Biomedical subjects

H E Hummel

Publications and source records attributed to H E Hummel.

11 recordsLinked to original sources

PubMed2005

A promising biotechnical approach to pest management of Diabrotica virgifera virgifera in Illinois maize fields under kairomonal shielding with the new MSD technique.

Environmentally compatible and sustainable plant protection requires novel approaches to pest management characterized by minimal emphasis on toxicants. Classical toxicants traditionally dominated economic entomology for half a century. But worldwide problems with environmental pollution and with increasing resistance levels in all major pesticide classes and in many key insect species including Diabrotica virgifera virgifera (D.v.v.) strongly advocate a rethinking and a change in management paradigms used. Soft, minimally invasive, biological, biotechnical and cultural approaches should replace hard pesticides which are in favor up to now. Fortunately, pheromones, kairomones, plant attractants, better traps, new plant varieties and cultural methods like crop rotation, in short more sophisticated methods are now available as pressure for finding and exploring novel strategies increases. Facing this situation, a new biotechnical approach of population reduction of D.v.v., called "MSD" technique, is introduced. MSD is characterized as an approach combining mass trapping, shielding and deflecting of adult insects along an invisible odor barrier of synthetic kairomone which diminishes the flux of insects across a high capacity trap line baited with kairomone, thus reducing both the population fluctuation and number and its reproductive success within the shielded area. In the case of D.v.v. in Zea mays fields, effects realized by the MSD technique have been measured simultaneously by a number of independent criteria during the summers of 2003 and 2004 at 2 different locations in Illinois maize fields of up to one half hectare size. Results observed are statistically significant and cannot be explained by mass trapping alone. There is also an additional shielding and deflection, in short "diversion" effect whose basic sensory and behavioral mechanisms call for future exploration.

Animals↗

PubMed2005

The western corn rootworm diabrotica Virgifera virgifera en route to Germany.

The western corn rootworm Diabrotica virgifera virgifera LeConte (Col.:Chrysomelidae) (D.v.v.) is one of the most important maize pests in North America. Ever since its invasion into Europe and its detection near Belgrade airport by BACA in 1993 it quickly spread all over southeastern Europe and is now advancing towards central Europe. Up until summer 2004 considered free of D.v.v., Germany is, with the exception of its northern and northeastern borders, surrounded by countries with proven D.v.v. infestations. In addition to simultaneous spot introductions by airplanes, three main routes for terrestrial introduction into Germany are likely: 1. from south to north via Lombardy (Italy) through Switzerland to the State of Baden-Wuerttemberg in the southwest; 2. from south east to northwest via Croatia, Slovenia, Austria into the State of Bavaria; and 3. from Belgium and the Netherlands in southeasterly direction to the state of Northrhine-Westfalia. From these, progress of D.v.v. along route 1 is so far the most advanced. It follows the well established network of road and rail connections through Switzerland and underscores the active role mankind and its technology plays as an active distribution vector for D.v.v. Mandatory crop rotation in the Swiss Canton of Ticino did slow down but could not prevent the northbound advance of D.v.v. in 2004. Considering the recent discovery of D.v.vu near the South German border, its introduction into German territory is only a matter of time and may be ecologically unavoidable. In Slovenla, another relatively small southern transit state, the D.v.v. population density is still much lower than in Switzerland but with significantly increasing trend during 2004 and with special emphasis in its southeastern provinces. Considering its relatively short distance to southeastern Bavaria and the well developed transalpine rail, road and tunnel system, Slovenia as a transit state may provide another access route for D.v.v. of lesser but still significant importance to Germany.

Agriculture↗

PubMed2005

Monitoring presence and advance of the alien invasive western corn rootworm beetle in eastern Slovenia with highly sensitive Metcalf traps.

The American Chrysomelid beetle Diabrotica virgifera virgifera LeConte (D.v.v.), also called the western corn rootworm, spread from the location of its original introduction into Europe, Belgrade airport (BACA 1993), in all directions. Within a decade it occupied almost all countries of South-eastern and Central Europe. However, it reached Slovenia as late as 2003: Only 19 specimen were found in maize fields of the eastern and also western provinces. Already in the summer of 2004, their number had risen to 386 which were mainly found in the eastern provinces near the borders to Croatia, Austria and Hungary. For their monitoring, a simple trap is being described which can be acquired in high numbers at a very low price and can guaranty a most sensitive detection of beetles. The Metcalf cup trap which in Slovenia so far has been unknown performed the task of monitoring quite well at five locations. It will also facilitate the future search for new and increasing infestations. Comparing 2004 with the year 2003, D.v.v. expanded its range in eastern Slovenia by about 15 km. These new infestations will include territories in which fields of the regionally Important oil seed pumpkin Cucurbita pepo are located. With important traffic connections between South-eastern and Central Europe, Slovenia will occupy a bridgehead function in the preventive protection of maize from D.v.v. spreading into more northerly European regions including western Austria and southern Germany.

