Abstract  Parasitoids are important biological control agents for many agricultural pests. Mating and parasitizing hosts are the two most prominent behaviors of parasitoids and are essential for their reproduction and survival. Therefore, the identification of the infochemicals involved in mating and parasitizing is an important first step to understanding the chemical ecology of these species. In recent decades, state-of-the-art chemical analysis techniques, such as gas chromatography- electroantennographic detection (GC-EAD), has resulted in the identification of an increasing number of infochemicals that regulate parasitoid behavior. Herbivore-induced plant volatiles (HIPVs) and host-derived kairomones are two major categories of chemical cues guiding host detection. Based on this, the concept of “tritrophic” (plant-pest-parasitoid) interactions has been developed, significantly deepening our understanding of the mechanisms underlying host identification by parasitoids. Identification of parasitoid sex pheromones has been challenging due to their small body size and the correspondingly small amounts of sex pheromones released. The sex pheromone communication mechanism in a parasitoid, Campoletis chlorideae, has recently been elucidated. The results indicate that sex pheromones can enhance the parasitizing capacity of parasitoids by facilitating mating. In this review we summarize the infochemicals that regulate parasitoid behaviors and discuss the prospects and challenges of applying these infochemicals to control insect pests.