The manifestation of sexual dimorphism in the preimago phases of 2 species of the genus Hyalomma (Ixodoidea, Ixodidae)

Experiments on laboratory cultures of Hyalomma asiaticum and H. anatolicum have shown that at the nymphal phase sexual dimorphism manifests itself in statistically reliable differences between general sizes and mass of the body of male and female individuals. Larger nymphs moult mostly into females, small ones mostly into males. Reliable differences have been noted in the sizes of scutum, gnathosoma and its appendages in male and female nymphs of both species. At the larval phase sexual dimorphism does not manifest itself in the sizes of individuals.     

Sexual dimorphism of the larvae and nymphs of the taiga tick--Ixodes persulcatus

Manifestations of sexual dimorphism at the preimaginal phase was studied on the laboratory culture of Ixodes persulcatus. It has been found out that larger engorged larvae produce, in general, larger nymphs and smaller larvae produce smaller nymphs. The classification of engorged nymphs into large (over 2.9 mm) and small ones (less than 2.9 mm) has made it possible (with 100% probability) to obtain females from the former and males from the latter. Differences in linear sizes of scutum, gnathosoma and its appendages in male and female nymphs were determined that has made possible the identification of sex in hungry nymphs.     

A description of the female and larva of the relic species Ixodes ghilarovi (Ixodidae)

Ixodes (Exopalpiger) ghilarovi was found in 4 separated localities of the Great Caucasus at a height of 1000 to 2200 m above sea level. Female differs from palaearctic I. (Exopalpiger) trianguliceps in 4-4 pairs of setae of the anal valve, shape of scutum, longer setae of alloscutum, more round peritreme, correlation between the length of peritreme longitudinal diameter and the length of longitudinal diameter of the anal ring, presence of auricles and shape of palps. Larva differs from I. trianguliceps in longer setae of alloscutum, longer ventrolateral tooth of 1st palpal joint and longer medial tooth of coxae I.     

The ontogenetic variability of the morphometric traits of 2 species of ixodid ticks in the genus Rhipicephalus]

Variability of 10 morphometric characters at all phases was investigated on laboratory cultures of R. turanicus and R. bursa. It has been shown that variability increases from phase to phase. R. turanicus nymphs of both sexes differ in the length of gnathostoma and length of the 1st tarsus. In nymphs of R. bursa sexual dimorphism manifests itself on 8 characters, in all cases sizes of organs are greater in female nymphs. Besides, engorged female nymphs are reliably greater than male ones in length and mass of the body. Mature females and males of R. bursa also reliably differ in the total body length as well as in sizes of all examined structures. Females and males of R. turanicus do not differ in body length but differ in 9 other morphometric characters. Correlation analysis of characters was carried out individually for each phase and sex. Correlation coefficient between characters are most low in larvae. In R. turanicus male and female nymphs the coefficients are close. In R. bursa female nymphs correlation coefficients are noticeably lower than in male ones. The level of independence of characters in female nymphs defines the degree of manifestation of sexual dimorphism at this phase: the closer the links between characters, the lesser the number of characters revealing sexual differences. Coefficients of correlation of characters coincide in males of both species. In females of R. turanicus they are lower than in males that determines the strengthening of sexual dimorphism at the phase of imago.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnosis of species by the larval phase in the genus Rhipicephalus Koch (Ixodidae) in USSR fauna

The key for identification of species of the genus Rhipicephalus (the fauna of the USSR) on the larval phase is based on the material reared under laboratory conditions. The structure of scutum, organs of gnathosoma and coxae, chaetotaxy of idiosoma and gnathosoma were used for differential diagnosis. In addition morphometric characteristics of the above structures and their proportions were used. A special attention has been given to coexistence of species in sympatric zones, which was revealed or confirmed as a result of identification of species of the genus on larva in the ranges of the fauna of the USSR.     