Animals↗

PubMed2003

Homage to Robert Lee Metcalf (1916-1998): entomologist, environmental toxicologist, and insect chemical ecologist.

The late Professor R.L. Metcalf is being honored as one of the leading entomologists of the 20th century, whose worldwide influence on entomology, insecticide and environmental toxicology, and insect chemical ecology was enormous. His 82-year life span mirrored the transition in entomology from the early descriptive phase of insect and plant and animal interactions to the more detailed integration of the biochemical, physiological, behavioral, ecological, and environmental understanding of nature within the context of societal issues and needs. New techniques, some relatively simple but never-the-less ingenious, paved his way to fame. Metcalf was an enormously productive scientist. His 450+ research publications, numerous books and editorships, patents, internationally oriented staff of students, postdocs and associates, and his contributions to teaching and to public service let him stand out as a challenging role model for those young minds starting their careers at the beginning of the 21st century.

Awards and Prizes↗

PubMed2003

Introduction of Diabrotica virgifera virgifera into the Old World and its consequences: a recently acquired invasive alien pest species on Zea mays from North America.

Diabrotica v. virgifera LeConte (Coleoptera: Chrysomelidae), (in short D.v.v.), with common name western corn rootworm, is endemic to the New World. Originating in the regions from South America to Mexico where it was in biological equilibrium with its natural enemies, predators and pathogens, it moved north with its food plants. Probably due to human agricultural farm practices with preference for monoculture of maize, the insect found open niches for expanding to the midwestern US where LeConte first described the species in Nebraska in 1867. Cyclodiene insecticide resistance, discovered in 1961, accelerated its spread and movement across the Great Plaines to the Atlantic Coast where it arrived around 1980. D.v.v. is a costly adversary to maize, to cucurbit, and, because of recent hostshifts, a threat to soybean production. Booming air travel and shipments of goods by air provided opportunities for D.v.v., without its natural enemies, to invade Europe where the insect was first described by F. Baca in 1993 near Belgrade airport (Baca 1993, Camprag & Baca 1995). From this focal point, D.v.v. expanded its range in all directions. Ten years later, in 2002, most of southeastern Europe has D.v.v. populations, some of them reaching economic damage levels such as those in Serbia, Croatia, and Hungary. New spot infestations in Northern Italy (Veneto, Lombardy, Piemonte) and in the Ticino region of Southern Switzerland, but also in Austria, Slovakia, Czechia, the Ukraine, even France, signal the final arrival of D.v.v. in Central Europe. The Alps, formerlyconsidered a natural barrier, might be circumvented or trespassed via air and road traffic. Model calculations by Baufeld and Enzian (2003) show that climatic and survival conditions are favorable for D.v.v. in all of Central Europe. Yet, in spite of well known annual losses of one billion dollars in the US, an effective and sustainable European strategy for keeping D.v.v. in check is still missing.

Animals↗

PubMed2003

A monitoring trap for Diabrotica virgifera virgifera and D. barberi adults lured with a poisoned cucurbitacin bait.

A trap is described that uses as a simple natural ingredient a cucurbitacin mixture to capture and carbaryl insecticide to kill northern and western corn rootworm beetles (Diabrotica barberi Smith and Lawrence, and Diabrotica virgifera virgifera LeConte (D.v.v.), respectively). The trap is consistent in numbers of beetles captured per trap per day, and it should be useful in integrated pest management programs to monitor the population density of rootworm beetles in corn fields. Captures between 1981 and 1983 in Illinois showed that western corn rootworm adults that disperse into first-year cornfields were predominantly females. These traps are being utilized today (2003) by many researchers in the New World desiring to know more about rootworm beetle movement and activities. Entomologists in the Old World confronted with the alien invasive pest D.v.v. should profit likewise from increased knowledge and availability of these traps for Diabrotica management.

Animals↗

PubMed2003

Diabrotica egg separation from soil: an efficient and fast procedure for monitoring egg stages of corn rootworm populations.

Maize growers repeatedly are confronted with the need to make predictions and decisions about which of their fields are likely to develop corn rootworm populations above the economic threshold and are in need of treatment. One of the best parameters that can help as a basis for these decisions are corn rootworm egg counts in the soil. The Western corn rootworms have one generation each year. Females oviposit eggs in the soil in corn fields from late July through early September. These eggs overwinter in the soil and almost all hatch the following June. An apparatus is described that utilizes water, MgSO4 solution and differing screen sieves for extracting the rootworm eggs from the soil samples collected from the field after deciding on an acceptable sampling procedure. Samples may be a composite of subsamples or a number of individual samples taken at various locations in a field. The Illinois machine and the final separation of eggs, using flotation in 2 molar MgSO4 solution, are highly efficient, and recoveries of 97% of rootworm eggs manually placed in samples of soil have repeatedly been achieved. Thus, this would be a useful tool in integrated pest management programs that monitor the density of corn rootworm eggs in corn fields.

