofA. hebraeum may also attach to sheep. The differences in the attachment rates ofA. hebraeum andA. variegatum provide a possible explanation for observed differences in the epidemiology of heartwater associated with these two vector species.     

Male Parasitic Spawning in Two Species of Triplefin Blenny (Tripterigiidae): Contrasts in Demography, Behaviour and Gonadal Characteristics

Axoclinus nigricaudus and A. carminalis are blennioid fishes from the Gulf of California, Mexico. Males show alternative mating tactics; territorial individuals attract females while non-territorial individuals parasitically spawn with territorial males' females. Demography and gonadal characteristics were related to the degree of parasitic spawning (sperm competition) within and between species. Males of both species showed bimodal size distributions that largely reflected the two tactics. Territorial males spawned much more frequently than non-territorial males, but parasitic spawning was significant. Non-territorial males were more common and rates of parasitic spawning were much higher in A. nigricaudus indicating that it experienced higher sperm competition. In agreement with sperm competition theory, relative testis weight was greater in A. nigricaudus. In A. nigricaudus, the majority of parasitic matings were by non-territorial males, whereas in A. carminalis, both male-types parasitised frequently. Accordingly, only in A. nigricaudus did non-territorial males have relatively heavier testis than territorial males. In both species the testicular gland, that produces accessory products for sperm transfer, was large in territorial males, but small or undeveloped in non-territorial males suggesting male-types differ in fertilisation mode.     

黄土丘陵区辽东栎群落优势种和主要伴生种树干液流动态特征

运用Granier热扩散探针法(TDP),于2011年5月对黄土丘陵区延安市南郊公路山辽东栎群落优势种(辽东栎)和3个伴生种(山杏、细裂槭、桃叶卫矛)树干液流进行连续测定,并同步监测气象环境因子(太阳辐射、空气温度和相对湿度)和土壤水分动态,比较分析辽东栎、山杏、细裂槭、桃叶卫矛的树干液流通量密度日变化动态及其对环境因子的响应特征。结果表明,辽东栎、山杏、细裂槭和桃叶卫矛液流通量密度日变化动态特征总体上反映了气象环境因子变化的昼夜规律性,呈单峰或双峰型曲线,但辽东栎与山杏、细裂槭、桃叶卫矛液流通量密度日变化规律存在一定的差异。辽东栎液流启动时间较早,通常在5:00左右,而山杏、细裂槭和桃叶卫矛液流启动时间均晚于辽东栎一个小时以上。辽东栎液流达到峰值的时间也较其它树种早,通常出现在9:00前后;细裂槭、桃叶卫矛和山杏液流通量密度达到峰值的时间分别在10:00、11:00和13:00前后。细裂槭和桃叶卫矛液流通量密度日变化曲线峰值较窄。除此之外,土壤水分状况对伴生种的影响程度要比优势种的大。相关分析表明,树干液流通量密度与太阳辐射和空气水汽压亏缺均呈极显著正相关。优势种与伴生种的液流动态差异可能与树木本身特性以及群落对光能的限制性再分配有关。