MONOMORPHISM,REDUCED GENE FLOW,AND CLEISTOGAMY IN RARE AND COMMON SPECIES OF LESPEDEZA (FABACEAE)

Population genetic structure was analyzed in the rare, native prairie legume Lespedeza leptostachya Engelm. and in the widespread L. capitata Michx. Both species produce a mixture of chasmogamous and cleistogamous flowers. Allozymes were analyzed for 32 loci from 224 individuals from 12 populations of L. leptostachya and for 34 loci in 291 individuals from 12 populations of L. capitata. L. leptostachya is entirely monomorphic at all loci studied, while L. capitata shows strong among-population differentiation for the limited variation that occurs in that species. Allozyme data suggest that the level of gene flow among populations of L. capitata is very low, and that very low levels of outcrossing are effected by the chasmogamous flowers in L. capitata.     

Orange-derived stimuli regulating oviposition in the Mediterranean fruit fly

Abstract:  Some visual and olfactory host stimuli influencing oviposition of the Mediterranean fruit fly ( Ceratitis capitata Wiedemann) in orange fruit were investigated in a laboratory-reared strain of this species. Mated females of C. capitata were found to be attracted to the same extent by fragrant orange fruits and odourless sham oranges, while unmated females were notably less attracted than mated females by the above objects. Mated females laid significantly more eggs in orange-coloured than in whitish (optically neutral) spherical wax dummies (diameter, 9.0 cm) as well as in both orange-coloured and whitish wax dummies supplemented with high internal humidity (80–100%) compared with respective wax dummies supplied with low internal humidity (30–50%). The orange-like colour together with high internal humidity provides basic stimuli supporting adequate oviposition of C. capitata in oranges. The oviposition rate of female C. capitata was not significantly changed when graded dosages ranging from 0.004 to 19.6  μ l of orange peel oil per cm² were added to orange-coloured wax dummies, while oviposition was considerably subdued by addition of 3.9  μ l orange peel oil and completely disrupted by addition of 9.8 or 19.6  μ l of orange peel oil per cm² of whitish wax dummies. Oviposition of C. capitata in ripe orange fruit may thus be interpreted by the predilection of this tephritid species for an orange-coloured, glossy pericarp, being capable of counteracting the deterrent effect of the essential oil found in orange flavedo.     

北京猛禽寄生合饰带属旋尾线虫的报道及一新种记述(线虫纲,针形总科,针形科)

记述了寄生于北京猛禽体内的2种合饰带属线虫,其中一种为新种,一种为中国新纪录种.标本保存于北京师范大学生命科学学院.红角鸮合饰带线虫Synhimantus(Dispharynx)oti sp.nov.(图1～7)新种与Synhimantus(Dispharynx)capitata(Molin,1860)和S.(D.)buccalis(Gogoi and Sarmah,1988)较相似,但新种在第5对肛后乳突内侧有1对无柄乳突,左交合刺末端分叉,饰带长而与S.(D.)capitata有明显区别.新种与S.(D.)buccalis的主要区别为肛后乳突5对,左交合刺短,颈乳突三叉状位于饰带之后,阴门位于体中之前.正模♂,副模♀,采自红角鸮Otus scops(Linnaeus,1758)的食道.词源:新种的种名来自宿主名.纵纹腹小鸮合饰带线虫乌兹别克斯坦亚种Synhimantus(Dispharynx)noctuae uzbehistanica(Sultanov,1950)中国新纪录(图8～10)从纵纹腹小鸮Athene noctua(Scopoli,1769)的食道和口腔中采到3条雄虫.作者所采标本与Sultanov(1950)的原始描述基本相同,但前者饰带稍有波浪状的弯曲而原始描述为直的.     

