Diversity and the role of butterflies species at PT Permata Sawit Mandiri, West Kalimantan

The use of chemicals indicates a cost inefficiency and makes oil palm plantations considered environmentally unfriendly causing a decrease in environmental quality. These problems indicate the need to increase the role of biodiversity to optimize oil palm productivity and be environmentally friendly. Based on this, research is needed on the diversity and role of butterfly species in palm oil agrosystems. The purpose of this study is to identify the species of butterflies in various land cover and analyzes the role of butterflies in the palm oil agrosystem. The research was conducted at PT Permata Sawit Mandiri, West Kalimantan. Diversity data was obtained through pollard transect and trapping methods, while role data was obtained through the literature study method. The pollard transect method was carried out along a line measuring 2 × 1,000 m long and 10 m wide at 08.00-11.00. The trapping method was carried out by placing 5 traps in each observation line for 3 × 24 hours. The results showed that there were 190 individuals belonging to Papilionidae (3 species), Pieridae (8 species), Nymphalidae (37 species), Lycaenidae (7 species), and Hesperidae (4 species). There are variations of butterfly species between land covers with the highest number of species found in rubber gardens (27 species). 7 species of butterflies have the potential as oil palm pollinators with the highest potential owned by Elymnias hypermnestra. The Papilionidae (Graphium agamemnon, Papilio polytes, Papilio memnon) can be environmental bioindicators because more sensitive to the environment.


Introduction
Palm oil is one of Indonesia's industries with enormous development potential.The area of oil palm plantations in Indonesia is increasing by 0.91% annually and is expected to be 15,081,021 ha in 2021 [1].One of the challenges in developing the palm oil industry is the use of chemical fertilizers and the imbalance of the role of biodiversity.The use of chemical fertilizers is considered ineffective and expensive due to the government's reduction of fertilizer subsidies.Procuring fertilizer can cost 40-50% of the total cost of palm oil production [2].Chemical fertilizers have a high level of toxicity to the environment and biodiversity.Other studies have shown that 70% of pesticides used in oil palm plantations are harmful to non-target species [3].
The inefficiency of using chemicals in palm oil management indicates the need for other alternatives to control the constraints of the palm oil industry.Optimizing the role of biodiversity can solve this problem.One type of biodiversity that can be used as an alternative is butterflies.Butterflies are insects of the order Lepidoptera that have an important ecological role in the environment.Butterflies have an ecological role as predators' prey so they can maintain biological diversity [4].Butterflies also act as 1243 (2023) 012013 IOP Publishing doi:10.1088/1755-1315/1243/1/012013 2 pollinators during the day and environmental bioindicators, thus impacting plant regeneration and ecosystem balance [5,6].
The presence of butterflies in the oil palm agrosystem area can be used as one of the focuses of biodiversity studies.PT PSM is one of the oil palm agrosystems in West Kalimantan Province that has biodiversity potential in the form of butterflies because the PT PSM area has various types of land cover that can be a habitat for butterflies.In addition, information about the role of butterflies in the palm oil agrosystem in Indonesia still needs to be improved, including in PT PSM.Based on this, research related to the diversity and role of butterflies in the palm oil agrosystem is required.This study aimed to identify butterfly species in various land covers and analyze the role of butterflies in the palm oil agrosystem.

Method
The research was conducted at PT Permata Sawit Mandiri, Ketapang Regency, Kalimantan Province.The research was carried out in January-April 2020.The related diversity data collection was carried out using the pollard transect and trapping methods.The pollard transect method was carried out along the transect line measuring 10 meters wide and 2 x 1,000 m long at 08.00-11.00(Figure 1).The trapping method used five traps for each observation line (2,000 m) for 3 × 24 hours.Data related to the role of butterflies were taken through the literature study method.

