Oleander aphid - Aphis nerii - Interesting Insects

Oleander aphid - Aphis nerii

By N A Martin (2017)

Caption:

Classification

Phylum

Arthropoda

Class

Insecta

Order

Hemiptera

Superfamily

Aphidoidea

Family

Aphididae

Scientific name

Aphis nerii Boyer de Fonscolombe, 1841

Common names

Oleander aphid, Swan plant aphid, Milkweed aphid

Synonyms

Aphis (Aphis) nerii Boyer de Fonscolombe, 1841

Cerosipha (Cerosipha) nerii (Boyer de Fonscolombe, 1841)

Myzus nerii (Boyer de Fonscolombe, 1841)

Aphis (Myzus) nerii (Boyer de Fonscolombe, 1841)

Myzus asclepiadis Passerini, 1863

Aphis calotropidis Del Guercio, 1916

Aphis foveolata Del Guercio, 1916

Aphis gomphoricarpi Eastop & Hille Ris Lambers, 1976

Aphis gomphorocarpi van der Goot, 1912

Siphonophora leptadeniae (Vuillet & Vuillet, 1914)

Aphis lutescens Monell, 1879

Aphis (Aphis) neriastri Boisduval, 1867

Cryptosiphum nerii de Stefani Perez, 1901

Aphis nigripes Theobald, 1914

Aphis paolii Del Guercio, 1916

Biostatus and distribution

This adventive aphid is found in many countries especially in tropical and subtropical regions including many Pacific islands. It is believed to have spread from the Mediterranean region where it lived on Oleander, Nerium oleander. It is mainly found plants in the family Apocynaceae, but it has not been recorded from native Parsonsia species. It is regarded as a pest of Swan plants.

Conservation status: It is mainly found plants in the family Apocynaceae. It is regarded as a pest of Swan plants.

Life stages and annual cycle

In most parts of the world only female Oleander aphids are present. The adult females give live birth to nymphs. Oleander aphids are bright lemon yellow and most life stages have dusky to black siphunculi, legs and antennae. The body of a wingless adult is about 1.5-2.6 mm long and it also has a black cauda. The winged adult also has black on its head, thorax (middle part of the body) legs, and cauda. Adults and nymphs have three pairs of legs and a pair of antennae. On the underside of the head is the rostrum, that holds the stylets used for feeding. When not in use the rostrum points back between the legs. Towards the rear of the abdomen is a pair of tubes, siphunculae, from which honeydew is secreted. The cauda is a central projection at rear of abdomen.

Adult females give live birth to nymphs that look like small wingless adults. The first instar (stage) nymph has pale legs and siphuncles, and the end of the abdomen is rounded. There are four nymphal stages. Nymphs go from one stage to the next by moulting, changing their skin. The mature nymph moults into the adult. Nymphs that are going to develop into winged adults have wing buds.

Colonies of Oleander aphid are usually seen on young growth of host plants in the spring or early summer. Colonies then reappear in late summer and autumn when plants are producing new growth.

Feeding and honeydew

Like other Hemiptera, the Oleander aphid has sucking mouthparts. The two pairs of long stylets (specially shaped rods) are held in the rostrum. When it wishes to feed, the aphid moves the tip of the rostrum to the surface of the plant. The stylets are then gradually pushed into the plant. One pair of stylets, the maxillae, form two tubes; one through which saliva is injected into the plant and a second through which plants juices are sucked up into the insect. The Oleander aphid inserts the stylets into the phloem (the plant vessels for transmitting sap from the leaves to other parts of the plant). The sap has a high volume of water and sugars, more than the insect needs. Excess water and sugar is excreted from the siphuncles and called honeydew.

