Ostrinia Nubilalis Hbn Research Articles

Yield performance of the European Union Maize Landrace Core Collection under multiple corn borer infestations

In Europe, corn borer attack is the main biotic stressor for the maize ( Zea mays L.) crop. European corn borer ( Ostrinia nubilalis Hbn.) is the most important maize pest in central and north Europe, while pink stem borer ( Sesamia nonagrioides Lef.) is predominant in warmer areas of southern Europe. The objective of this study was the evaluation of the European Maize Union Landrace Core Collection (EUMLCC) for yield under infestation with European corn borer ( O. nubilalis) and pink stem borer ( S. nonagrioides). Eighty-five landraces from Germany, Spain, France, Greece, Italy, and Portugal were evaluated, under corn borer infestation, for yield, grain moisture, and days to flowering at two locations in Spain. Landraces were evaluated separately in four trials that corresponded to four maturity groups. In each maturity group, there were significant differences among landraces for yield of infested plants. Extra-early landraces, ESP0090214, FRA0410010, and ESP0070339; early landraces, FRA0410022, and ESP11985022; midseason landraces, PRT00100392 and ESP11981047; and late landraces, PRT00100569 and PRT00100530, were promising sources of high-yielding maize under corn borer infestation and showed relative earliness within their maturity groups.

Vegetative Phase Transition and Corn Borer Resistance of shrunken2 versus sugary1 Sweet Corn Near-isogenic Inbred Lines

The genes sugary1 (su1) and shrunken2 (sh2) are commonly used to produce sweet and super-sweet corn (Zea mays L.), respectively. In this work we compare corn borer [european corn borer (ECB) (Ostrinia nubilalis Hbn.) and pink stem borer (PSB) (Sesamia nonagrioides Lef.)] susceptibility in seven pairs of su1 and sh2 near-isogenic sweet corn inbreds (101t, C23, C40, C68, Ia453, Ia5125, and P39) and the relationship between corn borer resistance and vegetative phase transition. The seven pairs of near-isogenic inbreds were evaluated under corn borer infestation during 3 years in northwestern Spain. Differences among inbreds were significant for most of the traits, although resistance was partial. Ia5125su1 and C40su1 were the most resistant inbreds. Differences between a few pairs of near-isogenic su1 and sh2 strains were significant for some vegetative phase change and corn borer damage-related traits. Generally su1 strains flowered earlier, had a shorter juvenile phase, fewer PSB, and more ECB larvae than sh2 strains. However su1 and sh2 strains did not differ significantly for most traits related to phase transition and corn borer damage; notably ear damage was not significantly different between su1 and sh2 strains. These results suggest that theoretical and practical results of sweet corn (sugary1) breeding for corn borer resistance could be capitalized for super-sweet corn (shrunken2) breeding.

Damage in Corn Production and in Hybrid Multiplication Caused by Species of the Anthicidae (Coleoptera) Family

Fungal attack on maize ears by Fusarium spp. leads to severe yield losses in Hungary almost every year. The severity of damage is influenced by modifying ecological factors (e.g. late sowing, susceptible varieties, hybrids of long vegetation periods, high plant densities, foggy or humid weather at the end of summer, etc.) as well as by damage caused by insect pests like the European corn borer, Ostrinia nubilalis HBN. Different maize varieties were included in comparative studies on industrial scale plots at Bacsalmas Sunflower Production Company in 1994. In the course of studies on the incidence of the fusariosis disease, the feeding of minute beetles was observed on the ends of the ears not covered by husk leaves. By determining these beetles of 4 to 6 mm they were found to belong to the group Heteromera, family of Anthicidae, species of Notoxus and Fonnicomus. Notoxus brachycerus FALD., Notoxus appendicinus DESBR. and Fonnicomus pedestris ROSSI were the most common of these insects. Both coleopterus genera (Notoxus and Fonnicomus) feed on the maize seeds at the end of July or in early August, each ear may contain 10 to 15 beetles injuring the young seeds (stage: waxy ripeness). The opened, partly consumed seeds present good growing conditions for Fusarium fungi that may spread under suitable humid weather conditions to the whole ear, causing not only yield reduction but also the appearance of fungal toxins dangerous for domestic animals or even humans. Earlier literature data reported the mass appearance of anthicid beetles as scavengers on cadavers of other Coleoptera that contain cantharidin, foremost on Melon species. It needs further research to establish whether the feeding of Anthicidae signalled a change in their originally necrophagous feeding habits or feeding on such substitute aliments has been caused by the prolonged drought period that had prevailed in Hungary in 1994. Be as it may, the damage they caused in year 2000 had been the most significant ever.

