Tri-trophic-interaction
Guides
Bruchus loti
Bruchus loti is a seed-feeding beetle in the family Chrysomelidae that primarily attacks seeds of Lathyrus japonicus, a legume species. Its larvae bore through hard seed coats to consume seed contents, a behavior that can enhance germination by breaking seed dormancy. However, heavy consumption by unparasitised larvae reduces seed survival. The species is subject to parasitism by at least two idiobiont parasitoid wasp species, Pteromalus sp. and Dinarmus sp., which indirectly benefit the plant by reducing larval feeding intensity and improving seed germination outcomes.
Parasyrphus
Bristleside Flies
Parasyrphus is a genus of hoverflies (Syrphidae) comprising 31 described species distributed across the Holarctic region. Adults are small to medium-sized (5.6–11 mm) with characteristic yellow abdominal markings. The genus exhibits notable larval trophic diversity: most known larvae are aphid predators on trees, while at least two species (P. nigritarsis and P. melanderi) are specialist predators of leaf beetle eggs and larvae. This dietary specialization is unusual among syrphid flies and involves sophisticated chemical ecology where predators exploit prey defensive secretions as foraging cues.
Rhyssa persuasoria
Sabre Wasp, Giant Ichneumon
Rhyssa persuasoria is a large ichneumonid wasp and one of the largest in Europe, commonly known as the sabre wasp or giant ichneumon. Females possess an exceptionally long ovipositor used to drill into wood and parasitize larvae of wood-boring insects, particularly siricid woodwasps and longhorn beetles. The species has been introduced to several countries as a biological control agent for invasive woodwasps. It exhibits geographic variation in coloration patterns correlated with host tree bark characteristics, suggesting adaptive cryptic coloration.