Since the establishment of the brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) in North America and Europe, there has been a large, multi-group effort to characterize the composition and impact of the indigenous community of arthropod natural enemies attacking this invasive pest. In this review, we combine 98 indigenous natural enemy datasets spanning a variety of sampling methods, habitats, and geographic areas. To date, the vast majority of H. halys biological control research has focused on the egg stage, using sentinel egg masses to characterize indigenous parasitoid and predator communities and their contribution to H. halys egg mortality. Although egg parasitism and predation levels by indigenous natural enemies are low (typically <10% each) in most surveys, total egg mortality attributable to natural enemies can be higher (typically between 5 and 25%; up to 83%)—even though these values were likely underestimated in most cases because some mortality due to biological control was not recognized. In North America, where the most data are available, it appears that the relative prevalence of different indigenous parasitoid species varies among habitat types, particularly between crop and non-crop habitats. Predator species responsible for egg mortality are much less commonly identified, but appear to include a wide variety of generalist chewing and sucking predators. To date, studies of natural enemies attacking H. halys nymphs and adults are relatively rare. Based on our review, we identify a number of key research gaps and suggest several directions for future research

Experiments conÞrmed that female Pseudococcus longispinus (Targioni Tozzetti), Pseudococcus viburni (Signoret), and Planococcus ficus Signoret (Hemiptera: Pseudococcidae) must mate to produce viable offspring. Females of all three species were capable of mating multiple times on the same day and on sequential days (range, 1Ð 8 times). Female reproductive output was not increased by multiple copulations. Male P. longispinus, P. viburni, and P. ficus also mated multiple times during their lifetimes (maximum of 9, 11, and 19 times, respectively). Male P. ficus had the highest mean number of copulations (9.6 Ϯ 0.6), followed by P. longispinus and P. viburni. More than half of the P. ficus males survived their Þrst day of copulations and remated the next day when presented with unmated females. P. viburni males also readily mated with unmated females on the day subsequent to their Þrst copulations. Median times between copulations were short for males of all species (Ͻ2 min). Constant exposure to pheromone had no detectable effect on the activity levels of male P. ficus and P. longispinus, whereas P. viburni males exposed to pheromone emerged signiÞcantly earlier from their cocoons than control males without pheromone exposure. Constant exposure to pheromone had no effect on the longevity of males of any species compared with controls. The implications of the results of these experiments for pheromone-based methods of managing mealybugs are discussed.

Halyomorpha halys is an invasive, widespread stink bug for which only short-term solutions are currently available for pest control worldwide. The need for long-term management solutions for H. halys has driven studies on augmentative and classical biological control of this species, especially by its egg parasitoids. Numerous investigations in Asia, USA, and Europe on native and exotic egg parasitoids of H. halys, and the effects on non-target pentatomids, have improved the global knowledge of parasitoid-host relationships, uncovered new associations, and led to the discovery of new species. This trend continues with Acroclisoides sinicus, a pteromalid that was described in the 1980's from Asia. In this work we report recent findings of this species in North America and Europe. Moreover, we propose that Acroclisoides solus syn. nov., a species described originally from the USA, is conspecific with A. sinicus based on morphological and molecular analysis.

Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae) was found in southern California, USA, on March 17, 2014, in Riverside County, University of California Riverside Campus (UCR), and has been common there since then. It has also been found in other locations in southern California, including San Diego County (San Diego Safari Park on November 1, 2014), and Orange County (Laguna Niguel Regional Park). Specimens collected from UCR were compared with voucher specimens of O. maskelli collected from Lazio, Italy, and were found to be conspecific. This represents the first report of O. maskelli from the Western Hemisphere.

Operational parameters of traps baited with the pheromones of three mealybug species were optimized in nurseries producing ornamental plants. All pheromone doses (1-320 microg) attracted Pseudococcus longispinus (Targioni Tozzetti) and Pseudococcus viburni (Signoret) males, with the lowest dose (1 microg) attracting the fewest males for both species. Doses of 3.2-100 microg were as attractive to male P. longispinus as the highest dose (320 microg); doses from 10 to 320 microg were equally attractive for P. viburni males. Lures containing 25-microg doses of either pheromone had effective field lifetimes of at least 12 wk. Experiments were performed to test the efficacy of combining multiple pheromones to attract several species of mealybugs simultaneously. Lures loaded with a mixture of the pheromones of P. longispinus, P. viburni, and Planococcus citri (Risso) were as attractive to P. viburni and P. citri as lures with their individual pheromones. Response of P. longispinus to the blend was decreased by 38% compared with its pheromone as a single component. A subsequent trial with two-component blends showed that the pheromone ofP. citri was responsible for this modest decrease in P. longispinus response. This should not affect the overall efficacy of using these lures for monitoring the presence of all three mealybug species simultaneously. Pheromone traps were used to detect infestations of P. longispinus throughout the season and to track population cycles. When pheromone-baited traps for P. longispinus were compared with manual sampling, trap counts of male mealybugs were significantly correlated with mealybugs counted on plants in the vicinity of the traps.