Systematic revision of the subgenus Ceratitis MacLeay s.s. (Diptera, Tephritidae)

The fruit fly genus Ceratitis MacLeay (Diptera, Tephritidae) comprises several important pest species attacking a wide range of unrelated fruits. This is the third paper in a series revising the genus, and deals with representatives of the subgenus Ceratitis s.s . Eight species are recognized: Ceratitis brachychaeta Freidberg, C. caetrata Munro, C. capitata (Wiedemann), C. catoirii Guerin-Meneville, C. comuta (Bezzi), C. malgassa Munro, C. manjakatompo Hancock and C. pinax Munro. Lectotypes are designated for C. catoirii and C. pinax . A key for both sexes is provided, with illustrations of cephalic bristles, mesonotal and wing patterns, and shape of aculeus. All species are Afrotropical, except for 67. capitata , which has become widespread. The phylogeny and biogeography of Ceratitis s.s . are discussed, based on a cladistic analysis, and showing indications that the mediterranean fruit fly, C. capitata , may have its origins in eastern Africa. The relationship of this subgenus within the genus Ceratitis s.l . is also outlined.     

Description and ecology of Cytaeis capitata n. sp. (Hydrozoa,Cytaeididae) from Bunaken Marine Park (North Sulawesi,Indonesia)

Hydrobiologia - A new hydroid species, Cytaeis capitata n. sp. (family Cytaeididae), is described. This species, an epibiont of gastropod shells living in the shallow water of the Bunaken National...     

Comparative analysis of microsatellite loci in four fruit fly species of the genus Ceratitis (Diptera: Tephritidae)

The possibility to cross-species amplify microsatellites in fruit flies of the genus Ceratitis was tested with the polymerase chain reaction (PCR) by analysing 23 Ceratitis capitata (Wiedemann) microsatellite markers on the genomic DNA of three other economically important, congeneric species: C. rosa (Karsch), C. fasciventris (Bezzi) and C. cosyra (Walker). Twenty-two primer pairs produced amplification products in at least one of the three species tested. The majority of the products were similar, if not identical in size to those expected in C. capitata. The structures of the repeat motifs and their flanking sequences were examined for a total of 79 alleles from the three species. Sequence analysis revealed the same repeat type as the homologous C. capitata microsatellites in the majority of the loci, suggesting their utility for population analysis across the species range. A total of seven loci were differentially present/absent in C. capitata, C. rosa, C. fasciventris and C. cosyra, suggesting that it may be possible to differentiate these four species using a simple sequence repeat-based PCR assay. It is proposed that medfly-based microsatellite markers could be utilized in the identification and tracing of the geographical origins of colonist pest populations of the four tested species and in the assessment of their risk and invasive potentials; thereby assisting regulatory authorities in implementing quarantine restrictions and other pest control measures.     

Pathogenicity of Metarhizium anisopliae (Metsch.) Sorokin and Beauveria bassiana (Balsamo) Vuillemin,to three adult fruit fly species: Ceratitis capitata (Weidemann), C. rosa var. fasciventris Karsch and C. cosyra (Walker) (Diptera :Tephritidae)

The pathogenicity of two isolates of Beauveria bassiana and 12 of Metarhizium anisopliae towards adult fruit flies, Ceratitis capitata and Ceratitis rosa var. fasciventris was tested in the laboratory. Fruit flies were exposed to dry conidia evenly spread on velvet material covering the inner side of a cylindrical plastic tube. All isolates tested were pathogenic to both species of fruit flies. Mortality ranged from 7 to 100% in C. capitata and from 11.4 to 100% in C. rosa var. fasciventris at 4 days post-inoculation. Six isolates, M. anisopliae ICIPE 18, 20, 32, 40, 41 and 62, were highly pathogenic to both C. capitata and C. rosa var. fasciventris. The LT90 values of the most pathogenic isolates ranged between 3-4 days in both insects. Because of the difficulties in rearing C. cosyra, only the isolates that were highly pathogenic to both C. rosa var. fasciventris and C. capitata were tested against adult C. cosyra. They caused mortality of between 72-78% at 4 days post-inoculation. The LT90 values in all the isolates did not exceed 4 days. One of the most pathogenic isolates, M. anisopliae ICIPE 20, was evaluated against C. capitata and C. rosa var. fasciventris in cage experiments using three autoinoculators (maize cob, cheesecloth and Petri dish) in an autoinoculative device consisting of plastic mineral bottle. Mortality of between 70-93% was observed in flies of both species that were captured from the cages and held under laboratory conditions. These results indicate the possibility of fruit fly suppression with entomopathogenic fungi using an autoinoculative device.     

