Platynaspis luteorubra (Goeze, 1777)
Ant-nest Ladybird

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POLYPHAGA Emery, 1886

CUCUJOIDEA Latreille, 1802

COCCINELLIDAE Latreille, 1807

CHILOCORINAE Mulsant, 1846

Platynaspis Redtenbacher, 1843

This very widespread ladybird is generally very local and scarce over much of its range, it occurs in grassy lowland and low mountain habitats throughout Europe from the Mediterranean north to southern parts of the UK and Fennoscandia and east through Asia Minor to Afghanistan, Kazakhstan and Siberia. Here it is widespread in the southeast; from the Wash to Dorset and there a few coastal records from South Wales and the West Country, the typical habitats are dry pasture, meadows, grassy hillsides, forest margins and road verges, especially on open calcareous or sandy soils exposed to the sun. The species is a specialist myrmecophilous ladybird that exploits aphids tended by various ants, in the UK especially the Black Garden Ant, Lasius niger (Linnaeus, 1758) but in Europe also Tatramorium caespitum (Linnaeus, 1758) and other species, adults usually occur low down among grass and herbaceous vegetation although have occasionally been found on various trees and shrubs, they generally appear by sweeping but usually as single specimens and appear never to occur in numbers, they are present year-round, overwintering among tussocks and leaf-litter or under bark and are active over a long season from early spring. Both adults and larvae predate a range of aphid species as they hunt among vegetation but larvae also develop underground, feeding on subterranean aphids among or near to ant nests, they are thought to grow through the summer and either produce new-generation adults later in the year or a small proportion of larvae or pupae may overwinter and produce adults in the spring. Both larvae and pupae differ from the usual coccinellid forms, presumably as an adaptation to living among ants. Larvae are pale brown or grey, oval and continuous in outline with all body segments widely transverse, the margins are fringed with stiff hairs of several different lengths and the robust and pointed legs are concealed beneath the body, the head is produced forward when the insect is hunting but can be retracted into the thorax when threatened, the lateral margins of the body are rather steeply angled and the dorsal surface is flattened, they are often found among dense colonies of aphids being tended by ants. The pupa is pale yellowish brown, turning dark when as the adult forms, cylindrical in form and covered with erect setae of various lengths, it is generally formed on the upper surface of a leaf, near to the midrib, and they may also form underground.

Platynaspis luteorubra 1

Platynaspis luteorubra 1

Platynaspis luteorubra 2

Platynaspis luteorubra 2

© U.Schmidt

Platynaspis luteorubra 3

Platynaspis luteorubra 3

© Lech Borowiec

Adults are small, 2.5-3.5mm and finely pubescent and so might be confused with some of our maculate species of Nephus Mulsant, 1846 or Scymnus Kugelann, 1794 but the present species is generally larger and may be distinguished by the form of the clypeus which is pale and extends broadly below the eyes, covering the labrum. Body elongate-oval and continuous in outline, about 1.5X longer than wide, black with two spots on each elytron and the pronotal margins pale, head yellow in males, black in females, legs pale brown, entire dorsal surface finely punctured and pubescent; on the elytra parallel to the suture, on the pronotum oblique or horizontal, ventral surface black and densely pubescent. Antennae 10-segmented and short, inserted below the clypeus. Legs robust, with strongly flattened femora and tibiae and tarsi of typical coccinellid form; 4-segmented with a strongly lobed second segment largely concealing the tiny third segment, terminal segment elongate and claws with a distinct basal tooth.