Cacopsylla pyricola

(Foerster, 1848)

pear sucker, pear psylla

is a phloem-feeding in the and a major economic pest of pear trees (Pyrus communis). to Europe, it was to the eastern United States in the early 1800s and has since spread to major pear-growing regions including the Pacific Northwest. The exhibits distinct seasonal : summerforms are pale while winterforms are reddish- to black. It is a of 'Candidatus Phytoplasma pyri', the causative agent of .

Chrysopa sp. larva by Bradley Higbee. Used under a CC BY 3.0 us license.

Pronunciation

How to pronounce Cacopsylla pyricola: //ˌkækəˈsɪlə/ /ˌpaɪˈrɪkələ//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from other by association with pear (Pyrus) as , presence of knobbed bristles on nymphal , and seasonal morphotypic variation. The combination of red-eyed with wing bud bristles and roof-like posture separates it from and other . Molecular identification via can confirm when morphological characters are ambiguous.

Images

Habitat

Found in pear orchards and areas with pear trees (Pyrus communis) and quince (Cydonia oblonga). seek shelter on bark or twigs of pear trees, or on adjacent trees and shrubs near orchards. occur on undersides of leaves and on and shoots of plants.

Distribution

to Europe (Austria, Belgium, Bulgaria, Czech Republic, Denmark, France, Germany, Hungary, Italy, Moldova, Netherlands, Norway, Poland, Romania, Russia, Serbia, Spain, Sweden, Switzerland, UK). to North America: eastern United States (early 1800s), spread to Pacific Northwest by early 1900s. Present in Canada (British Columbia, Nova Scotia, Ontario). Also reported in Asia (China, Georgia, Iran, Israel, Japan, Korea, Lebanon, Syria) and North Africa (Algeria, Morocco, Tunisia).

Seasonality

Multiple per year (up to six in favorable conditions). emerge from in late winter to early spring. laying begins on twigs and expanding shoots, shifting to leaf later in season. develop through five in weeks. Fall period of winterforms occurs September-November as they seek overwintering sites.

Diet

Phloem sap of pear (Pyrus communis) and quince (Cydonia oblonga). feed on , flowers, and leaf phloem; feed on phloem of shoots and leaves. Feeding characterized by activities, sustained phloem ingestion, and occasional xylem ingestion as revealed by electrical penetration graph studies.

Host Associations

Pyrus communis - primary European pear; essential for and development
Cydonia oblonga - secondary Quince; supports survival but less optimal for

Life Cycle

development with five nymphal . hatch in 0.3-0.4 days under laboratory conditions (32°C). Total nymphal period approximately 0.7 days under optimal laboratory conditions, though field development is longer and temperature-dependent. have pre- period of ~0.3 days and oviposition period of ~1.3 days. : 400-650 eggs per female. Adult longevity: males ~62 days, females ~61 days under laboratory conditions. Up to six per year in favorable climates.

Behavior

are largely , feeding in place on tissue. are capable of ; winterforms exhibit increased flight activity September-November consistent with to sites. Males are attracted to volatile odors from female-infested or previously infested pear shoots, suggesting for mating. Overwintering adults enter reproductive . Nymphs produce copious , attracting , , and . content analysis reveals movement between and non-crop hosts including hops (Humulus lupulus) in Washington State.

Ecological Role

and of . Transmits 'Candidatus Phytoplasma pyri', causing disease. production supports growth and attracts other , potentially altering local composition. Serves as for in orchard .

Human Relevance

Major economic pest of pear production in North America and Europe. Feeding damage causes direct yield loss; production reduces fruit quality and supports ; phytoplasma transmission causes tree decline and death. Management relies on combining , , and selective . Research subject for development of pear and alternative management strategies including vibrational disruption.

Similar Taxa

Cacopsylla bidensAlso associated with pear; distinguished by morphological details of and requiring microscopic examination
Cacopsylla pyrisugaEuropean pear ; overlapping range and distribution; separation requires examination of structure and other genitalic characters
Psylla pyriFormerly confused with C. pyricola; now recognized as distinct with different preferences and morphological features

More Details

Endosymbiont Associations

Maintains obligate relationships with dual endosymymbionts: 'Candidatus Carsonella ruddii' and 'Candidatus Psyllophila symbiotica'. Carsonella remain high during vegetative periods but drop during reproductive ; Psyllophila titers are consistently higher and fluctuate seasonally, possibly related to age.

Resistant Host Cultivars

Certain pear exhibit feeding and . 'Bacui-1' and 'Bacui-2' are highly ; 'Karamanlika' and NY10352 are moderately resistant. mechanisms include reduced feeding stimulation and direct to .

Movement Ecology

content analysis reveals that utilize non- 'whistle stop' plants during landscape movement, including hops (Humulus lupulus) in Washington State, with documented travel distances of several kilometers between .