Figure 1. Butterfly observation transect illustration
Data analysis includes quantitative and descriptive qualitative analysis.Quantitative analysis used species diversity indices, while descriptive qualitative analysis described the condition of land cover species and the role of butterfly species.To determine the variation of species diversity in various types of land cover used calculations consist of species richness index (1), evenness index (2), and similarity index (3) (   The HF land cover type has large rivers and the topography is hilly land.The canopy type is dense and has 104 plants, with the dominant species originating from meranti batu (Shorea sp.) and pudu (Horsfieldia iryaghedhi) plants.The type of HG land cover is wavy and hilly with very dense canopy cover.This forest type has 80 plant species with the dominant species originating from kayu bunga (Carallia brachiata) and reribu (Diospyros sp.).The topography of the rubber plantation is hilly with a fairly dense garden floor cover and mineral soil type.The rubber plantation area has 52 plant species, with the dominant species being rubber (Hevea brasiliensis) and coffee (Coffea robusta).

Diversity of butterfly species
The observations showed that in PT Permata Sawit Mandiri there were 190 individuals of 59 species consisting of the Papilionidae family (3 species), the Pieridae family (8 species), the Nymphalidae family (37 species), the Lycaenidae family (7 species), and the Hesperidae family (4 species) (Figure 2).The results of another study in PT ASMR Central Kalimantan oil palm plantations showed the results of as many as 34 species from 202 individuals [7], in PTPN V Tamora Riau showed results of 299 individuals from 39 species [8], in PT Gunung Tua Abadi Sumatera Selatan showed the results of 164 individuals from 41 species [9], and in Taman Bunga Merangin Garden Bangko Jambi showed results of 88 individuals from 16 species [10].Based on these comparisons, this study found more species.The difference in the number of species and individuals of butterflies found can be due to differences in the environmental conditions of both biotic and abiotic components.Biotic components such as feed sources, places to lay eggs and shelters affect the presence of butterflies.Abiotic components related to habitat characteristics such as water availability, temperature, and sunlight also affect the presence of butterflies [11,12].

Figure 2. Number of species and number of individuals of each butterfly family found
Figure 2 shows that the Family Nymphalidae is the family that has the highest number of species and number of individuals found in the oil palm plantations of PT Permata Sawit Mandiri.The high diversity of species of the family Nymphalidae is due to the butterfly family Nymphalidae being the family with the largest number of species in the order Lepidoptera.This is evidenced by the high level of the meeting of the Nymphalidae family in other studies at PTPN V Tamora Oil Palm Plantation Kampar Riau [8]; in Gunung Bonsu Area, Rokan Hulu Regency, Riau Province [13]; in Gunung Ciremai National Park [14]; in Bogor Botanical Garden [15].Family Nymphalidae is adaptable and classified as polyphages [16].The nature of polyphages (can eat various species of plants) causes the family Nymphalidae not to rely on only one feed plant so that it is more adaptive in various environmental conditions.The high diversity of species of the family Nymphalidae is also due to the high availability of feed plants and host plants at the study site.The feed vegetation found at this study site included those of the Euphorbiaceae, Rubiaceae, Poaceae, Leguminosae, and Compositae families.The preference of feed plants from the The species of butterflies found based on their land cover type vary widely.The calculation results show that the number of butterfly species at PT Permata Sawit Mandiri varies from 7 to 21 species.The highest number of species is found in the rubber plantation land cover type (KK), while the highest number of individuals is found in the old oil palm land cover type (ST) (Figure 3).

