Biology, images, analysis, design...
|"It has long been an axiom of mine that the little things are infinitely the most important" |
Pomegranate aphidOn this page: Identification & Distribution Biology & Ecology Natural enemies Other aphids on the same host Damage & Control
Identification & Distribution
Adult apterae of Aphis punicae are yellowish-green, green or grey-green with siphunculi pale green to brown with darker apices (but wholly dark in spring) and a pale cauda (cf. Aphis achyranthi, Aphis aurantii, Aphis craccivora, Aphis fabae and Aphis spiraecola, which all have both the cauda and siphunculi very dark). All the segments of antennae are pale, except for the base of segment VI and the terminal process which are darkened. The antennae are almost half as long as the body, with the terminal process about twice as long as the base of antennal segment VI. The rostrum does not reach the third pair of coxae. There are marginal tubercles on the pronotum and on abdominal tergite I. The legs are pale, with tarsi dusky to dark. The siphunculi are 1.1-1.5 times the caudal length. (cf. Aphis gossypii, which usually has siphunculi more than 1.5 times the length of the cauda). The cauda is 0.35-0.44 times as long as the width of the head across the eyes, and has 7-9 hairs (cf. Aphis gossypii, which usually has 4-7 hairs on its cauda). The anal plate is dark. The body length of adult Aphis punicae apterae is 1.0-1.7 mm.
Images above by permission, copyright Sunil Joshi & Poorani, J. Aphids of Karnataka (accessed 12/2/20).
Aphis punicae alatae (see second picture above) are greenish-brown and have secondary rhinaria distributed 4-11 on antennal segment III, and 0-5 on segment IV. The first picture below shows a clarified mount of an aptera of Aphis punicae - note the cauda and legs are actually pale in this species, but seem to stain more intensely in these preparations.
Aphis punicae typically colonize the upper sides of mature leaves of pomegranate (Punica granatum), concentrating along the midribs and around the leaf margins. It is also found on the flowers and fruits, and is considered a major pest in pomegranate orchards. It has also been recorded from pigeon berry (Duranta erecta) and common lantana (Lantana camara) (both in Verbenaceae), crossvine (Bignonia sp.) and trumpet vine (Capsis radicans) (both in Bignoniaceae), and cape leadwort (Plumbago auriculata = P. capensis) (Plumbaginaceae). Aphis punicae is native to the Mediterranean area, but is now also found in the Middle East, Ethiopia, India, Pakistan, Japan, and Korea.
Biology & Ecology
Yaghobi et al. (2018) looked at the natural enemies of Aphis punicae in Ilam in the Kurdish region of Iran, where the aphid is an important pest of pomegranate. Four insect predators, the syrphid Xanthogramma pedissequum, the coccinellids Coccinella septempunctata and Oenopia congelobata (see picture below of Oenopia) and the chrysopid Chrysoperla carnea were identified as natural enemies of Aphis punicae in Ilam.
Image above copyright Gilles San Martin under a Creative Commons licence.
Larvae of Xanthogramma pedissequum were the commonest predator. The natural enemies occurred during March to May in both years of the study.
Sreedevi & Verghese (2007) looked at the natural enemies of Aphis punicae in Bangalore, India. The major predators found preying on Aphis punicae were the coccinellids Cheilomenes sexmaculata, Pseudaspidemerus circumflexo & Scymnus sp., the syrphids Paragus serratus and Ischiodon scutellaris and a chrysopid species. The population of predators started building up along with the aphid population and reached maximum at high aphid densities and declined as the prey availability declined.
Other aphids on the same host
Blackman & Eastop list 13 species of aphid as feeding on pomegranate (Punica granatum) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 11 as occurring in Britain (Show British list).
Damage and control
The pomegranate aphid, Aphis punicae is a major pest of pomegranate groves in many countries. They feed on leaves, inflorescences and fruits. Infestation by aphids result in pale and curled leaves, retarded development and fallen flowers.
Abd Ella (2015) carried out a field trial in Assiut, Egypt to compare the efficacy of different insecticides for control of Aphis punicae. The results obtained indicate that the foliar application of four neonicitinoid insecticides (acetamiprid, imidacloprid, thiamethoxam and dinotefuran) in comparison with the commonly used malathion, have the highest efficiency against pomegranate aphid. However pirimicarb was more effective than dinotefuran. The insecticides were also compared on their effect against predators, in this case Coccinella undecimpunctata, Syrphus corolla and Chrysopa carnea. Going from most harmful to least, their order was malathion > pirimicarb > thiamethoxam > acetamiprid > imidacloprid > dinotefuran. It was concluded that the neonicitinoid insecticides can be considered as promising candidates for controlling the pomegranate aphid. Although they do have some harmful effects on predators, they are significantly less toxic to these beneficial organisms than malathion and pirimicarb. Jadhao et al. (2018) carried out a field trial in Maharashtra, India to test some newer insecticides. The most effective was clothianidin followed by thiamethoxam and imidacloprid.