首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 484 毫秒
1.
Dicyphus errans (Wolff) (Hemiptera: Miridae) is an omnivorous predator of several pests attacking tomato and other vegetable crops. The nymphal development of D. errans was studied in the presence of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs with or without a water source and in the presence of a leaf of cucumber, eggplant or tomato supplemented with variable food types (E. kuehniella eggs, Artemia sp. cysts, pollen or milk powder) or without the provision of any food. Water provision was found to be essential for the completion of nymphal development even when animal food was offered to predators. When nymphs foraged on leaves in the absence of any food type, development was significantly more favoured on eggplant and cucumber than on tomato. E. kuehniella eggs and Artemia sp. cysts enhanced development of D. errans in comparison to milk powder and pollen. Development and female weight were improved when the food types were offered to the nymphs on a plant leaf than when were provided together with only water. This study contributes to understanding the importance of water vs. plant feeding for the development of D. errans and reveals implications for its mass rearing and application in biological control.  相似文献   

2.
Many species of the butterfly genus Phengaris are regarded as endangered in many parts of their distribution. Several species are also widely distributed across northern China. Due to land use change and overgrazing, their habitats are declining and many patches have been lost. This paper investigates the distribution and habitats of the Chinese Phengaris species (of the subgenus Maculinea). Shrub-grassland near forests seem the most frequent habitat for Phengaris, while flat open grasslands are mostly over-grazed and thus survival for Phengaris butterflies there seems difficult. Throughout Europe, P. teleius is an endangered species, while there is still no information on its status in China. To improve the knowledge on the population ecology of P. teleius, its population structure, adult behaviour and movement were studied through mark–release–recapture methods in the Qinling Mountains of Taibai County. Eight grassland patches which were potentially suitable were found in the area in 2013. In total, 480 individuals (274 females) were marked, resulting in an overall recapture rate of 16 %. The average daily population size was 44 butterflies (±23 SD) during the adult flight period. Sixty-seven percent of the females and 38 % of the males moved less than 50 m, and 17 % of recaptured females and 38 % of males moved more than 200 m. The mean movement distance was 107 ± 177 m for males and 182 ± 122 m for females. The majority of the recaptures (86 %) were made within the patches, only a few individuals (14 %) moved between patches. Due to human disturbance and destruction, all of the eight potentially suitable patches are becoming smaller and increasingly isolated, thus these populations of P. teleius may face an increasing risk of extinction, which may well be a tip of the iceberg of habitat loss and fragmentation of P. teleius in Taibai County and possibly beyond. Hence we hope our initial study of P. teleius could have positive impacts on the conservation of Phengaris butterflies in China.  相似文献   

3.

Background

Phylogeographic analyses on the Western Euroasiatic Fagus taxa (F. orientalis, F. sylvatica, F. taurica and F. moesiaca) is available, however, the subdivision of Fagus spp. is unresolved and there is no consensus on the phylogeny and on the identification (both with morphological than molecular markers) of Fagus Eurasiatic taxa.For the first time molecular analyses of ancient pollen, dated at least 45,000 years ago, were used in combination with the phylogeny analysis on current species, to identify the Fagus spp. present during the Last Interglacial period in Italy.In this work we aim at testing if the trn L-trn F chloroplast DNA (cpDNA) region, that has been previously proved efficient in discriminating different Quercus taxa, can be employed in distinguishing the Fagus species and in identifying the ancient pollen.

Results

86 populations from 4 Western Euroasistic taxa were sampled, and sequenced for the trn L-trn F region to verify the efficiency of this cpDNA region in identifying the Fagus spp.. Furthermore, Fagus crenata (2 populations), Fagus grandifolia (2 populations), Fagus japonica, Fagus hayatae, Quercus species and Castanea species were analysed to better resolve the phylogenetic inference.Our results show that this cpDNA region harbour some informative sites that allow to infer relationships among the species within the Fagaceae family. In particular, few specific and fixed mutations were able to discriminate and identify all the different Fagus species.Considering a short fragment of 176 base pairs within the trn L intron, 2 transversions were found able in distinguishing the F. orientalis complex taxa (F. orientalis, F. taurica and F. moesiaca) from the remaining Fagus spp. (F. sylvatica, F. japonica, F. hayataea, F. crenata and F. grandifolia). This permits to analyse this fragment also in ancient samples, where DNA is usually highly degraded.The sequences data indicate that the DNA recovered from ancient pollen belongs to the F. orientalis complex since it displays the informative sites characteristic of this complex.

