In a search for an entomopathogenic nematode to control cranberry insect pests, three Oscheius populations (Rhabditidae) were recovered through the Galleria-bait method from one sample taken in a wild cranberry marsh in Jackson County, Wisconsin, USA. Morphological studies with light microscopy and scanning electron microscopy, as well as molecular analyses of the near-full-length small subunit rDNA gene, D2/D3 expansion segments of the large subunit rDNA gene, internal transcribed spacer, and mitochondrial cytochrome oxidase subunit 1 (CoxI) genes revealed this as Oscheius onirici, a species recently described from a karst cave soil of central Italy. The species belongs to the dolichura-group and is characterized by its DNA sequences; hermaphroditic reproduction; and males not found. A Bacillus-like bacterium appears to be associated with this nematode based on our microscopic and SEM observations; however its identity and persistent association with the nematode has not been confirmed. Nonetheless, this nematode is capable of infecting and killing the sparganothis fruitworm Sparganothis sulfureana Clemens (Lepidoptera: Tortricidae), the brown-banded cockroach Supella longipalpa Fabricius (Blattodea: Ectobiidae), and the cranberry fruitworm Acrobasis vaccinii Riley (Lepidoptera: Pyralidae), under laboratory conditions, and each in less than 72 hr. The mealworm Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae) and the greater wax moth Galleria mellonella Linnaeus (Lepidoptera: Pyralidae), are also susceptible, but take 3.5 and 5.2 days to die, respectively. This species is a new potential bio-control agent on insects.

The processes by which organic life is consumed and reborn in a complex ecosystem were investigated through a multiomics approach applied to the tripartite Xenorhabdus bacterium- Steinernema nematode- Galleria insect symbiosis. Trophic analyses demonstrate the primary consumers of the insect are the bacteria, and the nematode in turn consumes the bacteria.

The spotted-wing drosophila, Drosophila suzukii Matsumura, is an exotic species in North America and represents a major threat to fruit production. Efforts to manage D. suzukii have focused primarily on insecticides, but such controls may, at times, be unreliable, given that D. suzukii larvae are often ensconced within fruit. The fruit interior, however, may represent suitable foraging substrates for carnivorous/entomopathogenic nematodes. In preliminary trials, a rare nematode species, Oscheius onirici Torrini et al., was shown to be highly virulent against D. suzukii when the nematodes were applied directly to fly larvae. To address the more important question of whether this nematode would be as virulent when applied to fruit, we set up assays in which blueberries were infested with D. suzukii larvae and then sprayed with O. onirici infective juveniles (IJs). Across two laboratory trials, O. onirici IJs suppressed D. suzukii puparia by 78.2%. Oscheius onirici IJs were able to search effectively within fruit substrates, find the fly larvae therein, and kill the flies before they could pupariate. Oscheius onirici, therefore, may represent a viable new bio-control agent for D. suzukii management and should be field-tested across a broader diversity of cropping systems.

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