Differentiation of subspecies of the polymorphic species Hyalomma marginatum (Acari: Ixodidae) based on immature stages

Study of morphological characters to identify the subspecies of Hyalomma marginatum immature stages is based on material collected throughout all the geographical range of the species. As it was found, the discrimination of subspecies of H. marginatum immature stages needs a complex use of structural and morphometrical characters. Only H. m. marginatum larvae and H. m. isaaci nymphs may be easily differentiated from other subspecies based on the structural (qualitative) characters. Besides, morphometric (quantitative) characters should be used only in combinations for identification of the subspecies. In regard to structural characters of larvae, it was found that the shape and size of coxal spurs of H. marginatum allow differentiating this subspecies from the others (Fig. 3, 5, 6). Based on morphometrical characters of larvae, the following characteristic features of subspecies have been found: in H. m. marginatum, the capitulum is wide, the palpi, hypostome and genua I are short and narrow; in H. m. turanicum, the capitulum is narrow, the palpi are short and narrow, the hypostome is short and wide, the genua I are long and narrow; in H. m. rufipes, the scutum is large, the capitulum is wide, the palpi are long and narrow, the hypostome and genua I are long and wide; in H. m. isaaci, the scutum is small, the capitulum is narrow, the palpi and hypostome are long and narrow, the genua I are short and narrow. Among structural characters of nymph, several discriminative features of subspecies have been found. The shape of the scutum in H. m. isaaci (Fig. 2, 2) clearly differentiates this subspecies from the others (Fig. 2, 1). In H. m. marginatum, the setae of alloscutum as a rule have bluntly rounded apices (Fig. 1, 2), while in the other subspecies these setae are more tapering apically (Fig. 1, 1). The shape of spiracular plates is rather variable within the species, but in H. m. marginatum and H. m. isaaci (Fig. 1, 3) the plates are larger and more perforated than in H. m. rufipes and H. m. turanicum (Fig. 1, 4). In H. m. isaaci, the spurs of coxae I are narrower than in other subspecies (Fig. 1, 8). Based on morphometrical characters of nymphs, the following discriminative features of subspecies have been found: in H. m. marginatum, the capitulum is wide, the palpi are short and wide; in H. m. turanicum, the capitulum is narrow, the palpi are long and narrow; in H. m. rufipes, the scutum is wide, the capitulum is narrow, the palpi are long and narrow, the hypostome is long; in H. m. isaaci, the scutum is long and narrow, the capitulum is wide, the palpi are short and wide, the hypostome is short.     

Diagnosis of species of the genus Dermacentor Koch in Siberia and the Far East by the sexually immature phases (Ixodoidea, Ixodidae)

Keys to four known species of the genus Dermacentor from Siberia and Far East of the USSR are based on their nymphs and larvae. Analysis of laboratory cultures served as a basis for distinguishing differential characters of preimaginal phases. Stability of characters in the distribution area of each species was verified on natural material from many geographical localities. A wide range of structures was used for species identification as follows: peculiarities of scutum, peritreme, anal valve, organs of gnathosoma, chaetotaxy and morphometrical characteristics and ratios. Keys can be used for identifying species from the European part of the USSR and north-eastern Kazakhstan.     

Identification of species of Hyalomma asiaticum group (Ixodidae) in areas of their sympatry based on immature stages