Conclusion

The ancient DNA sequences demonstrate for the first time that, in contrast to current knowledge based on palynological and macrofossil data, the F. orientalis complex was already present during the Tyrrhenian period in what is now the Venice lagoon (Italy).This is a new and important insight considering that nowadays West Europe is not the natural area of Fagus orientalis complex, and up to now nobody has hypothesized the presence during the Last Interglacial period of F. orientalis complex in Italy.
  相似文献   

4.
Patch-related behaviour of a generalist predator may be influenced by patch prey diversity and result in more time being spent in patches with more than one prey species to increase the benefits of mixed diet. To examine if generalist predators are able to discern differences in prey diversity in and among patches, we examined the patch-related behaviour of the predatory mite Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae). Three lab experiments using clean, single-prey or mixed-prey patches were conducted, using whiteflies and spider mites as prey. The experiments were: (1) patch leaving tendency and residence time in absence and (2) presence of another patch, (3) patch preference. A. swirskii recognized prey-inhabited patches from a distance and showed a preference for mixed-prey patches over single-prey patches. The patch-related behaviour of A. swirskii, which seems tuned to exploiting the fitness gains of a mixed diet, is influenced by both local and distant cues.  相似文献   

5.
The red palm mite, Raoiella indica (Acari: Tenuipalpidae), is an important pest of palms (Arecaceae) and other species within the Zingiberaceae, Musaceae and Strelitziaceae families. Raoiella indica was discovered in the USA (Palm Beach and Broward counties, Florida) late in 2007, and it subsequently spread to other Florida counties. The predatory mite Amblyseius largoensis (Acari: Phytoseiidae) has been found associated with R. indica in Florida. In order to verify whether A. largoensis can develop and reproduce when feeding exclusively on R. indica, the biology of this predator was evaluated on various food sources, including R. indica. Five diets [R. indica, Tetranychus gloveri¸ Aonidiella orientalis, Nipaecocus nipae, oak (Quercus virginiana) pollen] and a no-food control were tested to determine the predators’ development, survivorship, oviposition rate, sex ratio and longevity at 26.5 ± 1°C, 70 ± 5% RH and a 12:12 L:D photophase. Amblyseius largoensis was able to complete its life cycle and reproduce when fed exclusively on R. indica. The development of immature stages of A. largoensis was faster and fecundity and survivorship were higher when fed on R. indica or T. gloveri compared to the other food sources. The intrinsic rate of natural increase of A. largoensis was significantly higher when fed on R. indica than on other diets. These results suggest that, despite earlier assessments, A. largoensis can play a role in controlling R. indica.  相似文献   

6.
Three of the five European species of Branchinecta have a disjunct distribution. In this study, we analyze populations of B. ferox and B. orientalis for mitochondrial (cox1) and nuclear (ITS2) molecular markers. We compare intraspecific genetic divergences between geographically distant populations of B. orientalis, from its only known Spanish population (originally described as B. cervantesi) and from a Hungarian population (assigned to B. orientalis since its discovery), with data from two relatively close Iberian populations of B. ferox. Results indicate that isolation between B. ferox and B. orientalis clades is ancient, and that the clade including the two Iberian populations of B. ferox is geographically structured. Conversely, Iberian and Hungarian populations of B. orientalis do not show geographical structure for the mitochondrial fragment. Lack of geographic structure coupled with very low genetic distances indicates that current Iberian and Hungarian populations of B. orientalis originated from a common population stock, and that the time elapsed since their separation has not been long enough to render the clades reciprocally monophyletic. We hypothesize that colonization of the Iberian Peninsula by B. orientalis is probably the consequence of a single recent dispersal event, and consequently we confirm the synonymy between B. cervantesi and B. orientalis.  相似文献   

