The Occurrence and Sex Ratio of Diabrotica virgifera Le Conte Beetles on Sweet Maize (Zea mays var. Saccharata) In South-Eastern Poland Near Rzeszów in 2007-2009

Abstract

The Occurrence and Sex Ratio of Diabrotica virgifera Le Conte Beetles on Sweet Maize (Zea mays var. Saccharata) In South-Eastern Poland Near Rzeszów in 2007-2009 Studies were conducted in 2007-2009 on sweet maize (Zea mays var. saccharata), Candle variety, in Terliczka near Rzeszów. The observations were carried out based on an permission from the Main Inspectorate of Plant Health and Seed Inspection, No. WF-411d/5/2008. The objective of the conducted study was to specify the occurrence dynamics of Western corn rootworm (WCR) (Diabrotica virgifera) beetles on sweet maize in order to establish the optimal period for their control. In addition their sexual structure between July and September were specified. In south-eastern Poland D. virgifera beetles began their flights onto sweet maize plants from the second decade of July. Male occurred first, and the flights of females began several days later. Moreover, it was found that the maximum number of males on plants is recorded earlier than that of females. During the feeding of beetles on maize the period of their most abundant occurrence was from the end of July to the third decade of August. During the flight of adult one population peak was usually recorded: in the third decade of July and the first decade of August, and only in 2007 was it in the second decade of July. In 2007-2009, D. virgifera ended their feeding in late September. Females dominated among the captured insects during the study years. Their percentage share in the total number of captured beetles was from 59.7 to 84.1%. The population of males in individual years varied, and their percentage share was between 15.9 and 40.3%.

Population dynamics of Western corn rootworm beetles on different varieties of maize identified using pheromone and floral baited traps

“…Similar observations of female beetles being captured after males have already been reported in Poland (Bereś& Sionek 2010), Hungary (Imrei et al 2001), Romania (Grozea & Lauer 2004) and the USA (Darnell et al 2000). It was also observed that the peak count of males on maize plants comes earlier than in the case of females (Darnell et al 2000;Bereś& Sionek 2010). The presented research confirmed this type of correlation with the counts found in PTs and FTs.…”

“…The analysis of both types of trap indicated that in south-eastern Poland the first WCR adults occured in maize in the second ten days of July. The date is very close to that observed for the area in previous years (Bereś & Sionek 2010), as well as in several states of the USA (i.e. Nebraska and Iowa) (Darnell et al .…”

“…This finding could result from the fact that at that time females outnumbered males. Earlier research (2007 and 2009) conducted in the same area found that there were significantly more females captured between August and the end of the growing season (59·7 and 84·1% in the respective years) (Bereś & Sionek 2010).…”

The effects of chemical control used against males of Diabrotica virgifera LeConte in maize in southern Poland in 2011–2012

“…The study also revealed differences in optimum dates for the control of D. virgifera beetles between regions of Poland. In south-eastern Poland the optimum date for the control of WCR beetles usually falls in the first half of August (Bereś, 2013;Bereś and Sionek, 2010b), but in this study it was the second half of August, which is in line with previous findings by Drzewiecki and Pietryga (2009) for southern Poland.…”

The Glycolytic Enzymes Activity in the Midgut ofDiabrotica virgifera virgifera(Coleoptera: Chrysomelidae) adult and their Seasonal Changes

“…2001 , Hammack and Petroski 2004 , Bernklau and Bjostad 2008 , Hibbard et al. 2008 , Bereś and Sionek 2010 ).…”