Propylea quattuordecimpunctata (Linnaeus, 1758)
A generally common Palaearctic species occurring throughout Europe to the arctic circle and east through India and Pakistan to China and Japan. Repeated introductions to the U.S.A. in the 1960’s were unsuccessful. During 1987-1993 more than half a million lab-reared beetles were released into sixteen western U.S. stated to help control the Russian Wheat Aphid (Diuraphas noxia (Kurdjumer)) but follow up studies have not detected and established populations. However, nowadays (2015) it has become widespread and is found coast to coast from Canada to Mexico. It is established in Canada from accidentally introduced specimens. This is the only species of the genus to occur in the U.K. It is common or abundant throughout England and Wales north to the Scottish borders and including all the islands. In Scotland there are records scattered north to Inverness including a few from the Western Isles. There are records scattered throughout Ireland. The species occurs from lowlands to subalpine regions in a wide range of habitats; forests, arable land, parks, gardens and wasteland etc. Adults and larvae feed on soft-bodied insects, typically aphids and whiteflies but also mites, caterpillars and insect eggs etc. They occur on a very wide range of broadleaf trees, shrubs and herbaceous plants generally, in fact anywhere that can provide a sufficient prey population. Adults can also feed on pollen and nectar and may be found on a variety of flowers, perhaps more particularly umbels, in warm weather. The species overwinters in the adult stage and this usually lasts longer than in other ladybirds, adults sometimes not seen until early May in the U.K. During mild spells they become active; in January 2013 we found them locally in several locations active beneath Rumex leaves. Winter is generally passed near to the ground, among grass tussocks, leaf litter or in stems but they may also join groups of other overwintering ladybirds e.g. Adalia bipunctata Linnaeus or Coccinella undecimpunctata Linnaeus. The beetles are thought to overwinter twice. Each female lays a total of around 400 eggs in batches of 4-15 on stems or leaves and development is rapid; in the United States development from egg to adult in 12 days has been recorded. The larvae are distinctive; pale grey with the centre and lateral margins of each segment white and with a pair of black marks either side of the middle. The larval stage lasts about two weeks and the first pupae are seen in late June or July. The pupal stage lasts for about two weeks before the adult ecloses. Fresh adults tend to be more deeply coloured than older ones. Adults can exude a very pungent orange defence fluid from the joints when handled. They generally remain common until August or September, occasionally later.
This is a very variable species but most specimens seen will be of the typical form with the central ‘anchor’ mark. At least 7 varieties have been named and there is a very rare melanic form. There are some very striking dark forms worth a look online.
3.5-4.5mm. Elongate and strongly rounded, ground colour yellow, with very variable black marks but the typical form is by far the most abundant. Upper surface glabrous. Head yellow with the base black, finely punctured and microsculptured. Frons yellow in the male, in the female there is a dark spot in the centre. Clypeus narrowed in front of eyes. Mouthparts and antennae yellow. Antennae longer than the head width, with a 3-segmented club. Segments 3-9 elongate, terminal segment rounded at apex. Mandibles bidentate at tips. Pronotum transverse and broadest at the rounded hind angles. Hind margin rounded and weakly sinuate. Side margins weakly edged and front angles produced forward. Surface finely punctured and microsculptured, with 6 dark marks which are usually fused to some extent; often into a single characteristic mark. Scutellum triangular, very finely punctured and microsculptured. Elytra punctured and shiny, the puncturation stronger than that on the pronotum, without microsculpture. Typical pattern of dark marks distinctive, variable but with the suture dark, a character shared only with Tytthaspis. Margins explanate laterally but this narrows towards the apex. Underside mostly black but the meso- and metepimera are conspicouosly white. Entire surface with sparse pale pubescence. Prosternal process with strong longitudinal ridges either side so that it appears furrowed. Front margin of the first abdominal segment broadly rounded between the meta coxae and finely bordered. Legs mostly yellow but the coxae and femora are black to some extent, often almost entirely so. Claws smooth, with a tooth at the base which may appear as a rounded, translucent lobe. A rare melanic form occurs f. merheri.
PROPYLEA Mulsant, 1846
A small genus of 4 Palaearctic and Oriental species. All feed on small insects etc and all are superficially similar in appearance. 2.5-5mm. With, in typical forms, yellow or orange ground colour and various dark markings. All occur on a wide range of trees and shrubs and several have been used as biological control agents. In temperate regions development is very rapid.
Propylea dissecta (Mulsant, 1850) is widely distributed through India, Pakistan and further east. A notably variable species.
Propylea japonica (Thunberg, 1780). Occurs throughout India, Pakistan and east to China and Japan.
Propylea quattuordecimpunctata (Linnaeus, 1758). A widespread Palaearctic and Asian species.
Propylea luteopustulata (Mulsant, 1850) Widespread in Asia and east to Japan and Thailand. A dull orange species with black marks arranged in transverse bands on the elytra. Trialled as a biological control agent in Japan.