Karya Utama - Academia.edu (original) (raw)

Papers by Karya Utama

Biodiversitas Journal of Biological Diversity

Gall midge (Procontarinia robusta) is an important pest of mango plants in various countries in t... more Gall midge (Procontarinia robusta) is an important pest of mango plants in various countries in the world, including Indonesia. This pest causes very serious damage to mango leaves which until now has not been reported. This study aims to map the distribution and abundance of the pest population and identify the pest species using the DNA barcode method on mango tree plantations in Bali, Indonesia. The survey method was used to collect data from various districts and cities in Bali Province, Indonesia. Mitochondrial COI primers were used to identify DNA barcodes. The results showed that the highest population abundance of P. robusta was found in Denpasar City. These pests have spread evenly throughout the Province of Bali, from the lowlands to the middle and highlands. Through a molecular approach, the insect pest that causes mango leaf gall in Bali Province is identified as P. robusta as the first report that can be used by researchers, related agencies, and farmers to be alert and ready with strategies and control tactics in the future. Further research is needed related to monitoring using sex pheromones or plant volatiles and the search for natural enemies for monitoring purposes and initiation towards biological control.

Biodiversitas Journal of Biological Diversity

The cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) is a very destructive pest ... more The cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) is a very destructive pest in cassava farming in Indonesia. The insect has already made its way into Indonesia, where it has attacked cassava plants with indications of a bunchy top, which may cause plant death. The objectives of this study were to 1) discover and identify an invasive pest of cassava mealybug pest, P. manihoti, that attacks cassava plants in Bali; 2) map the distribution and abundance of these pest species populations on cassava plants in Bali; 3) describe the structure of the pest population in cassava plantations in Bali; 4) identify the dominant factors that influence the population structure of P. manihoti in Bali, and 5) evaluate the predator fauna in regulating the population. The findings revealed that the mealybug species that attacked cassava in Bali was P. manihoti, an exotic species that had never been published earlier. With a high population abundance, the pest has spread far and effectively overall in regencies/cities in Bali Province. In all regency/city regions, the population structure of P. manihoti was dominated by age groups of instar-1 and two nymphs, with the exception of the Buleleng Regency, which was dominated by age groups of nymphs instar 3 and 4. The nature of polyphagy and cosmopolite features that are readily adaptable to the environment and host plant variables, farming pattern, temperature and rainfall factors were the key factors impacting the population structure of P. manihoti in the field. Cryptolaemus montrouzieri, Chrysoperla carnea, and Scymnus sp. were discovered to have a role in managing P. manihoti populations in the field. The predator fauna community is structurally diverse, abundant, and has a low dominance. Cryptolaemus montrouzieri was the most dominant of the three producer species in the field. These results indicate that there is a positive potential shown by predatory mealybugs in the field and can be used as an initial model by related parties in formulating policies related to controlling insect pests of cassava plants.

Biodiversitas Journal of Biological Diversity, 2021

Sycanus aurantiacus Ishikawa et Okajima (Hemiptera: Heteroptera) is a valuable predatory insect t... more Sycanus aurantiacus Ishikawa et Okajima (Hemiptera: Heteroptera) is a valuable predatory insect that can be cultivated in biological pest control programs, particularly in vegetable crops. The research aimed to investigate the preferences and functional responses of the predator Sycanus aurantiacus to three different prey species in the laboratory conditions, included Plutella xylostella (Linnaeus), Crocidolomia pavonana (Fabricius), and Tenebrio molitor (Linnaeus). The preference experiment was carried out by monitoring the prey on which S. aurantiacus preyed the most. The functional responsiveness of S. aurantiacus was determined by measuring the time it took to detect and prey on various kinds of prey, as well as the number of prey that were successfully preyed upon when the quantity of prey was increased. The predatory S. aurantiacus preferred P. xylostella over C. pavonana and T. molitor. S. aurantiacus functional response to three kinds of prey, including type II, is shown. In P. xylostella, the instantaneous prey search rate (a) was 0.2/hour, with a handling time (Th) of 1 hour 40 minutes/prey, which was quicker than the other two kinds of prey. As a result of our findings, the predator S. aurantiacus can be maintained in the lab and has the potential to be developed as an efficient biocontrol agent, particularly against the cabbage leaf caterpillar P. xylostella.

