The aim of this study was to evaluate the effect of temperature (10, 15, 20, 25, 30 and 35°C), on the development time and lifetime fecundity of Trichopria anastrephae Lima, 1940 (Hymenoptera: Diapriidae) parasitizing Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae). D. suzukii pupae that were up to 24-hr old were submitted to T. anastrephae parasitism for 24 hr. They were placed in plastic containers (50 ml) (ten pupae per container) in climatic chambers at temperatures of 10, 15, 20, 25, 30 and 35°C ± 1°C with a relative humidity of 70% ± 10% and a 12 hr photoperiod. For the adult phase, T. anastrephae couples that were up to 24 hr old were each placed in plastic cages (300 ml) and kept at the same temperatures cited above until their deaths. The higher numbers of parasitism and offspring production were obtained at temperatures between 15 and 25ºC. At the temperatures of 10 and 35ºC, there was no emergence of individuals. The lower thermal threshold (Tt) for the egg to adult period was ≈ 14.6°C for males and females with thermal constants (K) of 384.61 and 432.90, respectively. In terms of the fertility life table, T. anastrephae at 20 and 25°C presented shorter generation time (T) and higher net reproductive rates (Ro) in relation to other temperatures. The data show the ability of T. anastrephae to adapt to different thermal conditions, which is important for biological control programmes of D. suzukii.

The parasitoids Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae) and Trichopria anastrephae Costa Lima (Hymenoptera: Diapriidae) have great potential in controlling Drosophila suzukii (Matsumura); however, both, compete for the same resources. In this study, we evaluated whether the different stages of development of the primary parasitoid reduce the negative effect of intrinsic competition. For this, we first defined the duration of each immature stage of both parasitoid species and then offered D. suzukii pupae containing the first parasitoid (P. vindemmiae or T. anastrephae) at different stages of development to the second parasitoid (P. vindemmiae or T. anastrephae). We also checked the second parasitoid’s preference (P. vindemmiae or T. anastrephae) for the primary parasitoid at different stages of development (P. vindemmiae or T. anastrephae) or D. suzukii pupae nonparasitized. Our evaluations showed that T. anastrephae preferred to parasitize pupae that were not previously parasitized and that had not parasitized puparia of D. suzukii when P. vindemmiae was in later stage to the 1st instar. However, P. vindemmiae preferred to parasitize pupae previously parasitized by T. anastrephae. In an environment of intrinsic competition, the first parasitoid to parasitize has an advantage, except when the pupal stage of T. anastrephae is parasitized by P. vindemmiae. The variation in the parasitoids’ oviposition time mitigates the competition effect; however, for use in biological control programs, the hyperparasitoids P. vindemmiae, does not prove to be advantageous, as they can affect the establishment of primary parasitoids such as T. anastrephae, and can act as competitors for resources.

Palpita forficifera Munroe, 1959 (Lepidoptera: Crambidae) is the main pest of the olive tree (Olea europaea L., Oleaceae) in Brazil. We observed the stink bug Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) predating larvae of P. forficifera in olive orchards. Therefore, the aim of this study was to register the occurrence of this predator in olive orchards as well as verify the predation of nymphs of P. nigrispinus when offered different numbers of P. forficifera larvae. In laboratory bioassays, it was verified that duration (days) of insects of 4th and 5th instars of P. nigripinus was prolonged when fewer larvae were offered (Dietary regime 1). The average consumtion of 3rd instar larvae of P. forficifera per instar of P. nigrispinus was superior for the dietary regime 2, where there was a greater availability of preys, resulting in a higher total consumption of larvae of P. forficifera over time. In addition, in the availability of larger quantities of P. forficifera larvae, adults of P. nigrispinus showed a higher weight gain. The sex ratio was not affected by dieraty contition. This study reports the first occurrence of nymphs and adults of P. nigrispinus predating larvae of P. forficifera in field, and shows the predation potential of P. nigrispinus in larvae of P. forficifera, demonstrating the importance of preserving this natural enemy in olive orchards.

In South America, the resident pupal parasitoid Trichopria anastrephae Costa Lima (Hymenoptera: Diapriidae) is a potential biological control agent of the pest Drosophila suzukii Matsumura (Diptera: Drosophilidae). In the present study we 1) examined the behavior of T. anastrephae towards different host (D. suzukii) and host-substrate (strawberry) cues in choice and non-choice bioassays in laboratory, and 2) examined the density-dependent parasitism of T. anastrephae in D. suzukii-infested strawberries in a greenhouse. We tested infested and non-infested strawberries for the behavioral assays in a four-chamber olfactometer. For the greenhouse bioassay, we set five walk-in cages with strawberry plants in a greenhouse, released D. suzukii adults, and then released different numbers of parasitoids (0, 60, 120, 240, and 360) in each cage. In non-choice bioassays, female parasitoids showed a preference towards D. suzukii-infested strawberries containing larvae, pupae or inoculated pupae, or healthy overripe fruits. When given a choice, female parasitoids walked longer over chambers with fruits infested with eggs, larvae, or pupae of D. suzukii, when compared to healthy uninfested strawberries, and over overripe fruits when compared to unripe or ripe fruits. In the greenhouse assay, we observed an increase in parasitism and a decrease in the number of D. suzukii emerging per fruit with an increase in the number of parasitoids released. Our results allow a better understanding of the behavior and parasitism of T. anastrephae in D. suzukii-infested strawberries and provide useful data for potential biological control programs using this parasitoid.

Hymenopteran parasitoids, like any other insect, employ strategies to ensure their reproduction. Here, we present mating strategies used by the pupal parasitoid Trichopria anastrephae Lima (Hymenoptera: Diapriidae), a potential biocontrol agent of the invasive pest species Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Adults from this species emerge in the first hours of photophase, and males emerge before females, demonstrating that T. anastrephae is a protandrous species. Parasitoid age when first mated influences the parasitism and sex ratio. Younger females result in a higher number of offspring, while older males result in a more female-biased sex ratio of offspring. Both males and females are polygamic, and the order in which a female is mated by the male affects parasitism, viability of parasitized pupae, and sex ratio of offspring, with the first female performing the highest parasitism and sex ratio, but the lowest viability. Females that are allowed to mate multiple times generate lower numbers of offspring when compared to virgin or single-mated females, but the highest sex ratio. Data present in this study can be used to improve parasitoid rearing and field releases of T. anastrephae, to be used in biological control programs for D. suzukii.