WilliamB's picture

Large Birch Sawfly (Cimbex femoratus)

Observed: 22nd April 2011 By: WilliamBWilliamB’s reputation in InvertebratesWilliamB’s reputation in InvertebratesWilliamB’s reputation in Invertebrates
P1000271 1
P1000271 1 2
P1000271 1 2 3
P1000271 1 2 3 4
P1000271 1 2 3 4 5
P1000271 1 2 3 4 5 6

This is the adult that emerged from the larva I posted picture of July 5th. 2010. Can someone tell me if it's eating an insect or are those mouth parts I can see hanging out?

Species interactions

No interactions present.


DavidNotton's picture


The stuff under the head is the mouthparts, best seen in pic 4 & 6, at the front a pair of mandibles, and behind is the labio-maxillary complex comprising two maxillae each with a long palp and labium with two short palps. The mandibles are used to chew through the cocoon, and can deliver a powerful defensive bite. Many sawflies actively attack and feed on smaller insects, I don't know if this is true for cimbicids but if so the mandibles would be useful for that. The labiomaxillary complex works as a functional unit in processing food items into the gullet, the palps are sensory. Also it is used for cleaning the legs etc. which are drawn through the mouthparts. The structure is broadly similar in most insects with variations on a theme, sometime extreme. http://en.wikipedia.org/wiki/Insect_mouthparts

WilliamB's picture


The mandibles I recognised, but as for the labio maxillary complex, well I will try to remember in future. Thanks a lot David.