Light-Trapping of the European Corn Borer (Ostrinia nubilalis Hbn.) at Different Values of the Q-index Expressing the Different Intensities of Solar Flares

The paper deals with connections between solar flare activities and light-trap collection of insects. The authors have worked out the catch data of European corn borer (Ostrinia nubilalis Hbn.) adults, as published for the period of 1976–1997 by the Hungarian national light-trap network. The results proved that both the daily and annual catches were significantly modified by the Q-indexes, expressing the different lengths and intensities of the solar flares. On days with high Q-indexes relative to the ones of the average swarming periods, the number of catches are considerably lower. In those years when the Q-index is high, the average individual number and the number of caught moths are lower by 30% as compared to the average number of total cycles (11 years) and the average population density of a given biotope. On the contrary, in years with low Q-indexes an increase as high as 45% can be experienced in the number of individuals collected. Thus, by evaluating the light-trap catches a strong modifying e...

Assessment of 10 years of maize pedigree breeding for European corn borer tolerance and high-yielding combining ability

A multitrait pedigree breeding system including evaluation for European corn borer (Ostrinia nubilalis Hbn.) tolerance and other agronomic traits (yield, earliness, stalk lodging) was used for 16 years to create inbred lines from very different temperate germplasms. The ultimate evaluation of the 63 inbred lines was made in comparison with stable known references. The results allowed us to classify this material into three tolerance classes to the insect and demon- strated the efficacy of the method. High-yielding combining ability might be associated with earliness, lodging toleran- ce and good insect tolerance. The value of some early flint European materials and of Argentinian sources was discus- sed to improve European corn borer tolerance. (© Inra/Elsevier, Paris.)

Synthesis and application of insect attractants in Vietnam

Abstract Detrimental effects of synthetic pesticides on health, environment and organisms have necessitated the exploration of alternative strategies for insect control. The insect attractants represent an important link within these systems. In Vietnam, since 1970, methyleugenol and its analogues have been synthesized for mass trapping of the fruitfly Daccus dorsalis Hendel. This chemical reduced the damage on the oranges of many plantations in our country. In the period 1978–1980, for the first time some selected types of pheromones were tested. The trials verified and provided evidence of the occurrence of six species of moth in southeast Vietnam: Archips micaceanus, Archips seminubilus, Cadra caustella, Spodoptera exigua, Chysodeixis eriosoma and Parapoynx sp. The last decade has seen intense activity in the elaboration and application of some complex systems of fighting plant pests. Pheromones of moth and weevils have been prepared in the Institute of Agrochemistry and the Institute of Tropical Biology NCST: Ostrinia nubilalis Hbn, Heliothis armigera Hbn, Plutella xylostella Curt, Adoxophyes sp, Lyonetia clerckella, Trogoderma granarium, Diabrotica virgifera virgifera, Diabrotica undecimpunctata, Blattela germanica, Diprion, Neodiprion, Scolytus multistriatus, Scolytus scolytus, Lasioderma sericorne, Tribolium cofusum. Some synthetic aspects of these pheromones are described. The use of pheromone traps for monitoring and mass trapping the Scolytus multistriatus, Tribolium confusum, Plutella xylostella Curt, Heliothis armigera Hbn, Cylas formicarius elegantulus will be discussed.

Statistical analysis of insect preference in two-choice experiments

Many studies of insect behavior in relation to chemicals from different plants require the use of statistical tests for determining whether attraction, repulsion, or neutrality is significant. In this paper, we propose a simple and efficient nonparametric statistical procedure for testing hypotheses about insect preference in two-choice experiments with individual insects. Three criteria are provided in order to detect the following alternatives to neutrality: (i) general attraction (or repulsion) in a sample population, (ii) strong variability of the individual responses, and (iii) slight but similar behavioral effects. Illustrations are given from two-choice experiments concerning the European corn borer (Ostrinia nubilalisHbn.) female's oviposition behavior.

Modelling damage on maize by the European Corn Borer, Ostrinia nubilalis

SummaryThe European Corn Borer (ECB), Ostrinia nubilalis Hbn. (Lepidoptera: Pyralidae), is a major pest of maize in many countries. Yield losses caused by larvae of this insect depend mainly on the extent of cavity damage, the timing of tunnelling, and their within‐plant distribution. To describe these factors, a mechanistic model of cavity appearance is proposed here. It takes into account the main biological processes which determine damage. These are the development, mortality and within‐plant distribution of the ECB larvae. The model has been estimated and tested on field data collected at INRA‐Versailles in France. Model fittings showed that (i) creation and lengthwise extension rates of cavities per larva depend on location and instar of the larvae, and that (ii) only instars 4 and 5 make cavities. This model described, with a high precision level, the appearance and lengthwise extension of cavities over time and their within‐plant distribution for two maize varieties, several infestation dates and levels, and various climatic sequences.

