South Sulawesi Province is one of the centers for soybean development in Indonesia. The varieties that are widely planted by farmers in South Sulawesi include Anjasmoro, Argomulyo, Grobogan, Gema, Dering-1, and Burangrang. These varieties have different levels of seed yield and damage levels. This paper aims to provide an overview and information about the types of soybean varieties, the level of pest damage, and the types of pests that cause damage to soybean varieties developed by farmers in South Sulawesi Province. The method used is to collect various information in the form of secondary data and primary data from research results related to soybean varieties, types of pests that damage soybean plants and the level of damage caused by soybean pests in South Sulawes. The results obtained provide information that the highest level of leaf damage caused by Spodoptera litura F. occurred in the Anjasmoro variety 10.94–32.69% followed by Argomulyo 10.16–26.17% and Grobogan 8.61–24.81%. The highest level of pod damage due to pod sucking was found in Burangrang varieties, namely 13.20%, Gema 12.51%, Dering 10.5%, Argomulyo 9.40%, Grobogan 8.50%, and Anjasmoro 7.70%. The level of fruit damage caused by the fruit borer Etiella zinckenella T., the highest occurred in Detam-1 15.71%, Ring 14.50%, Burangrang 10.60%, Gema 10.0%, Argomulyo 8.20%, Grobogan 7.10%, and Anjasmoro 6.70%. The rate of soybean yield loss caused by S. litura F. was the highest at Anjasmoro 8.97%–11.29%, then Grobogan 7.88–12.80%, and Argomulyo 6.77–14.90%. Meanwhile, the percentage of seed yield loss caused by the attack of the pest Nezara viridula L. ranged from 10.0–41.0% for all varieties. Likewise with Riptortus linearis F., the percentage of soybean seed loss caused ranged from 15 to 79% for all varieties.
- main pests
Soybean has a strategic position as a source of vegetable protein and functional food that has been affordable to all levels of society. Soy products such as tempe, tahu, soy milk, soy sauce, chips and so on are needed every day of the year. To meet the demand for raw materials for the processing industry, Indonesia needs around 2.2 million tons of soybean raw materials per year. Meanwhile, domestic soybean production is currently only able to meet 30–40% of national needs .
The national soybean productivity achieved by farmers in Indonesia only reaches 1.80 t / ha, while the potential national soybean productivity can reach 2.5 t/ha . One of the factors causing low soybean productivity is the high pest attack. Pest attacks on soybean plants can reduce yields up to 80%, even puso if no control measures are taken . According to Oerke , the loss of soybean yields due to pest attacks can reach 26–29%.
In the tropics, there are about 60 types of insects that can cause significant leaf damage in soybeans . Meanwhile in India, there are about 150 species of insects that can cause serious damage to soybeans from planting to harvest .
Pests on soybean plants are classified into pests that destroy leaves and pests that destroy pods. Pests that destroy soybean leaves include whitefly (
In Indonesia, armyworms,
2. Soybean varieties developed by farmers in South Sulawesi
2.1 Anjasmoro variety
The Anjasmoro variety has a purple hypocotyl color, purple epicotyl color, white stem coat color, purple flower color, yellow seed coat color, light brown ripe pods, and yellowish brownish hilarity of seeds. This variety also has oval leaf shape, wide leaf size, deterministic growth type, flowering age 35–39 days, pod ripe age 82–92 days, plant height 64–68 cm, number of branches 2–5 branches, has a large seed size (weight of 100 seeds 14.8–15.3 g). The seeds contain 41.8–42.1% protein, 17.2–18.6% fat content, and are not resistant to falling. Anjasmoro variety is moderate to leaf rust, and the pods do not break easily . Meanwhile, according to Hendrival et al. , Anjasmoro variety has 83.38 pods, 24.69 empty pods, 173.27 seeds per plant and 3.81–9.39%
2.2 Argomulyo variety
Argomulyo variety has purple hypocotyl, brown fur color, purple flower color, yellow seed coat, bright white hilarity of seeds, deterministic growth type, flowering age 35 days, age at harvest 80–82 days, plant height 40 cm, number of branches per plant 3–4 stems from the main stem, has a large seed size (weight 100 seeds 16.0 g), has a seed yield of 1.5–2.0 t ha −1, has a protein content of 39.4%, contains fat, 20.8%, has a fall resistance property . In addition, the Argomulyo variety is tolerant of leaf rust disease and this variety is suitable for soy milk as raw material. Meanwhile, according to Poniman et al. , the Argomulyo variety had the number of pods filled with 79.00, the weight of 100 seeds was 15.38 g, and the percentage of pod damage caused by pod borer attack was 13.11%.
