The larvicidal activities of the peel oils of three citrus fruits against Culex pipiens.

The larviciddal action of three ethanol extracts of peel oils of lemon, grapefruit and navel orange were tested against the early 4th instar larvae of Culex pipiens and the resulting pupae. The LC50 were 18.5, 20.3 and 26.5 and the slope functions were 2.9, 2.9 and 3.9 respectively. The action of the lemon extract extended to the pupae which resulted from larvae exposed to sublethal dose. Some of the pupae were unable to escape from the larval exuviae.

Eimeria pipistrellus n. sp. from Pipistrellus kuhlii (Chiroptera: Vespertilionidae) in Saudi Arabia.

Fecal samples from 12 Pipistrellus kuhlii captured at Shagrah, Saudi Arabia, were examined for coccidia and three (25%) found to harbor a undescribed eimerian, herein described as Eimeria pipistrellus n. sp. Sporulated oocysts were subspherical, 24.8 x 23.2 (22-27 x 20-25) microns, with a bilayered and smooth wall. The micropyle was absent, but a large oocyst residuum and a single polar granule were present. Sporocysts were ovoid, 11.6 x 8.3 (10.5-13 x 7.5-9) microns, with a prominent Stieda body, but without a substiedal body; sporozoites lay head to tail in sporocysts and contained one large posterior refractile body. Eimeria pipistrellus n. sp. is the 3rd species of the genus Eimeria found from bats of the genus Pipistrellus.

Natural Lieshmania infection in sand cats captured in Riyadh district, Saudi Arabia.

Felis margarita or sand cat is a nocturnal carnivore occurs in sandy areas of desert in many African and Arabin countries. Ten sand cats were captured alive in Riyadh district. Indirect haemagglutioation reactions against leishmaniasis were detected in four of them at dilutions 1/64 (1), 1/512 (1) and 1/1024 (2). On the other hand, Leishmania amastigotes were detected in the splenic smears of four (40%), two of which had amastigotes in the liver smears as well (20%). Unfortunately, culture for typing was not done. The role of sand cats as zoonotic host of leishmaniasis was discussed.

Characterization of Leishmania aethiopica from rock hyrax, Procavia capensis trapped in Najran, Saudi Arabia.

Cutaneous leishmaniasis caused by L. aethiopica is endemic in Ethiopia, Kenya and South-west Africa. In a previous paper, the present authors reported natural Leishmania species infection in two hyraxes, P. capensis. In this paper, an isolate from a rock hyrax. P. capensis (Pallas, 1766) was enzymatically characterized by demonstrating the mobilities of seven enzymes, to be identical with the reference strain of L. aethiopica.

Natural Leishmania infection in rock hyrax, Procavia capensis (Pallas, 1766) order: Hyracoidea, trapped in Najran, Saudi Arabia.

Cutaneous leishmaniasis caused by Leishmania major (zoonotic, ZCL) and L. tropica (anthroponotic, ACL) is found in most countries of the Eastern Mediterranean Region. Phlebotomus papatasii is the proven vector of L. major and rodents Rhombomys opimus, Psammomys obesus, Meriones spp. and Gerbillus spp. serve as animal reservoirs. Ph. sergenti is the vector of L. tropica in the majority of endemic foci. On the other hand; in the Eastern African highlands (mainly Ethiopia and Kenya), stable foci of L. aethiopica are maintanined by hyraxes and transmitted by Ph. longipes and Ph. pedifer. In this paper, natural Leishmania sp. infection was demonstrated serologically (IHAT) and parasitologically (smear examination) in two out of four rock hyraxes trapped in the highlands of Najran, southern part of the Kingdom. It is concluded that the identity of the Leishmania parasite(s)in such a focus is essential since it has implication in control and treatment. Also, passive case-detection and isolates from man and sandfly in the vicinity of Najran for typing is a must.