7.
We investigated the host suitability of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) for a polyphagous koinobiont endoparasitoid Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae), a common natural enemy of various pest lepidopteran larvae. The estimated probability of adult wasp emergence was 80% or higher when eggs were laid in nearly fully grown larvae of E. kuehniella (fresh weight, >?20.0 mg). The body size of emerged adult wasps increased with the initial weight of the host larvae at oviposition. The fresh weight of adult wasps reared on E. kuehniella was approximately 60% of that when reared on a natural host Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), and the lifetime fecundity of wasps reared on E. kuehniella was approximately half of that when reared on S. litura. Ephestia kuehniella was shown to be a positive host candidate for the mass rearing of M. pulchricornis, but further investigation is needed to increase the body size of wasps for more practical use of this species as a biocontrol agent.  相似文献   

8.
Artibeus jamaicensis is a medium-sized frugivorous microchiropteran bat that complements its diet with nectar and pollen during the dry season. We investigated which species of pollen are carried by A. jamaicensis in order to determine its potential role as a plant pollinator in the northern Yucatan Peninsula. We collected pollen from the fur of 192 individuals throughout the year from April 2004 to March 2005. We recorded pollen from nine plant species of eight families and found five unidentified pollen types, with the highest pollen species richness recorded in June. A. jamaicensis moved pollen of Erythrina standleyana and Mimosa bahamensis, which have not hitherto been reported as visited by this species. The most abundant pollen in the samples was found to be that of three tree species: Ceiba pentandra, C. aesculifolia and Lysiloma latisiliquum. Very few samples contained pollen in the rainy season, when the bats fed mainly on fruits. A. jamaicensis can fly several kilometres among foraging locations and dispersed large amounts of pollen from tree species growing near cenotes as well as those not present at cenotes but occurring in other forest fragments, highlighting its importance as a pollen vector among forest fragments in the largely deforested landscape of the Yucatan Peninsula, helping to reduce the negative effects of forest fragmentation. Ceiba appears to benefit from the role of A. jamaicensis as a pollen vector, and the species play an important ecological role in the Yucatán landscape, supplying shade, nectar and fruit for wildlife.  相似文献   

9.
10.
Understanding the environmental factors that affect the distribution and abundance of rare and threatened species can help identify priority sites for conservation action such as habitat management. The moth Cucullia lychnitis is identified in UK legislation as a priority species for conservation. Its conspicuous larvae feed on a patchily distributed host plant Verbascum nigrum, but are entirely absent from some host plant patches within the species’ range. Environmental variability among patches was investigated to understand factors affecting (i) patch occupancy by C. lychnitis and (ii) abundance of C. lychnitis, where present. Occupancy of individual V. nigrum plants within occupied patches was also investigated. The likelihood of patch occupancy increased with patch size, and decreased with patch isolation. Abundance of C. lychnitis was negatively correlated with patch isolation and with abundance of the weevil Cionus nigritarsis, which exploits the same host plant and may be a competitor. Within occupied patches, larvae of C. lychnitis were significantly more likely to be found on taller plants with more flower spikes; such plants are typical of established rather than newly-created patches. These results may help to guide efforts to conserve C. lychnitis, highlighting the importance of habitat connectivity and indicating potential management actions to promote features positively associated with larval incidence and abundance.  相似文献   

11.
Macrocystis integrifolia and Lessonia trabeculata form vast kelp beds providing a three-dimensional habitat for a diverse invertebrate and fish fauna off northern Chile. Habitat modifications caused by the El Niño Southern Oscillation (ENSO) are likely to alter the inhabiting communities. The aim of this study was to reveal relationships between distinct habitat structures of a M. integrifolia kelp bed, a dense L. trabeculata kelp bed and L. trabeculata patches colonizing a barren ground, and the associated dominant macrobenthic key species. Seasonally 15 sampling units (10 m2 each) of any of the three habitats were monitored by SCUBA divers, which counted sporophytes and macroinvertebrates living between the latter. Furthermore, samples of plants were analysed in the laboratory to measure the morphological variables: total plant length, maximal holdfast diameter, stipe number, number of dichotomies per stipe, frond width and total drained wet mass. Multivariate analysis showed that the L. trabeculata kelp bed is denser, with a higher number of dichotomies per stipe, whereas sporophytes of M. integrifolia are longer with more stipes and wider fronds. Sporophytes of L. trabeculata patchily present on barren ground are shorter and have more stipes compared with those in the dense L. trabeculata kelp bed. Thus, the habitats provide different three-dimensional structures. The associated macrobenthic communities show a variable degree of overlapping; however, key faunal assemblages were distinguished for each habitat. Our study provides evidence that habitat diversity drives species diversity, the more homogeneous, monospecifically composed kelp bed habitats show comparatively low diversity, mainly caused by the dominance of the ascidian P. chilensis and T. tridentata in the M. integrifolia bed, and the mussel A. ater only present in the L. trabeculata bed. Species richness and diversity is highest in the heterogeneous habitat where L. trabeculata patches interrupt the barren ground. Our study revealed morphological differences between M. integrifolia and L. trabeculata kelp beds reflected in stipe number, plant length, dichotomies per stipe, and wet mass, which influence the composition of the associated characteristic fauna and its functional relations i.e. T. niger and T. tridentata.  相似文献   

