Effect of forest betel leaf extract (Piper aduncum L.) from various altitudes on the mortality of fall armyworm (S. frugiperda J.E. Smith) in the laboratory

S. frugiperda pests can attack corn plants in the vegetative and generative phases, resulting in yield losses ranging from 15% to 73%. Forest betel plant (P. aduncum L.) is one type of plant that can be used effectively as a botanical pesticide to control these pests. The effectiveness of a plant as a source of botanical insecticide is influenced by the ecology, geography, and climate where the plant grows. This study aimed to obtain the best and most effective forest betel leaf extract from various growing heights against S. frugiperda mortality. The research was conducted at the Plant Pest Laboratory, Faculty of Agriculture, Riau University, from April to June 2023, using a completely randomized design (CRD) consisting of three treatments and six replicates. Application of forest betel leaf extract at different altitudes above sea level, namely 200 meters, 500 meters, and 800 meters. The results showed that the difference in altitude significantly affected the mortality of S. frugiperda. Forest betel leaf extract from 200 meters above sea level was the best treatment for controlling armyworm pests, with a total mortality of 96.67%.


Introduction
The fall armyworm is one pest that attacks corn (S. frugiperda J.E. Smith.).S. frugiperda is an invasive insect that has become a major pest on corn plants (Zea mays L.) in Indonesia.This insect is native to America and has spread to various countries [1].This pest was found in corn plantations located in the Sumatra area in early 2019 [2].S. frugiperda pests have been identified as entering the Riau Province and attacking the corn plants of the Riau people.The first appearance of S. frugiperda in Riau was in July 2019 in Bangkinang District, Kampar Regency [13].
S. frugiperda, a common pest, launches attacks on plants from their vegetative phase until they reach the generative stage.The larvae of S. frugiperda have a high consuming ability.Larvae will enter some parts of the pant and actively consume there, so if the population is in a small percentage, it will be more difficult to detect.Imago S. frugiperda is a strong aviator and has a high cruising capability [4].These pests are known for causing plant damage, characterized by residual grains resembling coarse sawdust on corn plants, particularly on the upper surface of leaf blades or around the shoots, along with visible bite marks from the larvae [5].
The effect of armyworm attack on corn plants during the young leaf phase that is still rolling causes yield losses of 15-73% if the affected population reaches 55-100%.Empress [6] stated that the attack of S. frugiperda per year can result in a significant loss of 4-8 million tons of corn crop production, so this pest needs to be controlled.
Synthetic insecticide control is still farmers' primary choice because of its more accessible and faster use.The use of synthetic insecticides, when viewed from an ecological point of view, will affect non-target organisms because they can cause the killing of natural enemies, the emergence of pest resistance, and damage ecosystems [7].A practical and environmentally friendly solution to prevent 1346 (2024) 012011 IOP Publishing doi:10.1088/1755-1315/1346/1/012011 2 the negative impact of synthetic insecticides in controlling pests and supporting the concept of integrated pest control is with plant-based insecticides.Using plant-based insecticides for pest control is considered better for the environment because they are more specific in killing target pests, are not harmful to the environment, and do not quickly cause resistance compared to synthetic insecticides [8].One potential plant that can be used as a botanical insecticide is forest betel (P.aduncum L.).
According to [9], the forest betel plant (P.aduncum L.) is among the plant species that are suitable for a botanical insecticide.The leaf is one of the parts of the forest betel plant that is used as a botanical insecticide.Forest betel is a group of plants that come from the family piperaceae.Active compounds contained in piperaceae plants, such as piperine, piperidine, piperlongumin, and guininsin, are included in the piperamide group [10].According to [11], piperamide group compounds enter as contact poisons through natural holes in insects.Piperamide compounds will work as nerve toxins by disrupting nerve impulses in nerve axons [12].Forest betel also contains other group compounds with methanol solvents such as hexane, cyanide, saponins, tannins, flavonoids, steroids, alkaloids, and essential oils that enter as stomach toxins through the process of eating [13].
The research conducted by [14] demonstrates the effectiveness of utilizing forest betel leaf extract.It was found that a concentration of 75 g.l-1, when mixed with water, serves as an effective formulation for controlling S. frugiperda pests, resulting in a remarkable 80% total mortality rate.According to [9], botanical insecticides are considered effective if they can achieve pest mortality rates of ≥ 80% when they use water-based solvents with a maximum concentration of 10% or organic solvents at concentrations not exceeding 1%.
Additionally, research by [13] confirms that the active components present in forest betel can indeed be employed as botanical insecticides.However, it's worth noting that the secondary metabolite content within plants is influenced by factors such as the plant's growth location, particularly the altitude at which it is cultivated.
The influence of altitude on metabolic processes is proven in the research of [15], which states that weed control of thorn spinach due to the administration of abandoned ethyl acetate extract produced at an altitude of 19 masl at 7-14 HSA can reduce the high rate of thorn spinach better than ethyl acetate babadotan extract produced at an altitude of 261 masl and 1259 masl.Babadotan treatment from a height of 19 meters above sea level with a concentration of 10% showed control up to 100% at 7 HSA.The effectiveness of a plant as a source of botanical insecticides is influenced by plant ecology, geography, and climate conditions where the plant grows [16].
Plant materials from different locations can have different plant-based pesticide capabilities.According to [17], the height of the place is one of the factors that influence the growth of a plant.The height difference affects the growth and development of plants.As a result, a series of metabolic processes in these plants will also be disrupted so that the compounds produced from these processes will be different at each altitude of the place.Therefore, researchers have tested the metabolic compounds of forest betel leaves from different heights to control S. frugiperda.This study aimed to obtain the best forest betel leaf extract (P.aduncum L.) based on altitude against the mortality of corn armyworm pests (S. frugiperda J.E. Smith).

