Editorial-Impact assessment, ecology and management of animal pests affecting field crop establishment: An introduction to the special issue

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

population density of these pests or the associated damage to maize crops at the crop 82 establishment phase. These results are encourgaing for an increased adoption of no-till 83 practices, which provide numerous environmental benefits including reduced soil 84 erosion. 85 Mice cause significant damage to crops worldwide by digging up and consuming newly 86 planted seeds, or by cutting seedlings and stems, and feeding on developing grains. 87 Under favorable conditions, mice can rapidly increase in abundance to form mouse 88 plagues. Forecasting mice population dynamics can assist management to keep this pest 89 species at tolerable densities. This is important for preventative management of the pest 90 that is sustainable in the long-term compared with reactive management, the latter   In this way, birds are deprived of essential aural information; they vacate the impacted 105 area for more secure locations beyond the reach of Sonic Net. By testing this device 106 through basic small-plot field experiments, the authors demonstrated the effectiveness 107 of the sonic net that reduced damage to sunflowers by 23% to 64% at maturity, 108 depending on field locations. The authors predict that the effect of the Sonic Net 109 treatment may be greater in other crop phases and types, such as in the establishment 110 phase or ground cover crops. Indeed, a relative lack of tall, three-dimensional 111 vegetational structure at the crop establishment phase may allow a more effective 112 spread of the Sonic Net sound offering fewer physical refugia for birds to lower their 113 perceived predation risk. Future studies should test the efficacy of this device on other 114 crops and specifically at the crop establishment phase.

115
Feral or wild pigs represent one of the most important invasive species that cause 116 severe economic crop losses worldwide. These animal pests may attack a large number 117 of crop species and the crop establishment phase is particularly vulnerable to their 118 attacks. More specifically to maize, feral pigs' damage to this crop mainly occurs 119 immediately following planting as these pests consume the freshly planted and 120 germinated seeds. Protecting the maize seeds or seedlings from feral pigs is important to 121 ensure a good quality of maize establishment. Snow et al. (2021) propose an 122 anthraquinone repellent seed treatment to limit seed and seedling damage due to feral 123 pigs. The authors showed that the repellency rate was affected by the concentration of 124 anthraquinone used and that treating the maize seed with 3% anthraquinone resulted in 125 J o u r n a l P r e -p r o o f the greatest reduction in damage. Testing of this method under a wide range of field 126 conditions and monitoring for the damage rate as well as the duration of protection 127 offered by this seed treatment method may provide further insights into the usefulness 128 of this method for growers to limit feral pig damage to maize. Nevertheless, unlike in the 129 US, the use of this product is forbidden in many countries including those of the 130 European Union.

131
Identification of the potential risk factors triggering animal pest damage to maize 132 seedlings and an accurate assessment of seedling losses represent the first step towards   to animal pests has become an emerging problem for some crops such as sunflower, 184 maize, and soybean. However, the solution to this problem, especially that due to birds, 185 is increasingly difficult due to a number of issues as highlighted by Sausse et al. (2021a).

186
In addition, because many bird species provide both ecosystem services and disservices, 187 it is difficult to consider them only as « a pest », which further complicates their     Figure 1. Crop establishment is a phase that consists of three sub-phases viz. sowing to seed germination; seed germination to seedling emergence; and seedling emergence to initial competition among young plants. The former two sub-phases are heterotrophic (i.e. the radicle and seedling development relies on the seed reserves) while the last sub-phase is autrotrophic (i.e. the seedling has already developed true leaves that are capable to perform photosynthesis and, thus, do not depend anymore on seed reserves that are already exhausted at this stage).

Figure 2.
Poor field emergence of faba bean (a) and brown mustard (b) due to unknown reasons. Identification of the causes leading to non-emergence is a first step to better manage biotic and abiotic factors affecting seed germination and seedling emergence via best cropping practices.

Figure 3.
Seed predation due to slugs under directly sown soybean in a relay cropping system. These pests can cause partial (a) or total (b) seed predation when the sowing quality is not optimal (superficial sowing depth, poor soil-seed contact etc.).

Figure 4.
Characteristic symptoms of post-emergence seedling damage due to animal pests. Slug feeding (a), and cutting and uprooting by common wood pigeon (b) of soybean seedlings.