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Aphid Predator (Coleoptera: Coccinellidae)
Cream-streaked ladybirdOn this page: Identification & Distribution Biological Control of Aphids
Identification & Distribution
The cream-streaked ladybird, Harmonia quadripunctata, is a very variable species. The 'typical' form of this ladybird (see first picture below) is bright red with 16 or 18 black spots, and streaked with cream. But in many specimens, most of the black spots are missing (see second picture below), leaving only the four marginal spots, two on each side. This form gave the name 'quadripunctata' to the species. The elytra usually have pale outer edges. The pronotum is white with a fairly consistent pattern of black markings, 7 of which are large and bold. The underside of Harmonia quadripunctata is dark with orange-brown sides.
Second image copyright entomart. The fourth-instar larva (see third picture above) is black, with thick dorsal spines coming from each tubercle, each branching from the base into three prongs. It has a bright orange line on each side, made from orange spots on the dorsolateral tubercles of abdominal segments one to four. There is one pair of orange dots on the inner dorsal tubercles on abdominal segment four.
Second image copyright entomart.
The fourth-instar larva (see third picture above) is black, with thick dorsal spines coming from each tubercle, each branching from the base into three prongs. It has a bright orange line on each side, made from orange spots on the dorsolateral tubercles of abdominal segments one to four. There is one pair of orange dots on the inner dorsal tubercles on abdominal segment four.
The cream-streaked ladybird is the most common large ladybird found on conifers, usually Scots pine, but also exotic pines, Douglas fir and Norway spruce, where it feeds on aphids. They may occasionally be found on herbaceous plants and shrubs such as nettle and gorse, but these are usually situated close to conifers. Harmonia quadripunctata is widespread from northern to southern Europe and in the eastern Palearctic and the Near East. They have also been found occasionally as vagrants in eastern North America, and may well be established in Massachusetts.
Biological Control of Aphids
Predation of conifer aphids
Various conifer aphids have been recorded as prey of Harmonia quadripunctata including the spruce-shoot aphid, Cinara pilicornis, (sometimes given as Lachnus pinicola) and the Scots pine adelgid, Pineus pini (Coleoptera Poloniae). We have found Harmonia quadripunctata on Scots Pine in Petworth Park, West Sussex, laying its eggs on the pine needles (see picture below).
On a neighbouring branch we found a group of newly hatched coccinellid larvae (see picture below) which were most likely this species given the presence of several ovipositing female cream-streaked ladybirds.
We have also found larvae of the cream-streaked ladybird on Montezuma Pine, Pinus montezumae, (see picture below) where they were feeding on a variety of eulachnids including the recently discovered (in Britain) Monterey pine needle aphid, Essigella californica.
Predation of almond aphids
Almatni and Khalil (2008) carried out a survey of natural enemies of Brachycaudus amygdalinus in almond and peach orchards during the seasons of 2002, 2003 and 2004 in southern Syria. 30 species of natural enemies were recorded, including 15 Coccinellidae, 4 of each Anthocoridae and Miridae, 3 of Syrphidae, one species of each of Chrysopidae and Chamaemyiidae, and one beetle, in addition to one parasitoid At the beginning of the season the most numerous predator was Coccinella septempunctata, followed later with Scymnus (Pullus) subvillosus and Hippodamia variegata. Harmonia quadripunctata was one of the less common coccinellid predators.
Biology & Ecology
Development rate and fecundity
Belyakova et al. (2016) looked at the influence of temperature, photoperiod, and diet on development and reproduction in the cream-streaked ladybird, Harmonia quadripunctata. A constant temperature of 30°C was lethal to the embryos. The lower developmental threshold was 12°C with a total egg-to-adult development period of 274 degree-days. Development was somewhat faster under short-day conditions, the threshold for this photoperiodic response being approximately 14 h at the rearing temperatures of 20 and 25°C. The preoviposition period (measured from adult emergence to the first egg laid) also depended on temperature and had a lower threshold of 13.4°C and a sum of effective temperatures of 152 degree-days. Maximum fecundity was observed at 25°C and 16-h day length; under these conditions, the oviposition period lasted over 100 days, and the average lifetime fecundity was about 800 eggs per female.
At a temperature of 25°C, the mean body mass of newly emerged adults was greater for those individuals that during the larval stage had been fed on the green peach aphid, Myzus persicae, was about 20% greater than in those fed with the wheat aphid, Schizaphis graminum. Under short-day conditions, females of Harmonia quadripunctata entered reproductive diapause. The photoperiodic threshold for this qualitative response at the temperatures of 20 and 25°C was about 14 hours when fed on the peach aphid, and 15 hours when fed on the wheat aphid. Relatively small body size, low fecundity, and a strong photoperiodic response that hinders rapid adaptation to novel climates probably explain the fact that Harmonia quadripunctata, in contrast to Harmonia axyridis, has not become an aggressive invader.
Coexistence with ants
It is generally believed that most aphidophagous insects avoid ant-tended colonies of Homoptera, owing to the ant aggression they encounter there. However, because aphid colonies which are ant-tended often persist for longer than untended colonies, some aphid-eaters may utilise ant-tended Homoptera when untended colonies are scarce. Furthermore, a few coccinellids such as Coccinella magnifica are myrmecophilous (habitually coexisting with ants). In order to investigate the occurence and possible evolution of myrmecophily amongst Coccinellidae, Sloggett & Majerus (2000) studied the aphids and aphidophagous coccinellids on Scots pine, Pinus sylvestris, growing in areas foraged and unforaged by the wood ant, Formica rufa.
A number of conifer aphids species were present including ant-tended Cinara species and non-tended Schizolachnus pineti. The latter species exhibited a marked population decline in late summer, but persisted in both areas at very low density. Facultatively-tended Cinara aphids exhibited higher population densities when associated with wood ants, and by late summer remaining colonies of these aphids were only found associated with ants. Coccinellids exhibited considerable variability between species in their level of association with wood ants, and there was some evidence of an increase in certain species' frequencies of occurrence with the ant in late summer when Cinara aphids were all ant-attended. Coexistence with ants appears to be associated with either their need for high aphid densities as young larvae, as in Harmonia quadripunctata and Coccinella septempunctata, or with extreme dietary specialization, as in Myzia oblongoguttata. The need for high aphid densities as young larvae was probably of importance in the initial stages of the evolution of myrmecophily in Coccinella magnifica.
Rate of spread
Harmonia quadripunctata is often regarded as a native species of coccinellid in Britain, but its arrival is fairly recent following the expansion of its range northwards within Europe (Majerus & Kearns, 1989). It is not considered an invasive species, and certainly its rate of spread was much slower than that of the congeneric Harmonia axyridis. Harmonia quadripunctata was first recorded in Britain in East Anglia in 1937, and took 50 years to spread west to Devon in south-west England. It took Harmonia axyridis just two years to spread from East Anglia to Devon! (Brown et al., 2008).