Methods
The research was conducted at the Plant Pest Laboratory at the Faculty of Agriculture, University of Riau, Bina Widya Campus km 12.5 in Pekanbaru.This study spanned three months, from April 2023 to June 2023.The ingredients used during the study included sweet corn cobs, fall armyworm larvae (S. frugiperda) instar III, forest betel leaves (P.aduncum L.) from three altitudes as a source of extract, sawdust, honey, cotton, tissues, aquades, and cream soap.The tools used during the study include glass cups with a diameter of 5.5 cm and a height of 4.5 cm as a container for breeding pests, jars with a diameter of 20 cm and a height of 30 cm as a place for the development of the pupa phase, glass cup containers with a diameter of 8 cm and a height of 12 cm as a container for pest infestation, scissors, blenders, brushes, analytical scales, Gauze, measuring cup, beaker cup, 40 mesh strainer, stirring IOP Publishing doi:10.1088/1755-1315/1346/1/0120113 rod, 250 ml hand sprayer, thermohygrometer, label paper, camera, stationery and Google Earth application version 9.1620.2.
The study was conducted experimentally using a complete randomized design (RAL).This design featured three distinct treatments, and each was replicated six times, resulting in a total of 18 experimental units.Each experimental unit was infested with ten larvae of S. frugiperda instar III.The treatment given is some forest betel leaf extract concentration of 10% from various altitudes with water solvent (A), namely: A, 1: Forest betel leaf extract from the lowlands (400 masl), A 2: Forest betel leaf extract from the medium land (400-700 masl), A 3: Forest betel leaf extract from the highlands (>700 masl).The parameter observed was the initial time of death of S. frugiperda (hours), lethal time 50 (lt50) (hours), daily mortality (%), and total mortality (%).
The daily mortality data collected from the study will be analyzed descriptively and presented as graphs.Additionally, data from the observation of the initial time of death, lethal time 50 (LT50), and total mortality were analyzed statistically using variance analysis.Variance analysis data with a significant effect were further tested using the honest real difference (BNJ) test at the 5% level.Data from the analysis of variance and further tests were analyzed using the SAS version 9.1.

