Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Increase or maintain the proportion of natural or semi‐natural habitat in the farmed landscape Twelve studies evaluated the effects of increasing or maintaining the proportion of natural or semi-natural habitat in the farmed landscape on butterflies and moths. Three studies were in Switzerland, two were in each of Germany, Sweden and the UK, and one was in each of the USA, Malaysia, and New Zealand. COMMUNITY RESPONSE (11 STUDIES) Richness/diversity (11 studies): Nine of eleven studies (including one replicated, randomized, controlled study, one before-and-after study and eight replicated, site comparison studies) in Germany, Sweden, Malaysia, Switzerland, the UK, and New Zealand found that the species richness of butterflies, burnet moths and all moths was higher on farms with a greater proportion of semi-natural habitat or with a greater proportion of woodland in the surrounding landscape, or after semi-natural habitat had been created, compared to conventional farmland or farmland with a greater proportion of arable land in the surrounding landscape. One study found that species richness of butterflies in oil palm plantations was higher where ground coverage of weeds had been maintained but similar whether or not epiphyte or fern coverage was maintained. The eleventh study found that the species richness of butterflies was similar on farms with different proportions of semi-natural habitat. POPULATION RESPONSE (8 STUDIES) Abundance (8 studies): Six replicated studies (including one randomized, controlled study and five site comparison studies) in Sweden, the UK, New Zealand, and Switzerland found that the abundance of butterflies and moths was higher on farms with a greater proportion of semi-natural habitat, or in semi-natural habitat compared to conventional farmland. One of two replicated, site comparison studies in the USA and Sweden found that the abundance of four out of eight species of butterflies was higher on farms surrounded by woodland, but the abundance of least skipper was lower on farms with more semi-natural habitat. The other study found that overall butterfly abundance was similar on farms surrounded by different proportions of woodland and arable land. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3910https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3910Wed, 10 Aug 2022 14:34:14 +0100Collected Evidence: Collected Evidence: Pay farmers to cover the costs of conservation measures (as in agri-environment schemes or conservation incentives) Thirty-two studies evaluated the effects of paying farmers to cover the costs of conservation measures on butterflies and moths. Eighteen studies were in the UK, eight were in Switzerland two were in Finland, and one was in each of Sweden, the Czech Republic, the USA and Germany. COMMUNITY RESPONSE (18 STUDIES) Community composition (1 study): One replicated, controlled study in Switzerland found that the community composition of butterflies on grasslands that farmers were paid to manage for wildlife was similar to intensively managed grasslands. Richness/diversity (19 studies): Twelve of 15 studies (including eight controlled, one before-and-after and five site comparison studies) in Switzerland, the United Kingdom and Sweden found that the species richness or diversity of butterflies and moths on grassland, field margins, wildflower strips or whole farms managed under agri-environment schemes was higher than on conventional fields or farms. The other three studies found that the species richness of butterflies and micro-moths on grassland, field margins, wildflower strips or whole farms managed under agri-environment schemes was similar to conventional fields or farms. One of two replicated, site comparison studies in Switzerland found that the species richness of butterflies was higher in landscapes with a greater proportion of land managed under agri-environment schemes than in landscapes with a smaller proportion of agri-environment schemes, but the other study found that species richness of butterflies was similar on individual farms with more land managed under agri-environment schemes than on farms with smaller areas of agri-environment schemes. One replicated, site comparison study in the USA found that the species richness of butterflies on grassland sown under a conservation incentive program was similar to that on native prairie. One replicated, site comparison study in Finland found that the species richness of butterflies and day-flying moths on grassland managed under an agri-environment scheme was lower than on abandoned, unmanaged grassland. POPULATION RESPONSE (27 STUDIES) Abundance (27 studies): Seventeen of 19 studies (including seven controlled studies, one replicated, site comparison study, two before-and-after studies, and eight site comparison studies) in the UK, Sweden, Switzerland and Germany found that the abundance of butterflies and moths overall, and of specific species of butterflies or moths, in woodland, grassland, field margins, wildflower strips or whole farms managed under agri-environment schemes was higher than in unmanaged woodland or conventional fields or farms. The other two studies found that the abundance of butterflies and macro-moths on field margins managed under agri-environment schemes was similar to conventional margins. Three of four replicated studies (including one controlled and three site comparison studies) in the UK and Switzerland found that the abundance of butterflies was higher on farms or in