Beijing News (reporter Zhou Huaizong) Recently, the reporter learned from the Chinese Academy of Agricultural Sciences that for the first time from the perspective of biological control, researchers have conducted research on the new major malignant invasive insect tomato leafminer moth, revealing its host selection behavior mechanism, which has promoted the understanding of the interaction between leafless pests and parasitic wasps. The results of the research are published online in General Entomology.
According to Zhang Yibo, an associate researcher at the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, the tomato leafminer moth belongs to the order Lepidoptera and the wheat moth family, and is a major malignant invasive species in the world, mainly attacking vegetables, fruits, tobacco, grain, sugar and other crops. It not only affects the photosynthesis of plants by submerging the leaves of the host plant, but also eats the stems and fruits of the plants, resulting in plant death and fruit shedding and rotting, causing huge economic losses. The pest has a wide range of hosts, large fecundity, short life cycle, serious generational overlap, and rapid spread, posing a huge threat to China's tomato industry.
Adult tomato leafminer moth in mating. Courtesy of the Chinese Academy of Agricultural Sciences
However, this powerful major pest also has natural enemies in nature, so at the level of biological control, the introduction of natural enemies with origin advantage is one of the important strategies for preventing and controlling these invasive alien species. It is understood that in November 2019, the Plant Protection Institute introduced its dominant parasitic bee leafminer moth Wasp from Spain. Leaf-diving moths have strong parasitic, feeding and direct lethality control behaviors for tomato leafminer moth larvae, and the biocontrol potential is huge, but the selection behavior of tomato leafminer moth hosts is not clear.
Based on the harm situation of tomato leafminer moth in China, researchers have studied the mechanism of parasitic tomato leafminer moth of leafminer moth, and found that leafminer moth Wasp has four typical host selection behaviors for tomato leafminer moth larvae, namely parasitism, feeding, direct death and rejection. The four host selection behaviors contain 8 different behavioral units, namely search, prick, combing, egg layer insertion (egg layer stabbing, egg layer agitation, egg laying), feeding host fluid, rest, etc. The researchers plotted a flowchart of the three host selection behaviors of parasitic wasps parasitism, feeding and direct death. The ovipositic insertion behavior of parasitic wasps is divided into three behavioral units of ovipositer stabbing, ovipositor agitation and egg laying, based on these three behavioral units, the selection behavior of parasitic bees to the target host can be quickly judged.
There are four behavioral units of leafminer moth female wasp rest (A), oosome assassination (B), feeding on the main fluid of the host body (C), and spawning (D). Courtesy of the Chinese Academy of Agricultural Sciences
The study also found that parasitic wasps tend to feed on larvae of the 1-2 instar tomato leafminer moth, parasitizing 3-instar larvae and directly killing 4-instar larvae. As the host age increased, the duration of selective behavior of parasitic wasps increased significantly.
According to reports, this research result has laid a theoretical foundation for the research and development of the technical system for the control of tomato leafminer moth using the parasitic bee. The research was funded by the National Natural Science Foundation of China and the National Key R&D Program.
Beijing News reporter Zhou Huaizong
Edited by Tang Zheng Proofreader Wei Zhuo