Morphological characters of immature stages of three closely related tick species, Hyalomma asiaticum Schulze et Schlottke, 1929, H. dromedarii Koch, 1844 and H. schulzei Olenev, 1931, collected mainly in areas of their sympatry (Fig. 1) were investigated. The larvae and nymphs of these three species were collected in Egypt, Iran, Turkmenistan, Uzbekistan, Afghanistan and Tadjikistan: 159 larvae and 137 nymphs of H. asiaticum from 12 localities; 78 larvae and 167 nymphs of H. dromedarii from 5 localities; 30 larvae and 6 nymphs of H. schulzei from one locality. Both qualitative morphological features and measured character (in mkm) were used to discriminate these species. Main discriminant characters for larvae. H. asiaticum (Fig. 3). Scutum: length < 246, width < 389; base of capitulum: width < 158, dorsally hexagonal, apices of lateral projections directed forward; palpae (II and III segments): length < 106, width < 42; hypostome: length < 87, width < 25; the spur of coxa I small, equilateral triangular; patella: length < 154. H. dromedarii (Fig. 4). Scutum: length > 236, width > 379; base of capitulum: width > 158, dorsally almost triangular, apices of lateral projections directed laterally or backward; palpae: length > 110, width < 46; hypostome: length > 87, width < 26; the spur of coxa I large, isosceles triangular; patella: length > 115. H. schulzei (Fig. 5). Scutum: length > 249, width > 407; base of capitulum: width > 162, dorsally hexagonal, apices of lateral projections directed forward; palpae: length > 114, width > 44; hypostome: length > 89, width > 28; the spur of coxa I large, isosceles triangular; patella: length > 164. Main discriminant characters for nymphs: H. asiaticum (Fig. 3). Scutum: small, width < 650, length and width subequal, posterior margin widely rounded, lateral incisions weakly developed; spiracular plates with distinct, pointed dorsal projection, marginal row of perforations distant from the base of dorsal projection, submarginal row with a gap; base of capitulum: lateral projections situated in posterior half of capitulum; palpae (II segment) short and narrow; hypostome short and narrow, width < 69; pore of coxae I-III present. H. dromedarii (Fig. 4). Scutum: large, width > 650, length shorter than width, posterior margin widely rounded, lateral incisions moderately developed; spiracular plates: with distinct and wide dorsal projection, marginal row of perforations distant from the base of dorsal projection, submarginal row present, without gap; base of capitulum: lateral projections situated in the middle part of capitulum; palpae long and narrow; hypostome long and wide, width > 69; coxal pore lacking. H. schulzei (Fig. 5). Scutum: small, width < 630, length larger than width, posterior margin narrow rounded, lateral incisions weakly developed; spiracular plates: with weakly developed dorsal projections, marginal row of perforation situated just behind the base of dorsal projection, submarginal row with a gap; base capitulum: lateral projections situated in posterior half of capitulum; palpae short and wide; hypostome long and narrow, width < 73; coxal pore lacking.     

Redescription of the male and description of the female of <Emphasis Type="Italic">Ixodes abrocomae</Emphasis> Lahille, 1916 (Acari: Ixodidae)

The male of Ixodes abrocomae Lahille, 1916 (Acari: Ixodidae) is redescribed and the female described for the first time from specimens collected on the rodents Abrothrix longipilis (Waterhouse), A. olivaceous (Waterhouse) and Phyllotis xanthopygus (Waterhouse) at Coquimbo, Chile. The males of I. abrocomae are peculiar in having the combination of the following features: length and width less than 2 mm and 1 mm, respectively; hypostome notched with two rows of stout denticles and several small internal denticles; article II of the palpi with two conspicuous dorsal setae; coxa I with two subequal spurs; coxae II–IV with a single spur plus an indication of a second spur; and a scutum with long, scattered hairs except for the glabrous postero-median field which reaches to the marginal fold. The females of I. abrocomae are peculiar in possessing a combination of: a pointed hypostome, with a 3/3 dentition of flared denticles; a long, narrow scutum with few ‘hairs’ and with punctations which are especially numerous in the posterior region; a triangular basis capituli, with oval porose areas lacking definitive borders and separated by the width of one area, and a sinuous posterior margin with small cornuae; one spur on coxae I–IV; and conspicuous setae on the interno-dorsal face of palpal article II and the ventral face of article I. Sequences of 16S rDNA were identical for male and female I. abrocomae, but differ by 3.8% and 5.5% from sequences of their closest relatives, I. stilesi Neumann, 1911 and I. sigelos Keirans, Clifford & Corwin, 1976, respectively. Characters enabling the separation of I. abrocomae from Ixodes spp. distributed in the southwestern Neotropics are presented. Records of I. abrocomae in different climatic areas and on different, widely distributed rodent hosts indicate that this species may be present beyond its known Chilean territorial range (Regions III and IV).     