2.3 Grobogan variety
According to the description of the soybean variety , the Grobogan variety has a determinitic growth type, purple hypocotyl color, purple epicotyl color, brown stem coat color, purple flower color, dark brown pod color, lanceolate leaf shape and hilarity brown seed color, plant height 50–60 cm, flowering age 30–32 days, mature pods 76 days, have large seed size (weight 100 seeds, 18 g), potential seed yields 3.40 t/ha, and an average seed yield of 2.77 t ha−1. The seeds have a fat content of 18.4% and a protein content of 43.9%. It is well adapted to several different growing environmental conditions, has pods that are not easily broken, and at harvest 95–100% of the leaves are shed (Figure 1).
2.4 Burangrang variety
The Burangrang variety has purple hypocotyls, yellowish brown fur, purple flowers, yellow seeds, bright hilium seeds, oblong leaves, pointed tips, deterministic growth type, number of branches 1–2 branches, flowering age 35 days, pod age cook 80–82 days, plant height 60–70 cm, large seeds (weight of 100 seeds 16 g), seed yields range from 1.6–2.5 t ha−1, have 39% protein content, 20% fat content, not easy to fall down, tolerant of leaf rust disease. This variety is suitable for soy milk, tempe, and tahu .
2.5 Dering varieties
Dering variety has a deterministic growth type, flowering age 35 days after planting and 81 days after planting, plant height 57 cm, brown fur, oval leaf shape, purple hypocotyl color, purple epicotyl color, purple flower color, brown pod skin color., yellow seed coat color, dark yellow hilium seed color, white cotyledon color, resistant to falling, the number of branches 3–6 stems per plant . Meanwhile, according to Poniman et al. , the Dering variety has medium seed size (100 seeds 10.7 g weight), the potential yield of seeds is 2.80 t ha−1, the average seed yield is 2.0 t ha−1, the seeds contain 34.2% protein and 17.1% fat content. Furthermore, it was said that the variety was resistant to pod borer (
2.6 Gema varieties
According to Poniman et al. , the Gema variety has a deterministic type of growth with light brown coat color, purple cotyledon color, purple hypocotyl color, green epicotyl color, and white cotyledon color. Furthermore, it is said that this Gema variety has a plant height of 55 cm, has a medium seed size (100 seeds weight 11.90 g), a flowering age of 35 days, a harvest age of 73 days, a potential yield of 3.06 t ha−1, an average seed yield. 2.47 t ha−1, brown pod color, purple flower color, round seed shape, light yellow seed coat color, and brown hilium color. The seeds have a protein content of 39.07% and a fat content of 19.11%. The Gema variety is sensitive to leaf virus (CMMV) and moderate to rust disease . In addition, these varieties are also somewhat susceptible to pod suckers, somewhat resistant to pod borer, and moderate to armyworm pests (Figure 2) .