12.
13.
We analyzed the pollen content in the gut and on the body of hoverflies (Diptera: Syrphidae), mostly from three genera (Eristalis, Syrphus s. l., and Sphaerophoria) that visited flowers of two jointly flowering species of Apiaceae with indistinguishable pollen (Anthriscus sylvestris and Aegopodium podagraria) and of Bunias orientalis (Brassicaceae). Pollen compositions depended on the plant from which the flies were collected rather than on the insect genus. At the same time, individual preferences of the studied flies to food plant species were confirmed. The pollen compositions in the gut and on the body were weakly correlated. Two possible reasons for such a weak correlation are discussed: individual differences in the fly feeding habits and different time of pollen preservation in the gut and on the body.  相似文献   

14.
Having knowledge of the habitat requirements of top predators is important for their conservation and also for the stability of wildlife communities since they are keystone species of ecosystems. This study aims to predict suitable habitats for the Persian leopard (Panther pardus saxicolor, Pocock 1927) in Tandooreh National Park, Iran. This species is the largest leopard subspecies in the Middle East and is at high risk of extinction. Presence points for the species have been obtained from field data, literature review, atlas data, and IUCN records. Variables related to human disturbance, terrain, land use/land cover, and the leopards’ prey were used to predict the habitat selection of the Persian leopard by employing binary logistic regression. Our model predicted that the presence of Persian leopards is restricted to the southern, north-western, and western areas of the park which are under severe fragmentation threat. Moreover, leopards avoided areas near human development such as roads. We have also found that the availability of prey such as Capra aegagrus, Ovis vignei, and Ovis orientalis is one of the important parameters to predict habitat suitability for leopards. Our model provides a suitable tool for national park managers to identify biodiversity hotspots since leopards are often associated with high biodiversity.  相似文献   

15.
Scorpions are dominant predators in some environments. Nevertheless, most studies of predatory behavior in scorpions have focused on diet composition whereas some other relevant aspects, such as predatory strategy, have been poorly explored. Herein we evaluate the prey acceptance and predatory strategy of the scorpion Bothriurus bonariensis against sympatric prey with different defenses. As prey, we selected earwigs (Forficula cf. auricularia) which use pincer-like defensive appendages, hard-bodied isopods (Armadillium vulgare) known for their conglobation defensive strategy, soft bodied isopods (Porcellio cf. scaber), which secrete noxious substances as defense mechanisms, cockroaches with limited defensive mechanisms (Blatta cf. orientalis.) and spiders (Lycosa cf. poliostoma) which possess venomous fangs. Prey were offered to 21 adults of B. bonariensis in random order until all prey had been offered to all scorpions. Prey consumption and the number of attempts needed for capture were recorded. We also evaluated the effect of sting use on immobilization time as well as the prey capture strategies on the most consumed prey. We found that despite using a similar number of attempts for capturing all prey, spiders and armadillid isopods were less consumed than other prey. Immobilization times were longer for earwigs than for armadillid isopods and cockroaches. Scorpions used alternative predatory strategies against these aforementioned prey, although the stinger was used against all of them. These results show that scorpions are able to use different predatory strategies which might allow them to include prey with diverse defensive strategies in their diet.  相似文献   