landscapes with a higher proportion of land managed under agri-environment schemes than in areas with less land in agri-environment schemes. The other study found that the abundance of some species was higher, but others were lower, on farms with enhanced agri-environment management compared to simple management. Three studies (including one before-and-after and two replicated, site comparison studies) in Finland and the Czech Republic found that grassland grazed or restored under agri-environment scheme prescriptions had a lower abundance of all but three butterfly and day-flying moth species compared to unmanaged grassland, and that Danube clouded yellow abundance declined after agri-environment scheme mowing was initiated on abandoned grasslands. One replicated, site comparison study in the USA found that the abundance of butterflies on grassland sown under a conservation incentive program was lower than on native prairie. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3915https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3915Wed, 10 Aug 2022 15:41:00 +0100Collected Evidence: Collected Evidence: Reduce field size (or maintain small fields) Five studies evaluated the effects of reducing field size on butterflies and moths. Two studies were in Switzerland, and one was in each of Germany, Sweden and the Czech Republic and Poland. COMMUNITY RESPONSE (5 STUDIES) Richness/diversity (5 studies): Two of four replicated, site comparison studies in Sweden, the Czech Republic and Poland and Switzerland found that arable farms (in more diverse landscapes) and landscapes with smaller fields had a higher species richness of butterflies and burnet moths than areas with larger fields. The other two studies found that mixed farms and landscapes with smaller fields had a similar species richness of butterflies to areas with larger fields. One before-and-after study in Germany found that after reducing field size by increasing the length of field edges on a farm, along with increasing the area of meadows and field margins, the species richness of butterflies and burnet moths increased. POPULATION RESPONSE (4 STUDIES) Abundance (4 studies): Four replicated, site comparison studies in Sweden, the Czech Republic and Poland and Switzerland found that arable and mixed farms and landscapes with smaller fields had a higher abundance of butterflies and burnet moths than areas with larger fields. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3974https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3974Thu, 18 Aug 2022 09:04:31 +0100Collected Evidence: Collected Evidence: Manage hedgerows to benefit wildlife (e.g. no spray, gap-filling and laying) Seventeen studies evaluated the effects of managing hedgerows to benefit wildlife on butterflies and moths. Fourteen studies were in the UK, and one was in each of Belgium, Costa Rica and Italy. COMMUNITY RESPONSE (9 STUDIES) Richness/diversity (9 studies): Three replicated, site comparison studies in the UK and Costa Rica found that hedgerows with trees or a more complex structure had a higher species richness or diversity of butterflies and macro-moths than simpler hedgerows without trees. Three of six replicated studies (including three randomized, paired, controlled studies, one randomized, site comparison, and two site comparison studies) in the UK and Italy found that hedgerows cut to allow incremental growth had a higher diversity of caterpillars and pupae than hedgerows cut to the same size, that hedgerows kept between 1–2 m tall had a higher species richness of butterflies than hedgerows kept below 1 m tall and that fields with hedgerows of a larger volume had higher species richness of butterflies than those with hedgerows of a smaller volume, but only in one of two study years. The other three studies found that hedgerows managed according to agri-environment scheme prescriptions (including less frequent or winter cutting, gap-filling and restricted mowing, in one case in combination with other agri-environment scheme habitat) had a similar species richness of butterflies and moths to conventionally managed hedgerows. POPULATION RESPONSE (17 STUDIES) Abundance (17 studies): Four of six replicated studies (including four randomized, paired, controlled studies, one controlled study, and one paired, site comparison study) in the UK found that hedgerows cut once every 2–3 years, cut in autumn, or cut to allow incremental growth, had a higher abundance of adult butterflies and moths, moth caterpillars and pupae and brown hairstreak eggs than hedgerows cut to the same size every winter. However, one of these studies also found that hedgerows cut to allow incremental growth had a similar abundance of moth caterpillars and pupae to hedgerows cut to the same size. The other two studies found that hedgerows managed by gap-filling and cutting every three years had a similar abundance of moths to conventionally managed hedgerows, and that hedgerows cut in winter, or less frequently in autumn, had more concealed moth caterpillars, but a similar abundance of free-living caterpillars, to hedgerows cut annually in autumn. Three of five replicated, site comparison studies (including one paired study) in the UK and Costa Rica found that hedgerows with trees had a similar total abundance of macro-moths to hedgerows without trees. The other two studies found that hedgerows with trees, or with a more complex structure, had a higher abundance of butterflies and pale shining brown moths than simple hedgerows. Two replicated, site comparison studies