Wasp-Mimic Sawfly - Allantus viennensis
Having recently showcased 3 species of splendid Orthopterans over the last few posts, it's time to change viewpoints and examine pictures of a different insect order. At first glance, today's specimen may after to be a banded Wasp, but a closer look (or reading this post's title) reveals the identity of this insect as a Sawfly. While this specie's mimicry is very convincing when compared against several varieties of solitary Wasp, a lack of a wasp-waist (petiole) indicates that we aren't looking at a typical Hymenopteran. The visible saw-shaped "stinger" near the tip of the abdomen further lends from credibility to this mimic, but of course, it isn't a stinger. Instead of a venomous defensive tool, this Sawfly wields a saw-shaped ovipositor designed to make incisions into plants and strategically place her eggs safely. This is the way of the Sawfly, and if a specie is lucky enough to mimic the appearance of a more defensive Wasp specie in order for predators to leave them be as they search for rose plants, so much the better.
For this specie in particular (and as mentioned in an earlier post), the adult insect relies on roses as a suitable host for its eggs, but it may also be able to partake in a rose's nectar and pollen as a source of food, along with the nectar and pollen of other nearby flowers. That is of course, if other pollinators haven't taken the nectar reward first, if more aggressive pollinators (such as Wasps or Woolcarder Bees) don't force them away, and if they actually partake in eating flower-related consumables. Without a means to defend themselves beyond mimicry and flying away, a Sawfly must choose its battles carefully. Nevertheless, flight and deception are better defenses than what the wingless, soft-bodied, wriggling larvae have in their arsenal. As they feed, it's likely they would curl up to protect themselves or fall to the soil below in they sensed a nearby threat or intruder, such as a gardener. If you're a decorative gardener with a fondness for roses, this may be one specie to watch out for. Although I spoke in an earlier post that this specie may skeletonize rose leaves, it would appear was mistaken. Looking at records of this insect's feeding behavior in Europe (its original habitat), the larvae can defoliate roses entirely with their feeding habits (even eating petals on occasion) and appear to pupate within the stem(s) of the rose plant after growing large enough. An aggregation of this larvae could prove to be a gardener's nightmare!
Pictures were taken on June 4, 2020 with a Google Pixel 4.
