Response of Tuta absoluta (Lepidoptera: Gelechiidae) to superparasitism of Pseudapantelesdingus (Hymenoptera: Braconidae): Implications for biological control

NIEVES, ELIANA LORENA; PEREYRA, PATRICIA CECILIA; LUNA, MARÍA GABRIELA; D´AURO, FRANCO; SÁNCHEZ, NORMA ELVA

Berlin

Congreso; XVIII. International Plant Protection Congress; 2015

Conventus Congressmanagement & Marketing GmbH

South American tomato pinworm Tuta absoluta causes great economic losses in tomatoes and disperses rapidly in Europe, Africa and Asia. Pseudapanteles dignus is themain larval endoparasitoid and despite being solitary, superparasitism is detected in field and laboratory. Host larvae in turn, respond to parasitism through encapsulation. Superparasitism of P. dignus and host response were examined in laboratory. We exposed 20-25 T. absoluta larvae to each P. dignus female (n=10) daily. Host larvae were removed and reared for 72h until dissection. Eggs and larvae/host and encapsulated individuals were recorded. Monoparasitized (MP) vs. superparasitized (SP) larvae were compared daily for each female. Frequency and efficiency of encapsulation (EF and EE), and survival probability of one parasitoid/host larvae were calculated for different levels of parasitism (1, 2,? n individuals). Percentage of offspring loss for each female was estimated by adding percentage loss due to SP (encapsulation + larval competition) + percentage loss in MP larvae due to encapsulation, at each level of parasitism. Of 1,705 dissected larvae, 50% were parasitized; 63% were MP and 37% were SP (P=0.05). Most frequent values were 2 (22%) and 3 (10%) parasitoids/host, though maximum number of parasitoids/host was 9. SP was observed throughout the lifetime of P. dignus female. During the first 3 days, no differences (P=0.05) were found between MP and SP, but SP decreased relative to MP with age female (Fig. 1). Since host larvae could contain both developing parasitoids and encapsulated eggs and larvae, the percentage of EE was lower than thepercentage of EF (Fig. 2). EF increased with P. dignus offspring / host, and was highest with 5 parasitoids (