Figure 3. Butterfly diversity according to land cover type
The high number of individuals in the ST land cover type is caused by the availability of habitat components needed by butterflies such as the presence of water sources, rare canopy cover so that sunlight can enter, and on the garden floor, there are many undergrowths and grasses needed by butterflies as a source of feed.The land cover that has the lowest number of individuals is HG.This land cover is a natural forest area with a very dense canopy cover that causes very limited sunlight to enter, as well as the availability of undergrowth as butterfly feed is very small.This condition causes the small number of individual butterflies found.Butterflies have a dependence on sunlight in out their activities [18].
The high number of species, species wealth and species diversity in KK land cover is due to the rich species of vegetation contained in this land cover that is used by butterflies as a source of host feed and adult butterfly feed such as rubber vegetation that dominates and chocolate, coffee, rambutan, and pepper.The existence of butterflies is very dependent on their feed plants, both as hosts for larvae and as a source of nectar for adult butterflies [16].Butterflies do many foraging activities in rubber gardens, especially in the afternoon [19].In the land cover of rubber plantations, there is also a small lake as a source of water.The source of water is an important factor for butterflies.Adult butterflies are actively looking for the water needed just like nectar, especially waters that contain minerals needed by butterflies to perform puddling (puddling) [20].The low number of species, species wealth, and species diversity in SM land cover are due to the absence of habitat factors needed by butterflies, such as feed vegetation, protective vegetation, and water.This land cover is a very open area, does not yet have protective vegetation with a very high intensity of sunlight, and the absence of undergrowth on the garden floor as a source of feed for butterflies.

Evenness of butterfly species
Based on the calculation results, all types of land cover at the study site showed that an evenness value close to 1 means that all land cover has evenly distributed butterfly species and no dominant butterfly species are found.The results of the analysis of the equivalence value of the butterfly produced an evenness value of 0.84-0.98(Figure 4).The evenness index can draw the level of distribution and dominance of species [21].The evenness of animals in a location shows that environmental conditions are good and stable so that they can support the survival of the species [22].Figure 4 shows that the highest equality value is found in the HG land cover type (E=0.98),while the lowest evenness value is found in the ST land cover type (E=0.84).This is different from the another in PKWE Ketapang Plantation, West Kalimantan [23]; in PTPN V Tamora, Kampar, Riau [8]; and in PT Gunung Tua Abadi, South Sumatera [9].Differences in the level of evenness are influenced by differences in environmental conditions mainly related to temperature, humidity, and vegetation type.The evenness value in the old palm cover type has the lowest value due to the dominance of the Junonia atlites (Nymphalidae) type.Junonia atlites are found in the ST land cover type because they like bright places and host plants in the form of shrubs and grasses that are abundant in the ST land cover type.

Similarity of butterfly spesies
In general, the results of the analysis related to the similarity of butterfly communities between land cover types showed that the value of the level of community similarity was quite low.The results of the analysis of the index of similarity of species can be seen in Table 2.  2 shows that the index of community similarity in 6 land cover in PT PSM is valued at 0.06 -0.36 (low).The value of ≤25% indicates a very different degree of similarity, 25 -50% indicates no similarity, and 50 -< 75% [24].The highest similarity value is found in SM with SS land cover, and SM with HF land cover, while the lowest similarity value is found in SM with KK land cover.The high value of similarity between SM and SS can be caused by the characteristic conditions of both locations that are almost the same, while in SM and HF it is caused by the factor of proximity.The low value of similarity in SM with KK land cover is influenced by differences in vegetation composition.SM is an oil palm area while KK is a plantation dominated by rubber plants.Other research explained that the factor of the occurrence of type similarities between two habitats is the distance between adjacent habitats and the same vegetation composition [25].

