Authors:C Szőke, Z. Zsubori, I Pók, F. Rácz, O. Illés, and I. Szegedi
The European corn borer (Ostrinia nubilalis Hübn.), which is to be found almost universally in Europe and America, is an extremely important pest from the economic point of view. Losses caused by the pest range from 250-1000 kg/ha depending on the degree of infestation, the year and the yield averages. This fact justifies protection measures in Hungary on the whole of the seed production and sweetcorn fields and on 40% of the commercial maize sowing area. In addition to the direct damage, indirect losses are also considerable, since the injuries caused by the pest facilitate infection by Fusarium species. For the above reasons it is worth reviewing the habits of this pest, the extent of the economic loss resulting from the damage, and ways of controlling it.
Silicon (Si) is reported to improve plant resistance to a range of biotic and abiotic stresses, with consequent yield increases. Silicon plays an important role in providing defense for crops of great economic importance against insect pests attack. In this study, the interaction between plants treated with silicon and reduced insect damage was reviewed. The current review presents the agronomic importance of silicon in plants, the control of insect pests in different major crop plants by silicon treatment, the different mechanisms of silicon- enhanced resistance, and the absence of silicon effects on insect pests. By integrating the data presented in this paper, a good knowledge of the association between silicon treatment, increasing plant resistance, and decreasing insect pest damage could be attainted.
Fundamental differences between Cry1Ab-based Bt-bioinsecticides and MON 810 maize varieties render these technologies not equivalent. While the former contain at least five different crystalline (Cry) toxins, the latter produce a single Cry1Ab toxin as active ingredient. Moreover, the lectin type toxin protein produced by these plants is a truncated version of microbial Cry1Ab. The majority of the results reported for Cry1Ab content is, therefore, subject to correction between microbial Cry1Ab protoxin and plant-expressed preactivated Cry1Ab toxin, and the latter is not a registered insecticide active ingredient. Cry1Ab toxin is produced continuously and not at the highest concentration in those plant parts, where the pest occurs. In turn, MON 810 maize does not comply with IPM principles, as control cannot be limited to the period of pest damage above threshold level. The target insect, Ostrinia nubilalis is a practically inconsiderable pest in Hungary, therefore, the use of MON 810 maize is mainly groundless. Pollen settling on Urtica dioica, Rubus spp. or Datura stramonium near or in maize fields may exert toxicity on caterpillars of protected butterflies, e.g. the peacock butterfly (Nymphalis io). Decaying Bt-maize material potentially affect other non-target organisms. Occurrence of Cry1 toxin resistance in pests is facilitated by the fact that MON 810 maize produces only a single Cry protein, preactivated Cry1Ab toxin.
Hedya nubiferana (Haworth) (Lepidoptera: Tortricidae) is a polyphagous pest damaging apple, pear, peach, plum and other related fruits. In tests conducted in Hungary, traps baited with a female-targeted lure [ethyl (E,Z)-2,4-decadienoate (pear ester) + acetic acid; abbreviated later as PE+AA] caught comparable number of moths as pheromone baited traps. Traps with PE+AA lures caught (females and males together) on an average 30% of the catch in traps baited with the synthetic green budworm moth sex pheromone (catching all males). This suggested that the PE+AA lure had a trapping performance comparable with that of pheromone traps, which latter are in practical use by farmers today. The seasonal flight patterns recorded with the PE+AA baited traps were similar to those with the sex pheromone baited ones, with respect to detection of beginning of flight and quantitative trends of catches during the flight. Consequently, the PE+AA lure shows potential for future practical applications as a female-targeted lure for H. nubiferana.
Authors:T. Jermy, Á. Szentesi, M. Tóth, and G. Szôcs
From 1880, the year of funding the
National Phylloxera Research Station, the predecessor of the present Department
of Zoology of the Plant Protection Institute, the main thrust of entomological
research was towards solving practical problems in agriculture, which mission
governs our recent activity and guides our plans for the future. Our studies on
the behaviour of herbivorous insects have shown that oligophagy is mainly due
to the sensitivity of the insects'
chemosensory system to deterrent chemicals occurring in the non-host plants.
This enables the use of antifeedants in pest control. In field experiments the
insects found their hosts largely by chance, which has implications for crop
rotation. The ability of learning in some herbivorous insect species has been
demonstrated. It may result in induced preference for some otherwise avoided
plants. Ecological studies indicated that predispersal seed predators do not
necessarily affect plant population dynamics and that there is no interspecific
competition among them. Studying the presumable processes that drive the
evolution of insect-plant associations resulted in elaborating the theory of
sequential evolution instead of the theory of coevolution. In course of 30 year
studies, female-produced sex pheromones were evidenced in behavioural studies,
isolated, and chemically identified in cooperations with organic chemical
laboratories, for a few dozens of lepidopterous species. Related sex
attractants were established by means of field trappings for further dozens of
species. Based on these results, the role of sex pheromones in maintaining
reproductive isolation between taxonomically closely related, sympatric
species, as well as the chemotaxonomical value of sex attractants in higher
taxa of Lepidoptera are discussed. As a result of our studies on Elateridae
(Coleoptera) we developed and optimized pheromone baits and traps for catching
males of all important pest Agriotes click beetles in Central and Western
Europe. The most effective pheromone combinations for each species were tested
in a Europe-wide comparative effort, giving information on the probable
importance of the respective species in the respective area. In Scarabaeidae
(Coleoptera) we discovered sex attractants for 3 species of the genus Anomala,
and floral attractants for 4 species of the subfamily Cetoniinae, all orchard
pests damaging fruits or flowers. Traps were developed for these scarabs taking
into consideration the optimal visual and chemical cues for each respective
species. The trap and bait combinations show preliminary evidence that their
use for direct control through mass trapping is possible. Among chrysomelid
beetles, new trap types were developed for the western corn rootworm Diabrotica
v. virgifera. These trap types are widely used in Europe for the detection and
monitoring of the pest. Most recent results concern the relationships between
host-plant related and pheromonal communication in flea beetles (Phyllotreta