Native and introduced host plants of Anastrepha fraterculus and Ceratitis capitata (Diptera: Tephritidae) in northwestern Argentina

Wild or commercially grown, native and exotic fruit were collected in 30 localities in the Tucumán province (NW Argentina) from January 1990 to December 1995 to determine their status as hosts of Anastrepha fraterculus (Wiedemann) and/or Ceratitis capitata (Wiedemann), the only two fruit fly species of economic and quarantine importance in Argentina. A total of 84,094 fruit (3,466.1 kg) representing 33 species (7 native and 26 exotic) in 15 plant families were sampled. We determined the following 17 host plant associations: Annona cherimola Miller (Annonaceae), Citrus paradisi Macfadyn (Rutaceae), Diospyros kaki L. (Ebenaceae), Eugenia uniflora L., Psidium guajava L., Myrcianthes pungens (Berg) Legrand (Myrtaceae), Ficus carica L. (Moraceae), Juglans australis Grisebach (Juglandaceae), Mangifera indica L. (Anacardiaceae), Eriobotrya japonica (Thunb.) Lindl., Prunus armeniaca L., P. domestica L., and P. persica (L.) Batsch (Rosaceae) were infested by both A. fraterculus and C. capitata. Citrus aurantium L., Citrus reticulata Blanco, Citrus sinensis (L.) Osbeck (Rutaceae), and Passiflora caerulea L. (Passifloraceae) were only infested by Ceratitis capitata. Out of a total of 99,627 adults that emerged from pupae, 69,180 (approximately 69.5%) were Anastrepha fraterculus, 30,138 (approximately 30.2%) were C. capitata, and 309 (approximately 0.3%) were an unidentified Anastrepha species. Anastrepha fraterculus predominated in native plant species while C. capitata did so in introduced species. Infestation rates (number of larvae/kg of fruit) varied sharply from year to year and between host plant species (overall there was a significant negative correlation between fruit size and infestation level). We provide information on fruiting phenology of all the reported hosts and discuss our findings in light of their practical (e.g., management of A. fraterculus and C. capitata in citrus groves) implications.     

Development of a diagnostic DNA probe for the fruit flies Ceratitis capitata and Ceratitis rosa (Diptera: Tephritidae) using amplified fragment-length polymorphism

The AFLP technique (amplified fragment-length polymorphism) was employed to identify and isolate species specific markers in tephritids. We have found that the technique has good potential for this purpose, with the only difficult part being the reamplification of AFLP fragments from silver stained gels. Cloning of putative species-specific markers and genomic dot blot hybridizations resulted in the development of diagnostic probes for tephritid identification. A repetitive DNA sequence from the genome of Ceratitis capitata (Wiedemann) was isolated. This sequence rapidly and reliably identified C. capitata and C. rosa Karsch in a collection of closely related and outgroup species tested in this study. Although this probe has been developed for C. capitata and C. rosa, the proposed methodology can be applied to any group of organisms.     

Developmental rates at constant temperatures of three economically important Ceratitis spp. (Diptera: Tephritidae) from southern Africa

Three species of Ceratitis MacLeay are of economic importance in southern Africa. To learn more about the influence of temperature on the development of these species, the developmental rates of South African populations of Ceratitis (Ceratitis) capitata (Wiedemann), C. (Pterandrus) rosa Karsch, and C. (Ceratalaspis) cosyra (Walker) were compared at constant temperatures of 14, 18, 22, 26, and 30 degrees C. The duration of each life stage and the percentage survival of the immature life stages of each species were determined. One linear and three nonlinear developmental rate models (Briére, Lactin, and Logan-6) were found to fit the data well and were used to generate the minimum, optimum, and maximum developmental thresholds, in addition to the life cycle thermal constants for the three species. These parameter values were 9.6, 28.5, 33.0, and 338 for C. capitata, 9.7, 28.8, 33.2, and 376 for C. cosyra, and 8.6, 27.7, 33.0, and 429 for C. rosa, respectively. The parameters for C. capitata are similar to those found by other researchers for this species in Reunion but the parameters for C. rosa differ substantially from published values for a Reunion population of this species, suggesting that these are different biotypes. The similarities between the developmental parameters for C. capitata and C. cosyra do not support known differences in the distribution of these species so other limiting factors such as relative humidity and the availability of host species may be important. This finding therefore cautions against basing predictions of potential global distributions of species solely on life table or climatic parameter values.     

