Ovipositional strategy of Dineulophus phtorimaeae de Santis (Hymenoptera: Eulophidae), a natural enemy of the tomato moth Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a major pest in tomato crops in South America, and it is currently considered an important invasive species in Europe and Northern Africa. Its biological control is a tool of increasing interest to be applied in Argentina and abroad. Previous works have reported the larval ectoparasitoid Dineulophus phtorimaeae de Santis (Hymenoptera: Eulophidae) as an apparently synovigenic and non-concurrent host feeder with good potential for its use as biocontrol agent on T. absoluta. Ovigeny strategy of D. phtorimaeae was analyzed by registering egg production (oocytes in abdomen upon dissections + eggs laid on hosts), in adult females exposed to 6-8 hosts (3rd instar T. absoluta larvae) at 0, 3-, and 5 days after emergence (n=10 per age). Eggs were counted and measured. Host-feeding was also recorded. Naïve wasps emerged without mature eggs and since then, there was a progressive maturation of oocytes throughout adult lifetime. At age 3 days, no parasitism was observed. Females practiced host-feeding during the oocyte maturation process. Thus, a typical synovygenic behavior was confirmed for D. phtorimaeae. As reported elsewhere, host feeding is closely related to a synovigeny strategy because wasps need protein for egg development. This behaviour results advantageous for a biocontrol agent, by producing extra mortality.