Effects of the non-steroidal ecdysone mimic, RH-5849, on diapause and non-diapause larvae of the European corn borer, Ostrinia nubilalis Hbn

Topical applications of the non-steroidal ecdysone mimic, RH-5849, as expected, initiated a premature moult in last larval instar of the European corn borer, Ostrinia nubilalis. However, RH-5849 induced a perfect supernumerary larval moult in diapause and non-diapause larvae when the application was performed very early in the instar. The compound induced larval-pupal intermediates and normal pupae if it was applied after 2 days in the last instar of non-diapause larvae and after 5–6 days in diapause larvae. The occurrence of larval-pupal moults and normal pupae demonstrated the onset of pupal commitment of the diapause larvae. Moulting to normal pupae was greatly improved by a double topical application of 1 μg RH-5849 onto diapause larvae. Although the rate of normal pupation was rather low, the ecdysone mimic could break the larval diapause of the European corn borer and produce normal pupae. From these results, the endocrine control of diapause induction is discussed.

Olfactory responses ofTrichogramma maidis Pint, et Voeg.: Effects of chemical cues and behavioral plasticity

Oriented responses of Trichogramma maidisPint, et Voeg. to airborne odors were observed in a four-armed olfactometer. Experiments were carried out with odors of host eggs, the sex pheromone of Ostrinia nubilalisHbn, and maize extract, offered singly or in combination, both to naive wasps and to wasps previously exposed to the tested odor during an oviposition experience. The exploratory behavior in the olfactometer was quantified by means of a computer program which performed a space-time analysis of the insect 's movements. Whereas the naive wasps did not respond to the odor of the eggs, the synthetic sex pheromone of O. nubilalis,or the maize extract presented singly, they did react to a mixture of these three volatile cues. Prior oviposition in the odor of maize extract or in the combination of odors induced an increased preference toward the conditioning scent. This phenomenon did not occur when the wasps were conditioned to egg odor or sex pheromone alone. These results suggest that females can learn to associate some olfactory cues with the presence of the host. Immediately following the presentation of the combination of odors, a strong attraction of experienced wasps occurred; it decreased as the experiment progressed and finally reached the level presented by naive insects. Adult conditioning to the combination of odors also resulted in reduced variability in the behavioral responses.

LODGING-ENHANCING TECHNIQUES FOR USE ON CORN PERFORMANCE TRIALS IN SHORT-SEASON AREAS

A study was conducted during the 2 yr, 1978 and 1979, to determine an effective method of enhancing stalk lodging in maize (Zea mays L.) with the objective of being able to differentiate among hybrids for lodging susceptibility under conditions of low natural lodging. Six maize hybrids representing a wide range of stalk lodging resistance were used in the study. The techniques utilized were inoculating plants with a stalk rot pathogen (Gibberella zeae (Schw.) Petch) and/or infesting plants with European corn borer (Ostrinia nubilalis Hbn.). Both techniques, individually or in combination, were effective in enhancing lodging. Under environmental conditions and cultural practices where natural stalk lodging was low and differences in stalk lodging among hybrids would have otherwise been masked, the two lodging-enhancing techniques allowed for improved detection of hybrid differences. Both treatment effects and differences among hybrids for stalk lodging increased as stalk lodging rating was delayed, indicating delayed rating is preferable. Disadvantages to delayed rating are discussed.

Preference Differences of Egg Laying European Corn Borer Adults among Maize Genotypes1

Abstract Six homozygous lines each of sweet- and pop-corn (Zea mays L) were covered with cages when in the whorl stage of development and exposed to egg-laying European com borer (Ostrinia nubilalis Hbn) adults. Differences among lines in regard to egg masses per plant were highly significant, with sweet, nonpubescent, and early lines showing fewer egg masses per plant.

Evaluation of Sweet Corn Inbreds for Resistance for European Corn Borer1

Abstract European corn borer (Ostrinia nubilalis Hbn.) damage to sweet corn (Zea mays L.) inbreds was evaluated by husk ratings, tip ratings, ear tunnel counts, and ear indexes for two years. Egg masses placed in the leaf whorl and on the ear shoot were used to simulate egg laying by first and second generation corn borer adults, respectively. Differences among inbreds for second generation corn borer ear damage were highly significant in both years. Husk rating and tip damage rating gave a consistent measurement of these differences in two markedly different seasons. Correlations for all measurements of second generation damage were highly significant within years. Measurements of first and second generation damage were not consistently related. Host maturity was negatively correlated, although not always significantly, with first and second generation damage parameters.