Palmaspis phoenicis Ramachandra Rao
(Also known as Asterolecanium phoenicis)
Common name: Date pit scale; green scale.
Geographical distribution: Middle East to Iraq.
Host plants: Date palm (Phoenix dactylifera L.)
Morphology: The shield of the female is translucent, greenish, somewhat concave and its margins carry whitish filaments. The anterior part of the female is red-brown, the posterior part yellow-green and narrower, the body is oval, 1.2-1.5 mm in length and 0.6-0.8 mm wide. The dorsal part of the body margin bears 8-shaped pores that extend to the level of the vulva. On the venter there are a few pores that extend from the spiracles to the margins. The antennae are very short, one-segmented. The male and crawler are greenish.
Life cycle: Production of crawlers continues throughout the year, with a distinct peak in autumn; as a result most of the overwintering population consists of juveniles. Another two generations are usually raised in summer, thus often completing three annual generations.
Economic importance: The scale attacks the rachis, the pinnae and even the fruit. Feeding (and possibly secretion of a toxin) on the pinnae induces extensive yellowing, which causes severe damage, even leading to tree decline and death. Fruit may be disfigured, reducing their market value.
Cultural control: The removal of infested pinnae and the torching of heavily-damaged trees (which does not affect subsequent tree growth) have greatly reduced pest populations.
Chemical control: A combination of organophosphates and white oils, best applied in autumn and winter (when most of the population consists of susceptible juveniles) may control the pest. The control of the scale is a prerequisite for the biological control of the Parlatoria date scale, Parlatoria blanchardi Targioni Tozzetti.
Biological control: The control of A. phoenicis and P. blanchardi by cultural and chemical methods reduced the use of chemicals in date palm groves, promoting the activities of natural enemies. The most important of these are the predatory Cybocephalidae and Coccinellidae.
Blumberg, D., Navon, A., Kehat, M., Eliahu, M., Levski, S., and Nakash, J. 2001. Date palm pests in Israel at the beginning of the third millennium. Alon Hanotea 55: 42-48 (in Hebrew with an English abstract).
Kehat, M. and Amitai, S. 1967. The morphology and phenology of the scale Asterolecanium phoenicis Rao on date palms in the Bet Shean valley. _The Israel Journal of Agricultural Research _ 17: 85-93.
Yousof, D.E., Mahmoud, M.E.E. and Mohamed, A.H. 2013. Prospects of biological control of date palm green pit scale Insect Asterolecanium phoenicis Rao (Homoptera: Asterolecaniidae) in Sudan. Persian Gulf Crop Protection 2: 42-48.