A Trio of Damsel Bugs
Damsel bugs or Nabidae are perhaps the closest thing the our countryside has to a a native preying mantis. These small predators use their large forelegs in a similar manner catching and restraining their prey before sucking out their insides. Prey comprises anything smaller than themselves or even includes each other if the opportunity presents itself. Nabids seem to have been particularly conspicuous over the past week or so, with three species being recorded from 3 sites, one of which being my garden.
Above is Nabis rugosus (the Common Damsel Bug), told from other species in part, by its small pronotum (tringle behind the wings just below the thorax) this is much larger in Nabis ferus (Field Damsel Bug below). Importantly N. ferus pronotum is wider than it is long. Another 'usually' more obvious feature is that N. rugosus tends to be brachypterus (the forewings stop before the tip of the abdomen) rather than the fully winged (macropterus) N. ferus which has wings which extend beyond the abdomen tip. As with many aspects of natural history this is not always the case as seen in the specimen above, who's wings clearly exceed/reach the abdomen tip. N. rugosus also tends to be a little smaller at 6.5-7.5mm compared to the more beefy N. ferus at 8-8.5mm.
Another rather beefy species is N. flavomarginatus (Broad Damsel Bug) at 7-9mm this is another brachypterus species, with its wings always stopping much shorter than the abdomen tip. It also has a beautiful covering of short golden hairs across its exposed abdomen at high magnifications, a good ID helper. The individual below, a female, shows the large developed forelegs for seizing prey really well.
These three Nabids are all characteristic of grassland environments, where the tussocks form a vast thick forest in which they can hunt during the summer. Niche separation within grassland habitats occurs between the three species with N. ferus preferentially choosing dry, well drained, grasslands. N. flavomarginatus has a preference for damp grasslands and N. rugosus is less selective being found across both. However saying that these three were all found outside of grasslands with the photographed N. ferus in my garden, N. rugosus in a woodland ride and N. flavomarginatus in a Juncus bed, albeit these habitats slightly matching their wider preferences if you stretch your mind a bit.
Both N. rugosus and N. ferus overwinter as adults. I typically find these two species amongst grass thatch, in tussock bases and beneath debris on grassland during the winter, where they clearly become active during warm weather, especially on sites with shallow soils like brownfield sites, quarries and local limestone grasslands. Both of these species complete their last moult in early autumn and do not mate until the following spring. N. flavomarginatus however adopts a different strategy laying eggs in the late summer months, these overwinter then hatch the following spring starting around early May.
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