Pointed-keeled Ladybird Rhyzobius litura

Other Names: Small Brown Ladybird, Pointed-keeled Rhyzobius

A common species of grassland habitats.

Identification Length 2.5-3.0mm

A pale brown, long-bodied oval species with long antennae.

Colour variable. Some are a pale yellow-brown lacking any dark markings.

Others are typically darker, a light oak brown colour, often with a dark U-shaped mark on the hind wing case.

Some have more extensive dark markings and can overlap with paler Round-keeled Ladybirds.

The pronotum (between head and wingcases) is gently curved, often still widening as it reaches the wing cases.

filsham pointed keeled ladybird_0776.JPG

Filsham Reedbeds, E. Sussex

Pigneys Wood, North Walsham, Norfolk

Gifford Wood, Epping Forest, Essex

Gifford Wood, Epping Forest, Essex

Rainham RSPB, Essex

Bowers Marsh, Lee Valley, Herts

Cornmill Meadows, Lee Valley, Essex

Clayton Hill, Lee Valley, Essex

With 24-spot and 16-spot Ladybirds

May Day Farm, The Brecks, Suffolk

The prosternal keel ( on the underside between the front pair of legs ) forms a narrow triangle with a pointed end. It resembles The Shard building in London.

Underside image taken with digimicroscope

Prosternal keel visible in digital camera image taken in the field

The shape and length of the antennae are distinctive and a very useful way to rule out look-alike beetle species.

The clubbed antennae are slightly longer than the head width. There is usually a distinct bend at the half way point. This combined with the antennae thinness and the fact that they are often held to the side gives them a resemblance to a wire coat hanger.

Antennae held forward but still with distinct kink at halfway point.

Antennae held in typical coat hanger pose

Right hand antenna held straight but kink still visible in left hand one

Both antennae held straight, but slight curve still visible

The above photograph is the only one of several hundred that I have of live Pointed-keeled Ladybirds that shows almost straight antennae.

When searching for photos on the internet, there many images of dead pinned Pointed-keeled Ladybirds from collections that have straight antennae held at 90 degrees from each other. Whilst this is not impossible on live specimens it is atypical. This is not representative of how this species usually looks whilst alive.

Habitat

This is a common species of grassland, often found with 16-spot and 24-spot Ladybirds whilst sweep netting.

It can be found by eye, but patience or luck is required.

With 16-spot Ladybird

With 24-spot Ladybird

Often in drier habitats such as hayfields and can be especially common in coastal areas.

Grassland

Upshire, Essex

Herb rich grassland

Gunpowder Park, Lee Valley, Essex

Dry grassland

Fishers Green, Lee Valley, Essex

Occurs in damper sites, such as edges of ponds and ditches and can also be found in Nettle patches

Grass on edge of pond Upshire, Essex

Grassy hollow with nettles Upshire, Essex

Streamside grasses and herbage

Cornmill Meadows, Lee Valley, Essex

Slightly damp flush in area of dry grassland

Fishers Green, Lee Valley, Essex

Patch of Black Horehound

Fishers Green, Lee Valley, Essex

Burdock seedheads

Silvermeade, Lee Valley, Herts

Nettle patch

Fishers Green, Lee Valley, Essex

Can occasionally be found in more mixed habitats, including gardens. I have found them in flower beds whilst clearing out old Daylilys Hemerocallis.

As ladybirds are mobile they can easily turn up in unexpected places and could be found amongst Round-keeled Ladybirds in ornamental shrubs. I have beaten 16-spot Ladybird

(another grassland specialist) out of Firethorn Pyracantha in a garden surrounded by grassland, so whilst habitat is a very good clue, other supporting features need to be checked.

Look-alike Species

Unidentified beetle swept from grassland

I swept the above unidentified beetle from grassland along side several Pointed-keeled Ladybirds. It was a similar size and the same colour as a pale individual but it did not quite look right. When I looked closer it was obvious that the antennae were too long for any ladybird species and they were held out straight and to the front.

This is typical of many other types of beetles, including the Leaf Beetles Chrysomelidae, several of which can be confused with various ladybird species. Checking the antennae is often the quickest way to rule out look-alike species.