Workers of the pest ant Paratrechina longicornis participate in a type of group hunting. Each individual forages with its long antennae wide open and moves quickly (6.3 cm/s) along an erratic path surrounded by nestmates behaving in the same way and within range of a recruiting pheromone. They detect prey by contact with successful workers singly capturing and retrieving small prey and seizing larger ones by an appendage. Then they recruit nestmates at short-range; all together they spread-eagle the prey and retrieve them whole.

We studied the foraging and predatory behaviors of the invasive African myrmicine ant, Pheidole megacephala (F.) in its native range. Workers can singly capture a wide range of insects, including relatively large prey items. For still larger prey, they recruit at short range those nestmates situated within reach of an alarm pheromone and together spread-eagle the insect. These behaviors are complimented by a long-range recruitment (of nestmates remaining in the nest) based on prey size. P. megacephala scouts also use long-range recruitment when they detect the landmarks of termites and competing ant species, thus permitting them to avoid confronting these termites and ants solitarily.

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.

In the mutualisms involving certain pseudomyrmicine ants and different myrmecophytes (i.e., plants sheltering colonies of specialized “plant-ant” species in hollow structures), the ant venom contributes to the host plant biotic defenses by inducing the rapid paralysis of defoliating insects and causing intense pain to browsing mammals. Using integrated transcriptomic and proteomic approaches, we identified the venom peptidome of the plant-ant Tetraponera aethiops (Pseudomyrmecinae). The transcriptomic analysis of its venom glands revealed that 40% of the expressed contigs encoded only seven peptide precursors related to the ant venom peptides from the A-superfamily. Among the 12 peptide masses detected by liquid chromatography-mass spectrometry (LC–MS), nine mature peptide sequences were characterized and confirmed through proteomic analysis. These venom peptides, called pseudomyrmecitoxins (PSDTX), share amino acid sequence identities with myrmeciitoxins known for their dual offensive and defensive functions on both insects and mammals. Furthermore, we demonstrated through reduction/alkylation of the crude venom that four PSDTXs were homo- and heterodimeric. Thus, we provide the first insights into the defensive venom composition of the ant genus Tetraponera indicative of a streamlined peptidome.

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 µg/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.