16.
Although chondrichthyans are conspicuously present in shallow waters, many ecological aspects of neritic species in the Humboldt Current System remain unknown. This study provides a first assessment of the diet of seven commercially exploited and understudied sympatric chondrichthyans inhabiting nearshore habitats off the central coast of Peru: four stingrays (Hypanus dipterurus, Myliobatis peruvianus, M. chilensis, and Urotrygon chilensis), a guitarfish (Pseudobatos planiceps), a smooth-hound shark (Mustelus mento), and a chimaera (Callorhinchus callorynchus). A total of 166 stomachs were examined between 2012 and 2015 and prey items were pooled for the total of years for analysis. Although our analysis did not account for inter seasons variability, our results suggest diet partitioning among species, except for the stingrays’ group. A diet based on soft-bottom polychaetes and fish was shared by H. dipterurus, M. peruvianus, and M. chilensis, while soft-bottom polychaetes and crabs were more important in U. chilensis. The smooth-hound shark and guitarfish exhibited a diet dominated by crabs, and the chimaera consumed mainly hard-bottom mollusks. Foraging habitat estimations distinguished two main habitats of association: Benthic, including the stingray U. chilensis, the chimaera, and the smooth-hound shark; and benthic-demersal, including the guitarfish, and the rest of stingrays. A pattern of feeding specialization was observed for H. dipterurus, P. planiceps, and C. callorynchus. Preliminary trophic level estimations based on diet composition placed these species as secondary consumers. Intraspecific dietary variation was assessed for P. planiceps and H. dipterurus as their sampled sizes allowed meaningful comparisons. The diet of P. planiceps varied from small to large sizes but not for H. dipterurus. No differences were detected on diet composition between males and females in either species. Despite the limited temporal resolution, this study provides the first insights of chondrichthyans predatory activity, suggesting diet partitioning among the species of this assemblage in a nearshore habitat of the central coast of Peru. Enhancing the temporal resolution of this type of studies would improve our knowledge on trophic functioning in the Humboldt Current ecosystem.  相似文献   

17.
The study of the gut content of several bombyliid species revealed sex-related differences in their diets: the females consumed much more pollen than males. No difference was observed in the consumption of pollen between long-proboscid (Bombylius major, B. canescens, and Systoechus gradatus) and short-proboscid (Hemipenthes maurus and H. morio) species. Both sexes were capable of digestion of pollen. The pollen appears to be accumulated in the crop first and then enter the midgut by large portions.  相似文献   

18.
Pollen ultrastructure has been studied in two relict and rare species of the genus Aristolochia, A. contorta Bunge and A. manshuriensis Kom. (Aristolochiaceae). Both species have inaperturate, spheroidal, sometimes distally monocolpate or distally bicolpate pollen grains. The equatorial and polar axes of pollen grain in A. manshuriensis are 48.5 and 44.0 μm, respectively. The percentage of defective pollen grains in A. manshuriensis is 3.4%. The fossulate, perforated exine is up to 2.3 μm in thickness; the sexine and the nexine are almost equal in thickness. In A. contorta, the equatorial axis of pollen grain is 36.6 μm: the defectiveness percentage, 24.5%. The exine is verrucate, up to 0.3 μm in thickness, while the sexine is two to three times thicker than the nexine. The pollen germination experiments have shown that pollen of A. manshuriensis, in contrast to A. contorta, can germinate in 10–20% sucrose at 22°С. These data and the high percentage of pollen defectiveness in A. contorta indicate that the androecium function in this species is reduced. The reduction of the androecium function is evidenced by a small amount of pollen grains in anthers or empty anthers and a high percentage of defective pollen grains.  相似文献   

19.
20.
Four species of western US Osmia (3 Cephalosmia) that are Asteraceae specialists (mesoleges) were observed using a stereotypical means of collecting pollen—abdominal drumming—to gather pollen from 21 flowering species representing nine tribes of Asteraceae. Abdominal drumming is a rapid dorso-ventral motion of the female’s abdomen (467 pats/min) used to directly collect and place pollen in the bee’s ventral scopa. A co-occurring generalist, O. lignaria, never drummed Asteraceae flowers for pollen, but instead used its legs to harvest pollen. Observed drumming by several other osmiines is noted. A different pollen-harvesting behavior, abdominal tapping, is described for two eucerine bees (Melissodes agilis and Svastra obliqua), both oligolectic for the Asteraceae. The behavior also involves a dorso-ventral motion, but they tap their distal abdominal venter against disk flowers at a slower tempo (304 taps/min). These females’ distal sternites have distinctly dense and long hair brushes for acquiring pollen by this behavior. Brief accounts of similar abdominal pollen gathering behaviors by other megachilids are summarized.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号