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Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most devastating pests of tomato. We studied whether partially sterile T. absoluta males and fully sterile females were capable of suppressing wild populations of this moth in semi-controlled conditions. After irradiating T. absoluta pupae with 200 Gy, emerged males and females were released at 10:1 (treated:untreated) and 15:1 over-flooding ratios inside field cages containing tomato plants. The number of eggs and larvae produced was recorded once per wk during 3 mo. An over-flooding ratio of 10:1 caused a decline in larvae production compared with the untreated control cages, but these differences were not statistically significant. Using an over-flooding ratio of 15:1, the moth population in the cages with irradiated insects decreased significantly compared with those in the untreated control cages. In addition, the possibility of combining inherited sterility and a natural enemy as a strategy to manage this pest was investigated. We studied in no choice and choice tests the predation behavior of females of the egg predator Tupiocoris cucurbitaceus (Hemiptera: Miridae) on eggs derived from the following parental T. absoluta crosses:  U ×  U (control),  U ×  I and  I ×  U (where U = untreated, I = irradiated). In the no choice test, females of the T. cucurbitaceus readily consumed T. absoluta eggs regardless of their origin. In the choice test, T. cucurbitaceus females consumed similar numbers of eggs of untreated parents and eggs oviposited from crosses in which the male had been irradiated. However, the mirid females preyed on significantly more eggs-roughly 20% more-from irradiated females than on eggs from untreated females. We conclude that it is possible to achieve a certain level of suppression of a T. absoluta wild population through the release of irradiated insects, and that it is technically feasible to combine the use of the predator T. cucurbitaceus with inherited sterility to control this moth pest.

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1 The red gum lerp psyllid Glycaspis brimblecombei is an invasive insect species, native from Australia, that specifically feeds on Eucalyptus trees. It has invaded several countries throughout the world. In Argentina, it was first recorded in 2005, although little is known about its ecology in the region. 2 We assessed G. brimblecombei population development on Eucalypus camaldulensis and Eucalyptus dunnii using samples of branches for the immature stages and yellow sticky traps for the adults. We also identified the meteorological variables associated with changes in the red gum lerp psyllid abundance. 3 The abundance of eggs, nymphs and adults stages of G. brimblecombei was significantly greater on E. camaldulensis than on E. dunnii in the 2 years of the survey. 4 Glycaspis brimblecombei development was complete on E. camaldulensis where all instars were present, even in the unfavourable seasons. The full development of the psyllid population was not observed in E. dunnii where a high mortality of the first and second nymphal instars was detected. 5 Temperature and relative humidity were the variables that mostly affected red gum lerp psyllid abundance, whereas no effect of rainfall was detected.

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Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a key pest of tomato crops. Tupiocoris cucurbitaceus (Spinola) (Hemiptera: Miridae) is a neotropical predator capable of consuming T. absoluta eggs. We evaluated the life history traits of T. cucurbitaceus on three different diets: T. absoluta eggs from irradiated parental males and untreated parents, and Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) eggs (control). The nymphal development of T. cucurbitaceus was reached in 13 days with a similar survival for all diets (58-65%). Mirid female longevity and oviposition period were statistically similar when the diets consisted of T. absoluta eggs from untreated parents and S. cerealella eggs, although the number of nymphs laid was larger with the second diet. Moreover, mirid females feeding on T. absoluta eggs from untreated parents lived longer and laid double number of nymphs than when fed on T. absoluta eggs from irradiated parental males. The highest intrinsic rate of increase (r m ) was observed for the S. cerealella eggs diet, while differences were not observed between the two types of T. absoluta eggs. These results indicate that the mirid could develop and reproduce by feeding exclusively on both types of T. absoluta eggs. As conclusion, the use of more environmentally friendly strategies to control this pest, such as the biological control and inherited sterility, is possible through the release of T. cucurbitaceus and irradiated T. absoluta individuals.

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