Spermatogenesis in the Ixodid tick Haemaphysalis (Herpetobia) sulcata (Acarina:Ixodidae).

Haemaphysalis sulcata (Acarina, Ixodidae) is a common ectoparasite of wild artiodactyls (mouflon and wild goat) in Sierra Nevada (Granada, southern Spain). A study of the spermatogonial meiosis of 15 H. sulcata males was carried out. The diploid complement is 2n = 21 and its sex determination is XX:XO. The behavior of the chromosomes in the different stages of meiosis was also investigated, and the possible presence of a secondary nucleolar organizer region in H. sulcata is discussed.

Studies on the transmission of Theileria annulata to cattle by the tick Hyalomma lusitanicum.

The role of the ixodid tick Hyalomma lusitanicum Koch 1844 as a vector of Mediterranean or tropical theileriosis (caused by the protozoan parasite Theileria annulata Dschunkowsky et Luhs 1904) in southern Spain was studied. Hyalomma lusitanicum was the most common tick, and the only species of the genus Hyalomma L., found on T. annulata-infected cattle from the theileriosis enzootic area studied (province of Cádiz, southern Spain). Likewise, we found that all sera of the cattle previously considered as suspected of theileriosis by clinical signs, tested for T. annulata antibodies, were positive and all blood samples of these suspected cattle examined had infected erythrocytes. Partially fed H. lusitanicum adults were collected in the field on T. annulata-infected cattle in this enzootic area and fed on an uninfected calf in an experimental farm free of theileriosis and ticks. At approximately 3 weeks post-tick feeding on the calf, this became positive for T. annulata antibodies and T. annulata merozoites were found in erythrocytes from blood smears. These results show the ability of H. lusitanicum to transmit the protozoan parasite T. annulata to susceptible cattle and indicate that H. lusitanicum is probably an important vector of T. annulata in the enzootic area surveyed.