Dispersal and spatiotemporal distribution of Protapion fulvipes in white clover fields: implications for pest management

Veronica Hederström,Franklin N Nyabuga,Mattias C Larsson,Olle Anderbrant,Åsa Lankinen,Maj Rundlöf,Glenn P Svensson

doi:10.1007/s10340-021-01408-w

Abstract

Yield loss caused by insect pests remains a substantial problem in agriculture. Chemical control, with potential negative effects on non-target organisms, is still the main tool for pest management. For pest species with limited dispersal capacity, rotation of the crop in time and space has potential as an alternative management measure. This is particularly important in organic farming, where most agrochemicals are prohibited, but also relevant as a complementary pest management strategy in conventional agriculture. Clover is an important crop used for animal feed and as green manure; however, seed-eating weevils can severely limit the seed yield. We hypothesized that the previous year’s clover seed fields constitute the major sources of weevil pests. Consequently, a greater distance to, and a smaller pest load from, this source should reduce the number of weevils colonizing the new seed fields. To map population dynamics and dispersal range of Protapion fulvipes, an economically important seed weevil specialized on white clover, we conducted field studies over four years in 45 white clover seed fields. We found that P. fulvipes overwinters close to its source field and disperses to new fields in early spring the following year. Pest abundance increased with pest load in the previous year’s seed field, but decreased by 68% per km distance to the previous year’s field. Thus, separation of seed production fields between years by 2–3 km would create a spatiotemporal pest management tool to reduce the pest infestation below the estimated economic injury level.

Highlights

Despite extensive use of chemical control, crop yield losses caused by pests have remained proportionally constant or even increased in some areas in the latter half of the last century (Oerke et al 1994; Pimentel et al 1991; Oerke 2006)
Seventy-six percent of P. fulvipes, 83% of Hypera spp., and 67% of Sitona spp. individuals were found at the source field, whereas 13% of the P. fulvipes were found at the study field and 11% at midpoints (Table 2)
We found that the major seed pest, P. fulvipes and other clover-associated weevil pests primarily overwintered adjacent to the source field, i.e., the field grown with clover the year before the weevils emerge after winter

Summary

Introduction

Despite extensive use of chemical control, crop yield losses caused by pests have remained proportionally constant or even increased in some areas in the latter half of the last century (Oerke et al 1994; Pimentel et al 1991; Oerke 2006). For pest species with limited dispersal capacity, moving the resource in time and space by crop rotation can be an important measure to control population buildup (Bullock 1992; Dent 2000; Mohler and Johnson 2009). This measure, requires knowledge on pest dispersal ability. We know that insects disperse and migrate to escape unfavorable environmental conditions or in search of resources such as suitable habitat, food, mates and oviposition sites (Wolfenbarger 1946; Dingle and Drake 2007; Dingle 2014; Chapman et al 2015).

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Conclusion