Oviposition deterrence against Sitodiplosis mosellana (Diptera: Cecidomyiidae) in spring wheat (Gramineae)

Abstract

Spring wheats, Triticum aestivum L., previously identified as being lightly infested by eggs or larvae of wheat midge, Sitodiplosis mosellana (GChin), were tested to determine if reduced infestation was the result of oviposition deterrence. Oviposition deterrence was measured as the number of eggs deposited on a wheat line relative to that on a check. Egg densities on some of these lines were 10% or less compared with the susceptible commercial cultivar 'Roblin' in choice tests and 20% or less in no-choice tests in the laboratory. These lines also deterred oviposition in the field, reducing egg densities by at least 50% in single-row and multi-row field plots. Other experimental lines showed levels of oviposition deterrence intermediate between the most deterrent lines and 'Roblin'. One of 12 commercial cultivars tested, 'AC Superb', also had low egg densities in the laboratory and in single-row field tests, but this possible oviposition deterrence was not consistently present in large plots or commercial fields. The most deterrent experimental lines showed a level of oviposition deterrence that would be agriculturally useful and desirable in combination with a previously described antibiotic resistance.

Assessment of wheat ear insects in winter wheat varieties in central Germany

“…Furthermore, larvae that hatch from eggs laid on the rachis must travel a greater distance to reach their feeding site. Therefore, it is likely that deterrence of oviposition on glumes would not only reduce egg density but also the subsequent performance of wheat midge eggs and newly hatched larvae as reported by Lamb et al (2001Lamb et al ( , 2002. Identifiable morphological traits have been associated with a similar oviposition deterrence that occurs in some wheat varieties such as Capo (with hair) or Vitco which is an early variety which escape from WBM infestation as stated in other studies by .…”

“…Producers are urged to monitor crops closely in all areas where S. mosellana is present during the susceptible period (emergence of the wheat head from the boot until anthesis begins) as recommended by Lamb et al (2002). If a lower degree of infestation is predicted, producers may stick to their plans to grow wheat, but may choose one of the resistant varieties or a less susceptible wheat variety and plant early to avoid high midge populations during heading.…”

Non-native insects in agriculture: strategies to manage the economic and environmental impact of wheat midge, Sitodiplosis mosellana, in Saskatchewan

“…For example, the recent development of wheat cultivars that are resistant to wheat midge feeding (Lamb et al 2002a) will negatively impact localized populations of the parasitoid in situations where the host is decimated. Smith et al (2004) designed an agronomic practice of providing a refuge for virulent S. mosellana which allows producers to grow resistant wheats while at the same time protecting the resistance gene from being overcome by S. mosellana, and providing a host population for preserving parasitoid populations.…”

“…Prior to the growing season, forecast maps predict high risk areas ). If the rotation allows, the producer may choose not to grow wheat, grow a resistant variety of wheat (Lamb et al 2002a), or grow an alternate resistant crop instead. If a lower degree of infestation is predicted, producers may stick to their plans to grow wheat, but may choose a less susceptible wheat cultivar and plant early to avoid high midge populations during heading (Elliott et al 2000a).…”

Insect invasions of agroecosystems in the western Canadian prairies: case histories, patterns, and implications for ecosystem function

“…In the case of S. mosellana, forecasts and risk warnings are published annually before planting, and monitoring tools, cultural, chemical, and biological control strategies are all available to enable producers to effectively manage infestations Elliott et al 2007). A noteworthy recent development is the availability of wheat germplasm resistant to wheat midge, which promises to drastically reduce insecticide applications (Lamb et al 2002;Smith et al 2004). In the case of flea beetles, attempts to achieve host plant resistance and classical biological control have been unsuccessful, but several cultural practices have been developed that can be implemented in an integrated manner to substantially reduce insecticide use in some ecoregions (Dosdall et al 1999;Dosdall and Stevenson 2005;Elliott et al 2008).…”