Sándor Keszthelyi

Morphometrical and front wing abrasion analysis of a Hungarian cotton bollworm Helicoverpa armigera (Lepidoptera: Noctuidae) population

To determine the cotton bollworm migrating population rate in Hungary, we examined the weights and the front wing morphological feautures of trapped moths. We used sex pheromone traps to monitor field populations during the maize vegetation cycle period in 2008. We examined moths trapped at various times, and measured their body mass (m) and morphological features, namely the front wing quotient (fWQ = quotient of length of front wing/width of front wing), modified wing loading (WL = weight of moth/surface of front wing), and the relative thorax size (RTS = width of thorax/width of head). The data were analysed by Student t-test, anterior wing abrasion and darkness were analysed by a Adobe Photoshop 7.0 software. The Hungarian appearance of three cottom bollworm generations in 2008 was also observed. Based on the examined morphological features we found regularity in body mass, front wing quotient and modified wing loading changes during the flight period. The specimens trapped in the first and third part of the flight period had lower body mass, larger wing surface, longer wings and more favourable modified wing loading than the specimens trapped in the middle of the flight period. The abrasion and colour of the anterior wings of cotton bollworms were concordant to morphometric investigations. The abrasion in darker spots E1 and E3 clearly showed a more intensive usage of the wings in case of specimens trapped at the beginning and at the end of the flight period.

Flight dynamics analysis of the European corn borer (Ostrinia nubilalis (Hübner)) populations in Hungary from the second part of the twentieth century until the present

The data originating from six different points of the Hungarian Light Trap Network (1960–2005) were processed for comprehensive examination of the European corn borers (ECB) (Ostrinia nubilalis Hübner) flight dynamics. The annual flight diagrams were visually assayed. The annual alteration tendency of the quotients of the total trapped individual numbers (Σ), the relative individual number per day (1RIN) and the flight peak (FQ) were examined by means of linear regression analysis. The period and time of the alterations with comparative assay of five consecutive years series of data with Students t-probe were revealed. Eventually I investigated the effects of annual average temperature on the examined flight parameters with the help of variance analysis. The change of ecology and flight dynamics of the ECB started in the first and extended to the second part of twentieth century is now continuing. This statement has been confirmed by the increasing number of trapped individuals (regression quotient calculated from Σ, etc.: Velence-Sukoró: 65.58; Tarhos: 131). This phenomenon can be best characterised by the appearance and spreading of the second late summer flight peak (average regression quotient calculated from FQ, etc.: 0.082). According to my experiment the gradually increasing temperature and climate play a part in the background of the national flight changes [significant connection between the annual average temperatures of Hungary and Σ (P = 0.021), - 1RIN (P = 0.043)]. The spreading of the bivoltine ecotype can be predicted from these results and the literary data of Hungary.

Comparative light trap studies in Hungary on the flight of the European corn borer (Ostrinia nubilalis hübner) in 1999 – 2001

Abstract The investigations were aimed at acquiring the widest possible information on the flight dynamics of the European corn borer (Ostrinia nubilalis Hübner). I wanted to know what the trend of the flight curves in the 45 surveying places of the country was, and whether the already published flight dynamic rules proved true in 1999, 2000 and 2001. Further, I tried to find out how the abiotic elements influenced the number of individuals of the European corn borer populations caught by the light traps. It can be said that due to the mild spring and the hot rainy summer the area of the bivoltinism appearance of the European corn borer has shifted northwards in Hungary, as supported by the relevant data of the generation quotients: the average generation quotient was 3,94 for Csongrád – and 0,22 for Györ-Moson-Sopron county. The meteorological factors significantly influenced the number of individuals caught by the light traps. Significant correlations were found between the individual number of trapped corn borers on the one hand, and the maximum – (p = 99.2%; r = 0.472), minimum – (p = 99.8%; r = 0.549) and average temperature (p = 99.8%; r = 0.534), the precipitation (p = 95.7%; r = 0.327) and the air humidity (p = 97.3%; r = 0.265), respectively, on the other.