Description of a new species of <Emphasis Type="Italic">Amblyomma</Emphasis> Koch, 1844 (Acari: Ixodidae), parasite of deer (Artiodactyla: Cervidae) and wild pigs (Artiodactyla: Suidae) in the Philippines

Amblyomma anicornuta n. sp. (Acari: Ixodidae) is described based on adults and nymphs ex deer (Artiodactyla: Cervidae) and wild pigs (Artiodactyla: Suidae) from Luzon, Philippines. Adults of A. anicornuta n. sp. are similar to those of several Asian and Australasian species of Amblyomma Koch, 1844 with a 4/4 dental formula on the hypostome but can be distinguished by the colouration and pattern of punctations on the conscutum in the male and scutum in the female, the absence of a marginal groove on the conscutum in the male, the possession of long, thick, prominent setae on the alloscutum in the female, projections on anal valves and sclerotised ring around them in the male, a large median sclerite ventrally in the male, as well by the shape of the genital aperture in the female and the size and shape of spurs on coxae I–IV in both sexes. The nymph of A. anicornuta n. sp. is somewhat similar to that of A. babirussae Schulze, 1933 and A. geoemydae (Cantor, 1847) but can be distinguished by the colouration pattern on the scutum, the presence of dorsal cornua and the size of the spurs on coxae I–IV.     

Morphological Comparison of Diophrys scutum (Dujardin, 1841) and Diophrys peloetes n. sp. (Hypotrichida, Ciliophora)

SYNOPSIS. Diophrys scutum , collected from four locations on the New Hampshire coast, ranged from 89–195 7mu; in length, 50–105 μ in width, and 68–88 μ in buccal cavity length. The end of the adoral zone of membranelles (AZM) extends 37–59 μ (average = 45.6 μ) posteriorly in a groove on the right side of the body. Dorsally are five rows of stiff cilia. The silverline system (Chatton-Llvoff technique) appears as a fine meshwork, entirely different from that found in Euplotes or Uronychia . There are two elongate macronuclei (Feulgen reaction) and several micronuclei. Diophrys peloetes n. sp., collected from one location in Alligator Harbor. Florida, ranged from 95–134 μ in length, 62–84 μ in width. and 60–80 μ in buccal cavity length. The terminal portion of the AZM extends posteriorly in a groove 30–44 7mu; (average = 36.8 μ) on the right side of the body. Dorsally are eight rows of stiff cilia. The details of the silverline system are similar to those of D. scutum .
There is insufficient difference in ranges of body length, width. and buccal cavity length to use these characters in separating the two species. However, a statistical analysis shows that the length of the portion of the AZM on the right side of the body in D. scutum is significantly different (longer) from that of D. peloetes. Furthermore, these two species differ not only in number of dorsal ciliary rows, but also in the number of cilia per row. The degree of difference in these two species is similar to that between closely related species in other hypotrich genera, and also to that between some varieties of Paramecium aurelia.     

Variability of morphological traits in Drosophila bipectinata complex

Phenotypic or morphological differences among different populations and sexual dimorphism in certain metric traits were analysed in D. bipectinata complex. It was noticed that different populations of D. bipectinata species group harbour large amount of variation for these characters. In all the populations, morphometric characters such as lengths of femur, tibia and wing length, wing width, number of sternopleural bristles and bristles on epandrium varied significantly among populations. The study indicates that the morphological variations are due to the interplay of genetic and environmental endowments. Further, females had significantly larger values, for lengths of femur, tibia and wing length, wing width and sternopleural bristles.     

Variability of the hard dorsal idiosomal tegument pattern and other phenotypic characters as a manifestation of microevolution in Dermacentor marginatus (Acari: Ixodidae)

