Description of the male Ixodes (Scaphixodes) unicavatus Neumann, 1908 (Acarina, Ixodidae)

The male, still unknown is described on the basis of one specimen from the Glenan Archipelago (Morbihan Country, France). This male is assigned as neallotype.     

The taiga tick Ixodes persulcatus (Acari: Ixodidae) in the Sakha Republic (Yakutia) of Russia: distributional and reproductive ranges

The finding of an unfed adult female of the taiga tick Ixodes persulcatus Schulze is reported from the northern part of Eastern Siberia (the central part of the Sakha Republic [former Yakutia]) of Russia. This finding supplements other reported single findings of the taiga tick in different sites of the central part of the Sakha Republic, thus increasing its distributional range. The reproductive range of the taiga tick is limited to two separate areas in the southern parts of the Republic. The most probable mode of tick introduction northwards from the border of the reproductive range is by spring bird migrations from their wintering areas to breeding sites. The possibility of the establishment of stable tick populations in the areas of introduction is also considered.     

Life cycle of Ixodes (Ixodes) loricatus (Acari: Ixodidae) under laboratory conditions

The life cycle of Ixodes (Ixodes) loricatus Neumann, reared in the laboratory, is described. Engorged females collected from opossums trapped in the states of Minas Gerais and S?o Paulo, Brazil, which were used to start the laboratory colonies, were designated as BMG and CSP, respectively. Larval and nymphal ticks from both colonies fed separately on Rattus norvergicus Berkenhout or Calomys callosus Rengger, whereas Didelphis marsupialis L and Didelphis albiventris Lund were used as hosts for BMG and CSP adults, respectively. Biological and developmental data obtained from ticks of both the BMG and CSP colonies that were reared separately for two consecutive generations were compared. The percentage of fed or molted ticks reared on C. callosus was higher than that recorded for ticks fed on R. norvergicus in the majority of the observations. Despite significant differences among several of the biological parameters, the pattern of the life cycles of the two tick colonies was similar. Results indicated that the mean life cycle duration of I. (I.) loricatus was approximately 7 mo from parental oviposition to the occurrence of F1 eggs, regardless of geographic origin or host species.     

Ixodes dammini (Acari: Ixodidae) in Indiana

Ixodes dammini Spielman, Clifford, Piesman and Corwin is reported from Indiana for the first time. Four specimens were taken from deer and one from a dog. All specimens are adult females and all were collected in 1987. The significance of this finding is discussed.     

Taxonomic status of Ixodes didelphidis (Acari: Ixodidae)

Ixodes didelphilis Fonseca & Arag?o was described in Brazil in 1952 as a new tick species that differed from Ixodes loricatus Neumann by the spiracular plate pattern. We have reared four tick colonies from different geographic areas in the laboratory that were started from single engorged females originally identified as I. didelphidis (BMG, colony ) and I. Iocicatus (CSP, PSP, and TRJ colonies). We analyzed the spiracular plate morphology of F1 adult ticks from each tick colony, compared their biological 11th, and performed a molecular analysis of the second internal transcribed rDNA spacer (ITS2) to test the validity of the species I. didelphidis. The spiracular plate analysis of laboratory F1 adult ticks yielded single females from the four colonies showed variations that invalidate morphological parameters for differentiation of loricatus and I. didelphidis. Biological data of the BMC, CSP, and TRJ colonies were similar. The biology ofthe PSP colony was not evaluated. The ITS2 sequence variations observed between the tick colonies ranged from 1.3 to 4.9%, and the similarity tree constructed by the neighbor-joining method with nucleotide distances showerl that the distances between the samples were similar to what is expected for intraspecific variations found in other ticks species. The morphological and biological results, in conjunction with the ITS2 analysis, supported the conspecificity I. loricatus and I. didelphidis.     

Seasonal activity and host associations of Ixodes scapularis (Acari: Ixodidae) in southeastern Missouri

Based on tick collections recovered from wild vertebrates and by dragging, the seasonal occurrence of adult blacklegged ticks, Ixodes scapularis Say, extended from October through May in southeastern Missouri. Adult activity was bimodal with the higher peak occurring in November followed by a lower peak in February. The activity of immature I. scapularis had the general pattern of that found in the Northeast where Lyme disease is hyperendemic, with larval activity (July) peaking after that of nymphs (May and June). Vertebrates varied in their importance as hosts of I. scapularis. White-tailed deer, Odocoileus virginanus (Zimmerman), and coyotes, Canis latrans Say, were the primary hosts of adult I. scapularis. Broad-headed skinks, Eumeces laticeps (Schneider), and eastern fence lizards, Sceloporus undulatus (Latreille), were the primary hosts of nymphal I. scapularis. The broad-headed skink, 5-lined skink, Eumeces fasciatus (L.), and Carolina wren, Thryothorus ludovicianus (Latham), were the primary hosts of larval I. scapularis. Homeotherms were important hosts of immature I. scapularis, accounting for 30% of nymphs and 39% of larvae collected. The eastern cottontail rabbit, Sylvilagus floridanus (Allen), may play an important role in the epidemiology of Lyme disease in Missouri. Isolates of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner were made from ticks recovered from rabbits, making the cottontail rabbit a key species for further study of the epidemiology of Lyme borreliosis in Missouri.     

Rickettsiella-like bacteria in Ixodes woodi (Acari: Ixodidae)

We examined a parthenogenetic strain of the hard tick Ixodes woodi Bishopp for the presence of endosymbiotic bacteria. Electron microscopic examination revealed the ovarian tissues and Malpighian tubules were infected with pleomorphic bacteria. Two basic types were observed: a larger granular cell and a smaller condensed cell. Cloning and sequence analysis of polymerase chain reaction (PCR) amplified 16S rRNA gene yielded a single sequence from bacteria present in I. woodi tissues. Phylogenetic analysis of the nearly complete 16S rDNA indicated that the ticks were infected with an endosymbiont belonging to the gamma subdivision of the Proteobacteria. It clustered with the insect pathogenic species Rickettsiellagrylli (Vago and Martoja 1963) and the animal pathogen Coxiella burnetii (Derrick 1939) Philip 1948. Our results suggest that the I. woodi females harbored a single endosymbiotic bacterium related to selected Rickettsiella species and to C burnetii.