Different catching series from light and pheromone trapping of Helicoverpa armigera (Lepidoptera: Noctuidae)

Abstract Monitoring the flight of Helicoverpa armigera (Lepidoptera: Noctuidae) by means of pheromone and light trapping are generally accepted and widely used methods. In the present study the catch data of 335 Hungarian light traps have been examined and compared to the field-observed results originated from light and pheromone traps in the quest of exploring potential differences in observation methods. There were obvious discrepancies in registered flight patterns between light and pheromone trap catches. In early summer, individuals of the migrant generation of H. armigera were not caught by Hungarian light traps. The recorded parameters in light and pheromone traps have revealed significant differences as shown by the Student t-values used for comparing the data. This phenomenon can be explained by the physiological features of H. armigera, the females (being heliophile) of the early, migrant generations which have more vitelline-cells in their ovaries.

New insight into the Delia platura Meigen caused alteration in nutrient content of soybean (Glycine max L. Merill)

Climate change has brought about an increasing level of seedcorn maggot (Delia platura Meigen, 1826) (Diptera: Anthomyiidae) damage in Hungary. In order to have a more accurate understanding of the effects of these plant injuries induced by the larvae of D. platura, the nutrient content of soybean (Glycine max L. Merill.) was studied. Our results show that the moisture, raw fat, raw fibre, and raw ash content of the batches damaged by D. platura were significantly less in comparison with that of the control samples. In response to the deleterious effect of the insect, the infected soybean plants showed forced ripening (P = 0.004) (P > 0.05). The difference of moisture content between damaged and control samples was 2.30% on average. The fact of nutritional value loss was also reflected by the alteration of sugar mobilisation. As the result of this experiment the sucrose breakdown to glucose and fructose during the germination was significantly slower in the damaged seeds than that of the control ones. Overall, this late and surprising damage caused by D. platura led to the forced ripening of the affected soybean plants and a significant change in their nutritional values. Based on the herein reported results, it is presumable that in cases when the current climatic extremities, which are envisaged to occur more frequently in the future, and effects of agricultural practices will be coincided in the future a qualitative change of the produced soybean batches can be expected through the damage caused by this fly species.

The effect of the diatomaceous earth formulation DiatoSec on mortality of granary weevil Sitophilus granarius (Coleoptera: Curculionidae) in grains

The insecticidal efficacy of the diatomaceous earth formulation DiatoSec® (Ediafilt Diatomite Mining and Processing Ltd., Hungary) against the granary weevil, Sitophilus granarius (Coleoptera: Curculionidae), was evaluated on maize and barley grain in laboratory tests. The diatomaceous earth formulation was applied at three doses of 1, 2 and 4 g kg-1of both grain types. Mortality of S. granarius adults was estimated after 24 and 48 h and 7, 14 and 21 d of exposure on treated grain. After the 21 d counts, all the exposed adults were removed and progeny production on treated grains was assessed 45 days later.The insecticidal efficacy of the examined diatomaceous earth against the granary weevil was highly influenced by grain type, exposure time and dose. The longer exposure times increased weevil mortality in the case of both grains. The efficacy on maize was unsatisfactory. On the other hand, 85% of the weevils were died after a 21 d exposure on barley treated with the highest dose. In addition, progeny production on treated barley was completely suppressed. In all, a satisfactory level of protection was only achieved with barley at a rate of 4 g kg−1. Differences in efficacy between grain types could be traced back to differences in grain surface. The lower efficacy — than some examined silica products — of DiatoSec as compared to similar products can be explained by the lower SiO2 content.

A kukoricaszemek beltartalom- és fehérjestruktúra-változása a gyapottok-bagolylepke ( Helicoverpa armigera Hbn.) csőkártételének hatására@@@Changes in the content and protein structure of maize grains as a result of the ear damage caused by Cotton Bollworm ( Helicoverpa armigera Hbn.)

Summary During our examinations, we determined the change in the content and protein structure of maize grains as a result of the ear damage caused by Cotton Bollworm. We compared the dry matter, raw fat, raw protein and starch contents of partially damaged and damaged samples and we also examined the protein structures of each group. Our examination data did not show increased water loss and forced ripening as a result of damaging. The decreases in raw fat (loss: 9.29 kg, 2.92%) and starch (loss: 214.03 kg, 3.55%) per one hectare as a result of damaging were registered. The change in the protein structure causing a parallel increase in raw protein was shown by SDS PAGE analyses, which is best demonstrated by the disappearance of small molecular weight zein proteins in the case of damaged grains. The increase of protein content is caused by the increase of the quantities of 114, 50, 46, 35 kDa molecular weight protein.