There are two scale insects, found wherever dates grow, that are troublesome to the orchardist. The Parlatoria scale (Parlatoria blanchardii Targ. Tozz.) remains dormant during the winter but is active in summer, sucking the plant juices from the leaves at the time when growth is most vigorous. The following description of the insect is condensed from T. D. A. Cockerell: To the naked eye the scales appear as small dark gray or black specks, edged with white. If the scale is lifted by means of a pin or the point of a knife, the soft, plump and juicy female, of a rose-pink color, is found underneath. The male scales, which are rarely seen, are much smaller and narrower than those of the female. About the middle of March the female lays eggs; the larvae hatch a fortnight later, crawl about restlessly for a time, and then settle down for the remainder of their lives.
The treatment is by dipping the offshoots in a solution of 1 gallon of Cresolin, 4 gallons of distillate, and 95 gallons of water. Mature palms may be sprayed with the same mixture. By these methods this scale is eventually eliminated.
The more dangerous Marlatt scale (Phoenicococcus marlatti Ckll.) is wine-colored, and secretes a white waxy substance. It usually lives at the base of the leaves, "inside" the palm, where it is almost inaccessible, coming out at intervals to molt. It can be destroyed by dipping the offshoots and following this by periodic spraying.
Date palms in moist regions are often attacked by parasitic fungi, which, however, yield to bordeaux mixture or other standard fungicides.
In some regions the palm is attacked by a borer (Rhynco-phorus) which, if not destroyed, is fatal to the tree. The only successful treatment seems to be to watch for the intruder and kill it before it has penetrated too far. Locusts, grasshoppers, rats, gophers, ants, bees, wasps, birds, and the like give trouble in various localities. The treatment resorted to against these pests in connection with other cultures will also serve for the date palm orchard.
Stored dates are likely to become infested with such common enemies of stored foods as the fig-moth (Ephestia cautella Walker) and the Indian meal-moth (Plodia interpunctella Hubner). The best protection against these is a packing-house that is reasonably insect-proof and is fumigated at the beginning of each season. The modern methods of preparing dates for the market usually include some system of disinfection which kills insect eggs. It is reported that in Egypt dates for export are dipped in dilute alcohol, or in alcohol and glycerine. "Dry" dates can be scalded; "soft" dates are, in America, frequently pasteurized by dry heat or by fumigation.