IOP Conference Series: Earth and Environmental Science, 2022

Star fruit (Averrhoa carambola) is a fruit plant that has a high consumption rate, especially in ... more Star fruit (Averrhoa carambola) is a fruit plant that has a high consumption rate, especially in the Central/South America and Asia-Pacific regions including Indonesia. The fruit fly, Bactrocera spp. become a major pest on star fruit commodities in Indonesia which can harm quantity and quality which in turn hampers export activities. The aims of this study was to identify the type of pest, the level of attack, and the type of parasitoid associated with star fruit flies in the Denpasar City area. Fruit samples were collected using a purposive sampling method, namely collecting symptomatic fruit planted in four sub-districts in Denpasar City. Identification was carried out on the types of fruit flies and parasitoids that emerged after the rearing period. The percentage of fruit damage and the degree of parasitization was also determined. The fruit flies identified were Bactrocera carambolae and B. dorsalis and two parasitoids, namely Fopius arisanus and Diachasmimorpha longicaudata. T...

Proceedings of the 2nd International Conference on Education and Technology (ICETECH 2021), 2022

The aim of this study is to assess the extent of attack and the potential for decreased productio... more The aim of this study is to assess the extent of attack and the potential for decreased production of maize types in the field caused to Spodoptera frugiperda. This study was carried out on a large scale, with four treatments and six replications (10 systematic sample replications). Parameters observed include population development, attack rate, the potential for production decline. The results show that this pest attack began to be found in maize 2 weeks after planting (wap) with an average population of 5.37 individu on sweet corn and 6.53 individu on glutinous corn. Furthermore, the population continued to increase up to 5 wap and lowering again to 8 wap. The regression analysis revealed a positive relationship between the larval population and the S. frugiperda attack rate. Sweet corn production decreased by 28.08 percent and glutinous corn output decreased by 25.04 percent, respectively. Overall, our results showed that S. frugiperda attacks continued to increase in both maize varieties (glutinous and sweet), which was indicated by an increase in population and a decrease in production on a field trial scale.

IOP Conference Series: Earth and Environmental Science, 2022

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an invasi... more The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an invasive pest from America and has recently become an important pest in Indonesia. In their new environment, these pests have very high migratory and adaptive skills, as well as aggressive feeding habits. The aim of this research was to monitor the distribution, percentage of attacks, and damage caused by S. frugiperda on maize fields in the Karo District of North Sumatra Province. The study was conducted using a survey method at various altitudes and the sample unit was determined using the diagonal method. Each sample unit has a size of 2 × 2 m2. The age of maize crop used as the sample is 2-4; 5-6; 7-8; 9-10; and 11 weeks after planting (wap). Symptoms of attack, number of larvae population, and percentage of FAW attack were observed directly on plants. The results showed that FAW spread evenly at various altitudes, with the highest population at an altitude of 500-1,000 m.a.s.l at the age ...

Students Journal of Accounting and Banking, 2014

Penelitian ini menguji pengaruh profitabilitas, struktur aset, dan pertumbuhan penjualan terhadap... more Penelitian ini menguji pengaruh profitabilitas, struktur aset, dan pertumbuhan penjualan terhadap struktur modal serta harga saham di perusahaan properti dan real estate yang terdaftar di Bursa Efek Indonesia tahun 2010-2012. Sampel penelitian ini mencakup 30 perusahaan dipilih melalui kriteria sampel. Penelitian ini menggunakan data sekunder yang telah lolos uji asumsi klasik dan dianalisis menggunakan analisis regresi linier berganda. Hasil analisis untuk variabel terikat pertama menunjukkan bahwa profitabilitas dan struktur aset berpengaruh terhadap struktur modal. Sedangkan pertumbuhan penjualan tidak berpengaruh terhadap struktur modal. Untuk variabel terikat kedua, hasil menunjukkan bahwa profitabilitas dan pertumbuhan penjualan berpengaruh terhadap harga saham. Sedangkan struktur aset tidak berpengaruh terhadap harga saham.

