Abstract
Seven different insect control regimes comprising of three green chemicals: two spinosyns, spinosad (Tracer (R) 24 SC) and spinetoram (Radiant (R) 12 SC), and the insect growth regulator (moulting hormone agonist) methoxyfenozide (Runner (R) 24 SC) were employed to control the pomegranate butterfly Viracola livia on date palm fruit in 2006/7. Each spray regime consisted of two applications per season applied at a 3 week interval.
The damage was very severe with larvae penetration reaching 99 and 85% in the untreated in 2006 and 2007, respectively, two weeks prior to harvest. At this assessment, the results illustrated that spinetoram at 2.4 g ai/100 L sprayed twice/season was equivalent to spinosad at 4.8 g ai/100 L with the same spray frequency, and was also on par when spinosad was followed with different rates of methoxyfenozide. However, at harvest time, the spinetoram rate showed significantly better results than spinosad, indicating that there is at least a two-fold better activity of spinetoram than spinosad on a rate to rate comparison. Alternation of spinosad at 4.8 g ai/100 L followed by methoxyfenozide at 3.6-6.0 g ai/100 L was equivalent with spinetoram. It is clear that both spinosyns, applied alone, are very effective to control the pomegranate butterfly, with spinetoram exhibiting a 2-fold greater activity than spinosad. The application of spinosad in rotation with methoxyfenozide is in line with the IPM strategy for management of date pests. All products proved to perform well under dry conditions and high temperatures (reaching 51 degrees C) without any phytotoxicity symptoms either on the fruit or the tree foliage.