Animals↗

PubMed2003

Distribution patterns of MCA-coated granules aerially applied to corn fields of Southern Hungary between 2000 and 2002.

Field studies in corn (Zea mays L.) were conducted to evaluate distribution patterns of 4-methoxy-cinnamaldehyde (MCA) coated corn grits after aerial application with a Dromader fixed wing aircraft. The kairomone mimic MCA is synthetically available and a quite specific and efficient adult attractant for the invasive alien maize pest western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte. Orientation disruptive properties of MCA for WCR when applied at unphysiologically high concentrations are currently under investigation. For successful implementation of the MCA disruption technique, the distribution patterns of MCA coated corn granules ('grits') in the field are important. Grits are degrained corn cobs, shredded to different sizes, coated with MCA and used as a carrier material to disseminate MCA vapors into corn fields. Granules of 10-12 mesh size were aerially applied eight times at rates ranging from 12.4 to 25.0 kg/ha. The goal is to evaluate distribution patterns of corn grits treated with MCA in three fields located at Csanadpalota, Kardoskút and Mezöhegyes in Southern Hungary between 2000 and 2002. Increasing rates reflect our attempts in finding and optimising the most even distribution of granules in the field. Field experiments were evaluated by collecting grits in 30-cm plastic saucers and by counting grits accumulated on corn plant parts. Variation in grit number per unit area and frequency of corn granule number per plant showed some transient technical application problems. Analysis of grits collected in the saucers revealed some statistical difference between the different application dates as well as differences in rates applied. Altogether grits in saucers were more evenly distributed in comparison to the grits collected on plant parts. As the corn plants age, their leaves and whorls present a smaller and smaller surface area where granules can accumulate. Altogether, however, grit distribution patterns indicate that aerial application is a viable tool for disseminating MCA in corn fields.

Acrolein↗

PubMed2003

Orientation disruption of Diabrotica virgifera virgifera in maize by a liquid MCA formulation released from paper squares in the Banat region of Serbia and Montenegro.

Serbia-Montenegro, formerly the Republic of Yugoslavia, is the first European Country where Diabrotica virgifera virgifera Le Conte (Col.: Chrysomelidae) (D.v.v.) was reported in 1992 as an invasive alien pest species, Baca (1993), Camprag and Baca, (1995): From a focal point near Belgrade airport, the maize pest quickly spread in all directions reaching the economic threshold in a number of surrounding countries around 1995. The field experiments described took place in the Banat region east of Belgrade in July of 2002. The plant kairomone mimic 4-methoxycinnamaldehyde (MCA) dissolved in acetone was slowly volatilized from paper squares. It permeated a maize field of known D.v.v. history of 0.5 ha size 3 km north of the village of Crepaja. With release rates of 266 g/ha, max. orientation disruption levels of 55% were achieved. The total amount of MCA was distributed in two manual applications. Readings of orientation levels were continued for eleven days during the latter part of July and into early August of 2002.

Acrolein↗

PubMed2001

Distribution patterns of MCA-coated corn grit formulation after aerial application to maize fields.

Field studies in corn (Zea mays L.) were conducted during the summer of 2000 to evaluate distribution patterns of corn grits treated with MCA (4-methoxy cinnamaldehyde). Aerial application was used in a 8 ha corn field situated in south-east Hungary. Corn granules ('grits') of 10-12 mesh size were applied on July 18th, August 1st and August 28th at rates of 18.3, 21.9 and 20.2 kg grits/ha and were covered with 80, 119 and 120 g MCA/ha. Experiments were evaluated by collecting grits in 30-cm plastic saucers and by counting grits accumulated on leaves and in leaf axils on corn plants. Analysis revealed a statistical difference between MCA treated and untreated grit application rates only at the first application date. Variation in grit number per unit area and frequency of corn granule number per plant showed some transient technical application problems. However, altogether, grit distribution patterns indicate that aerial application is a viable tool for disseminating MCA in corn fields. With it, orientation disruption of the introduced maize pest Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) recently introduced into SE Europe will come within reach.

Acrolein↗

PubMed1999

Insect-based BioFETs with improved signal characteristics.

Insect-based BioFETs (biologically sensitive field-effect transistors) with improved signal characteristics have been developed. These BioFETs require a specifically adapted signal interfacing between a FET as signal transducer and an intact insect antenna as biocomponent. Therefore, different field-effect transistors have been fabricated in order to study the signal transfer at the bioelectronic interface. As relevant features of the BioFET, its current-voltage characteristics, the transconductance and the signal-to-noise ratio have been investigated as affected by the choice of gate insulator materials and gate dimensions (width-to-length ratio, thickness of the dielectric layers). The performance of the improved FET arrangement in the isolated-antenna BioFET was validated by employing dilution series of the plant odour component Z-3-hexen-1-ol.

Animals↗