Natural toxoplasma infection sought in the Indian grey mongoose (H. edwardsi, Greffroy, 1818) trapped in the eastern region., Saudi Arabia.

No doubt, the world wide distributed Toxoplasma gondii is more prevalent in nearly all the Middle East countries including Saudi Arabia. In this paper, natural Toxoplasma infection was sought in six mongooses trapped in the Eastern Region of the Kingdom. Four had seropositivity by the indirect haemagglutination tests (IHAT), the parasite was demonstrated in the spleen smears of two of them and Toxoplasma parasites were successfully isolated by mice I.P. inoculation from one of them. The results were discussed. It was concluded that Toxoplasma infection, a zoonotic protozoal parasite, is increasing in Saudi Arabia and its epidemiological status should be studied.

Morphological studies on Phlebotomus papatasi (Scopoli) in Riyadh City, Saudi Arabia.

In general, leishmaniasis is more or less a problem not only in Saudi Arabia but also in all countries of the Eastern Mediterranean Region. In Saudi Arabia, the most important form is zoonotic cutaneous leishmaniasis (ZCI.). It's main vector, Phlebotomus papatasi has been reported and incriminated by many authors. In this paper, the diagnostic morphology of P. papatasi as compared to other species found in Riyadh as well as the immature stages was given. This is considered as a base line data for studying the ecology and biology of P. papatasi. No doubt the best control strategy is based on complete understanding of the insect vector of ZCL.

The seasonal and daily activities of Phlebotomus papatasi in Riyadh, Saudi Arabia.

The seasonal abundance of P. papatasi was determined by monthly collection. It was found that the greatest number of sandflies occurred most commonly during the summer season with a peak in June and another one in September. Male to female ratio was 1:1.25 in Riyadh and 1:1.48 in Al Kharj. During the winter season no insect was found and then the population density started to appear again from March. The daily indoor activity of P. papatasi was in May, in the periphery of Riyadh city, showed largest amount of Phlebotomus from 10-11 pm. with sex ratio (male to female) 1:3.5 and from 4-5 am. with a sex ratio (male to female) 1:3. In the central area of Riyadh city, the highest number was from 9-11 pm. with a sex ratio (male to female) 1:3.5 also from 4-5 am. with sex ratio 1: 3. The daily outdoor activity was in June, in the peripheral area in Al Kharj city, showed the highest number from 7-9 pm. with a sex ratio (male to female) 1: 2.3 and from 5-7 am. with a sex ratio 1:1.3, while in the central area of Al Kharj, the highest number was from 7-9 pm. with a sex ratio 1: 1.1 and from 5-7 am. with a sex ratio 1: 0.9. Both the indoor and outdoor collections showed that the number of females P. papatasi were higher than number of the males, and the sandflies were more abundant in the periphery than in the central of both Riyadh and Al Kharj cities.

Antibodies against toxoplasma in commensal rodents trapped in Riyadh Region, Saudi Arabia.

Toxoplasma gondii, that protozoal parasite which causes toxoplasmosis, pays no respect to boundaries of Zoology and Geography. It has been reported in a large number of birds and mammals including man from nearly all over the world. In Saudi Arabia, the incidence of human infection ranges between 21% and 49.3%. In this paper, the level of antibodies against Toxoplasma in sera of different species of rodents was measured by the indirect haemagglutination tests (IHA). The seropositivities ranged between 12.5% (Mus musculus) and 41.7% (Rattus norvegicus). The overall rate of infection was 35.6%. The role played by rodents in the spreading of the Toxoplasma infection was discussed.

Babesia infection in rodents trapped in Riyadh Region, Saudi Arabia, with a general discussion.

