Population dynamics of Chaetocnema tibialis Illiger and Phyllotreta vittula (Redtenbacher) on the weed Amaranthus retroflexus L. and cultivated Amaranthus caudatus L.
2006
Cagan, L.(Slovenska Polnohospodarska Univ., Nitra (Slovak Republic). Katedra Ochrany Rostlin) E-mail:[email protected] | Toth, P.(Slovenska Polnohospodarska Univ., Nitra (Slovak Republic). Katedra Ochrany Rostlin) | Tothova, M.(Slovenska Polnohospodarska Univ., Nitra (Slovak Republic). Katedra Trvalo Udrzatelneho Rozvoja)
Population dynamics of the Chaetocnema tibialis and Phyllotreta vittula, associated with Amaranthus retroflexus (wild species) and Amaranthus caudatus (cultivated species), were studied at the locality Nitra-Malanta (48°19'N, 18°09'E) in south-western Slovakia during the years 1995-1997. On both plant species, the number of C. tibialis adults was usually very low until the beginning of July. Their number increased during July, but sooner on the cultivated amaranth. An increased number of C. tibialis adults was observed on both amaranth species until the middle of September. Amaranth plants are thus a very important reservoir of C. tibialis. P. vittula was common during the whole summer, but its numbers never exceeded more than 10 adults per 25 plants. Low temperatures in winter had a negative effect on C. tibialis on both amaranth species and on P. vittula on A. retroflexus. The lower the precipitation was in July, the higher were the populations of both beetle species.
显示更多 [+] 显示较少 [-]