Use of ryegrass strips to enhance biological control of aphids by ladybirds in wheat fields

Abstract

Non-crop habitats may play a vital role in conservation biological control. This study tested the effect of ryegrass (Lolium multiflorum L.) strips on aphid and ladybird populations in adjacent winter wheat fields. The field experiment was conducted in three ryegrass-margin wheat plots and three control plots in 2010 in North China. In spring, the same aphid species, Sitobion miscanthi (Takahashi), was found in both the ryegrass strips and wheat plots. The population density of ladybirds in the ryegrass strips (3.5 ± 0.9/m 2 ) was significantly higher than in the wheat plots (1.5 ± 0.5/m 2 ). We cut the ryegrass, forcing the ladybirds to migrate to the wheat fields. Three and eight days after cutting the ryegrass, the aphid numbers in the ryegrass-margin wheat plots decreased significantly: they were 19.9% and 53.6%, respectively, lower than in control plots. In the early period of ladybird population development, the percentage of larvae was greater in the ryegrass-margin wheat plots than in controls, and the peak number of pupae in the ryegrass-margin wheat plots occurred 5 days earlier than in the control plots. The results suggest that ryegrass strips may promote the development of ladybird populations. Cutting ryegrass can manipulate ladybirds to enhance biological aphid control in wheat fields. The efficiency of this management approach is discussed.

Impacts of weed management on ladybird (Coleoptera: Coccinellidae) abundance and diversity on resident vegetation in a citrus orchard

“…Each weed management treatment favored different plant species, offering either refuge or alternative trophic resources (pollen, floral or extra floral nectar, alternative prey, honeydew). The effect of vegetation height may have been due to the high Poaceae abundance-the presence of ladybirds on plants of this family has often been reported (Koji et al, 2007;Dong et al, 2012;Diepenbrock and Finke, 2013;Rhino et al, 2016).…”

Temporal Resource (Dis)continuity for Conservation Biological Control: From Field to Landscape Scales

“…A Field Trophic Langer and Hance, 2004;Litsinger et al, 2006;Schmidt et al, 2007;Yoo and O'Neil, 2009;Unruh et al, 2012;Segoli and Rosenheim, 2013;Villegas et al, 2013;Derocles et al, 2014;Damien et al, 2017;Nelson et al, 2018B Structural Halaj et al, 2000Sorribas et al, 2016;Boinot et al, 2019;Ganser et al, 2019 Both/Unmeasured Hossain et al, 2002;Men et al, 2004;Prasifka et al, 2006;Dong et al, 2012;Koch et al, 2015;Ramsden et al, 2015;Tsutsui et al, 2016;Pellissier and Jabbour, 2018;Toivonen et al, 2018;Bowers et al, 2020C Landscape Trophic Settle et al, 1996Prasifka et al, 2004;Pfannenstiel et al, 2012;Heimoana et al, 2017;Bertrand et al, 2019D Structural Öberg et al, 2007Royauté and Buddle, 2012;Roume et al, 2013;Sarthou et al, 2014;Raymond et al, 2015;Hanson et al, 2017;Gallé et al, 2018;Mestre et al, 2018;Ng et al, 2018;Sutter et al, 2018;K...…”

“…In relay cropping systems, crops that have different phenologies are planted in the same field, and the first (early season or fast growing) crop is harvested before the second (late season or slow growing) crop. This strategy has proven especially effective in promoting early recruitment of lady beetles to control aphids in wheat-cotton (Men et al, 2004) and rye-wheat (Dong et al, 2012) relay cropping systems in China, as well as soybean planted into an alfalfa living mulch in Iowa (USA) (Schmidt et al, 2007). Alfalfa-clover living mulch has also been effective in increasing ground beetle abundance and predation of the European corn borer in an Iowa maize-soy-forage rotation (Prasifka et al, 2006).…”

Spring Forward: molecular detection of early season predation in agroecosystems

“…In addition, providing refugia increases spider abundance, spider species richness in soybeans increased by 60% with a concomitant 33% reduction in damage to seedlings in manipulated plots (Halaj et al, 7 2000). Moreover, in cropping systems with aphid pests, strip-planting with ryegrass may replace at least one insecticide application per season, which has long-term economic and environmental benefits (Dong et al, 2012). While there is a good deal of information on the effect of conservation biological control on pests, considerations of both spatial and temporal scales need to be taken into account when making pest management recommendations.…”