Abstract:  Diglyphus wasps are important bio-control agents for agromyzid leafminer, and have been studied and applied widely all over the world. In view that the agromyzid leafminers on vegetables, especially the invasive species, have rapidly spread and caused serious damage in China, the knowledge on the species, distribution, the occurrence and ecological dominance of this parasitoid in the field, as well as its control characteristics, biological and ecological adaptability, and field application, will provide important guidance for the biocontrol of the agromyzid leafminers. All Diglyphus species are idiobiont ecto-parasitoids, and 36 species have been identified up to now. The dominant species and the species that have been studied extensively include D. isaea, D. begini, D. intermedius, etc. This parasitoid causes the death of host larvae not only by reproductive host-killing by parasitizing but also by non-reproductive host-killing by feeding on or stinging without feeding and oviposition. The females prefer to parasitize the hosts with large size but feed on the host larvae with relatively small size, and the preference of female parasitoids to host larvae shows the host-size-dependent sex allocation behavior. Of the Diglyphus species, D. isaea has the widest temperature adaption and control potential against the agromyzid leafminer. The mass-rearing of the dominant parasitoid has been developed and widely used in the field, showing good control effect. We propose that the future researches on this parasitoid can focus on the following aspects: (1) the researches on the dominant species especially the populations or strains with wide temperature adaption or heat resistance, so as to increase the control effect on Liriomyza trifolii and L. sativae; (2) the researches on the feeding behavior and physiology mechanism of females for more efficient application; (3) the development of the mass-rearing and releasing techniques of this parasitoid according to different regions; (4) the researches on the cooperative control, and the competiveness and coexistence mechanism of this parasitoid with other parasitoids of agromyzid leafminer, so as to enhance the biocontrol effect on the agromyzid leafminer.

Key words: Diglyphus, agromyzid leafminer, synovigenic parasitoid, host feeding, host-size-dependent sex allocation, mass rearing, mass releasing