Wingless female Oleander aphid, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae): note the moulted nymphal skins. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MWA]

Adult wingless females and nymphs of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWL]

Adult wingless females and nymphs of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a stem of a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWJ]

Nymphs of Oleander aphid, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae): note the dark wing buds on the largest nymph. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MW7]

Nymph of Oleander aphid, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae): note the dark wing buds. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MW9]

Winged adults and nymphs of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MWB]

Side view of a winged Oleander aphid, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae): note the rostrum extending from the head to the leaf surface. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MWE]

Winged Oleander aphid, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MWD]

Side view of a winged Oleander aphid, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MWC]

Winged and wingless adult females and nymphs of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWN]

Colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWK]

Recognition

Normally aphids require specialist skills for their identification. Oleander aphids have a typical aphid shape. They are a distinctive yellow with dusky or black legs, antennae and siphunculae (the tubes towards the end of the abdomen through which honeydew is excreted). Wingless and winged adult females have a black cauda, a projection at the end of the abdomen. The winged female has black on their head and thorax, the middle part of the body.

Natural enemies

Several parasitoids and predators of Oleander aphids are known in New Zealand, but no fungal pathogen has been recorded.

Parasitoids

Five species of wasps have been reared from Oleander aphids. Some of these are hyperparasitoids, parasites of parasites. The female primary parasitoid lays an egg in the aphid. The wasp larva feeds on the aphid but does not kill it until the larva is fully grown. It then causes the aphid to swell and form a dark coloured skin. The wasp larva pupates inside this rigid skin which is called a mummy. When the adult wasp is ready to emerge it chews a hole in the mummified aphid skin.

Predators

Five species of ladybirds have been recorded feeding on Oleander aphids. Two of these ladybirds, Variable ladybird, Coelophora inaequalis and Yellow shouldered ladybird, Apolinus lividigaster, are specialist feeders on aphids. At least one kind of Lacewing has been found feeding on Oleander aphid. They are probably preyed on by Hoverflies, (Diptera: Syrphidae) other predatory insects and spiders.

Mummified Oleander aphid, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae). The aphid was killed by a parasitic wasp. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MW8]

Colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae): note that near the two winged adult females is a brown mummified aphid that was killed by a parasitic wasp. Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWM]

Two dead adult wasps (Hymenoptera) that emerged from mummified Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MWF]

Dead adult wasps (Hymenoptera) that emerged from mummified Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MWG]

Side view of an adult male yellow shouldered ladybird, Apolinus lividigaster (Coleoptera: Coccinellidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2E1C]

Adult Yellow shouldered ladybird, Apolinus lividigaster (Coleoptera: Coccinellidae) in a colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae) Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MW5]

Larva of yellow shouldered ladybird, Apolinus lividigaster (Coleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2KJ1]

Larva of yellow shouldered ladybird, Apolinus lividigaster (Coleoptera: Coccinellidae), feeding on an Oleander aphid, Aphis nerii (Hemiptera: Aphididae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2KJ0]

Larva of yellow shouldered ladybird, Apolinus lividigaster (Coleoptera: Coccinellidae), feeding on aphids on Pittosporum tenuifolium. Creator: Tim Holmes. © Plant & Food Research. [Image: 2AX3]

Larva (arrow) of Yellow shouldered ladybird, Apolinus lividigaster (Coleoptera: Coccinellidae) in a colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae) Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2MW6]

Pupa of yellow shouldered ladybird, Apolinus lividigaster (Coleoptera: Coccinellidae), surrounded by a halo of wax. Creator: Tim Holmes. © Plant & Food Research. [Image: 2E1A]

Adult two-spotted ladybird, Adalia bipunctata (Coleoptera: Coccinellidae), about 5 mm long. Creator: Tim Holmes. © Plant & Food Research. [Image: 2AB9]

Dark form of adult two-spotted ladybird, Adalia bipunctata (Coleoptera: Coccinellidae), showing wings. Creator: Tim Holmes. © Plant & Food Research. [Image: 2ABR]

Larva of two-spotted ladybird, Adalia bipunctata (Coleoptera: Coccinellidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 15VG]