Segregation of temporal and spatial distribution between kleptoparasites and parasitoids of the eusocial sweat bee, Lasioglossum malachurum (Hymenoptera: Halictidae, Mutillidae)

Cuckoo bees and velvet ants use different resources of their shared host bees, the former laying eggs on the host pollen stores and the latter on immature stages. We studied the activity patterns of the cuckoo bee Sphecodes monilicornis and the velvet ant Myrmilla capitata at two nesting sites of their host, the social digger bee Lasioglossum malachurum , over a 3 year period. Due to the difference in host exploitation, we expected different temporal patterns of the two natural enemies as well as a positive spatial association with host nest density for both species. At a daily level, S. monilicornis was more abundant between 10.00 and 15.00 h, while M. capitata was most active in the early morning and late afternoon; both species activities were independent from host provisioning activity. The activity of cuckoo bees was in general positively correlated with the density of open host nests (but not with the total number of nests), while that of velvet ants was rarely correlated with this factor. Sphecodes monilicornis was seen both attacking the guard bees and directly entering into the host nests or digging close to nest entrances, while M. capitata only gained access to host nests through digging. We conclude that the temporal and spatial segregation between the two species may be, at least partially, explained both by the different resources exploited and by the different dynamics of host interactions.     

Comparative evaluation of spinosad and phloxine B as toxicants in protein baits for suppression of three fruit fly (Diptera: Tephritidae) species

Spinosad and phloxine B are two more environmentally friendly alternative toxicants to malathion for use in bait sprays for tephritid fruit fly suppression or eradication programs. Laboratory tests were conducted to assess the relative toxicity of these two toxicants for melon fly, Bactrocera cucurbitae Coquillett; oriental fruit fly, Bactrocera dorsalis Hendel; and Mediterranean fruit fly, Ceratitis capitata (Wiedemann) females. Field tests also were conducted with all three species to compare these toxicants outdoors under higher light and temperature conditions. In laboratory tests, spinosad was effective at much lower concentrations with LC50 values at 5 h of 9.16, 9.03, and 4.30 compared with 250.0, 562.1, and 658.9 for phloxine B (27, 62, and 153 times higher) for these three species, respectively. At 16 ppm spinosad, LT50 values were lower for all three species (significantly lower for C. capitata and B. dorsalis) than 630 ppm phloxine B LT50 values. At 6.3 ppm spinosad, the LT50 value for C. capitata (3.94) was still significantly less than the 630 ppm phloxine B LT50 value (6.33). For all species, the 100 ppm spinosad concentrations gave LT50 values of < 2 h. In comparison among species, C. capitata was significantly more sensitive to spinosad than were B. cucurbitae or B. dorsalis, whereas B. cucurbitae was significantly more sensitive to phloxine B than were C. capitata or B. dorsalis. LC50 values were reduced for both toxicants in outdoor tests, with greater reductions for phloxine B than for spinosad for B. dorsalis and B. cucurbitae. Fly behavior, though, is likely to keep flies from being exposed to maximum possible outdoor light intensities. Comparable levels of population suppression for any of the three species tested here will require a much higher concentration of phloxine B than spinosad in the bait.     

