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The specimens studied were collected with sweep net and pitfall in the forests, agro-forests, herbaceous fallows, and crop fields of 14 localities in the southern part of Cameroon, from August 2015 to February 2018. The results show that Heteracris hannai sp. nov. and Heteracris lecoqi sp. nov. differ from previously known species of the same genus by the pattern of coloration and the details or shape of the phallic complex. H. lecoqi sp. nov. is characterized by light brownish body; male cercus with flattened, downcurved and obtuse apex; lophus strongly curved; interlophal space with V shape; apodeme of cingulum bow, convergent, with V-shape; valve of cingulum in lateral view longer than apical valve of penis; ramus in ventral view joined. H. hannai sp. nov. is distinct to other species by brown to grey body; male cercus with apex rounded, curved inside; lophus curved; interlophal space with U-shape; apodeme of cingulum thick, slightly parallel, with U shape; valve of cingulum in lateral view hardly longer than apical valve of penis; ramus in ventral view opened. The characteristics of H. guineensis are closer to H. hannai sp. nov. than to H. lecoqi sp. nov. H. lecoqi sp. nov. was collected only in the fallows while H. hannai sp. nov. was collected in the forests, agro-forests, fallows, and crop fields. Compared to H. guineensis, both new species are scarce in the natural vegetation and their distribution area is limited to two and four localities respectively for H. lecoqi sp. nov. and H. hannai sp. nov. All these three grasshopper's species were recorded as accidental species in all types of vegetation.

The Littoral Region of Cameroon is one of the most highly disturbed regions in Cameroon that remain poorly studied and where no investigation regarding the grasshopper fauna has been conducted. Hence a survey was conducted from August 2015 to November 2018 in 11 localities of this region. In each locality, grasshoppers were sampled in three vegetation types (forests, fallows and cultivated farms) using sweep nets sampling method. We collected in total 51 short-horned grasshopper species belonging to the families Acrididae, Chorotypidae, Euschmidtiidae, Pyrgomorphidae and Thericleidae. Among these species, 43 belong to Acrididae, 5 to Pyrgomorphidae and only one belongs to the Chorotypidae, Euschmidtiidae and Thericleidae respectively. The Chorotypidae species Hemierianthus mbongueensis Yetchom Xu sp.nov. is also described in this study. Twelve grasshopper species were widely distributed as they occurred in all study sites and 11 were recorded exclusively from one study site. This study showed that there is high species richness of short-horned grasshoppers in the Littoral Region of Cameroon. However, more sampling effort in different ecosystems of this region and other regions of Cameroon will certainly improve our understanding on grasshopper taxonomy, ecology and biogeography.

Background: Biological invasions are recognized as a major cause of biodiversity decline and have considerable impact on the economy and human health. The African big-headed ant Pheidole megacephala is considered one of the world's most harmful invasive species., Methodology/principal Findings: To better understand its ecological and demographic features, we combined behavioural (aggression tests), chemical (quantitative and qualitative analyses of cuticular lipids) and genetic (mitochondrial divergence and polymorphism of DNA microsatellite markers) data obtained for eight populations in Cameroon. Molecular data revealed two cryptic species of P. megacephala, one inhabiting urban areas and the other rainforests. Urban populations belong to the same phylogenetic group than those introduced in Australia and in other parts of the world. Behavioural analyses show that the eight populations sampled make up four mutually aggressive supercolonies. The maximum distance between nests from the same supercolony was 49 km and the closest distance between two nests belonging to two different supercolonies was 46 m. The genetic data and chemical analyses confirmed the behavioural tests as all of the nests were correctly assigned to their supercolony. Genetic diversity appears significantly greater in Africa than in introduced populations in Australia; by contrast, urban and Australian populations are characterized by a higher chemical diversity than rainforest ones., Conclusions/significance: Overall, our study shows that populations of P. megacephala in Cameroon adopt a unicolonial social structure, like invasive populations in Australia. However, the size of the supercolonies appears several orders of magnitude smaller in Africa. This implies competition between African supercolonies and explains why they persist over evolutionary time scales.

We studied the behaviour of the invasive African myrmicine ant, Pheidole megacephala, when confronted with colonies of other common ant species in Cameroon, a part of its native range, and in Mexico, where it has been introduced. P. megacephala raided the nests of the other ants in both cases. Eleven species out of 12 put up a rather strong resistance to raiding P. megacephala workers in Cameroon compared to only three species out of 11 in Mexico, where only colonies of Solenopsis geminata, Dorymyrmex pyramicus and Dolichoderus bispinosus resisted these raids. We conclude that P. megacephala's heightened ability to successfully raid colonies of competing ants may help explain its success and the decline of native ants in areas where it has been introduced.

Background: Vitamin A deficiency is still a major health problem mostly affecting people in developing countries. It contributes to increased mortality and morbidity through current infection. In Cameroon, it is a public health problem mostly in the northern part where palm oil, which is a principal source of provitamin A in the south of the country, is not consumed., Aim: We carried out this research to discover the relationship between vitamins (A and E) and blood lipids in a normal rural population living in vitamin A-deficiency area., Design: A cross-sectional study with 81 healthy volunteers (40 men and 41 women) aged 3-61 (mean 18.32 +/- 1.63) years and living in two neighboring villages (Doyan and Larao) in the northern part of Cameroon, where previous studies revealed a prevalence of vitamin A deficiency of 33.3%., Methods: Serum concentrations of vitamins A and E were measured by fluorometric methods. Serum cholesterol and lipids were assayed by enzymatic methods., Results: The mean +/- standard error for vitamin A and E were 15.09 +/- 0.82; 526.99 +/- 29.57 mug/100 ml, respectively. The concentrations of the serum parameters analyzed were similar for both sexes, whereas the atherogenic ration of cholesterol (ARC) was significantly (p < 0.036) higher in women. Serum lipids (total lipids, total cholesterol, low-density lipoprotein and phospholipids) correlated with vitamins A and E (p < 0.05). Vitamins A and E were highly correlated with each other (r = 0.42, p < 0.001). Age was positively associated with vitamin A (r = 0.42, p < 0.001) and vitamin E (r = 0.29, p < 0.01). Deficiency of vitamins A and E constitutes a public health problem with more than 56% of the subjects having low levels of these vitamins, while subjects tested had a low risk for cardiovascular diseases., Conclusion: In this population we noticed normal lipid levels and vitamin A deficiency probably resulting from diets poor in provitamin A., (Copyright 2005 S. Karger AG, Basel.)

We determined plasma lipids and apolipoproteins A-I and B in 142 subjects from Ngaoundere, in the north of Cameroon, as a means of evaluating atherosclerotic risks. The mean triglyceride concentration was 0.836 +/- 0.174 g/l; mean total cholesterol concentration was 1.276 +/- 0.251; mean HDL cholesterol concentration was 0.162 +/- 0.222; mean apolipoprotein A-I concentration was 0.577 +/- 0.096 and mean apolipoprotein B concentration was 0.836 +/- 0.174. These values differ from those reported for Caucasian populations but are similar to those reported in other studies in Cameroon. All lipid factors except HDL cholesterol concentration increased significantly with age (p < 0. 05). There were also differences between the sexes, with mean triglyceride, LDL cholesterol, HDL cholesterol and apolipoprotein B concentrations significantly higher (p < 0.01) in men than in women. There was no significant difference between the sexes, however, in total cholesterol and apolipoprotein A-I concentrations. Thus advanced age and being male are risk factors for atherosclerosis in this population.