engleski

The aphid fauna (Hemiptera: Aphidoidea) of watermelons

In this paper the fauna of aphids appearing on watermelons in the area of the Neretva valley is presented. Not only do they feed on the plants, but aphids can transmit virus diseases. The natural spread of aphid transmitted cucurbit viruses is often accomplished by Acyrthosiphon pisum (Harris), Aphis craccivora Koch, Aphis gossypii Glover and Myzus persicae (Sulzer). Aphidtransmitted viruses in cucurbits have been poorly investigated in Croatia, although Cucumber mosaic cucumovirus (CMV) sporadically occurs on cucurbits. The aim of this study was to investigate and identify aphid species in a watermelon field. The field experiment with watermelons [Citrullus lanatus (Thunb.) Matsum & Nakai] was conducted during 2004 and 2005 at Opuzen (43°00’N, 17°34’E, 3 m elevation), located in the Mediterranean area of Croatia. Opuzen is situated in the delta of the river Neretva River, the most important watermelon-growing area in Croatia. Aphid sampling was carried out using yellow water traps (70x70x12 cm). Traps were installed at the date of transplanting and observed daily in order to determine initial aphid flight prior to the first sampling. Insect samples were collected once a week. The collected material was inspected and aphids were separated out using a stereomicroscope (Zeiss, Stemi 2000). Aphid specimens were preserved in plastic vials containing 70 % ethanol until identification according to taxonomy keys. The dominance was calculated by the Balogh formula. The results (predominant, dominant, subdominant, recedent, subrecedent) are presented according to Tischler and Heydeman. During the study of the aphid population, 70 species in 48 genera were detected, with 63 species in 42 genera being identified in 2004 and 44 species in 31 genera in 2005. All species referred to the Aphididae. The overall seasonal percentage composition showed that Toxoptera aurantii (Boyer de Fonscolombe) (34 % in 2004 and 23 % in 2005) and A. gossypii (15 % in 2004 and 24 % in 2005) were consistently predominant in both years.

Aphids ; watermelon ; yellow water trap ; Croatia

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