INFLUENCE OF WHITE PEPPER POWDER ( Piper nigrum L.) VEGETABLE INSECTICIDE ON PEST MORTALITY OF RICE WEEVILS

A reduction in rice quality may result from pest infestations in storage facilities. In addition to being a major pest of rice, the rice weevil ( Sitophilus oryzae L.) is a problem in warehouses. Attacks by rice weevils may result in lower-quality rice. Using white pepper powder as a pesticide is one way to solve this issue. The purpose of this study is to ascertain how white pepper powder, a botanical pesticide, affects rice weevil pest mortality, as well as the optimal dosage and mode of administration. In this study, there were six treatments and four replications in a single factor totally randomized design. The rate at which rice weevil bugs died and the percentage of rice weight loss were the study's parameters. The results showed that the death of rice weevil pests was influenced using white pepper powder. The highest mortality rate was L5 at 52.5%, which is the best dose.


Introduction
Rice storage is very important in postharvest activities before distribution activities.During the storage period, there is usually a decrease in quality in the form of changes in the color of rice, crushed and dusty rice, the development of mold, weight shrinkage, and changes in taste and smell.A decrease in the quality of rice can occur due to warehouse pest attacks.The warehouse pest that attacks and is among the main pests of rice is Sitophilus oryzae L. (Haryadi et al., 2013).
Sitophilus oryzae L. or commonly called rice weevil is known as rice powder beetle.Rice lice inflict considerable damage.Seeds crumble and dust in a fairly short time.This pest attack can result in the development of mold so that the rice is damaged and the musty smell is unpleasant and cannot be consumed.In addition, rice lice cause rice grains to become hollow, rice to break and crumble into flour.
Warehouse pest control has so far been carried out by relying on synthetic insecticides.Insecticides commonly used as protection of agricultural products during the storage period include organochlor, organophosphate, and carbamate.Control of this pest is usually carried out using fumigation techniques.Judging from the ecological aspect, the use of this synthetic insecticide negatively affects the environment and can leave residues on the harvested material.To solve the problem can be used vegetable pesticides as alternative insecticides (Kardinan, 2004).
One of the plants that can be used as a vegetable insecticide is pepper.Pepper contains ORIGINAL ARTICLE active compounds that have toxic power, including saponins, flavonoids, essential oils, cavisin, and piperonal (Conectigue, 2012in Hasnah et al., 2014).Piperine compounds are repellent to sitophilus spp.Because it gives off a spicy aroma and taste so that it can affect insects in producing eggs and cause death (Hasnah et al., 2014).According to Pina (2015), the best dose of black pepper powder that can reduce the percentage of rice damage is at a dose of 17.5 g/ 100 g of rice.This is thought to be due to the highest dose, the most pungent odor.The presence of this pungent smell makes rice lice not eat the rice and will leave it.Because before eating insects first carry out the process of introduction to their future food.
Based on the above problems, it is necessary to conduct research to determine the effect of applying a vegetable insecticide of white pepper powder (Piper nigrum L.) On rice weevil pest mortality and find out the dose of vegetable insecticide white pepper powder (Piper nigrum L.) Which is most effective against rice weevil pest mortality.

Place and Time of Research
This research was carried out at the Production Laboratory and Integrated Laboratory of the Faculty of Agriculture, Lambung Mangkurat University.The study was conducted for 2 months (May-June 2022).

Materials and Tools
The ingredients used in this study were rice lice, white pepper seeds, rice, tea bag paper, and label paper.The tools used are jars, blenders, sieves, containers, spoons, digital scales, brushes, cameras, and stationery.

Research Implementation Propagation of Sitophilus oryzae L.
The breeding of Sitophilus oryzae was carried out in jars containing rice.After 15 days Sitophilus oryzae is taken.The rice of the former dwelling of Sitophilus oryzae was left in a jar.It is estimated that for 15 days Sitophilus oryzae has laid its eggs into holes made by the female imago on rice seeds.The rice is left for 35 days or until an adult Sitophilus oryzae pest appears as its first offspring.The first descendants of Sitophilus oryzae used in this study were 240 imago or 120 pairs of imago (Pina, 2015).

Manufacture of Vegetable Insecticides White Pepper Seed Powder
The white pepper seeds used for this study are intact white pepper seeds in the shape of a sphere.White pepper seeds are obtained by purchasing them on the nearest market.The seeds of white pepper are then separated and cleaned of impurities.White pepper seeds are then blended, then sifted to obtain white pepper seed powder that fits the desired size.The sifted white pepper seeds are put into the tea bag paper and weighed according to the treatment dose.
Investment Sitophilus oryzae L. Imago investment Sitophilus oryzae L. uses white rice of the whole Ciherang variety.Before the investment is made, the rice that will be used in this study is stored for a week to avoid the appearance of other unwanted insects.Then Sitophilus oryzae L. was taken as many as 240 imago from the culture which then the rice lice were satisfied for one day.The investment was made in the afternoon.The imago Sitophilus oryzae L. used is 25 days old or on blackishbrown imago stadia.

