Microhabitat use and seasonality of the sexually dimorphic West African centaurus beetle Augosoma centaurus

The sexually dimorphic dynastine centaurus beetle, genus Augosoma (Coleoptera: Scarabeidae), is endemic to tropical Africa where two species are found (A. centaurus and A. hippocrates). These beetles are consumed by rural populations, cause damage in plantations and are targets of insect collectors and traders. We present information on size differences and analyzed intersexual niche divergence and seasonality of A. centaurus in seven study sites in three West African countries (Ivory Coast, Togo and Nigeria). We recorded 711 light-attracted and/or opportunistically encountered individuals, as well as another 97 beetles in standardized transect surveys. In the latter, we found the adult sex ratio was equal, but was significantly skewed towards females in light-attracted and/or opportunistically encountered individuals. In a sample of 298 adult beetles, males were significantly larger than females, with almost no size overlap between sexes. Beetle activity was highly seasonal with most animals observed in November, active from 19:00 h to 24:00 h. Differences in habitat use were not significant between sexes, with most individuals observed in secondary forest. Males were found higher on vegetation than females and beetles of both sexes were found on Pandanus and raffia palms. Beetles were larger in sites with more vegetation cover, and there was a significant effect of tree species on body size of both sexes. Study area or country had no effect on any of the studied parameters. Our study confirms that transect surveys without light trapping can be an effective tool for understanding large-sized tropical beetles of similar ecological characteristics

Genome-wide association studies reveal novel loci associated with pyrethroid and organophosphate resistance in Anopheles gambiae

Resistance to insecticides in Anopheles mosquitoes threatens the effectiveness of malaria control, but the genetics of resistance are only partially understood. We performed a large scale multi-country genome-wide association study of resistance to two widely used insecticides: deltamethrin and pirimiphos-methyl, using sequencing data from An. gambiae and An. coluzzii from ten locations in West Africa. Resistance was highly multi-genic, multiallelic and variable between populations. While the strongest and most consistent association with deltamethrin resistance came from Cyp6aa1, this was based on several independent copy number variants (CNVs) in An. coluzzii, and on a non-CNV haplotype in An. gambiae. For pirimiphos-methyl, signals included Ace1, cytochrome P450s, glutathione S-transferases and the nAChR target site of neonicotinoid insecticides. The regions around Cyp9k1 and the Tep family of immune genes showed evidence of cross-resistance to both insecticides. These locally-varying, multi-allelic patterns highlight the challenges involved in genomic monitoring of resistance, and form the basis for improved surveillance methods

Essai de conservation des graines de niebe avec les huiles essentielles extraiteds de Cymbopogon schoenanthus L. Spreng. (Poaceae) et de Ocimum basilicum L. (Lamiaceae)

No Abstract. J. Rech. Sci. Univ. Lomé (Togo) Vol. 7(1) (Serie A) 2005: pp. 93-10

Evaluation de l’efficacite des moyens de lutte antivectorielle utilisés dans les ménages au Togo

Une étude réalisée à Lomé (Togo) a porté sur l’évaluation de la sensibilité des femelles d’Anopheles gambiae à jeun, âgées de 2 à 5 jours, aux classes d’insecticides utilisées en santé publique, sur la caractérisation des mécanismes de résistance, sur l’évaluation de l’efficacité de nouvelle génération de moustiquaires imprégnées à longue durée d’action (MILDA) et des produits insecticides à usage domestique. Les tests de sensibilité ont révélé que les moustiques sont tous sensibles au Fénitrothion 1% (100% de mortalité). Les bombes aérosols utilisés dans les ménages sont efficaces sur les moustiques à l’exception d’ORO, de MOBIL et de TOTAL. Quant aux spirales, seul le BAYGON a été efficace. L’identification spécifique a permis de mettre en évidence Anopheles gambiae s.s, Anopheles coluzzii et Anopheles gambiae. Anopheles coluzzii prédomine (95,55% spécimens) sur Anopheles gambiae (4,44% spécimens). La mutation génétique homozygote Kdr/Kdr est observée chez 81% spécimens d’Anopheles coluzzii contre 50% chez Anopheles gambiae. Une activité enzymatique élevée a été observée chez les spécimens de la souche sauvage. Toutes les MILDA testées sont efficaces même après les 20 lavages sur la souche Kisumu.Mots clés: Anopheles gambiae s.s, Anopheles coluzzii et Anopheles gambiae, Kdr, MILDA, insecticidesEnglish Title: Evaluation of the efficacy of household vector management tools used in TogoEnglish AbstractSusceptibility trials with 2 to 5 days old females Anopheles have been conducted in Lome (Togo) on insecticides used in public health and households. These trials concerned also the resistance mechanisms and bio efficacy of new generations of long lasting insecticidal nets (LLINs). The results showed that the mosquitoes were fully susceptible to Fenitrothion 1% (mortality: 100%). They were also susceptible to the  only mosquito coil BAYGON and most of the spray insecticides were effective except ORO, MOBIL and TOTAL. The specific characterization revealed the presence of only An. gambiae s.s with Anopheles coluzzii and Anopheles gambiae. Anopheles coluzzii is predominant (95.55% specimens) over Anopheles gambiae (4.44% specimens). Homozygote Kdr/Kdr has been observed in 81% of Anopheles coluzzii versus 50% in Anopheles gambiae. High enzymatic activity was obtained in most of the wild strain. All the LLINs were effective on the susceptible Kisumu strain even after 20 washes.Keywords: Anopheles gambiae s.s, Anopheles coluzzii and Anopheles gambiae, Kdr, LLINs, insecticides 

First report of the presence of L1014S Knockdown-resistance mutation in Anopheles gambiae s.s and Anopheles coluzzii from Togo, West Africa

Open Access Journal; Published online: 19 Mar 2018Background: To optimize the success of insecticide-based malaria control intervention, knowledge of the distribution of Anopheles gambiae species and insecticide resistance mechanisms is necessary. This paper reported an updated data on pyrethroids/DDT resistance in the An. gambiae s.l population from Togo. Methods: From December 2013 to April 2015, females of indoor-resting An. gambiae s.l were captured in three locations belonging to three different ecological zones. Resistance to DDT, permethrin and deltamethrin was screened in F1 progeny of collected mosquitoes using WHO susceptibility tests. The identification of species of An. gambiae complex and the detection of kdr and ace.1 R allele were carried out using DNA-based molecular techniques. Results: An. gambiae from Kovié and Nangbéto were highly resistant to DDT and permethrin with mortalities rate ranging from 0.83% to 1.58% for DDT and zero to 8.54% for permethrin. Mosquitoes collected in Nangbéto displayed 81.53% mortality with deltamethrin. An. coluzzii and An. gambiae s.s were found in sympatry in Nangbéto and Mango . The allelic frequency of L1014F was high, ranging from 66 to 100% in both An. coluzzii and An. gambiae s.s. For the first time we detected the L1014S allele in both An. coluzzii and An. gambiae s.s. from Togo at the frequency ranging from 5% to 13% in all the sites. The kdr N1575Y was present at various frequencies in both species ranging from 10% to 45%. Both An. gambiae s.s. and An. coluzzii shared the ace1 R mutation in all investigated sites with allelic frequency ranging from 4% to 16%. Conclusion: These results showed that multiple mutations are involved in insecticides resistance in An. gambiae populations from Togo including the kdr L1014F, L1014S, and N1575Y and ace.1 R G119S mutations