HAYATI Journal of Biosciences

Leaf miners, Liriomyza spp., have developed as a severe pest in recent years, reducing the produc... more Leaf miners, Liriomyza spp., have developed as a severe pest in recent years, reducing the production of several ornamental and crops in Indonesia. As a result, monitoring and control mechanisms have been proposed. This research aimed to investigate community structure and identify Liriomyza spp., which impacts crops and natural parasitoids in Bali Province. Leaf samples of vegetables, ornamental plants, and related species were collected in all regencies/cities of Bali Province in 2019 and 2020 and preserved in the laboratory for observation and counting of leaf miners and related parasitoids. The findings revealed that four Liriomyza spp. were detected in host plants, namely Liriomyza sativae Blanchard (Diptera: Agromyzidae), Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae), Liriomyza chinensis Kato (Diptera: Agromyzidae), and Liriomyza trifolii Burgess (Diptera: Agromyzidae). Asteraceae species were the most common host plants attacked by leaf miners in the field. The same...

Biodiversitas Journal of Biological Diversity, 2022

The beet armyworm, Spodoptera exigua Hubner (Lepidoptera: Noctuidae), is a polyphagous insect tha... more The beet armyworm, Spodoptera exigua Hubner (Lepidoptera: Noctuidae), is a polyphagous insect that is the main pest and is responsible for the decline in shallot production in Indonesia. This study aims to (i) analyze preferences; (ii) colonization time; (iii) population development; (iv) attack of armyworms according to plant phenology in the shallot cultivars; and (v) identification species of armyworms. The research was conducted in Bangli Village, Tabanan Regency, Bali Province, Indonesia. The research design used was a randomized block design with the treatment of five shallot cultivars and five replications. Molecular analysis of armyworm larvae was carried out using the Polymerase Chain Reaction (PCR) method using forward Lep_F1 and reverse Lep_R1 primers at the Cytochrome Oxidase Subunit I (COI) gene. Our results indicate that the period of adult pest infestation has been seen since the emergence of plants, namely 7 days after planting (dap). The colonization period begins at 21 (dap), when plants and larvae begin to grow. The development of the egg and larva population was seen when the plants totaled 21 (dap) (for eggs) and 28 dap (for larvae). The most preferred shallot cultivars are "Bali Karet" and "Bima Brebes". Armyworm larvae, including S. exigua, were identified as related to the same group as isolate larvae from China, India, Pakistan, Thailand, and Japan. These findings indicated that S. exigua preferred the two cultivars of shallots in the fields and emerged at 21 dap. This shows that insect management activities must be carried out systematically both when the shallots plants are young, pre-and post-harvest. Control with natural enemies can also be done for further research.

Biodiversitas Journal of Biological Diversity

The black fig fly (Silba adipata) is newly emerging pests that attack cayenne pepper (Capsicum fr... more The black fig fly (Silba adipata) is newly emerging pests that attack cayenne pepper (Capsicum frutescens L.) plants in Bali Province, Indonesia. This study aimed to determine the parasitoid type, community structure, distribution, and parasitization rate of the parasitoids of S. adipata on cayenne pepper in Bali. The sampling method employed in this study involves purposive sampling techniques on 100-150 pieces of cayenne pepper infested with S. adipata at each location point, with the emerging parasitoids identified morphologically. Three types of parasitoid species were associated with S. adipata, which include Asobara japonica Belokobylskij, Fopius arisanus (Sonan), and Diachasmimorpha longicaudata (Ashmead). The parasitoid community structure associated with S. adipata had a low abundance index, low diversity index, and a moderate dominance index. Based on the distribution of the three parasitoids, D. longicaudata is distributed evenly in Bali, whereas F. arisanus was not found in Jembrana. Conversely, A. japonica was only found in Badung, Bangli, Gianyar, and Klungkung. As summary, D. laungicaudata had the highest parasitization rate compared to the F. arisanus and A. japonica. D. longicaudata is a potential parasitoid, which can be studied for the future biological control of S. adipata.

