foxy's picture


Observed: 6th February 2010 By: foxyfoxy’s reputation in Invertebratesfoxy’s reputation in Invertebratesfoxy’s reputation in Invertebratesfoxy’s reputation in Invertebrates

A 15-20mm caterpillar with pale line down back bordered with duller brown lines ,top half of body darker than lower half black spiracles and light chestnut brown head.

Species interactions

No interactions present.


foxy's picture

News to me !

When I found this caterpillar it was 150 mm under water on some plant stems.I assummed I had knocked it into the water in passing although it was 3-4 ft in front of me,today I received some books that mentioned aquatic moth larva and this caterpillar fits the description and available foodplants at site of observation.
The I.D should read Nymphula stagnata.



Martin Harvey's picture

aquatic larvae

Hi Foxy, which description does your caterpillar match (i.e. which book or website did you find)? I can't find much information on the larvae of Nymphula stagnata and the related aquatic pyralid moths, but what I have read suggests that they have fairly obvious gills along the body. Also, 15-20mm seems a bit on the large side for a caterpillar of this smallish moth.

Entomologist and biological recorder

foxy's picture

Aquatic larvae

Hi Martin,
the book is Collins pocket guide to freshwater life of Britain and Northern Europe.(page 134)
"body up to 20mm,yellow brown with darker head.Mine in tissue of Sparganium and may emerge only after pupation.Where foodplant is potamogeton natans or waterlily,younger larvae are miners,older emerging to make a case of cut leaf and silk.Widespread where foodplant is abundtant,".

As I said earlier it was on a stem under 6 inches of water I was surprised as it was a frosty night, and thought it unusual to see a caterpillar at all let, alone one under water and thought I may have dislodged it and knocked in to the water but thinking back it was to far in front of me when I saw it with my torch for this to be the case.

I had never heard of aquatic larvae either and presume by gills you mean like caddis fly larvae gills.Due to unrelenting frost here (averaging-5C)and falling water levels I have not seen anymore in the same area.

Thanks for i.d on crickets by the way