in Belgium and Italy found that hedgerows managed with scalloped edges, or maintained at below 1 m tall, had more brown hairstreak eggs and a higher abundance of adult butterflies, than hedgerows with straight edges or allowed to grow over 2 m tall. One of two studies (including one controlled and one replicated, site comparison study) in the UK found that laid or coppiced hedgerows had a higher abundance of butterflies than unmanaged hedgerows. The other study found that managed hedgerows had a lower abundance of caterpillars than remnant hedgerows. One replicated, randomized, site comparison study in the UK found that butterfly abundance was higher in fields with hedgerows of a larger volume, but only in one of two study years. One replicated, site comparison study in the UK found that field margins next to hedgerow trees had a higher abundance of most shrub- and tree-feeding, but not grass- and herb-feeding, moth species than margins away from hedgerow trees. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3975https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3975Thu, 18 Aug 2022 09:18:48 +0100Collected Evidence: Collected Evidence: Plant new hedges Seven studies evaluated the effects of planting new hedges on butterflies and moths. Five studies were in the UK and one was in each of Ireland and Canada. COMMUNITY RESPONSE (5 STUDIES) Richness/diversity (5 studies): Three of four site comparison studies (including three replicated and three paired studies) in the UK, Ireland and Canada found that established hedgerows had a higher species richness of butterflies and macro-moths than in-field beetle banks, crops or pasture. The other study found that hedgerows had a similar species richness of butterflies to grass banks between fields. One replicated study in the UK found that gorse, oak and blackthorn planted within hedgerows had more species of arthropods, including caterpillars, than more commonly planted hawthorn. POPULATION RESPONSE (6 STUDIES) Abundance (6 studies): Five of six studies (including one replicated, controlled study, three paired, site comparison studies and two site comparison studies) in the UK, Ireland and Canada found that the abundance of butterflies, moths, macro-moths and gatekeepers was higher along hedgerows than on beetle banks, grass margins without hedgerows, in field interiors, or 5–10 metres away from hedgerows.The other study found that the abundance of butterflies along hedgerows was similar to grass banks between fields without hedgerows. BEHAVIOUR (1 STUDY) Behaviour change (1 study): One site comparison study in the UK found that moths recorded close to hedgerows were more likely to be flying parallel to it than moths recorded further away. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3976https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3976Thu, 18 Aug 2022 10:00:38 +0100Collected Evidence: Collected Evidence: Manage ditches to benefit butterflies and moths We found no studies that evaluated the effects on butterflies and moths of managing ditches to benefit butterflies and moths. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3977https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3977Thu, 18 Aug 2022 10:39:00 +0100Collected Evidence: Collected Evidence: Protect in-field trees One study evaluated the effects of protecting in-field trees on butterflies and moths. The study was in Sweden. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, site comparison study in Sweden found that where more trees and trees of more species had been retained in pastures, butterfly species richness was higher, but richness was lower when a high proportion of those trees were large. POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3978https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3978Thu, 18 Aug 2022 10:40:32 +0100Collected Evidence: Collected Evidence: Plant in-field trees (e.g. copses) We found no studies that evaluated the effects of planting in-field trees on butterflies and moths. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3979https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3979Thu, 18 Aug 2022 10:41:45 +0100Collected Evidence: Collected Evidence: Provide or retain set‐aside areas in farmland Nine studies evaluated the effects of providing or retaining set-aside areas in farmland on butterflies and moths. Three studies were in the UK, and one was in each of Germany, Ireland, Switzerland, Hungary, Finland and the USA. COMMUNITY RESPONSE (5 STUDIES) Community composition (1 study): One replicated, site comparison study in Germany found that butterfly communities in older set-aside fields included species which were less migratory, spent longer as caterpillars, and had fewer generations/year than species found in newer set-aside fields. Richness/diversity (5 studies): Three of four replicated studies (including one randomized, controlled study and three site comparison studies) in Germany, Ireland, Hungary and Finland found that sown or naturally regenerating set-aside had a greater species richness of butterflies and day-flying moths than cereal fields or pasture, especially when the set-aside was sown with less competitive grasses. One of these studies found a higher species richness of butterflies and day-flying moths in second-year set-aside than in first-year set-aside, but another found no difference in butterfly species richness between 1–3-year-old set-aside. The other study found that set-aside fields had a similar species richness of butterflies and moths to arable