Biodiversitas Journal of Biological Diversity

Gall midge (Procontarinia robusta) is an important pest of mango plants in various countries in t... more Gall midge (Procontarinia robusta) is an important pest of mango plants in various countries in the world, including Indonesia. This pest causes very serious damage to mango leaves which until now has not been reported. This study aims to map the distribution and abundance of the pest population and identify the pest species using the DNA barcode method on mango tree plantations in Bali, Indonesia. The survey method was used to collect data from various districts and cities in Bali Province, Indonesia. Mitochondrial COI primers were used to identify DNA barcodes. The results showed that the highest population abundance of P. robusta was found in Denpasar City. These pests have spread evenly throughout the Province of Bali, from the lowlands to the middle and highlands. Through a molecular approach, the insect pest that causes mango leaf gall in Bali Province is identified as P. robusta as the first report that can be used by researchers, related agencies, and farmers to be alert and ready with strategies and control tactics in the future. Further research is needed related to monitoring using sex pheromones or plant volatiles and the search for natural enemies for monitoring purposes and initiation towards biological control.

Biodiversitas Journal of Biological Diversity

The cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) is a very destructive pest ... more The cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) is a very destructive pest in cassava farming in Indonesia. The insect has already made its way into Indonesia, where it has attacked cassava plants with indications of a bunchy top, which may cause plant death. The objectives of this study were to 1) discover and identify an invasive pest of cassava mealybug pest, P. manihoti, that attacks cassava plants in Bali; 2) map the distribution and abundance of these pest species populations on cassava plants in Bali; 3) describe the structure of the pest population in cassava plantations in Bali; 4) identify the dominant factors that influence the population structure of P. manihoti in Bali, and 5) evaluate the predator fauna in regulating the population. The findings revealed that the mealybug species that attacked cassava in Bali was P. manihoti, an exotic species that had never been published earlier. With a high population abundance, the pest has spread far and effectively overall in regencies/cities in Bali Province. In all regency/city regions, the population structure of P. manihoti was dominated by age groups of instar-1 and two nymphs, with the exception of the Buleleng Regency, which was dominated by age groups of nymphs instar 3 and 4. The nature of polyphagy and cosmopolite features that are readily adaptable to the environment and host plant variables, farming pattern, temperature and rainfall factors were the key factors impacting the population structure of P. manihoti in the field. Cryptolaemus montrouzieri, Chrysoperla carnea, and Scymnus sp. were discovered to have a role in managing P. manihoti populations in the field. The predator fauna community is structurally diverse, abundant, and has a low dominance. Cryptolaemus montrouzieri was the most dominant of the three producer species in the field. These results indicate that there is a positive potential shown by predatory mealybugs in the field and can be used as an initial model by related parties in formulating policies related to controlling insect pests of cassava plants.

Biodiversitas Journal of Biological Diversity, 2021

Sycanus aurantiacus Ishikawa et Okajima (Hemiptera: Heteroptera) is a valuable predatory insect t... more Sycanus aurantiacus Ishikawa et Okajima (Hemiptera: Heteroptera) is a valuable predatory insect that can be cultivated in biological pest control programs, particularly in vegetable crops. The research aimed to investigate the preferences and functional responses of the predator Sycanus aurantiacus to three different prey species in the laboratory conditions, included Plutella xylostella (Linnaeus), Crocidolomia pavonana (Fabricius), and Tenebrio molitor (Linnaeus). The preference experiment was carried out by monitoring the prey on which S. aurantiacus preyed the most. The functional responsiveness of S. aurantiacus was determined by measuring the time it took to detect and prey on various kinds of prey, as well as the number of prey that were successfully preyed upon when the quantity of prey was increased. The predatory S. aurantiacus preferred P. xylostella over C. pavonana and T. molitor. S. aurantiacus functional response to three kinds of prey, including type II, is shown. In P. xylostella, the instantaneous prey search rate (a) was 0.2/hour, with a handling time (Th) of 1 hour 40 minutes/prey, which was quicker than the other two kinds of prey. As a result of our findings, the predator S. aurantiacus can be maintained in the lab and has the potential to be developed as an efficient biocontrol agent, particularly against the cabbage leaf caterpillar P. xylostella.

IOP Conference Series: Earth and Environmental Science, 2022

Star fruit (Averrhoa carambola) is a fruit plant that has a high consumption rate, especially in ... more Star fruit (Averrhoa carambola) is a fruit plant that has a high consumption rate, especially in the Central/South America and Asia-Pacific regions including Indonesia. The fruit fly, Bactrocera spp. become a major pest on star fruit commodities in Indonesia which can harm quantity and quality which in turn hampers export activities. The aims of this study was to identify the type of pest, the level of attack, and the type of parasitoid associated with star fruit flies in the Denpasar City area. Fruit samples were collected using a purposive sampling method, namely collecting symptomatic fruit planted in four sub-districts in Denpasar City. Identification was carried out on the types of fruit flies and parasitoids that emerged after the rearing period. The percentage of fruit damage and the degree of parasitization was also determined. The fruit flies identified were Bactrocera carambolae and B. dorsalis and two parasitoids, namely Fopius arisanus and Diachasmimorpha longicaudata. T...