Role of butterflies
Butterflies are animals that have high ecological value.Butterflies come from the class of insects that have a role as pollinators.Butterflies can help the flower pollination process to be more optimal and perfect so that certain species can seed and continue their survival.Butterflies also have the potential as natural bioindicators for the environment because they are sensitive to changes in habitat conditions [26].Butterflies like areas that are not polluted and can show a response to disturbances and reflect the conditions of their habitat [27].The analysis results show that there are seven species of butterflies that have the potential to be pollinators of oil palm and three species of butterflies that have the potential as bioindicators in oil palm agrosystems (Table 3).  3 shows that the butterflies that act as pollinators are primarily found in the ST land cover type.In the ST land cover type, many old individuals have flowered and attracted pollinating butterflies to the location.The male and female flowers of oil palm have the potential to emerge from each midrib after the plant is one-year old [28].Butterflies in the HF land cover type also have the potential to become pollinators in the oil palm agrosystem because they are located close to the oil palm area.Pollinating butterflies were also found in the SM and SS cover types because there were already emerging flowers.The time it takes from leaf one to form flower buds is 232 days [28].
All species of pollinating butterflies in Table 3 prefer forage plants from the Arecaceae family.Oil palm comes from the Arecaceae family which is one source of food plants for butterflies [29].Male and female flowers in oil palms are located separately and rarely bloom at the same time, so an intermediary is needed that can transfer pollen from male flowers to female flowers that are in bloom [28].The species with the most potential to become oil palm pollinators is Elymnias hypermnestra.Oil palm is a main feed plant of the butterfly Elymnias hypermnestra [30].This shows that the butterfly Elymnias hypermnestra utilizes palm nectar as a feed ingredient.Elymnias hypermnestra is widely distributed in the habitat of oil palm plantations [31].One of the factors causing the determination of butterfly feed plants is the morphology of flowers, namely the color of flowers.Palm flowers are yellowish-white and are loved by butterflies.This is following Butterflies are interest with yellow, white, red, orange, blue, and purple flowers [32].In addition to the color of the flowers, the nectar content is also a factor of preference for butterfly-feed plants.Butterflies tend to choose plants that produce a fairly large amount of nectar at about 29% with a sugar composition of ±70% [33].Based on this, butterflies have the potential to become pollinators of oil palm because palm oil contains an average total sugar content of 71.5% [34].This is in accordance with [35,36,37] which states that Butterflies come to visit flowers by first seeing the flower character, such as shape, color, aroma and others.
The analysis results show that the butterflies that can be used as bioindicators of environmental quality generally come from the Papilionidae family and are found in the HF land cover type.The high number of encounters with butterflies that act as environmental bioindicators is related to a large number of vegetation in the HF cover type (104 species), most of which have the potential as butterfly feed plants.Butterflies are particular for forage plants and may use natural forests around oil palm plantations to source forage crops [38].HF land cover is in the form of forest overgrown with dense trees and rarely human activities, so the vegetation condition is more stable.
Family Papilionidae has specific habitat characteristics and is sensitive to changes so it can be used as a bioindicator.In general, butterflies of the family Papilionidae have a more beautiful pattern and shades of wings compared to other families.Beautifully colored species of butterflies have recently become rare.The occurrence of forest destruction can result in a reduction in the number of host plants.This will have an impact on reducing the number of species and the number of individuals from butterflies.Butterflies of the family Papilionidae have a larger morphological size so that they are easy to identify and observe periodically so that they can be used as indicators.Another research state that the species selected as indicators must be sufficiently sensitive to environmental changes and can be studied continuously at varying degrees of change or pressure [39,40].Graphium agamemnon, Papilio memnon, and Papilio polytes show strong associations with environmental factors such as low frequency of attendance, certain habitats (open areas with high light intensity), and proximity to water or mineral sources.This shows that the type has a higher level of susceptibility and sensitivity to changes in environmental quality.

Conclusion
The diversity of butterflies at PT Permata Sawit Mandiri consists of 190 individuals belonging to 59 species, namely Papilionidae (3 species), Pieridae (8 species), Nymphalidae (37 species), Lycaenidae (7 species), and Hesperidae (4 species).The highest number of butterfly species was found in the rubber plantation land cover type (27 species), while the lowest number was found in the young oil palm land cover type (7 species).The land cover type with the most complete composition of butterfly roles was found in the secondary forest land cover type in block F (HF), while the secondary forest land cover type in block G (HG) did not find any butterfly species that play a role in the oil palm agrosystem.
family Nymphalidae is from the tribes Asteraceae, Verbenaceae, Athiriceae, Urticaceae, Araceae, Mimosaceae, Melastomaceaea, Solanaceae, and Poaceae[17].The butterfly species of the family Papilionidae are the least number of individuals and the number of species due to the unavailability of host plants belonging to the family Rutaceae at the study site.

Figure 4 .
Figure 4. Evenness index according to land cover type

Table
Index of similarity of butterfly species in PT PSM

Table 3 .
Potential role of butterflies based on land cover type