12 research outputs found
Impacts of Bacillus thuringiensis var. israelensis and Bacillus sphaericus insect larvicides on mosquito larval densities in Lusaka, Zambia
The study assessed the impact of bio-larvicides- Bacillus thuringiensis var. israelensis (Bti) and B. sphaericus (Bs) on anopheline mosquito larval densities in four selected areas of Lusaka urban district. Larval densities were determined using a standard WHO protocol at each study area prior to and after larviciding. Ninety percent (90%) of the collected mosquito larvae and pupae were preserved in 70% ethanol, while 10% were reared to adults for species identification. Prior to larviciding, the largest number of mosquito larvae collected was culicines. Among the anophelines, Anopheles coustani Laveran (13.5%) (n = 111) and An. squamosus Theobald (9.5%) (n = 78) were identified from all the study areas with An. rufipes Gough (1.1%) (n = 9) collected from one study area only. None of the major malaria vector species reported for Zambia were identified. No mosquito larvae were found in freshwater bodies following the larviciding exercise. Possible reasons for the absence of known major malaria vectors could be the re-introduction of effective vector control and loss of suitable breeding grounds. The study highlights the potential of larviciding using Bti and Bs for malaria vector control and its integration with indoor residual spraying and insecticide treated nets
ISOLATION OF Cryptococcus neoformans FROM ENVIRONMENTAL SAMPLES COLLECTED IN SOUTHEASTERN NIGERIA
SUMMARY Cryptococcosis caused by Cryptococcus neoformans is the second most common fungal opportunistic pathogen and a lifethreatening infection with serious clinical manifestations especially in HIV/AIDS and other immunocompromised patients. In Nigeria, HIV/AIDS infection has reached an alarming level. Despite this, information on the presence of this fungus in clinical and environmental samples is very scanty in Nigeria and many other parts of Africa. We set out to evaluate the presence of Cryptococcus neoformans or C. gattii in pigeon droppings obtained from Southeastern Nigeria. One hundred and seventy-seven samples of pigeon droppings from six sample types were collected. The area covered comprised of ten cities and other locations spanning across five States in Nigeria. Using established techniques, Cryptococcus neoformans was isolated from 39 of the 177 (22.0%) samples overall. No C. gattiiwas isolated. Most of the isolates (32.4%) were recovered from dovecotes (11 of 34) followed closely by samples taken from markets (31.8%; seven of 22) and least from the church (4.0%; one of 25). The highest isolation rate (38.9%) was found in samples from Enugu-Ezike(seven of 23) while the least came from Afikpoand the other locations each with 9.1% isolation rate. This is the first large-scale screening of Cryptococcus neoformans from pigeon droppings in Nigeria. The ecological and epidemiological significance of these findings are discussed
Sounds, Behaviour, and Auditory Receptors of the Armoured Ground Cricket, Acanthoplus longipes
The auditory sensory system of the taxon Hetrodinae has not been studied previously. Males of the African armoured ground cricket, Acanthoplus longipes (Orthoptera: Tettigoniidae: Hetrodinae) produce a calling song that lasts for minutes and consists of verses with two pulses. About three impulses are in the first pulse and about five impulses are in the second pulse. In contrast, the disturbance stridulation consists of verses with about 14 impulses that are not separated in pulses. Furthermore, the inter-impulse intervals of both types of sounds are different, whereas verses have similar durations. This indicates that the neuronal networks for sound generation are not identical. The frequency spectrum peaks at about 15 kHz in both types of sounds, whereas the hearing threshold has the greatest sensitivity between 4 and 10 kHz. The auditory afferents project into the prothoracic ganglion. The foreleg contains about 27 sensory neurons in the crista acustica; the midleg has 18 sensory neurons, and the hindleg has 14. The auditory system is similar to those of other Tettigoniidae
Signaling or Not-Signaling: Variation in Vulnerability and Defense Tactics of Armored Ground Crickets (Acanthoplus Speiseri: Orthoptera, Tettigoniidae, Hetrodinae)
Male Orthoptera singing from exposed perches are at risk from acoustically- and visually-hunting predators. The defensive reactions of armored ground crickets (Acanthoplus speiseri) include falling silent, dropping from their perch, alarm stridulation and autohaemorrhaging. Male and female ground crickets show different reactivity (i.e. the number or intensity of defense tactics used) to predation, depending on level of exposure: calling males were more reactive when approached during daylight, compared with in the dark. During daylight, calling males were more reactive than silent, cryptic, males and females. The level of response presumably reflected the riskiness of the individual’s behavior and situation at that time. Plasticity of response to predation allows individuals to balance risky behavior (i.e. acoustic signaling from exposed perches) by being more reactive to potential threats
The effects of regulation, legislation and policy on consumption of edible insects in the global world
Cricket singing means rain: semiotic meaning of insects in the district of Pedra Branca, Bahia State, northeastern Brazil
Fungal agents in different anatomical sites in Public Health Services in Cuiabá, state of Mato Grosso, Brazil
INTRODUCTION: A contribution to the regional epidemiological profile of the most common fungal agents in Public Health Services in Cuiabá, state of Mato Grosso, including university hospitals and polyclinics. METHODS: Clinical specimens (n = 1,496) from 1,078 patients were collected, submitted to direct mycological exam (potash or stick tape method) and cultured in specific mediums. Dermatophytic and non-dermatophytic agents were identified according to micromorphology (Ridell technique). RESULTS: The majority of the 1,496 specimens were skin (n = 985) and nail exams (n = 472). Of the 800 positive cultures, 246 (30.8%) corresponded to dermatophytes and 336 (42%) to yeasts of the genus Candida, 190 (23.7%) to other yeasts, 27 (3.4%) to non-dermatophytic filamentous fungi and one (0.1%) the agent of subcutaneous mycosis. Lesions considered primary occurred in greater numbers (59.5%) than recurrent lesions (37.4%), with a greater concentration of positivity occurring on the arms and legs. CONCLUSIONS: Comorbidities, allergies and diabetes mellitus were conditions associated with greater positivity in direct mycological exams and cultures. Positive culture was considered a definitive diagnosis of fungal infection and confirmed 47.8% of diagnostic hypotheses