Environmental Entomology (2019) 48, 404-409

David E. Jennings, Xiao-Yi Wang and Jian J. Duan (2019)
Influence of density on interspecific competition between Spathius galinae (Hymenoptera: Braconidae) and Tetrastichus planipennisi (Hymenoptera: Eulophidae), larval parasitoids of the invasive emerald ash borer (Coleoptera: Buprestidae)
Environmental Entomology 48 (2), 404-409
Abstract: The outcomes of interspecific interactions between parasitoids depend on a variety of factors. Understanding the influence of these factors is important for classical biological control, where the success of parasitoid releases partly depends on interactions with native and other introduced species. However, results from laboratory experiments may not always reflect those in the field, as densities may be artificially inflated. To mitigate this problem, we examined the effects of multiple densities on interspecific competition between two larval parasitoids of emerald ash borer (Agrilus planipennis Fairmaire): Spathius galinae Belokobylskij and Tetrastichus planipennisi Yang. Parasitoid species were housed individually or together at two different densities, and we measured the effects on percent parasitism and progeny production, before calculating the interaction strengths. We found no significant effects of parasitoid density on percent parasitism, but the effect of competition on parasitism generally was reduced at lower densities. However, there were significant differences in parasitism by species, with S. galinae parasitizing more larvae than T. planipennisi. There were also no significant effects of parasitoid density on the number of progeny produced by each species, though the effect of competition on progeny production was greater at higher densities. Similarly, though, there were significant differences between species in the number of progeny produced. Specifically, T. planipennisi consistently produced larger broods than S. galinae. Our findings complement existing research suggesting that competition between these two species in the field will likely be negligible.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Xiao-Yi Wang, Jian J. Duan

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Agrilus planipennis
Tetrastichus planipennisi (parasitoid)	Agrilus planipennis
Spathius galinae (parasitoid)	Agrilus planipennis