Larva of two-spotted ladybird, Adalia bipunctata (Coleoptera: Coccinellidae), note the yellow central tubercles on the 4th abdominal segment. Creator: Tim Holmes. © Plant & Food Research. [Image: 2AC6]

Adult Orange-spotted ladybird, Coccinella leonina (Coleoptera: Coccinellidae). Creator: Jon Sullivan. © Jon Sullivan. [Image: 2AW1]

Adult Orange-spotted ladybird, Coccinella leonina (Coleoptera: Coccinellidae), museum specimen. Creator: Birgit E Rhode. © Landcare Research. [Image: 2D3L]

Adult Orange-spotted ladybird, Coccinella leonina (Coleoptera: Coccinellidae), museum specimen. Creator: Birgit E Rhode. © Landcare Research. [Image: 2D3M]

Adult eleven-spotted ladybird, Coccinella undecimpunctata (Coleoptera: Coccinellidae) on a lettuce leaf. Creator: Plant & Food Research Photographer. © Plant & Food Research. [Image: 159M]

A fully grown larva of eleven-spotted ladybird, Coccinella undecimpunctata (Coleoptera: Coccinellidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 159Q]

Adult variable ladybird, Coelophora inaequalis (Coleoptera: Coccinellidae), about 5 mm long. Creator: Tim Holmes. © Plant & Food Research. [Image: 2AKY]

Adult variable ladybird, Coelophora inaequalis (Coleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2KJ3]

Larva of variable ladybird, Coelophora inaequalis (Coleoptera: Coccinellidae), feeding on aphids. Creator: Tim Holmes. © Plant & Food Research. [Image: 2AKP]

Larva of variable ladybird, Coelophora inaequalis (Coleoptera: Coccinellidae), and moulted larval skin. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2ALI]

Two pupae of variable ladybird, Coelophora inaequalis (Coleoptera: Coccinellidae), showing the variable background colour. Creator: Tim Holmes. © Plant & Food Research. [Image: 2AL9]

Two pupae of variable ladybird, Coelophora inaequalis (Coleoptera: Coccinellidae), showing the variable background colour. Creator: Tim Holmes. © Plant & Food Research. [Image: 2ALA]

Adult Variable ladybird, Coelophora inaequalis (Coleoptera: Coccinellidae) in a colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on leaf of a Swan plant Gomphocarpus fruticosus (Apocynaceae). © All rights reserved. [Image: 2MW4]

Table: Natural enemies of Oleander aphid, *Aphis nerii* (Hemiptera: Aphididae), from Plant-SyNZ database (16 December 2017). The reliability index shows the quality of evidence for the host association (0-10, 10=high quality).
Scientific Name	Common Name	Classification	Enemy Type	Reliability Index	Biostatus
Alloxysta victrix Westwood, 1833	(Wasp)	Hymenoptera: Figitidae	parasitoid	10	adventive
Aphelinus gossypii Timberlake, 1924	(Wasp)	Hymenoptera: Aphelinidae	parasitoid	10	adventive
Aphelinus mali (Haldeman, 1851)	Wooly apple aphid parasite (Wasp)	Hymenoptera: Aphelinidae	parasitoid	10	adventive
Dendrocerus carpenteri (Curtis, 1829)	(Wasp)	Hymenoptera: Megaspilidae	parasitoid	10	adventive
Pachyneuron aphidis (Bouche, 1834)	(Wasp)	Hymenoptera: Pteromalidae	parasitoid	10	adventive
Adalia bipunctata (Linnaeus, 1758)	Two-spotted ladybird (Beetle)	Coleoptera: Coccinellidae	predator	10	adventive
Apolinus lividigaster (Mulsant, 1853)	Yellow shouldered ladybird (Beetle)	Coleoptera: Coccinellidae	predator	10	adventive
Coccinella leonina Fabricius, 1775	Orange-spotted ladybird (Beetle)	Coleoptera: Coccinellidae	predator	10	endemic
Coccinella undecimpunctata Linnaeus, 1758	Eleven-spotted ladybird (Beetle)	Coleoptera: Coccinellidae	predator	10	adventive
Coelophora inaequalis (Fabricius, 1775)	Variable ladybird (Beetle)	Coleoptera: Coccinellidae	predator	10	adventive
Neuroptera sp.	Lacewing (Lacewing)	Neuroptera:	predator	5	unknown