Time of initial death (Hours)
The analysis of fingerprints revealed that the treatment involving various extracts of forest betel leaves (P.aduncum) obtained from different altitudes had a noteworthy impact on the initial time of mortality for S. frugiperda.The average results of BNT follow-up trials at the time of initial death of S. frugiperda at the level of 5% is explained in Table 1..50 a The numbers in the column of each treatment followed by unequal lowercase letters differ markedly according to the BNT test at the level of 5% after being transformed by √ .
Table 1 shows that applying several extracts of forest betel leaf obtained from varying altitudes yielded significantly divergent outcomes concerning the initial mortality time for S. frugiperda, falling within 3.00 to 5.50 hours.Notably, the treatment involving forest betel leaf extract sourced from an altitude of 200 meters above sea level resulted in the quickest initial mortality time, occurring at 3.00 hours post-application.This was significantly distinct from the treatments involving extracts from 500 meters above sea level and 800 meters above sea level, where the initial mortality times were recorded at 5.30 hours and 5.50 hours.

Lethal Time 50 (LT 50) (Hours)
The observations of LT50 (lethal time 50) for S. frugiperda larvae, following fingerprint analysis, revealed that the treatment involving various extracts of forest betel leaves (P.aduncum) sourced from different altitudes had a noteworthy impact on the time required to achieve a mortality rate of 50% for S. frugiperda.The average of BNT follow-up tests at the level of 5% is explained in Table 2. Table 2 shows that treatment of forest betel leaf extract obtained from different altitudes led to notably different outcomes in achieving a 50% mortality rate for S. frugiperda within 22.17 to 34.40 hours.Specifically, the forest betel leaf extract sourced from an altitude of 200 meters above sea level demonstrated a tendency to achieve this 50% mortality rate more quickly, taking approximately 22.17 hours.This result was not significantly different from the treatment involving extract from 500 meters above sea level but was significantly distinct from the treatment involving extract from 800 meters above sea level.These findings align with the earlier results regarding the initial time of death (as shown in Table 1), where forest betel extract from an altitude of 200 meters above sea level induced faster initial mortality in S. frugiperda larvae compared to other altitudes.

Daily mortality (%)
The observations of daily mortality in S. frugiperda, under various treatments involving forest betel leaf extracts (P.aduncum) from different altitudes, indicate that these extracts are indeed toxic to the larvae of S. frugiperda.The daily mortality of S. frugiperda is explained in Figure 1.sea level, the forest betel leaf extract resulted in the highest mortality rate of S. frugiperda, reaching 53.33%.At an altitude of 500 meters above sea level, the mortality rate was 40%, and at 800 meters above sea level, it was 36.67%.

Total mortality (%)
The results of the total mortality observation of S. frugiperda, following a variety analysis, demonstrated that the treatment involving forest betel leaf extract (P.aduncum) sourced from different altitudes had a notable impact on the overall mortality of S. frugiperda.The average results of BNT follow-up tests at the level of 5% can be seen in Table 3. 88.33 b The numbers in the column of each treatment followed by unequal lowercase letters differ markedly according to the BNT test at the level of 5% after being transformed by√ .
Table 3 shows that the treatment of several extracts of forest betel leaf (P.aduncum) obtained from different altitudes resulted in total mortality of S. frugiperda pests, within a range of 88.33% to 96.67%.Notably, the treatment using forest betel leaf extract sourced from an altitude of 200 meters above sea level proved to be the most effective concentration, leading to the highest mortality rate at 96.67%.This result was significantly different from the treatments using extracts from altitudes of 500 meters and 800 meters above sea level.

