Common insects in the main date varieties in Israel and methods local date growers use to ensure insect-free dates.

Agronomist Shimon Biton, Emunat Itecha 126 (5780)

Introduction

There are commercial date plantations throughout the Syrian-African Rift. In Israel, they can be found from northeast of the Kinneret down to Eilat in the south, and along the coastal plain from Rafah to Gaza City. While dates can grow in all regions of the country, they may not yield fruit suitable for commercial sale. Israel produces dates for the local market and for export to Western markets. The main export varieties are Medjool, Deglet Noor on Branches, Hayani, and Barhi, with the premium fruit designated for export. The Israeli population enjoys a rich basket of fruits composed of Mediterranean and subtropical fruits, with dates constituting a minor part, about one percent of the fruit basket (approximately one kg per capita annually). The primary consumers of dates in the country are its Arab residents.¹ Among the approximately ten varieties of dates, Medjool is the most consumed, making up about 85% of all dates consumed. This variety is grown along the Jordan River and in the Arava down to Eilat.

Problems and Solutions

Dried Dates

Medjool and Deglet Noor are the main varieties sold in Israel. Medjool is the principal and more widespread variety, exported to Europe and Southeast Asia. Most Medjool fruits are free from insects, but grade B fruits or those from neglected plantations may be infested with insects (a lower price indicates a higher likelihood of insect presence). Deglet Noor is harvested early when the fruits are still attached to the branches. The connection of the calyx leaves to the cluster and fruit is particularly strong, so fruits rarely fall off. The Deglet Noor clusters are not covered with mesh bags because they are harvested early and at a stage not susceptible to beetle attacks.

Fresh Dates

In recent years, fresh Medjool dates have been produced, requiring refrigeration, as well as the Hayani variety sold as frozen fruit. The Hayani variety has many health benefits, but due to its short shelf life, its demand has decreased. The Barhi variety is eaten fresh and sold as a seasonal fruit because it cannot be stored for long periods. In an advanced marketing system, the fruit harvested from the trees does not go directly to the trader but after undergoing a series of treatments to meet marketing requirements. The treatment system includes improving sanitary conditions, sorting by size and quality, and providing short or long-term storage services. It should be noted that fresh varieties are harvested at a stage not susceptible to beetle attacks. Freezing stops the ripening process, and only when the fruit is exposed to room temperature does it soften and become edible. In dry varieties, freezing preserves fruit quality and also protects against insects. Sometimes when fruit is frozen while infested with beetles, freezing kills the beetles inside or outside the fruit.

Sap Beetles

The main pest that poses a significant kashrut issue in date fruits is the sap beetle. There are several common species found in Israel, including the Carpophillus mutilates, C. humeralis, and C. hemiterus. Additionally, moth larvae, such as the date moth Ephestia calidella and the raisin moth Ephestia figuliella, are present but very infrequently. These larvae are white with four rows of maroon spots on their backs. Such larvae were found mainly in the Deglet Noor variety. Unrefrigerated fruit may be attacked by moths.² The sap beetle is 2.0–3.5 mm long, with a slightly curved body. Its color ranges from black to light brown. The larva is whitish or yellowish and 5 mm long. The pupa is white and 3.0 mm long.³ The beetle is a pest that penetrates the fruit under the calyx leaves or through wounds caused by tissue cracking due to water excess. Fermenting fruit attracts beetles to lay eggs. Typically, infested fruit appears shriveled, lacks calyx leaves, and shows yellow gnawing marks along with a characteristic fermented smell. When opening the fruit, one can see fragmented fruit tissue and larvae or even adult beetles inside.

Methods for Ensuring Insect-Free Fruit

Today, date growers generally disinfect the fruit to ensure it is completely free of live insects. There are means to expel any mobile insects from the fruit, however eggs and dead pupae remain inside. Disinfection is performed by creating conditions unfavorable for insects, causing them to leave the fruit. They usually fall to the floor of the disinfection chamber and die before the chamber is opened. Heating the fruit to 52°C for several hours causes insects to leave the fruit.⁴ To ensure the fruit is completely free from all stages of sap beetles, agricultural pest control advisors recommend that growers wrap Medjool clusters in densely woven nets of 40–50 mesh when the fruit is green, thus ensuring complete protection from beetle or moth infestation.⁵ Currently, about 50% of plantations cover Medjool clusters with dense nets, and the rest cover the clusters with 17 mesh nets that are permeable to sap beetles. Fruit marketed domestically or exported to Europe undergoes heat disinfection. Consequently, it is sorted carefully by machines that remove fruit that seems infested.

A Medjool date covered by dense netting that also passed through a careful sorting process can be considered insect-free. However, Grade B fruit from traders directly to the market may be infested with sap beetles. Also, Medjool fruit from Arab growers should be carefully checked for dead beetles on or inside the fruit. Purchased fruit must be refrigerated; otherwise, it is prone to being attacked by moths and beetles.
In any case, dates should be opened and inspected before eating.