Atividade predatória, armazenamento e controle de qualidade de três espécies de mirídeos para o controle de Tuta absoluta (Meyrick)(Lepidoptera, Gelechiidae)

Abstract

Predatory mirid bugs such as Campyloneuropsis infumatus (Carvalho), Engytatus varians (Distant) and Macrolophus basicornis (Stäl) (Hemiptera: Miridae) have demonstrated great potential in the control of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). This is an alternative way to reduce the use of pesticides to control this pest. However, there is a lack of information on the adult predation rates, responses to the different storage periods, post-storage flight behavior and the quality of the individuals produced in a mass rearing system. The objectives of this work were: (1) to evaluate the T. absoluta eggs predation rates by males and females and their longevity; (2) to evaluate the combined effect of four storage periods, three relative humidity and two temperatures, on the survival, fecundity and longevity of the mirids females; (3) to evaluate the post-storage effect through the predator flight behavior and (4) to evaluate biological parameters (fecundity, longevity, sex ratio, predation rate and flight activity) of mirids produced in the laboratory. The daily consumption of T. absoluta eggs by E. varians males (17.30 eggs) and females (49.01 eggs) was significantly higher than the consumption by C. infumatus and M. basicornis males (13.34 and 11.19 eggs) and females (38.99 and 35.38 eggs), respectively. The longevity of E. varians (males and females) was significantly lower compared to C. infumatus and M. basicornis. The fitness and the fecundity and longevity of E. varians were negatively affected after storage. Campyloneuropsis infumatus presented its optimal combination for storage at the period of two days, relative humidity of 40% and at 12ºC. However, for M. basicornis, the most favorable combination for its storage is the two-day period in the highest relative humidity (20 and 40%) at 12ºC, providing high fecundity and longevity. Regarding to quality control parameters, the potential fecundity of C. infumatus (9.5), E. varians (9.4) and M. basicornis (9.5 oocytes per female) was similar to daily fecundity (10, 4, 10.3 and 11.7 nymphs/females, respectively). The females longevity did not differ between the three species (31.4; 33.7 and 34.6 days) for C. infumatus, E. varians and M. basicornis, respectively. The species C. infumatus presented a higher proportion of females (0.86) compared to the other two species of predators, which in turn was 0.5. The daily T. absoluta eggs consumption by E. varians (49 eggs) was higher than C. infumatus (38 eggs) and M. basicornis (35 eggs). There was no difference in flight activity between species of mirids after 4h of release, which was 100% of flying insects. Understanding the responses obtained by these data may be fundamental for the advancement in the mass rearing methods of these predators as well as in the evaluation of their potential and effectiveness for use in augmentative biological control.