Discussions
Forest betel leaf extract from the lowest altitude gives a faster initial time of death because the influence of temperature and light intensity increases the active compounds present in plants.The temperature and intensity of light will be higher with the lower the growing place [18].As a form of adaptation to high environmental temperatures, plants will produce compounds that are antioxidants [19].Higher secondary metabolic compounds will be produced at higher temperatures as an extra synergy of defense against environmental stress [20].
Forest betel leaf extract contains the compound piperidine, a type of contact poison that worked earlier in killing S. frugiperda.Piperramidine compounds enter through natural holes in the insect cuticle and work as neurotoxins by disrupting the flow of nerve impulses.These compounds affect the survival of S. frugiperda larvae by causing irregularities in movement and seizures, which can eventually cause death in insects quickly [21].
Early symptoms of the death of S. frugiperda larvae are characterized by changes in behavior in test pests that were initially actively moving, eating young pieces of corn, becoming weaker, and not actively moving.The slow movement is due to the reaction of toxic compounds entering the larvae's body so that S. frugiperda becomes deprived of appetite, causing the larvae not to move.
In addition to changes in behavior, there are morphological changes in S. frugiperda larvae, namely changes in body color that was originally bright brown with black spots on the larval body turning reddish-yellow and the larval skin wrinkled and the larval body underwent a color change that became darker and turned black (melanization of the cuticle) after 24 hours of application.This is because P. aduncum leaf extract attached to the body of S. frugiperda enters toxic contact and will affect the nervous system in the body of S. frugiperda.The content of piperamidine compounds will inhibit the flow of nerve immunity of S. frugiperda and affect its survival [21].This shows that giving forest betel leaf extract from the lowlands faster kills 50% of S. frugiperda.The time difference is due to the processing of different amounts of active compounds.Extrak from an altitude of 200 masl produces stronger secondary metabolic compounds and accelerates the death process of S. frugiperda compared to altitudes of 500 masl and 800 masl.[22], states that occupancy with an altitude of <400 meters above sea level can produce optimal environmental conditions for making secondary metabolic in plants.The more extreme the environment, the higher the metabolic compounds produced by a plant, so the greater the effect on the speed of killing test pests.This is by the results of [23], forest betel leaf botanical pesticides from lower altitude plains have the highest ability to suppress Colletotrichum gloeosporioides colony area by 73.5%.[24], added that in lowlands, plants get longer irradiation with high light intensity so that the results of metabolic processes are produced more.These conditions differ from plants at high altitudes because they have environmental conditions with light intensity and low temperatures with rainfall and high humidity [25].This causes the active compounds of forest betel leaves from the highlands to have fewer amounts than the lowlands, so it takes longer to kill the larvae of S. frugiperda.
According to [26], the results of their research state that environmental conditions affect plants' flavonoid, phenolic, and antioxidant activity levels.The higher the temperature stress in the environment, the higher the levels of flavonoids, phenolics, and antioxidant activity produced.This affects the results of lethal time at an altitude of 500 masl and 800 masl, which gives a longer time than the height of 200 masl.The higher the altitude, the lower the active ingredients contained, so the active ingredients that enter the body of insects tend to be less.
These results suggest that the forest betel leaf extract contains compounds with significant toxicity, which act rapidly within the insect's body.Consequently, this swift action leads to the treatment achieving its peak pest mortality rate of up to 53.33% on the first day.The active compounds responsible for this rapid effect are identified as piperamidine, classified as a contact poison that functions as a nerve toxin [27].Piperimidine compounds are one of the active compounds that can kill pests quickly because they have pyrethroid-like performance that causes seizure effects.This opinion is supported by [28], who show that the active compound piperimidine can cause nerve spasm effects in insects and cause death quickly.So, with the entry of piperamidine into the body of insects, the compound immediately acts spontaneously, accumulates well, and works optimally, causing death in S. frugiperda from day one of application.
On the second day, the daily mortality of pests exhibited a decrease, with a percentage of daily mortality falling within the range of 20.00% to 30.00%,where treatment with an altitude of 200 meters above sea level showed mortality of 20.00%, an altitude of 500 meters above sea level showed mortality of 30.00%, an altitude of 800 meters above sea level showed a mortality of 25.00%%.The daily mortality percentage of S. frugiperda has decreased; this happens because the pest has passed the peak of mortality on the first day, which causes the number of pest populations to decrease and affects the second and subsequent daily mortality percentage rates.
On the third, fourth, and fifth days, the percentage of daily mortality of S. frugiperda pests still decreased, whereas, on the third day, the daily mortality of S. frugiperda tended to be low in the range of 11.67% -16.67% and in general continued to decline on the fourth and fifth days.This is because the active compound content of forest betel leaf extract that is applied is decreasing.Botanical pesticides are compounds that have volatile and easily degraded properties, so the active ingredients in botanical pesticides will decrease over time, and there is a decrease in their ability to kill S. frugiperda larvae.This is supported by the opinion of [29], which states that the active ingredients of botanical pesticides are volatile, so their ability decreases.This statement is also supported by [30], which shows that botanical ingredients decompose quickly, and their residues are easily lost.
These findings suggest that forest betel leaf extract from lower altitudes is more effective in causing a higher percentage of pest mortality, and the difference in altitude has influenced the variation in the total pest mortality percentage.This is likely attributed to the higher content of metabolic compounds in forest betel leaf extract from lower altitudes, which enhances its potency in killing pests.Factors that affect the production of secondary metabolites, which include environmental factors, are temperature stress; in this case, the altitude of 200 meters above sea level has a hotter temperature than the altitudes of 500 meters above sea level and 800 meters above sea level.Plants will produce compounds that are antioxidants to adapt to accepted extreme environmental conditions [31].Forest betel plants from lower altitudes will produce metabolic compounds such as piperamidine and more flavonoids.This compound is a type of contact poison and nerve toxin so it will inhibit the performance of nerve axons in S. frugiperda.
The research results conducted by [32] stated that forest betel boiled water from the lowlands reduced the highest germination of Colletotrichum gloeosporioides with an effective suppression of 23.28%.This shows that toxic compounds are produced from lowland plants more than in the highlands.The difference in the location of plants as botanical pesticides affects the content of poisonous power and compounds in it.
Betel leaves from an altitude of 200 meters above sea level are in unfavorable conditions due to temperature and humidity factors in the location of growing forest betel nuts.Forest betel at low altitudes experiences water deficit stress because it grows far from water sources, while betel from medium and high altitudes does not experience water deficit stress due to stable and high rainfall, so metabolic production is lower.This is in line with research conducted by [33], which states that environmental factors such as water deficit stress can increase secondary metabolites in medicinal plants.The effect of water deficit stress in increasing secondary metabolic activity will improve the quality and efficacy of plant simplisia drugs.This is reinforced by [34], stating that the activity of forest betel leaf and fruit extracts with less water plant conditions tends to be more toxic.
University of Riau for their assistance and cooperation during the implementation of this research and all those who have helped until this research was completed.The author hopes that this manuscript can provide benefits for readers.
The treatment involving forest betel leaf extract from an altitude of 200 meters above sea level achieved a remarkable total mortality rate of 96.67%.This treatment also exhibited a faster initial time of death (as shown in Table 1) at 3.00 hours, and an LT50 (as shown in Table 2) reached 22.57 hours.The sooner the initial time of death and LT50, the more the total mortality percentage of S. frugiperda larvae will be increased.Treatment of forest betel leaf extract from an altitude of 200 masl, 500 masl, and 800 masl can kill S. frugiperda larvae more than 80%.Therefore, it can be concluded that all these forest betel leaf extracts from various altitudes are effective according to the statement from reference [9], which defines botanical pesticides as effective when they can achieve a pest mortality rate of ≥80% using water solvents with concentrations not exceeding 10%.