The pattern of male conscutum and female scutum in Dermacentor marginatus has been examined in 6 points of the East-European and Asian parts of its range (Fig. 1). A high rate of modification variability of the pattern has been recovered in each geographical sample. It is shown that populations differ reliably from each other by the length of the dark patches on the marginal flank of the conscutum (nkappabeta, npkappabeta, 3kappabeta); some samples also differ by the number of these patches, complexes of other patches of the scutum and conscutum, and as well (visually) by the color density of light fields and contrast between them and the dark background on the conscutum and scutum (Table 1, 2). Besides, the samples differ reliably at each stage by the complexes of morphometric characters (Table 3, 4). The sample from the Peter the First Ridge is most deviate from others by the color contrast and complex of patches both in males and females. However, by the patches of marginal flank and morphometric characters of both sexes and perimaginal stages this sample differ less from others. The sample from the Stavropol plateau having most variable pattern (Fig. 3, 1-9, 4, 1-3) is characterized by the greater number of statistically reliable differences by the patches (nkappabeta, npkappabeta, 3kappabeta) and morphometric characters of all stages of the ontogenesis from all other samples. Other geographical samples have intermedial position in regard to degree of differences from each other. The samples examined are considered as morphotypes; degree of differences between morphotypes is unequal. The phenotypic differences have mosaic dispersion among ontogenetic stages and do not show a coherent direction in comparing the morphotypes. Differential characters of the morphotypes and related tick species belong to different structures or their different parameters. Possible ways of morphotype's origin and geochronological characteristics of morphotypes are discussed.     

The correlation variability of the morphometric traits in 4 species of ixodid tick species (Ixodidae)]

Correlation analysis of 10 characters was run in three species of Dermacentor, D. nuttalli, D. ushakovae, D. niveus, and in Ixodes persulcatus, separately for each phase and sex. Correlation coefficients are very low in larvae of all species. In male nymphs correlation coefficients are on the same level in all species while the correlation coefficient level in female nymphs reflects the degree of independence of the development of characters. This defines the degree of manifestation of sexual dimorphism at the nymphal phase: the more rigid the connections between the characters the less number of characters shows sexual differences. At the phase of imago the lowest correlation coefficients are in I. persulcatus. This species displays most distinct differences in the morphology of females and males. On the basis of comparison of correlation and variability coefficients the functional role of the characters is discussed.     

On systematics of mites of the genus Syringophiloidus (Acari: Syringophilidae) from the european part of Russia

A new species Syringophiloidus delichonum sp. n. (Acari: Syringophilidae) is described from quills of Delichon urbica (Hirundinidae) and S. glandarii (Fritsch, 1958) from Garrulus glandarius (Corvidae) is redescribed. Syringophiloidus glandarii, female: body length 650-680, width 160-180. Peritremes: longitudinal branch with 11-14 chambers, lateral--with 2 chambers. All propodosomal setae slightly serrate. Length of setae: vi 33-36, ve 87-96, sci 150-180, sce 180-240, h 200-230, dl 210-230, d2 140-170, d4 25-32, d5 33-40, l1 190-210, l2 150-170, l4 250-280, l5 310-320, pg1 140-150, pg2 120-160, pg3 190-200, g1, g2 40-45, a1, a2 25-33. Male. Body length 500-520, width 150-170. Peritremes: longitudinal branch with 13-14 chambers, lateral with 4 chambers. Length of setae: vi 32-36, ve 50-56, sci 74-80, sce 120-135, h 90-100, d1 135-140, d2 13-22, d5 20-22, l1 24-45, l2 13-22, l5 180-200, pg1 90-110, pg2 70-90. S. glandarii is closely related to S. presentalis Chirov et Kravsova, 1995. It is distinguished from the latter species by following characters. In female S. glandarii, setae vi, ve are thick and serrate, ve 87-96 in length. In female S. presentalis, setae vi, ve are thin and nude, ve 40-70 in length. Syringophiloidus delichonum sp. n., female (holotype): body length 900, width 135. Peritremes: longitudinal branch with 8 chambers, lateral--with 1-2 chambers. All setae nude. Length of setae: vi 45, ve 90, sci 200, sce 200, h 225, d2 90, d4 35, d5 33, l1 140, l2 ?, 155-160 in paratypes, l4 230, l5 320, pg1 135, pg2 120, pg3 170, g1, g2 40, a1, a2 17. Male Body length 506, width 135. Peritremes: longitudinal branch with 9 chambers, lateral with 2 chambers. Length of setae; vi 33, ve 78, sci 90, sce 123, h 130, d1 135, d2 15, d5 17, l1 22, l2 15, l5 180, pg1 105, pg2 45. S. delichonum sp. n. is closely related to S. presentalis, but differs by following characters. In female S. delichonum sp. n., body length is 850-920; longitudinal branch of peritreme includes 6-8 chambers; setae ve 85-90 in length; in male, longitudinal branch of peritreme include 9 chambers. In female S. glandarii, body length 630-700; longitudinal branch of peritreme include 10-11 chambers; setae ve 40-70 in length; in male, longitudinal branch of peritreme include 11-13 chambers.     

