Infestation Instability and Parasitism of Saw-Toothed Grain Beetle, Oryzaephilus Surinamensis (L.) on Prominent Dry and Semi-Dry Date Fruits

Abstract

The research study was conducted on staple fruit of Pakistan “dates” on five prominent date palm varieties of District: Khairpur, Sindh. The infested fruits were brought under laboratory conditions for pests and their biological control appearance. The maximum pest population was observed on variety; Karbalian on dry dates; 26.35 and on semi-dry; 24.45 with the minimum on dry dates; 08.45 and on semi-dry; 06-36; followed by Fasli, 21.25 and 23.10 to 05.10 and 08.45; Gajar, 22.45 and 20.33 to 07.20 and 04.70; Daki wari, semi-dry; 24.55 and dry; 16.80 to 09.80 and 06.10 in December and June with the Aseel, on dry dates; 19.45 semi-dry; 17.20 to 04.90-04-60 in January and July months. Thus; the variation of parasitism % was recorded with the maximum mean population on variety; Karbalian on dry dates; 24.35 and semi-dry dates; 26.70-22.40-15.60; Gajar, semi-dry; 24.35 and dry; 22.4 to 06.30-09.15; Daki wari, semi-dry; 27.20 dry; 18.90 to 13.80-06.70; Aseel, semi-dry; 25.80 and dry dates; 22.25 to 16.16-15.20 in January and July similarly, on variety; Fasli, dry dates; 22.45 semi-dry; 24.20 to 17.34-13.70 in December and July months, respectively. The present results indicated that pest infestation occurred in both types of fruits in all five varieties which were found with severe infestation hence; the overall mean population of parasitoids which is known as biological control agents that ultimately reduced the pest population under laboratory conditions that should be encouraged in dates producing factories and stored godowns to reduce the pest instability.