2.7 Deja-2 varieties
The Deja-2 variety has a deterministic growth type, ± 37 days of flowering, ± 80 days of maturity, purple hypocotyl color, purple epicotyl color, green leaf color, purple flower color, brown coat color, light brown pod skin color, seed coat color. Yellow, yellow cotyledon color, brown hilum color, oval leaf shape, medium leaf size, 3 branches per plant, the number of pods per plant ±38 pods, ± 52.3 cm plant height, lying with resistance to collapse, pod breaking with the pods are not easily broken, the size of the seeds is large, the weight of 100 seeds is ±14.8 grams, the shape of the seeds is oval, the potential yield is 2.75 t ha−1, the average yield is ±2.38 t ha−1, the protein content is ±37.9%, fat content ±17.2%, susceptible to armyworm pests, mildly resistant to pod borer, somewhat resistant to pod suckers, and somewhat resistant to leaf rust disease (Figure 3) .
2.8 Dena- 1
According to the description of the soybean variety , the Dena-1 variety has a deterministic growth type, purple flower color, purple fur color, purple hypocotyl color, green epicotyl color, and yellow-yellowish pod skin color. Flowering age 33 days, pod ripe age 78 days, oval leaf shape, number of branches 12 branches per plant, growth type determinant, flowering age ± 33 days, maturity ±78 days, hypocotyl purple color, green epicotyl color, green leaf color, purple flower color, brown fur color, yellowish brown pod skin color, yellow seed coat color, green cotyledon color, brown hilum color, oval leaf shape, medium leaf size, branching 3 branches per plant, number of pods planted ±29, plant height ± 59.0 cm, slightly resistant to falling apart, pods breaking easily, large seed size, weight of 100 seeds ±14.3 grams, oval seed shape, potential yield of 2.9 t ha−1, average yield ±1.7 t ha−1, protein content ±36.7% DM, fat content ±18.8% DM, resistance to pests, resistance to leaf rust disease, susceptible to pod sucker
2.9 Dega- 1
Has a deterministic growth type, ± 29 days of flowering, ± 71 days of maturity (69–73 days), purple hypocotyl, purple epicotyl color, green leaf color, purple flower color, brown coat color, light brown pod skin color, yellow seed coat, purple cotyledons, brown hilum color, oval leaves, medium-sized leaves, branching from 1 to 3 branches/plant), number of pods per plant ±29 pods, plant height ± 53 cm, resistant to falling, resistant to breaking pods, have a large seed size, weigh 100 seeds 22.98 g, have a potential yield of 3.98 t ha−1, have a protein content of 37.78% DM, a fat content of 17.29%, are resistant to leaf rust disease . According to Poniman et al. , the Dega-1 variety had 27.75 pods per plant, 100 seeds 21.38 g weight, and was somewhat resistant to pod borer attack.
2.10 Varieties of Detam- 1
The Detam-1 variety has a deterministic growth type, hypocotyl purple color, green epicotyl color, purple flower color, light brown hair color, dark brown pod skin color, black seed coat color, and yellow cotyledon color, slightly round leaf shape, and brightness of shiny seed coat. This variety also has a plant height of 58 cm, a flowering age of 35 days, a pod ripe age of 84 days, has a large seed size (100 seeds weight 14.84 g), has a potential yield of 3.45 t ha−1 and an average yield of 2 seeds. 2. 51 t ha−1, the seeds have a protein content of 45.36% and a fat content of 33.06%. The nature of resistance to pests, sensitive to armyworms and somewhat resistant to pod suckers and other properties are somewhat sensitive to drought (Figure 4) .
3. Armyworm life cycle, level of damage, percentage of yield loss, and economic threshold (ET) in armyworm pests
3.1 Life cycle of
3.1.1 Egg phase
Adult insects (imago) lay eggs in clusters containing about 350 eggs and covered in fine hairs. The total eggs laid by one female insect in one life cycle are around 2000–3000 eggs . Meanwhile, according to Schreiner ,
The eggs that almost hatch, turn brown in color and enlarge like fish eggs (Figure 5b). According to Kalshoven , the almost hatched eggs turn brown and get bigger. Then hatch into larvae 3–5 days. Meanwhile, Ahmad et al. , the eggs hatched 3 days after being laid by the female
3.1.2 Larva phase of
The newly hatched larvae feed from the leaves occupied by the eggs in groups (Figure 6a), then spread by using threads that come out of their mouths and are used to move from plant to plant. Armyworm larvae have different colors. The newly hatched larvae are light green, the sides are dark brown or brownish black and the last instar larvae have dark black necklaces (crescent moons) on the fourth and tenth abdominal segments. On the dorsal lateral side there is a yellow stripe, the larval stage consisting of 5 instars which lasts 20–46 days .
