Efficacy of abamectin against the fowl tick, Argas (Persicargas) persicus (Oken, 1818) (Ixodoidea: Argasidae).

Abamectin, in aqueous solutions of dose rates 0.0625, 0.125, 0.25, 0.5, and 1 mL/L, was sprayed on different feeding stages of the tick Argas (P.) persicus. The results revealed a marked increase of immobile and dead male or female ticks following a single treatment with the above doses, particularly the higher ones, and during the 5 weeks after treatment. Abamectin seriously decreased the percentage of fed ticks as well as that of oviposition and hatching. A decrease in the amount of emitted coxal fluid was observed also following treatment. Although the amount of ingested blood increased following abamectin treatment, digestion remained similar. The study also revealed that spraying a dose of 0.5 mL/L of abamectin in fowl shelters, i.e., floor, walls, ceiling, etc., is sufficient to eradicate A. persicus population.

Effect of ivermectin on the integument and dorsoventral muscles of the tick Argas (Persicargas) persicus (Oken) (Ixodoidea: Argasidae).

Light and transmission electron microscopy (TEM) revealed that integument of Argas persicus consisted of cuticle underlined with epidermal cells. Cuticle consisted of outer epicuticle and inner procuticle. Epicuticle is further subdivided into thin wax, thin electron dense cuticulin, and thick less electron dense protein epicuticle layers. The procuticle consisted of exo-, endo-, and subcuticle. The procuticle contained numerous pore canals emerged from epidermal cells. Dermal glands were scattered between epidermal cells. TEM showed that each muscle cell contained two types of myofilaments and numerous electron dense bodies. Cytoplasmic organelles are peripherally located and plasma lemma invaginated deeply forming sarcotubular system. Feeding resulted in marked increase in cytoplasmic organelles and secretions of both epidermal cells and dermal glands. It also led to stretching of myofilaments, proliferation of cytoplasmic organelles, and appearance of glycogen particles in muscle cells. Subcutaneous inoculation of ivermectin (IVM) at a dose of 400 mug/kg pigeon resulted in extensive alterations in the integument and muscle cells. Both exhibited intense vacuolation of the cytoplasm, damage of cytoplasmic organelles, and swelling of the nucleus. It also caused aggregation of pore canals in the procuticle, depletion of secretory vesicles in dermal gland cells, and destruction of myofilaments, dense bodies, and sarcotubular system in muscle cells. The results suggest that IVM probably binds to the neurotransmitters or the hormones involved in secretion processes of epidermal cells and dermal glands in the integument or those involved in contraction of dorsoventral muscles.

The fowl tick, Argas (Persicargas) persicus (Ixodoidea: Argasidae): description of the egg and redescription of the larva by scanning electron microscopy.

This scanning electron microscopy study revealed that the egg of Argas persicus was covered with chorion which appeared as a wrinkled layer containing regions of three textures. The first had elevated parts of slightly rough surface. The second had irregular smooth elevations; each carried numerous parallel horizontal foldings with vertical ridges. The last region had rough surface with irregularly shaped projections. Following the removal of the chorion, shell was observed to have one polar micropyle and numerous slit like openings. Length (L), width (W) and L/W ratio of the egg were measured. Investigation of larvae revealed extensively folded integument of idiosoma and spherical or elongated tubercles on dorsal plate. Mouth enclosed between ventral hypostome and two dorsal chelicerae. Hypostome carried four longitudinal rows of conical denticles. Each chelicera was made up of two segments; the basal one appeared as a pocket for the distal one. Haller's organ consisted of an anterior pit containing seven sensilla and a posterior capsule with four apertures. Distribution of chemo- and mechano-sensilla on the body was examined. Measurements of whole body, idiosoma, dorsal plate, capitulum, hypostome, palp and different types of sensilla both on the body and Haller's organ are also presented.

Impact of ivermectin on the ultrastructure of the testis of Argas (Persicargas) persicus (Ixodoidea: Argasidae).

Mated male Argas persicus were dissected 1 and 2 weeks after feeding on untreated and ivermectin (IVM)-treated pigeons. One week after feeding, testes of untreated ticks were filled with rounded spermatids with subplasmalemmal vesicles and cytoplasmic organelles, but lacking in treated ticks. Two weeks after feeding, testes were crowded with elongated spermatozoa supported by double-walled cisternal tubes. The tubes consisted of two opposite walls, each with outer-fringed processes and inner elongated cisternae. Both were supported with electron dense striated plates in the middle of the spermatozoon. Internally, the cisternal tubes contained mitochondria and vacuoles. The nuclei were elongated dense masses between the tubes and the cell membranes. Subcutaneous inoculation of IVM at the dose 400 microg/kg pigeon resulted in extensive alterations in the testis of A. persicus. IVM prevented the development of new spermatids. There was a break down of cell membranes and cytoplasmic organelles of spermatozoa. Multivesicular bodies and numerous vacuoles were noticed in their cytoplasm. Double membranes of elongated cisternae and striation of electron dense plates became indistinct. IVM caused granulation and vacuolization of the nucleus as well as injury of mitochondrial cristae. The results suggest that IVM may bind to the neurotransmitter or the hormone involved in the process of sperm development or may be toxic to the germinal cells of A. persicus testis.

Gram-negative bacteria from the camel tick Hyalomma dromedarii (Ixodidae) and the chicken tick Argas persicus (Argasidae) and their antibiotic sensitivities.

A total of nine species of gram-negative bacteria were isolated from organs and haemolymph of the hard tick Hyalomma (Hyalomma) dromedarii and the soft tick Argas (Persicargas) persicus. Four species namely Serratia liquefaciens, Stenotrophomonas maltophilia, Klebsiella ornithinolytica and Aeromonas hydrophila were isolated from H. dromedarii and five species namely Rahnella aquatilis, Pseudomonas fluorescens, Enterobacter cloacae, Chryseomonas luteola and Chryseobacterium meningosepticum were isolated from A. persicus. Isolated bacteria were identified using the analytical profile index 20E. Disk diffusion test was carried out on all isolated bacteria to determine antibiotic sensitivity of chloramphenicol, amoxillin/clavulanic acid, neomycin, streptomycin, triplesulphur tetracycline and nitrofurantion. The results were discussed.