# Cottony Cushion Scale (*icerya purchasi*)

The Cottony Cushion Scale (Icerya purchasi) is a notorious scale insect originally native to Australia, but now found globally. It is famous for its devastating historical impact on citrus orchards, which ultimately led to one of the most successful biological control triumphs in entomological history. These tiny sap-sucking insects form dense colonies on the branches, twigs, and leaves of their host plants, draining vital nutrients and secreting sticky honeydew.

- **Category:** [Insects](https://www.snappit.app/explore/categories/insect)
- **Rarity:** Common
- **Danger:** 1/5 · Very low
- **Snaps:** 1
- **Habitat:** Found in warm-temperate and tropical regions, typically on citrus trees, ornamental shrubs, and woody plants in agricultural areas and gardens.

![Cottony Cushion Scale](https://inaturalist-open-data.s3.amazonaws.com/photos/456541234/medium.jpg)

Photo: RAP, CC BY 4.0 · [iNaturalist](https://www.inaturalist.org/photos/456541234)

## Appearance

The adult female Cottony Cushion Scale is easily identified by her distinctive white, elongated, and deeply fluted egg sac, which is made of a waxy substance and can reach up to 1.5 centimeters in length. The insect's actual body is relatively small, reddish-brown, and nestled at one end of this prominent, cottony sac. Immature nymphs, or crawlers, are bright red with dark legs and antennae, lacking the massive white waxy coating of the adults.

## Taxonomy

- **Kingdom:** Animalia
- **Phylum:** Arthropoda
- **Class:** Insecta
- **Order:** Hemiptera
- **Family:** Monophlebidae
- **Genus:** Icerya

## Interesting facts

- Almost all individuals are hermaphrodites that fertilize their own eggs, while pure males are extremely rare and develop from unfertilized eggs.
- Ants will actively farm and protect these scales from predators in exchange for the sugary honeydew they secrete.
- The large white 'cushion' on the insect's rear is not its body, but an empty wax sac designed solely to shelter up to 1,000 eggs.
- This species was the target of the world's first highly successful classical biological control program in 1888, saving the California citrus industry from collapse.

## Special abilities

- **Waxy Armor Construction:** It secretes a dense, ribbed, white waxy ovisac that protects its eggs from both predators and environmental dehydration.
- **Hermaphroditic Reproduction:** Most individuals are self-fertilizing hermaphrodites, allowing a single scale insect to rapidly colonize a new host plant without needing a mate.
- **Honeydew Secretion:** It excretes excess plant sugars as sticky honeydew, which attracts protective ants and fosters the growth of sooty mold.

## Measurements & details

- **Length:** 1+ cm
- **Weight:** 0.00001+ kg
- **Lifespan:** 0+ years
- **Clutch Size:** 500+
- **Incubation:** 10+ days

## Diet & Feeding

Feeds on the nutrient-rich phloem sap of various woody host plants, particularly citrus and acacias.

- **Age differences:** Crawlers seek out thin leaf veins, whereas mature females settle permanently on larger twigs and branches.
- **Primary Foods:** Citrus sap, Acacia sap, Pittosporum sap, Rose sap
- **Foraging Method:** Grazing

## Ecological connections

- **Eaten by:** Vedalia Beetle (*Rodolia cardinalis*) — The Vedalia beetle is a famous predator introduced globally to control cottony cushion scale populations.
- **Parasite:** Parasitoid Fly (*Cryptochaetum iceryae*) — A tiny parasitic fly whose larvae develop inside the scale insect, acting as an effective natural control agent.
- **Host plant:** Sweet Orange (*Citrus sinensis*) — The primary host plant where the scale insect feeds on phloem sap, often causing leaf drop and branch dieback.

## Safety

**Danger:** 1/5 · Very low

No special safety notes yet.

## Frequently Asked Questions

### How to identify Cottony Cushion Scale?

Look for six legs, antennae, three body sections and the shape of the wings. Beetles have hardened front wings; flies have just one working pair. Tiny insects may need a close view before their group is clear. Insect Identifier: upload a photo and compare the visible details.

### How long is Cottony Cushion Scale?

1+ cm

### How much does Cottony Cushion Scale weigh?

0.00001+ kg

### How long does Cottony Cushion Scale live?

0+ years

### What does Cottony Cushion Scale eat?

Feeds on the nutrient-rich phloem sap of various woody host plants, particularly citrus and acacias.

### Where is Cottony Cushion Scale usually found?

Found in warm-temperate and tropical regions, typically on citrus trees, ornamental shrubs, and woody plants in agricultural areas and gardens.

### How does Cottony Cushion Scale hunt?

Grazing

### How many eggs does Cottony Cushion Scale lay?

500+

## Where to spot

- [Longwood Gardens](https://www.snappit.app/guides/places/longwood-gardens) — Pennsylvania, US · Botanical Garden
- [Micke Grove Zoo](https://www.snappit.app/guides/places/micke-grove-zoo) — California, US · Zoo

## More Insects

- [Common Eastern Bumble Bee](https://www.snappit.app/explore/common-eastern-bumble-bee) (*Bombus impatiens*)
- [Spotted Lanternfly](https://www.snappit.app/explore/spotted-lanternfly) (*Lycorma delicatula*)
- [Brown-belted Bumble Bee](https://www.snappit.app/explore/brown-belted-bumble-bee) (*Bombus griseocollis*)
- [Eastern Carpenter Bee](https://www.snappit.app/explore/eastern-carpenter-bee) (*Xylocopa virginica*)

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Source: [Cottony Cushion Scale: Facts & Places to See — Snappit](https://www.snappit.app/explore/cottony-cushion-scale)