3.1.3 Pupa phase
The last instar larvae enter the soil, then become inactive larvae (Pra pupa) (Figure 7a). Then it turns into a pupa (without a cocoon (Figure 7b). The pupa is in the ground with a depth of 0–3 cm . The pupa is reddish-brown, weighing about 0.341 g per pupa . The pupal stage ranges from 8 to 11 days .
3.2 The level of leaf damage due to attack by armyworm pests on soybeans
The young larvae (instar-1 and instar-2) damage the leaves by leaving remnants on the upper (transparent) epidermis and leaf bones. The rates of armyworm infestation differ between plant types and between varieties. In susceptible plants provide better growth for pests. Conversely, resistant varieties will give poor growth and development of armyworm pests. The results of research by Shahout et al. , of several types of plants tested on
Damage and yield loss due to armyworm attack is determined by the level of the pest population, the stage of insect development, the phase of plant growth, and the type of soybean varieties. Pest attacks on susceptible varieties will cause very significant losses. Leaf defoliation due to armyworm attack when it occurs during the full flowering phase and pod formation phase will result in greater yield losses than attacks in the full pod filling phase (Figure 9) .
Symptoms of damage to leaves due to
The level of damage to soybean leaves due to
3.3 Yield loss due to attack by armyworm pests on soybeans
The rate of loss of soybean seeds due to
The difference in the level of loss of soybean seeds due to
3.4 Economic threshold (ET) on
The national economic threshold set by the Government in the use of insecticides for the control of
Based on the results of Fattah’s research  from the results of data analysis, it was found that the average yield loss in Anjasmoro variety was around 130 kg, the total cost (Cost) was IDR 2,340,000 per ha, then the economic threshold (AE) for Anjasmoro was 2.25 tails. Larvae per plant or 2.0 larvae per plant. Furthermore, the economic threshold (ET) was found in the Argomulyo variety, if the average yield loss per hectare was 105 kg, then the economic threshold (ET) for Argomulyo variety was 2.78 larvae per plant or 3.0 larvae per plant. The economic threshold (ET) for Grobogan variety if the average yield loss is 91 kg per ha, then the economic threshold value is 3.21 larvae per plant or 3.0 larvae per plant .
According to Fattah  the economic threshold (ET) value of Anjasmoro variety (2 larvae plant−1) is lower than Argomulyo (3.0 larva plant−1) and Grobogan (3.0 larva plant−1), this is due to the variety Anjasmoro is more sensitive to armyworm attacks than Argomulyo and Grobogan. This is consistent with Fattah and Hamka , the attack rate of
4. Pod sucking pests
The pod sucker
According to Manurung et al. , the level of pod sucking pest
5. The pod borer
The pod borer
The level of damage to pods due to
6. Pod-sucking pests
South Sulawesi Province is one of the centers for soybean development in Indonesia. Farmers develop new high yielding varieties such as Anjasmoro, Argomulyo, Grobogan, Dering, Gema, Deja-2, Dena-1 Dega-1, Detap-1, and Detam-1. The level of leaf damage caused by
I thank all my fellow researchers at the South Sulawesi Agricultural Technology Research Center (BPTP) who have provided moral support so that the paper which is part of the book can be completed. In particular, I would like to thank Dr. Ir. Abdul Wahid, MS as the head of the South Sulawesi Agricultural Technology Research Center, who has provided assistance in the form of morals and in the form of finance.
Conflict of interest
All authors claim to have no conflicts of interest.