Host plants

Oleander aphids are mainly found plants in the family Apocynaceae, but sometimes are found on plants in other families. The species has not been recorded from native Parsonsia species. It is regarded as a pest of Swan plants.

This aphid is able to transmit several viruses.

Feeding and honeydew

Like other Hemiptera, Oleander aphids have sucking mouth parts. The long stylets, special shaped rods, are held in the rostrum. When it wishes to feed the aphid moves the tip of the rostrum to the surface of a leaf or stem. The stylets are then gradually pushed into the plant. The inner pair of stylets, form two tubes, one through which saliva is injected into the plant and a second through which plants juices are sucked up into the insect. Oleander aphids insert its stylets into the phloem, the plant vessels for transmitting sap from the leaves to other parts of the plant. The sap has a high volume of water and sugars, more than the insect needs. Aphids excrete the excess water and sugar, which is called honeydew.

Colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWH]

Colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWI]

Colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a Swan plant Gomphocarpus fruticosus (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWK]

Colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a Redhead cotton bush, Asclepias curassavica (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWP]

Colony of Oleander aphids, Aphis nerii (Hemiptera: Aphididae) on a Redhead cotton bush, Asclepias curassavica (Apocynaceae). Creator: Nicholas A. Martin. © Nicholas A. Martin. [Image: 2MWQ]

Table: Host plants of the Oleander aphid, *Aphis nerii* (Hemiptera: Aphididae) from Plant-SyNZ database (16 December 2017). The reliability score shows the quality of evidence for the host association (1-10, 10=high).
Common Name(s)	Scientific Name	Family	Reliability Index	Biostatus
Cruel plant, Kapok vine, Moth plant, White bladder flower	Araujia horturum E.Fourn.	Apocynaceae	10	naturalised
Bloodflower, Redhead cotton bush	Asclepias curassavica L.	Apocynaceae	10	naturalised
Butterfly weed, Pleurisy root	Asclepias tuberosa L.	Apocynaceae	10	cultivated
Swan plant, Narrow-leaf cotton bush	Gomphocarpus fruticosus (L.) W.T.Aiton	Apocynaceae	10	naturalised
Balloon cotton bush, Swan plant	Gomphocarpus physocarpus E.Mey.	Apocynaceae	10	naturalised
Wax plant	Hoya carnosa (L.f.) R.Br.	Apocynaceae	10	cultivated
Oleander, Rose-bay	Nerium oleander L.	Apocynaceae	10	naturalised
Tweedia	Oxypetalum caeruleum (D.Don) Decne.	Apocynaceae	10	naturalised
Dwarf bean, French bean, Garden bean, Green bean, Kidney bean, Pole bean, Snap bean, String bean	Phaseolus vulgaris L.	Leguminosae	8	cultivated
Frangipani, Temple tree	Plumeria sp.	Apocynaceae	7	cultivated

Information sources

Aphids on worlds plants; Aphis nerii www.aphidsonworldsplants.info/d_APHIDS_A.htm#Aphis.

Cottier W. 1953. Aphids of New Zealand. N.Z. Department of Scientific and Industrial Research Bulletin. 106: 1-382.

Plant-SyNZ: Invertebrate herbivore-host plant association database. plant-synz.landcareresearch.co.nz/.

Acknowledgements

Dr Robert Foottit, Canadian National Collection of Insects, Ottawa, Canada, for identification of aphids.

The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research) for permission to use photographs.

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