Date palm scale blanchardi

Fig. 1. colony on © Fera

Date palm scale Parlatoria blanchardi (Targioni Tozzetti) (= Apteronidia blanchardi (Targioni Tozzetti)) (: ) occurs widely in the warmer parts of the World and feeds on palms. It is a serious and widespread pest of commercial date palm orchards and ornamental palms. Parlatoria blanchardi has not been recorded from any of the United Kingdom Overseas Territories (UKOTs). There is a risk, however, of it being introduced to UKOTs with a tropical or subtropical climates (for example in the Caribbean) with ornamental palms imported for planting.

Geographical distribution Parlatoria blanchardi is suspected to be native to Mesopotamia but has spread with trade in date palms and ornamental palms to many tropical and subtropical areas. Afrotropical : Chad; Mali; Mauritania; Mauritius; Niger; Somalia; Sudan. Australasian : Australia. Nearctic : United States of America. Neotropical : Argentina; Bolivia; Brazil. Oriental : India; Pakistan. Palaearctic : Afghanistan; Algeria; Egypt; France; Iran; Iraq; Israel; Italy; Jordan; Libya; Morocco; Saudi Arabia; Spain; Syria; Tunisia; Turkey; Turkmenistan.

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Fig. 2. Parlatoria blanchardi colony on date palm © Fig. 3. Parlatoria blanchardi group of female scale Fera covers © Fera

Fig. 4. Parlatoria blanchardi female cover © Fera Fig. 5. Parlatoria blanchardi female with cover removed © Fera

Fig. 6. Parlatoria blanchardi male cover © Fera Fig. 7. Parlatoria blanchardi scale cover lifted to show the pinkish eggs © Fera

Host plants Parlatoria blanchardi is oligophagous on palms but has occasionally been found on non-palm hosts. Apocynaceae : . : Hyphaene sp., Hyphaene thebiaca , sp., Neowashingtonia sp., , Phoenix dactylifera , Phoenix sp., filifera , Pritchardia sp., , Washingtonia sp.. Oleaceae : Jasminum revolutum , Jasminum sp.. Rhamnaceae : .

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Description Adult female scale cover is relatively flat, elongate oval, tan, with a dark-brown or black central area (Figs 1-4). Adult female bodies are pink (Fig. 5) becoming yellow or tan with maturity. Male tests (protective covers) are smaller, elongate oval, and whitish (Fig. 6). The adult males occur in two forms, winged and wingless. The eggs are pink (Fig. 7). Slide mounted adult female P. blanchardi may be identified using the key published by Miller & Davidson (2005).

Pest biology, dispersal and detection The number of generations varies between two and five depending on the climatic conditions. For example, it has two generations per year in Egypt, and five in Iraq. The crawlers are the main natural dispersal stage. Parlatoria blanchardi can be difficult to detect as even large populations can be completely hidden beneath the overlapping leaf bases.

Economic importance and damage Parlatoria blanchardi is a serious and widespread pest of commercial dates and other palms. In Algeria, a major infestation of this scale caused the death of nearly 100,000 date palms in 1920. Heavy infestations on the pinnae cause them to wither and die and this damage reduces tree vigour and may render the dates unfit for human consumption. However, neglected palms are more susceptible and likely to be killed than palms in commercial orchards.

References Miller, D.R. & Davidson, J.A. 2005. Armored Scale Pests of Trees and Shrubs . Comstock Publishing Associates (A Division Cornell University Press). 442 pp.

Author: Chris Malumphy Address: The Food and Environment Research Agency, Sand Hutton, York, YO41 1LZ, UK. Email: [email protected] Date: 22/11/2013 Version 1 The production of this datasheet was partly funded by the Biodiversity Programme of the Department for Environment, Food and Rural Affairs.

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