Dialeurodes citri

(Ashmead, 1885)

Citrus Whitefly

, the citrus whitefly, is a pest native to Southeast Asia that has become established in citrus-growing regions worldwide. and stages feed on phloem sap, secreting honeydew that promotes growth. The completes 2–3 annually in most regions, with development arrested in the fourth instar during cooler months. It is distinguished from the similar Parabemisia myricae by its larger size, preference for fully developed leaves, and slower .

Dialeurodes citri by (c) Lauu, some rights reserved (CC BY), uploaded by Lauu. Used under a CC-BY license.

Dialeurodes citri larva by Kaldari. Used under a Public domain license.

Pronunciation

How to pronounce Dialeurodes citri: /dɪˌæl.jʊəˈroʊ.diːz ˈsɪtraɪ/

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

Identification

Larger than Parabemisia myricae; confined to fully developed leaves rather than youngest unfolded foliage. are small, -like whiteflies with white, powdery wings. stages are , -like, and found on lower leaf surfaces. Distinguished from P. myricae by : D. citri appears later in spring and completes only 2–3 per year versus 7–8 for P. myricae.

Images

Habitat

Dense citrus stands with high humidity and limited air movement; prefers inner and shaded sides of trees for oviposition. Thrives in orchard environments with minimal wind exposure.

Distribution

Native to Southeast Asia; established in Mediterranean region (Turkey since 1976, Israel since 1975, France, Greece, Italy, Spain), North Africa, South Asia (India, Pakistan, Bangladesh, Sri Lanka), East Asia (China, Japan, Korea, Taiwan), Middle East, Americas (USA including California and Florida, Mexico, Central and South America), and Australia.

Seasonality

Completes 2–3 per year in most regions; first generation April–June, second July–August, third September–April with in fourth instar. peaks vary regionally: October and April–August in Egypt; spring through fall activity in Mediterranean climates.

Diet

Phloem-feeding on Citrus and related Rutaceae; also recorded on Coffea arabica, Gardenia jasminoides, Melia species, and various ornamental trees and shrubs.

Life Cycle

→ four nymphal instars → pupal stage (fourth instar with red ) → . Under laboratory conditions (25°C, 16:8 L:D): egg 12.1 days, first instar 6.5 days, second instar 5.5 days, third instar 7.6 days, fourth instar 18 days, pupal (red eye) stage 4.7 days; total ~54 days. Field times: 65 days (spring), 52 days (summer), 8 months ( generation). Female averages 151 eggs. Adult longevity 16–19 days.

Behavior

preferentially oviposit on young, fully developed leaves in shaded inner positions. stages are and feed on lower leaf surfaces. Development arrested by shortened and reduced temperature October–April.

Ecological Role

Herbivore; honeydew secretion supports fungi that reduce . Preimaginal mortality in California ranges 56–94%, attributed primarily to . Serves as for introduced agent Encarsia lahorensis and subject to natural by fungus Aschersonia aleyrodis.

Human Relevance

Major pest of citrus production causing direct damage through sap removal and indirect damage via . Competes with other whitefly ; suppressed by cultural methods (wide spacing, pruning, white oil sprays) and . Subject to ongoing programs in commercial citrus regions.

Similar Taxa

Parabemisia myricaeOverlapping distribution and ; distinguished by smaller size, preference for youngest unfolded leaves, earlier spring appearance, and faster (7–8 annually). P. myricae competitively excludes D. citri where both occur, though of P. myricae can allow D. citri recovery.
Dialeurodes kirkaldyiCongeneric citrus whitefly with similar and ; precise distinction requires examination of pupal case characters.