Conclusion
Based on the test results of several extracts of forest betel leaf (P.aduncum L.) from various altitudes on the mortality of fall armyworm (S. frugiperda J.E Smith) in the laboratory, it was concluded that forest betel leaf extract from various heights proved effective in killing S. frugiperda.Extracts from an altitude of 200 meters above sea level are the best treatment in controlling armyworm pests (S. frugiperda J.E Smith) in the laboratory because this concentration can cause total mortality of 96.67% with an initial time of death of 3 hours after application and lethal time of 50 at 22.17 hours after application.

Acknowledgment
The author would like to thank the staff of the Laboratory of Plant Pests, Faculty of Agriculture,

Figure 1 .
Figure 1.Daily mortality of S. frugiperda after application of several extracts of forest betel from different altitudes of places.The graph in Figure1shows that the first day marks the highest daily mortality rate for S. frugiperda, falling within a range of 36.67% to 53.33%.Notably, at an altitude of 200 meters above 1346 (2024) 012011 IOP Publishing doi:10.1088/1755-1315/1346/1/0120116

Table 1 .
Time of initial death of S. frugiperda after application of several extracts of forest betel leaf

Table 2 .
Lethal time 50 (LT50) S. frugiperda after application of several extracts of forest betel leaves from different altitudes (hours) The height at which forest betel leaves grow (masl) The numbers in the column of each treatment followed by unequal lowercase letters differ markedly according to the BNT test at the level of 5% after being transformed by √ .

Table 3 .
Total mortality of S. frugiperda after application of some forest betel leaf extracts from