and pasture fields. One replicated, site comparison study in the USA found that set-aside fields had a similar species richness of butterflies to native prairies. POPULATION RESPONSE (8 STUDIES) Abundance (8 studies): Two of five replicated studies (including one randomized, controlled study and four site comparison studies) in the UK, Ireland, Hungary and Finland found that the abundance of butterflies and day-flying moths in sown set-aside was higher than in cereal fields, especially when the set-aside was sown with less competitive grasses. One of these studies found a higher abundance of butterflies and day-flying moths in second-year set-aside than in first-year set-aside, but another found no difference in butterfly abundance between 1–3-year-old set-aside. The other three studies found that fallow and stubble set-aside had a similar abundance of adult butterflies and butterfly and moth caterpillars to arable fields and pasture. Two site comparison studies (including one replicated study) in the UK and Switzerland found that set-aside fields had a similar abundance of butterfly and moth adults and caterpillars to uncultivated field boundaries and extensively farmed land. One replicated, site comparison study in the USA found that set-aside fields had a similar abundance of butterflies to native prairies in their first year, but a lower abundance of butterflies thereafter. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3980https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3980Thu, 18 Aug 2022 10:53:43 +0100Collected Evidence: Collected Evidence: Create uncultivated margins around intensive arable or pasture fields Ten studies evaluated the effects on butterflies and moths of creating uncultivated margins around intensive arable or pasture fields. Six studies were in the UK, two were in Sweden, and one was in each of Finland and Germany. COMMUNITY RESPONSE (9 STUDIES) Richness/diversity (9 studies): Two of five studies (including four replicated, one randomized, one paired, two controlled and two site comparison studies) in Sweden, the UK and Finland, found that uncultivated margins had a lower species richness or diversity of butterflies than margins sown with grasses and non-woody broadleaved plants (forbs) or wildflowers. One other study found that the species richness of butterflies and day-flying moths was higher in permanent uncultivated margins than in sown fallow plots, and the other two found that the species richness of butterflies and moths was similar in uncultivated and sown margins. Three replicated studies (including one randomized, controlled study and two site comparison studies) in the UK and Germany found that uncultivated margins which were not grazed or cut, or were only cut in spring or autumn, had a higher species richness of butterflies than margins which were cut in summer. Two site comparison studies (including one replicated study) in the UK and Germany found that the species richness of butterflies was higher in longer or wider uncultivated margins than in shorter, narrower or conventional width margins. One of two replicated studies (including one controlled study and one site comparison study) in the UK and Finland found that uncultivated margins had a higher species richness of butterflies and day-flying moths than cereal fields, but the other found that the species richness of butterflies was similar between regenerating margins and cropped field edges. One replicated, paired, site comparison study in Sweden found that uncultivated margins had a higher species richness of butterflies and burnet moths if they were located closer to existing grassland. POPULATION RESPONSE (9 STUDIES) Abundance (9 studies): Six of seven studies (including six replicated, two randomized, four controlled and three site comparison studies) in Sweden, the UK and Finland found that the abundance of butterflies and moths, and of adult but not caterpillar meadow brown, was lower in uncultivated margins than in margins sown with grasses, or grasses and non-woody broadleaved plants (forbs) or wildflowers, or a mixture of grasses and wildflowers. However, one of these studies found that uncultivated margins had similar abundance of butterflies to margins sown with grasses or cereal crop. The other study found that the abundance of butterflies and day-flying moths was higher in permanent uncultivated margins than in sown fallow plots. Two of three replicated, site comparison studies (including two randomized studies) in the UK found that uncultivated margins which were not cut, or were only cut in spring and autumn, had a higher abundance of butterflies, and adult but not caterpillar meadow brown, than margins cut in summer. The other study found that margins which were not cut and grazed had a similar abundance of butterflies to margins which were cut and grazed. Two replicated studies (including one controlled study and one site comparison study) in the UK and Finland found that uncultivated margins had a higher abundance of butterflies and day-flying moths than cereal fields or cropped field edges. One site comparison study in the UK found that the abundance of butterflies in wide uncultivated margins was higher than in conventional margins. One replicated, paired, site comparison study in Sweden found that uncultivated margins had a higher abundance of butterflies and burnet moths if they were located closer to existing grassland. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3981https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3981Thu, 18 Aug 2022 11:06:18 +0100Collected Evidence: Collected Evidence: Plant grass buffer strips/margins around arable or pasture fields Twenty-six studies evaluated the effects on butterflies and moths of planting grass margins around arable or pasture fields. Seventeen were in the UK, two were in each of Sweden, the Netherlands and the USA, and one was in each of China, France and Italy. COMMUNITY RESPONSE (15 STUDIES) Richness/diversity (15 studies): One of two replicated, controlled studies in the UK found that 2-m grass margins had a greater species richness of butterflies than cropped field edges, but 6-m grass margins did not. The other study found that the species richness of butterflies was similar in grass margins and cropped field edges. Five replicated, site comparison studies (including one paired study) in the USA, the UK and Italy found that wider grass margins (up to 6 m wide) had a greater species richness or diversity of butterflies, macro-moths and micro-moths than narrower or conventional width margins, although one of these studies found that the species richness of macro-moths was similar in wide and conventional grass margins. Three of five replicated studies (including three randomized, controlled studies, one controlled study, and one site comparison study) in the UK and Sweden found that floristically enhanced grass buffers or wildflower strips had a greater species richness of butterflies than standard grass margins. The other two studies found that farms with floristically enhanced margins (along with other enhanced agri-environment scheme (AES) options) had a similar species richness of butterflies and moths to farms with standard grass margins (along with basic AES options) and farms with no grass margins or other AES options. One site comparison study in Sweden found that grass margins sown with legumes or a clover and grass ley had a higher species richness of butterflies and moths than uncultivated margins, but less than a species-rich pasture. One replicated study in the Netherlands found that the species richness of butterflies increased over time after the establishment of grass margins. One replicated, randomized, controlled, before-and-after study in the USA found that disking or burning grass margins did not affect the species richness of butterflies. POPULATION RESPONSE (22 STUDIES) Abundance (21 studies): Three of four replicated, controlled studies in the UK found that grass margins had a higher abundance of butterflies than cropped field edges. The other study found that the abundance of gatekeepers on grass margins increased over four years after they were sown, but was only higher than cropped field edges at one of three farms after 2–4 years. Three of seven replicated, site comparison studies (including two paired studies) in the USA and the UK found that wider grass margins (up to 6 m wide) had a higher abundance of habitat-sensitive butterflies, macro-moths and micro-moths than narrower or conventional width margins. Two of these studies, and the other four studies, found that the abundance of disturbance-tolerant butterflies, macro-moths generally, and pale shining brown moths specifically, was similar in wide and conventional grass margins. Four replicated studies (including two randomized, controlled studies, one controlled study, and one site comparison study) in the UK and Sweden found that floristically enhanced grass buffers or wildflower strips had a higher abundance of butterflies than standard grass margins, uncultivated margins or margins sown with cereal crop. Two replicated, randomized, controlled studies in the UK found that farms with floristically enhanced margins (along with other enhanced agri-environment scheme (AES) options) had a higher abundance of some butterflies and micro-moths, a similar abundance of macro-moths, but a lower abundance of other butterflies, than farms with standard grass margins (along with basic AES options) and farms with no grass margins or other AES options. One site comparison study in Sweden found that grass margins sown with legumes or a clover and grass ley had a higher abundance of butterflies and moths than uncultivated margins or a species-rich pasture. Two replicated, before-and-after studies (including one randomized, controlled study) in the Netherlands and the USA found that mowing, disking or burning grass margins did not affect the abundance of butterflies and moths generally, or diamondback moths specifically, but that disking increased the abundance of disturbance-tolerant butterflies. One replicated, paired, site comparison study in the UK found that field margins had a similar abundance of butterfly and moth caterpillars to beetle banks established in the middle of fields. Survival (1 study): One site comparison study in China found that the survival of marsh fritillary caterpillars in grass margins around lightly cultivated fields was lower, but survival of egg clusters similar, to in uncultivated, grazed meadows. BEHAVIOUR (2 STUDIES) Use (2 studies): One replicated, site comparison study in China found that grass margins around lightly cultivated fields were more likely to be occupied by marsh fritillary eggs and caterpillars than uncultivated, grazed meadows. One replicated, paired, site comparison study in France found that meadow brown butterflies used grass margins in a similar way to meadows. Collected Evidencehttps%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3982https%3A%2F%2Fconservationevidencejournal.com%2Factions%2F3982Thu, 18 Aug 2022 11:38:08 +0100