Research Design
This study was designed using a single-factor Complete Randomized Design (RAL) with 6 treatments and 4 tests so that 24 experimental units were obtained.Each experimental unit consists of 10 imago rice lice.The dosage in this study was: L0 = without treatment of white pepper seed powder, L1 = 12.5 g white pepper seed powder / 100 g rice, L2 = 15 g white pepper seed powder / 100 g rice, L3 = 17.5 g white pepper seed powder / 100 g rice, L4 = 20 g white pepper seed powder / 100 g rice, and L5 = 22.5 g white pepper seed powder / 100 g rice.

Observation Parameters Total mortality
Mortality indicates the degree of ability or number of pest deaths caused by vegetable pesticides used and expressed in percent.
Mortality observations can be calculated by the formula (Epi, 2016):

The cesstlement of death
The speed of death shows how quickly white pepper seed powder affects the mortality of S. oryzae L. viewed from the number of deaths per day expressed in units of imago per day.The speed of death is calculated by the formula (Mayasari, 2016):

Data Analysis
The observational data obtained were analyzed first with a homogeneous test using the Barlett Test.If the data is homogeneous, it is continued with the Analysis of Variance Test (ANOVA).If the treatment shows a noticeable influence, it is followed by Duncan's Multiple Range Test (DMRT) multiple range test at a level of 5% to determine the noticeable difference between the treatments tested.

Total Mortality
The application of a plant-based insecticide of white pepper powder has an influence on the average total mortality of rice weevil pests (figure 1).The use of white pepper powder in the L5 treatment gave an average mortality of 17.5% higher compared to the L4 treatment.The L4 treatment was 12.5% higher compared to the L3 treatment.However, the average difference between rice weevil pests in the L2 and L1 treatments is not much different from the L3 treatment.Meanwhile, the L1 treatment was 13.5% higher than the L0 treatment.With a dose of L5 treatment, it was able to increase the average mortality of 50% compared to the L0 treatment.Based on the results of the analysis of the variety of application of vegetable insecticides pepper powder (Piper nigrum L.) has a very noticeable effect.The L0 or control treatment was the treatment with the lowest mortality rate, while L5 was the treatment with the highest mortality in this study.This difference in mortality rates is thought to be since the doses used in each treatment are different.The higher the dose the higher the mortality rate of rice weevil pests.This is supported by the research of Pina ( 2015), the highest dose that emits the most odors, increase in concentration causes aromatic nitrogen compounds called alkaloids in pepper extract to be disliked by insects.This is related to the concentration used, the higher the concentration, the higher the increase in the effect of toxins.In the L0 treatment (without pepper powder treatment) there was 1 imago rice weevil that died on the 7th day, this was due to an error during maintenance, the rice weevils entered the gap in the lid of the jar and squeezed in between it without knowing until the next day of observation it was found that the rice weevils had died.White pepper (Piper nigrum L.) has the potential to be a plant-based insecticide.This is because in pepper seeds there are chemical compounds or metabolites that are insecticides such as alkaloids, tannins, flavonoids, saponins, pipene, karyofilena, bitter substances, fatty oils, and essential oils (Septiatin, 2008) piperine is found as an active ingredient and is an alkaloid.Piperine can be used as an insecticide, where the content of this bioactive compound is able to be toxic to insects.According to Hasnah et al. (2014) pepper-containing piperine compounds are repellent in S. zeamais, because it emits a spicy aroma and taste so that it can affect in producing eggs and cause death.In addition, pepper powder also acts as a contact poison and respiratory poison.

Rice Weevil Pest Death Speed
The treatment of L5 is faster to kill rice weevil pests than with a mortality rate difference of 0.85 imago/day (Figure 2).The treatment of L4 is not much different from L3 the difference is 0.3 imago/day.The treatment of L0 has almost the same difference as L1 and L2.Meanwhile, the L5 treatment when compared to the L0 treatment has a difference in the mortality rate of 1.77 imago/ day.The speed of death shows how quickly pepper seed powder affects the death of rice weevil pests in terms of the number of deaths per day expressed in imago units per day.Observation of the speed of death is carried out daily for 7 days.Based on the results of the variety analysis, the application of vegetable insectides of pepper powder affects the speed of death of rice weevil pests.L2, L3, L4, and L5 treatments experienced pest death on the first day of observation.On the second day of observation deaths occurred in the treatment of L1, L2, L3, and L4.Death was still visible until the sixth day of observation.But on the seventh day the observation of death occurred only in L0 treatment or control resulting from the pinching of rice weevil pests on the sidelines of the jar lid.L0 treatment is a treatment without pepper powder administration, this results in L0 being a treatment with a low mortality speed value of 0.18 imago/ day.While the treatment with a high-speed value was found in the L5 treatment with a dose of pepper powder of 22.5 g / 100 g of rice, which is 1.95 imago / day.The high value of the speed of death in the L5 treatment is caused because the higher the dose of pepper powder, the more odor it emits (Pina, 2015).

