Glucosinolates present classical examples of plant compounds affecting insect-plant interactions. They are found mainly in the family Brassicaceae, which includes several important crops. More than 120 different glucosinolates are known. The enzyme myrosinase, which is stored in specialized plant cells, converts glucosinolates to the toxic isothiocyanates. Insect herbivores may reduce the toxicity of glucosinolates and their products by excretion, detoxification, or behavioral adaptations. Glucosinolates also affect higher trophic levels, via reduced host or prey quality or because specialist herbivores may sequester glucosinolates for their own defense. There is substantial quantitative and qualitative variation between plant genotypes, tissues, and ontogenetic stages, which poses specific challenges to insect herbivores. Even though glucosinolates are constitutive defenses, their levels are influenced by abiotic and biotic factors including insect damage. Plant breeders may use knowledge on glucosinolates to increase insect resistance in Brassica crops. State-of-the-art techniques, such as mutant analysis and metabolomics, are necessary to identify the exact role of glucosinolates.

The intolerable burden of malaria has for too long plagued humanity and the prospect of eradicating malaria is an optimistic, but reachable, target in the 21^st century. However, extensive knowledge is needed about the spatial structure of mosquito populations in order to develop effective interventions against malaria transmission. We hypothesized that the microbiota associated with a mosquito reflects acquisition of bacteria in different environments. By analyzing the whole-body bacterial flora of An. gambiae mosquitoes from Burkina Faso by 16 S amplicon sequencing, we found that the different environments gave each mosquito a specific bacterial profile. In addition, the bacterial profiles provided precise and predicting information on the spatial dynamics of the mosquito population as a whole and showed that the mosquitoes formed clear local populations within a meta-population network. We believe that using microbiotas as proxies for population structures will greatly aid improving the performance of vector interventions around the world.

The ecological context in which mosquitoes and malaria parasites interact has received little attention, compared to the genetic and molecular aspects of malaria transmission. Plant nectar and fruits are important for the nutritional ecology of malaria vectors, but how the natural diversity of plant-derived sugar sources affects mosquito competence for malaria parasites is unclear. To test this, we infected Anopheles coluzzi, an important African malaria vector, with sympatric field isolates of Plasmodium falciparum, using direct membrane feeding assays. Through a series of experiments, we then examined the effects of sugar meals from Thevetia neriifolia and Barleria lupilina cuttings that included flowers, and fruit from Lannea microcarpa and Mangifera indica on parasite and mosquito traits that are key for determining the intensity of malaria transmission. We found that the source of plant sugar meal differentially affected infection prevalence and intensity, the development duration of the parasites, as well as the survival and fecundity of the vector. These effects are likely the result of complex interactions between toxic secondary metabolites and the nutritional quality of the plant sugar source, as well as of host resource availability and parasite growth. Using an epidemiological model, we show that plant sugar source can be a significant driver of malaria transmission dynamics, with some plant species exhibiting either transmission-reducing or -enhancing activities. The Anopheles coluzzii mosquito is an effective vector of human Plasmodium falciparum malaria. Besides feeding on blood, females readily feed on natural sources of plant sugars; but how plant diversity affects their ability to transmit malaria parasites is currently unknown. Here we show that mosquito feeding on peridomestic plant- and fruit-derived sugar sources can affect its interaction with P. falciparum, and hence malaria transmission. The planting of anti-Plasmodium plant sugar sources may represent a promising alternative strategy to contribute to the control of malaria.

Native mosquito repellent plants have a good potential for integrated mosquito control in local settings. Ocimum forskolei, Lamiaceae, is used in Eritrea as a spatial mosquito repellent inside houses, either through crushing fresh plants or burning dry plants. We verified whether active repellent compounds could be identified using gas-chromatography coupled electroantennogram recordings (GC-EAD) with headspace extracts of crushed plants.