Population genetics of the potentially invasive African fruit fly species, Ceratitis rosa and Ceratitis fasciventris (Diptera: Tephritidae)

A set of 10 microsatellite markers was used to survey the levels of genetic variability and to analyse the genetic aspects of the population dynamics of two potentially invasive pest fruit fly species, Ceratitis rosa and C. fasciventris, in Africa. The loci were derived from the closely related species, C. capitata. The degree of microsatellite polymorphism in C. rosa and C. fasciventris was extensive and comparable to that of C. capitata. In C. rosa, the evolution of microsatellite polymorphism in its distribution area reflects the colonization history of this species. The mainland populations are more polymorphic than the island populations. Low levels of differentiation were found within the Africa mainland area, while greater levels of differentiation affect the islands. Ceratitis fasciventris is a central-east African species. The microsatellite data over the Uganda/Kenya spatial scale suggest a recent expansion and possibly continuing gene flow within this area. The microsatellite variability data from C. rosa and C. fasciventris, together with those of C. capitata, support the hypothesis of an east African origin of the Ceratitis spp.     

Attractiveness of 79 compounds and mixtures to wild Ceratitis capitata (Diptera: Tephritidae) in field trials

Seventy-nine volatile compounds chosen from those emitted by Mediterranean fruit fly males, fruits and food baits, were tested for their attractiveness to females of Ceratitis capitata (Wiedemann) in field trials with a wild population. To correct for density fluctuations, the results were presented as a percentage of males caught in the same type of traps baited with trimedlure, a known male attractant. The mixtures of corn steep liquor with ammonia compounds and amines were the most effective attractants for females. Other compounds exhibiting C. capitata attraction were a mixture ethyl acetate+acetic acid+ethanol for both sexes, and p-cymene, 1,3-diethylbenzene and borneol for females.     

Perimeter trapping strategy to reduce Mediterranean fruit fly (Diptera: Tephritidae) damage on different host species in Israel

To evaluate the perimeter trapping strategy as a control method, field tests were conducted in three different host species of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), in Israel. Dry traps baited with a three component food-based synthetic attractant that were hung in the peripheral rows of a plum, a pear, and a persimmon orchard, caught female C. capitata (up to 20.1, 1.4, and 4.1 female C. capitata per trap per day, respectively). Fruit damage, estimated at harvest, indicated a negligible percentage for the plum orchard (< 1%), 3% for the persimmon orchard (compared with 9% at an untreated neighboring plot), and no damaged fruit in the pear orchard. Finally, dissections of female C. capitata caught in dry traps on different host plant species indicate that a high percentage (range, 84-100%) contained mature eggs. The attraction of mature females to the dry traps might explain the successful results. Future research, to determine precisely how many traps should be placed and how frequently they should be serviced, is necessary before applying this strategy on a commercial basis.     

Allozyme differentiation between the lowland Carex capitata and the alpine Carex arctogena (Cyperaceae) in Scandinavia

Within Scandinavia, Carex capitata s.l, is usually divided into two taxa: the lowland to lowalpine C. capitata s.s., and the alpine C. arctogena. The systematic status of these taxa is uncertain, reflected by their taxonomic treatment in different floras. In this study, allozymes were used to assess the degree of genetic differentiation between and within taxa. Ten populations of Carex capitata s.s. and eight of C. arctogena, from Norway and Sweden, were included in the study. Sixteen loci in eleven different enzyme systems were analysed: five were variable within or between taxa, three could be interpreted in all plants. In all, 20 different alleles were found. Four of these alleles were confined to C. capitata s.s., and two to C. arctogena. In C. capitata s.s., three loci (18%) were polymorphic, while all loci were monomorphic in C. arctogena. The number of alleles per polymorphic locus was 2.2 in C. capitata s.l. The taxa had completely different alleles at two loci {Pgi-2, Pgm-1). Nei's genetic identity was 0.86 between taxa, and ranged between 0.95 and 1 in pairwise comparisons of populations of Carex capitata s.s., while it was 1 in all comparisons between populations of C. arctogena. The distinction of C. capitata s.s. and C. arctogena as separate species agrees well with the amount of differentiation found between other congeneric species. It is suggested that the low genetic variation observed in both taxa is due to ancient founder events. The difference in genetic variability between taxa may be due to differences in immigration history: whereas C. capitata s.s. may have colonized Scandinavia from several close refugia after the last glaciation, C. arctogena may have reached Scandinavia after long-distance dispersal of a limited number of propagules.     