利用核糖体DNA限制性酶切谱(ARDRA)分子技术和小亚基单位核糖体RNA(SSrRNA)基因序列分析对五种双眉虫(原生动物,纤毛门,游仆目)种内及种间关系的探讨

从12种限制性内切酶中筛选出6种可获得种间多样性的内切酶:Alu Ⅰ,Taq Ⅰ,Hae Ⅲ,Hinf Ⅰ,Msp Ⅰ,Xba Ⅰ,对广义双眉虫Diophrys-complex5个种(伪寡毛双眉虫Diophrys apoligothrix、悬游双眉虫D.appendiculata、盾圆双眉虫D.scutum、秀丽拟双眉虫Paradiophrys irmgard、针毛类双眉虫Diophryopsis hystrix)共7个种群的核糖体基因(18S小亚基、部分23S大亚基及其内转录间隔区域)进行多位点酶切。结果显示,种间差异明显大于种内差异。利用RAPDistance1.04软件构建的邻接树表明,盾圆双眉虫的3个种群表现出高度的同源性;3个近缘属(双眉虫属、拟双眉虫属、类双眉虫属)可以被明确区分,并支持类双眉虫属与拟双眉虫属的独立性。从GenBank/EMBL数据库中获得广义双眉虫及相近种的小亚基单位核糖体RNA(SSrRNA)基因序列,利用邻接法(NJ),贝叶斯法(Bayesian)和最大简约法(MP)构建的系统发生树具有基本一致的拓扑结构,结果显示:狭义双眉虫属Diophrys为单源发生系,并与类双眉虫属Diophryopsis组成姐妹群;尽管拟双眉虫属Paradiophrys具有广义双眉虫典型的形态学特征,但与尾刺虫属Uronychia有着较近的亲缘关系。本工作同时表明,核糖体DNA限制性酶切(ARDRA)技术可靠地区分纤毛虫的形态相似种,并在双眉虫属间水平的系统关系推定中存在一定的适用性。     

山羊蠕形螨扫描电镜观察

本文通过扫描电镜对寄生虫山羊体的山羊蠕形螨生活史各期颚体,足体和末体的超微结构观察,发现以下超微结构;一个圆锥状须乳突位于雌螨触须第２节背面;叶状背阳茎侧突和腹阳茎侧突竖立于阳茎同一基部,未受精雌螨船形阴门的一对瓣汇成纵线,雌螨交配后阴门半开,产卵后全部敞开,同时描述该螨的背基刺,锥状突,口下板,螯肢,基内叶,口孔,须爪和肛道等的超微结构,文中还讨论了锥状突,口下板,螯肢,基内叶,须爪和须乳突的功     

Quantitative analysis of sexual dimorphism and sex ratio in Hyphydrus ovatus (Coleoptera: Dytiscidae)

Sexual dimorphism in size, shape, and mass relative to length, and sex ratios are quantified for populations of Hyphydrus ovatus. a dytiscid beetle Males of H ovatus are not only longer than females, but also significantly larger in elytron length, thorax width, head width, leg length, total width, total depth, and abdominal segment length Two local populations differ slightly but significantly in total depth and abdominal segment length, but sexual dimorphism in size is similar for the two populations Hyphydrus ovatus are also sexually dimorphic in shape, with males having relatively broader heads and thoraxes than females The two populations differed slightly but significantly in relative abdominal segment length, but as with size, sexual dimorphism in shape is similar for the two populations Males are relatively heavier than females, although the slope of the log mass vs log length relationship is the same for the two sexes Sex ratios in field samples vary significantly over the summer, with percent females declining from c 50% to c 15% Sex ratios are significantly below 50% females m two of five monthly samples and in the total pooled set of samples Sexual dimorphism in size, shape, and relative mass, combined with male-biased sex ratios suggest that larger size of male H ovatus is a product of sexual selection