Species of Babesia are intraerythrocytic protozoal parasites of many species of mammalians in all parts of the world where the tick-vectors are found. Babesiosis or piroplasmosis causes considerable damage to the livestock and other animals. Human babesiosis has been documented in many countries. Consequently, babesiosis is a zoonotic disease of medical, veterinary and economic importance. In this study, a total of 310 rodents of different species were trapped from different areas in Riyadh Region, Saudi Arabia. These rodents were; Rattus rattus (142), R. norvegicus (24), Mus musculus (8), Meriones crassus (56), Jaculus jaculus (16), Gerbillus cheesmani (50) and Acomys c. dimidiatus (14). Natural Babesia infection was parasitologically detected in 95 of them (30.65%). The highest infection rate was among R. rattus (34.5%). The lowest rate was among G. cheesmani (20%). None of the M. musculus was infected. Since most of these rodents are commensal ie living in close contact with man, a general discussion on the pathogenesis, immunity and diagnosis was given.

Investigation on the presence of Leishmania natural infection and antibodies among rodents in Riyadh, Saudi Arabia.

Leishmaniases whether cutaneous and/or visceral are one of the public health problems in nearly all countries of the Eastern Mediterranean Region. The prevalence and the incidence are increasing. Control of the animal reservoir hosts in zoonotic forms is one of the best means of measures against leishmaniasis. This paper aimed to screen rodents for their role as reservoir for leishmaniasis. Natural Leishmania infection was detected in one Meriones crassus out of 3 which had cutaneous lesions. The lesion present on Gerbillus cheesmani was negative for amastigotes. Anti-leishmanial antibodies as detected by indirect haemagglutination tests (I.H.A.T.) showed reaction among the seven species of the trapped rodents. However, by interpretation of the diagnostic value of I.H.A. only three M. crassus (3/512) and one Gerbillus cheesmani (1/256) gave seropositive reactions. The whole results were discussed.

Studies on the interrelation between rodents and their ectoparasitic acarines in Riyadh region, Saudi Arabia.

The ectoparasitic acarines of commensal and wild rodents collected from various areas in Riyadh Region were four species of mites (Laelaps nutalli, Ornythonyssus bacoti, Cheyletus eruditus and Articholaelaps glasgowi), and two species of ticks. (Immature stages) Rhipicephalus spp. and Hyalomma spp. In urban areas the highest infestation rate by mites was 49.9% on Rattus rattus followed by 18.5% on Rattus norvegicus. The highest rat-mite index was 2.3 on R. rattus followed by 1.3 on R. norvegicus and 0.1 on Mus musculus. In semiarid areas, the highest rat-mite index was 2.1 on Gerbillus spp. followed by 1.7 on Meriones spp., 1.6 on Jaculus jaculus and 0.9 on Acomys dimidiatus. The highest infestation rate by mites was on Meriones spp. followed by Gerbillus spp. and then A. dimidiatus.

Studies on the ectoparasites (fleas and lice) on rodents in Riyadh and its surroundings, Saudi Arabia.

A survey was conducted on rodents from the Riyadh City and surroundings. Two species of fleas, Xenopsylla cheopis and Ctenocephalides felis felis together with Polyplax spinulosa were collected. The highest infestation rate by both fleas occurred on Rattus rattus followed by Rattus norvegicus and Mus musculus. Females of R. rattus and R. norvegicus were more infested by fleas than males. On the other hand, Meriones spp., Gerbillus spp., Jaculus jaculus and Acomys dimidiatus were infested with X. cheopis and C.f. felis. The highest infestation rate by fleas occurred on Gerbillus spp. followed by Meriones spp.

Studies on commensal rodents in Riyadh City, Saudi Arabia.

A trapping survey in Riyadh revealed that the abundant commensal rodent species were Rattus rattus frugivorous (43%), R.r. alexandrinus (18%), R.r. rattus (14%), R.r. flaviventris (12%), Rattus norvegicus (9%), Mus musculus praetetus (3%) and Mus m. gentilulus (1%). R.r. frugivorous was the predominant species in all the nine selected areas. The male: female ratio was 0.4: 0.6 for both R. norvegicus and R. rattus. In both R. norvegicus and R. rattus, the mature rats outnumbered the immature ones.