First incidence of a spider mite, Oligonychu stylus (Baker & Pritchard), in date palm (Phoenix dactylifera L.) groves of Kachchh in Gujarat, India

Abstract

Date palm (Phoenix dactylifera L.) is one of the oldest cultivated crops of the desert region. It is believed to be originated in Mesopotamia (Southern Iraq) during 5000 BC (Zohary and Hopf, 2000) and it is commercially cultivated in more than 40 countries with 100 million hectares with a production of 7-8 million tones of dates (FAO Stat, 2017). In India, date palm is commercially cultivated inthe western border, i.e., the coastal belt of Kachchh district of Gujarat having about 2.0 million trees producing 17 thousand tons of fresh dates (Anonymous, 2018). This region enjoys the monopoly of the commercial cultivation of date palm and it is one of the subsistent crops of the agrarian community of western part of India. One hundred and twelve species of insect and mite pests have been reported worldwide on date palm (El-Shafie, 2012). However, in the coastal belt of Kachchh, red palm weevil (Rhynchophorus ferrrugineus Oliver; Coleoptera: Curculionidae), rhinoceros beetle (Oryctus rhinoceros L.; Coleoptera: Scarabaeidae) and date palm white scale (Parlatoria blanchardi Targionii Tozzetii; Hemiptera: Diaspididae) cause economic damage (Muralidharan, 1993; Muralidharan et al., 2000). Mite infestation and damage to date palms were first recorded in Israel in the Southern Arava valley during the late 1970s (Gerson et al., 1983) and fifteen species of phytophagous mites have been reported from various date palm growing areas of the world (El-Shafie, 2012). However, no economic damage of mite incidence has reported so far from this crop from the Indian subcontinent. A survey conducted by the Date Palm Research Station (DPRS), Sardarkrushinagar Dantiwada Agricultural University (SDAU), Mundra, during May-2016 has brought to the notice, certain mite species infesting fruit bunches from Dhrub village of Mundra taluk for the first time. The fruits were near to colour breaking stage (khalal), and severe mite infestation/damage was evident with spinning webs around fruit bunch with dusty appearance (Fig. 1). Extensive mite feeding on date fruit with webbing and mites’ shed skins get covered by dust particles (Fig. 2). In addition to this, the highly turbulent wind carrying dust during summer months in the region was also responsible for this dusty appearance, which reduces the marketability of fruits. The mite specimens were identified morphologically as Oligonychus tylus by the All India Network Project on Agricultural Acarology at the University of Agricultural Sciences, Bangalore using 10 male and five female microscopic slide-mounted mite specimens. Also, molecular data (for the mitochondrial gene) were First incidence of a spider mite, Oligonychus tylus (Baker & Pritchard), in date palm (Phoenix dactylifera L.) groves of Kachchh in Gujarat, India