Percentage of Rice Weight Shrinkage
Percentage of weight loss of rice applied white pepper powder on 7 HSA shown in figure 3, after day 7 of the L0 treatment, it experienced a 0.027% higher weight loss compared to the L1 treatment.The L1 treatment experienced a weight loss of 0.086% higher than L2.L2 is 0.050% higher compared to L3. L3 experienced 0.006% higher weight loss than L4.Meanwhile, L5 experienced the lowest weight loss among all treatments which when compared to L0 the difference was 0.179%.The results showed that the application of white pepper powder had an influence on the shrinkage of rice weight due to the attack of rice weevil pests.This is aimed at the stability of the shrinkage weight value in the treatment of white pepper powder, where this culprit can maintain the initial weight of rice.The highest weight loss occurs in the L0 treatment.The high damage of seeds in control (L0) is due to the absence of chemical compounds that can inhibit insects from laying eggs.The purpose of insects damaging plants is to lay eggs, shelter, and as a source of food (Hasnah et al., 2014).While the lowest weight shrinkage is found in the L5 treatment.This is because L5 was the highest dose in this study.According to Pina (2015) the highest dose, the most odorous.The of an unwelcome smell and aroma causes insects not to eat the rice, because before eating it, insects first carry out a process of introduction and orientation to their prospective food (Pina, 2015;Teshale et al., 2017).
The decrease experiencen rice weight, decreased nutritional content, and economic losses such as farmers' income are indications of rice damage (Hendrival and Rika, 2016).According to Harinta (2016), the low percentage of seed damage will reduce weight shrinkage.This is because with fewer damaged seeds, the weight shrinkage caused will be lower.Based on the percentage of weight shrinkage can be seen the degree of damage.The highest level of damage occurred in the L0 treatment (without pepper powder treatment), while the lowest was in the L5 treatment (22.5 g of pepper powder / 100 g of rice).In other treatments such as L1, L2, L3, and L4 also experienced weight loss.This is thought to be due to pest deaths that on average only occur on day 2, so that rice lice can still carry out their consumption activities.Rice damage due to rice weevil pest attacks is also affected by the storage period and rice bug population during the storage period.In this study, the damage that occurred was still very small, such as the presence of grinding holes and scratching on rice grains.So, with the treatment of white pepper powder, it can minimize damage to rice, so this has an impact on the low percentage of weight shrinkage value.The smell of aromas that are not liked by pests causes vegetable ingredients to have antifeedant power could inhibit the laying of eggs by female insect mothers because female insects only want to put their eggs in an appropriate and supportive place, antifeedant properties cause insect consumption to decrease (Hendrayana, 2010).Ismail and Fatma (2020) also stated that pepper extract is more toxic and repellent than srikaya plant extract so that it has the potential to be used as an alternative way to control Sitophilus oryzae and Tribolium castaneum pests naturally.

Conclusion
Based on the research that has been carried out, it can be concluded that the vegetable insecticide white pepper powder (Piper nigrum L.) influences the mortality of rice weevil pests and the dose that affects the mortality of rice weevil pests is found in the L5 treatment at a dose of 22.5 g of white pepper powder / 100 g of rice.
Compliance with ethical standards n Information: V : Speed of death (imago/day) T : Day-to-day observation N : Number of dead pests (imago) n : Number of pests tested (imago)The percentage of weight loss of rice Observations of rice weight shrinkage were made on the last day of observation.The percentage of shrinkage of rice weight can be calculated using the formula(Astika, 2019): of rice weight shrinkage (%) A : Initial rice weight B : Final rice weight

Figure 1 .
Figure 1.Average total mortality applied white pepper powder at 7 HSA.

Figure 2 .
Figure 2. The speed of death of rice weevil pests applied white pepper powder on 7 HSA.

Figure 3 .
Figure 3. Percentage of weight loss of rice applied white pepper powder on 7 HSA.

Figure 4 .
Figure 4. Damage to rice due to attack by rice lice.