They can cause quite noticeable defoliation of dogwood shrubs but don’t kill the plants. In the landscape larvae can be removed from trees and killed by squishing or dropping them into boiling water, although this is not practical on a large scale. Having some of these in your garden is a wonderful way to not only control sawfly populations, but to eradicate them as well. This is a very primitive group – dating back 250 million years ago to the Triassic – and the majority (true sawflies, the Tenthredinoidea) are all herbivores, feeding on the foliage of many different plants, although one group (Orussoidea) are external parasites of wood boring beetles. Dusky birch sawfly, Croesus latitarsus, is a native species only found on birch. Naturalist Charley Eiseman has written about this interesting phenomenon on the BugTracks Blog at https://bugtracks.wordpress.com/2013/06/03/larvae-raining-from-pine-trees/. The striped, gray-green larvae with a black head and legs grow up to an inch long, feeding in groups only on the previous season’s needles.
When disturbed they hold on to the leaf with their front legs and wave their rear ends in the air. This question came to us over Twitter, and given my recent post about bee genetics I thought it was worth a discussion because it allows us to further explore the evolution of bees, wasps and ants. The parasitic Braconid wasp Asobara uses it to knock out the immune system of its host, while the predatory wasp Ampulex compressa uses it’s stinger to perform a very extreme version of host modification.
Symphyta are a sub-order of the order Hymenoptera. The eggs may be inserted into the plant tissue or glued to the surface. Larvae feeding habits can slow or stop plant growth, weaken leaves, and wilt stems. The ancestors of today’s wasps were thought to be plant-feeders, which shifted into parasitism. So let’s explore how different groups of wasps use their venom, and how male wasps defend themselves without this very important weapon. Sawflies are insects related to wasps and bees.
They favour open type flowers with large inflorescences of white or yellow. They lay their eggs inside the sawflies and, as their young grow, they feed on the host pest eventually killing it. https://www.amentsoc.org/insects/fact-files/orders/hymenoptera-symphyta.html People unfamiliar with sawflies may mistake this feature for a stinger, but there's no cause for concern. A handful have taken a couple pointers from the female wasp playbook and developed their own pointy defense mechanisms. How long do caterpillar stings last? The larvae feed on plants, and in plants as leaf miners or forming plant galls, and look very much like caterpillars.
Also, as an editorial note, this post contains some NSFW pictures of bug junk…so it might not be the most family-friendly post we’ve ever written. The light green larvae with orange heads grow to about ½ inch long as they feed on the upper leaf surface from mid-May through June, leaving only the leaf veins. The long, dark brown thing sticking out of her rear end is not a sting, but her ovipositor. In many species, males and females are similarly colored…so they’re protected because they look close enough to the girls to gain protection from their reputation. When columbine sawfl ies are numerous (L),damage can be dramatic (R). The larvae drop to the ground to overwinter in cocoons made of rotted wood.
There are around 10,000 species of saw fly in he world, and around 500 British species, although there are no native saw flies in New Zealand. If so, then they are sawfly larvae. https://www.earthlife.net/insects/symphyta.html. The Willow Sawfly, for example, is really good at defoliating willows. In addition to this species, there are two other sawflies that can be found on roses in Wisconsin. Sawfly larvae look like little slugs then they slowly start looking like caterpillars and then eventually end up looking like a cross between a fly and a wasp. ***image2***If you a sawfly infested tree or shrub near a window or other opening to the inside of your home, some of these larvae could have managed to find their way inside. Sawflies are not actually flies, but are in the same insect group as bees, wasps, and ants.
Most sawflies have a flat saw-shaped stinger which is great for slicing into things, but not so great at stabbing things. They secrete a slimy substance over their body surface that makes them resemble small slugs.
They often curl up into a circle when not feeding on the leaves. Keeping your trees and plants healthy. This morning I sort of forgot them when I was scraping mud from my shoes. The second step is to identify the plant on which they are feeding. https://www.extension.umn.edu/garden/insects/find/sawflies/ You could be describing the sawfly catepillar which can be found on many types of pine, spruce, birch, ash, willow or numerous other trees. Sawflies usually have one generation per year and spend the winter months in the larval or pupal stages. Birch leafminer, Fenusa pusilla, is a European species common on European, white, gray and paper birches but yellow and river birch can also be affected. This is called a ‘pseudostinger’, and it’s pretty much harmless because it doesn’t inject venom.