Thread subject: Diptera.info :: Under bark of dead beech (NL)

Posted by blaauw7 on 05-02-2017 11:06
#1

Found yesterday under bark of dead beech. Mid Netherlands. length 11 mm.

Gr Dick

Posted by blaauw7 on 05-02-2017 11:06
#2

2

Posted by blaauw7 on 05-02-2017 11:06
#3

3

Posted by Paul Beuk on 05-02-2017 16:01
#4

I think a larva of Xylota.

Posted by blaauw7 on 05-02-2017 21:42
#5

Thanks Paul.

If I read this http://www.dipteristsforum.org.uk/documents/DD/df_1_9_Colour_Guide_to%20Hoverfly_Larvae.pdf

I will end up with Chalcosyrphus.

Chalcosyrphus CUITan, 1925
Overall appearance. A short-taileD, slightly dorso-ventrally flattened larva; mouth-hooks internal; thorax with two groups of 1-2 black hooks, each group lateral to the anterior spiracle; below these hooks and separate from them there may be a smaller single black hook (c. nemorum).
Confirming characters. Anterior fold with a narrow band of 3-4 rows of spicules, second row with the largest spicules; prolegs small with 6 to 8 primary crochets; anal segment slightly extendeD (like X. segnis in Plate lit) with three pairs of evenly sized lappets.
Related taxa. Similar to Tropidia and other hook-bearing hoverfly larvae. The one or two groups of hooks on the lateral margins of the thorax and dorso-ventrally flattened shape with a barely extendeD anal segment distinguishes Chalcosyrphus from these taxa.
Biology. Larvae are found in sap runs and under bark in acumulations of decaying sap



Gr Dick