The complete nucleotide sequence of the mitochondrial genome of the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae)

The complete mitochondrial genome of the oriental fruit fly Bactrocera dorsalis s.s. has been sequenced, and is here described and compared with the homologous sequences of Bactrocera oleae and Ceratitis capitata. The genome is a circular molecule of 15,915 bp, and encodes the set of 37 genes generally found in animal mitochondrial genomes. The structure and organization of the molecule is typical and similar to the two closely related species B. oleae and C. capitata, although it presents an interesting case of putative intra-molecular recombination. The relevance of the growing comparative dataset of tephritid complete mitochondrial genomes is discussed in relation to the possibility to develop robust assays for species discrimination in quarantine and agricultural monitoring practices, as well as basic phylogeography/population genetic studies.     

Variation in morphological characters and habitat requirements in Carex capitata and Carex arctogena (Cyperaceae) in Norway and Sweden

Norwegian and Swedish populations of Carex capitata s. lat. were studied for variation in morphological characters. Canonical variates analysis (CVA) arranges populations in two discrete groups, corresponding to C. capitata s. str. and C. arctogena , respectively. In principal components analysis (PCA) of the total material a small overlap could be seen. However, separate PCA: s for the two regions in Scandinavia where the two taxa are sympatric show perfect separation. Student's t-test revealed significant differences in all morphological characters studied. Studies of companion plants, analysed with detrended correspondence analysis (DCA), indicate that the taxa have rather similar habitat demands in Oppland, Central Norway, although C. capitata s. str. seems to prefer wetter, and C. arctogena drier sites, respectively. Since the two taxa are distinct in morphology, they are best treated as separate species. The name Carex capitata is lectotypified.     

芥蓝和结球甘蓝染色体组型及C-带带型的研究

本文用改进的染色体标本制片技术,研究了芥蓝和结球甘蓝的染色体组型和 C-带带型。两种植物的二倍体均由4对中着丝粒、5对亚中着丝粒染色体组成,其中一对为随体染色体。芥蓝和结球甘蓝具有统一的染色体组型公式:2n=18=8m+10sm(2SAT),但两者的某些染色体在编号顺序上有差异。在结球甘蓝中观察,到4种不同形态的随体。用 BSG C-带方法得到 C-带带型,带型公式,芥蓝为2n=18=CITS 型=10C+2CI_++4CT~++2CS;结球甘蓝为2n=18=CITS 型=8c+2CI_++6CT~++2CS。某些带纹具多态性和杂合性。本文从染色体水平上讨论了芥蓝与甘蓝的亲缘关系。     

Comparison of the mitotic karyotypes of Ceratitis capitata, Ceratitis rosa, and Trirhithrum coffeae (Diptera: Tephritidae) by C-banding and FISH.

The sex chromosomes of the tephritid fruit fly Ceratitis capitata (Wiedemann) are heteromorphic. The male-determining region was located on the Y chromosome by deletion mapping using unbalanced offspring from several translocation strains. In addition, we showed that only 15% of the Y chromosome is required for male determination and male fertility. Based on this result, we expected to find Y-chromosomal length polymorphism in natural populations. Using fluorescence in situ hybridization with two repetitive DNA probes that label the Y chromosome, no obvious size differences were detected in seven wild-type strains and three mutant strains. As the medfly is probably of East African origin, we also analyzed two wild-type strains established recently from pupae sampled in Kenya. The Y chromosomes show a polymorphism in the hybridization pattern of a repetitive Y-specific medfly clone. However, the overall size of the Y chromosome is similar to that of the other strains. Besides C. capitata, the tephritid fruit flies Ceratitis (Pterandrus) rosa Karsch and Trirhithrum coffeae Bezzi also emerged from pupae sampled in Kenya. Their karyotype was analyzed by C-banding. Furthermore, the ribosomal genes were mapped to the sex chromosomes in these two species. Key words : Ceratitis capitata, Tephritidae, C-Banding, FISH, rDNA.