Predation by the carabid beetle Harpalus rufipes on the pest slug Deroceras reticulatum in the laboratory

Abstract

The Harpalini species Harpalus rufipes, as many other generalist carabids, consume a wide variety of prey and it is known to feed on pest slugs such as the grey field slug Deroceras reticulatum, but quantitative data about the predatory activity of H. rufipes on slugs are very scarce. In laboratory experiments, we assessed the capability of male H. rufipes to kill eggs and different-sized slugs of the pest species D. reticulatum in either the absence or the presence of alternative live prey (dipteran larvae and aphids). We also investigated the preference of H. rufipes for eggs and hatchlings of D. reticulatum in a choice experiment. H. rufipes killed considerable amounts of eggs and small juveniles (≤5.0 mg) of D. reticulatum, both in no-choice and in choice situations. Medium-sized juvenile slugs (10-20 mg) were seldom killed only in no-choice situations, and no large juveniles (50-60 mg) were killed. Dipteran larvae and aphids were killed also in no-choice and in choice situations. The type of alternative prey presented with slug eggs affected the survival of the eggs to H. rufipes predation. The presence of dipteran larvae as alternative prey did not affect the survival of juvenile slugs. When eggs and small juvenile slugs were offered together, the survivals of both items were similar. The obtained results under laboratory conditions suggest that the generalist predator H. rufipes might realise an important contribution to the control of pest slugs.

Convergent evolution of specialized generalists: Implications for phylogenetic and functional diversity of carabid feeding groups

“…Harpalus rufipes, for example, preys on a variety of seeds but also on slugs, spiders, and insects. Moreover, prey spectrum and the degree of specialization vary across seasons (El‐Danasoury, Cerecedo, Córdoba, & Iglesias‐Piñeiro, 2017; Loughridge & Luff, 1983; Roubinet et al., 2018). Amara similata is known to feed on aphids, but granivory plays a vital role in its diet (Jorgensen & Toft, 1997).…”

Predation by polyphagous carabid beetles on eggs of a pest slug: Potential implications of climate change

“…El‐Danasoury et al. () reported ranges of 6–11 and 7–13 eggs killed in 24 hrs by one H. rufipes in two different experiments performed at 16°C; in the laboratory experiment reported here, P. cupreus destroyed eggs in the range 0–10 and H. rufipes in the range 3–17 when all temperatures were pooled. In the outdoor experiment, two H. rufipes killed between 65% and 89% of the eggs in 72 hrs, while for two P. cupreus egg predation ranged from 15% to 17%.…”

“…It is known to predate on weed seeds (Honek, Martinkova, & Jarosik, ; Luff, ; Zhang, Drummond, Liebman, & Hartke, ), aphids (Jørgensen & Toft, ; Kielty et al., ; Kromp, ; Loughridge & Luff, ), dipteran eggs, larvae and pupae (Kromp, ; Monzó et al., ; Renkema, Manning, & Cutler, ; Urbaneja et al., ), lepidopteran larvae (Dempster, ) and even on the Colorado potato beetle Leptinotarsa decemlineata and on eggs and larvae of the cereal leaf beetle Oulema melanopus (Kromp, ). It also consumes small slugs in the laboratory (Ayre, ; El‐Danasoury et al., ), and Ayre and Port () found slug tissues in the gut of a high proportion of field‐caught H. rufipes by using enzyme‐linked immunosorbent assay. Eskelson, Chapman, Archbold, Obrycki, and Harwood () found species‐specific DNA of D. reticulatum in gut contents of the Nearctic H. pensylvanicus (DeGeer, 1774) in strawberry fields in Kentucky, where H. pensylvanicus was the dominant carabid predator.…”

“…Carabids are mainly ground‐dwelling predators (Kromp, ), and a number of species predate slug eggs (Ayre, ; Hatteland et al., ; Oberholzer & Frank, ; Pianezzola, Roth, & Hatteland, ). Harpalus rufipes (De Geer, 1774) and Poecilus cupreus (Linnaeus, 1758) are two polyphagous carabids abundant and widespread in agroecosystems of the temperate Northern Hemisphere (Kromp, ), which are known to destroy eggs of D. reticulatum in the laboratory (El‐Danasoury, Cerecedo, Córdoba, & Iglesias‐Piñeiro, ; Oberholzer & Frank, ). It is also known that temperature has a positive effect on the predatory activity of these and other generalist carabids when preying on live, moving prey, in the laboratory (Ayre, ; Frank & Bramböck, ; Kielty, Allen‐Williams, & Underwood, ).…”

The effect of plant identity and mixed feeding on the detection of seed DNA in regurgitates of carabid beetles

“…Compared to specialists, they are already present in a field at the pest's arrival and thus have the potential to prevent pest outbreaks (Chang & Kareiva, ; Symondson, Sunderland, et al, ; Wissinger, ). Carabids are widely recognized as important beneficial organisms in arable land, known to provide regulation services on aphids (Lang, ; Roubinet et al, ; Staudacher, Jonsson, & Traugott, ), pest slugs (Bohan, Bohan, Glen, Symondson, & Wiltshire, ; El‐Danasoury, Cerecedo, Córdoba, & Iglesias‐Piñeiro, ; Fusser, Pfister, Entling, & Schirmel, ; Symondson, Glen, Ives, Langdon, & Wiltshire, ; Thomas, Harwood, Glen, & Symondson, ), and weed seeds (Bohan, Boursault, Brooks, & Petit, ; Honek, Martinkova, & Jarosik, ; Tooley & Brust, ). According to a national‐scale study, the turnover of the weed seedbank in individual fields is negatively correlated to the abundance of carabids (Bohan et al, ).…”