Proceedings of the 2nd International Conference on Education and Technology (ICETECH 2021), 2022

The aim of this study is to assess the extent of attack and the potential for decreased productio... more The aim of this study is to assess the extent of attack and the potential for decreased production of maize types in the field caused to Spodoptera frugiperda. This study was carried out on a large scale, with four treatments and six replications (10 systematic sample replications). Parameters observed include population development, attack rate, the potential for production decline. The results show that this pest attack began to be found in maize 2 weeks after planting (wap) with an average population of 5.37 individu on sweet corn and 6.53 individu on glutinous corn. Furthermore, the population continued to increase up to 5 wap and lowering again to 8 wap. The regression analysis revealed a positive relationship between the larval population and the S. frugiperda attack rate. Sweet corn production decreased by 28.08 percent and glutinous corn output decreased by 25.04 percent, respectively. Overall, our results showed that S. frugiperda attacks continued to increase in both maize varieties (glutinous and sweet), which was indicated by an increase in population and a decrease in production on a field trial scale.

IOP Conference Series: Earth and Environmental Science, 2022

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an invasi... more The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is an invasive pest from America and has recently become an important pest in Indonesia. In their new environment, these pests have very high migratory and adaptive skills, as well as aggressive feeding habits. The aim of this research was to monitor the distribution, percentage of attacks, and damage caused by S. frugiperda on maize fields in the Karo District of North Sumatra Province. The study was conducted using a survey method at various altitudes and the sample unit was determined using the diagonal method. Each sample unit has a size of 2 × 2 m2. The age of maize crop used as the sample is 2-4; 5-6; 7-8; 9-10; and 11 weeks after planting (wap). Symptoms of attack, number of larvae population, and percentage of FAW attack were observed directly on plants. The results showed that FAW spread evenly at various altitudes, with the highest population at an altitude of 500-1,000 m.a.s.l at the age ...

Students Journal of Accounting and Banking, 2014

Penelitian ini menguji pengaruh profitabilitas, struktur aset, dan pertumbuhan penjualan terhadap... more Penelitian ini menguji pengaruh profitabilitas, struktur aset, dan pertumbuhan penjualan terhadap struktur modal serta harga saham di perusahaan properti dan real estate yang terdaftar di Bursa Efek Indonesia tahun 2010-2012. Sampel penelitian ini mencakup 30 perusahaan dipilih melalui kriteria sampel. Penelitian ini menggunakan data sekunder yang telah lolos uji asumsi klasik dan dianalisis menggunakan analisis regresi linier berganda. Hasil analisis untuk variabel terikat pertama menunjukkan bahwa profitabilitas dan struktur aset berpengaruh terhadap struktur modal. Sedangkan pertumbuhan penjualan tidak berpengaruh terhadap struktur modal. Untuk variabel terikat kedua, hasil menunjukkan bahwa profitabilitas dan pertumbuhan penjualan berpengaruh terhadap harga saham. Sedangkan struktur aset tidak berpengaruh terhadap harga saham.

HAYATI Journal of Biosciences

Leaf miners, Liriomyza spp., have developed as a severe pest in recent years, reducing the produc... more Leaf miners, Liriomyza spp., have developed as a severe pest in recent years, reducing the production of several ornamental and crops in Indonesia. As a result, monitoring and control mechanisms have been proposed. This research aimed to investigate community structure and identify Liriomyza spp., which impacts crops and natural parasitoids in Bali Province. Leaf samples of vegetables, ornamental plants, and related species were collected in all regencies/cities of Bali Province in 2019 and 2020 and preserved in the laboratory for observation and counting of leaf miners and related parasitoids. The findings revealed that four Liriomyza spp. were detected in host plants, namely Liriomyza sativae Blanchard (Diptera: Agromyzidae), Liriomyza huidobrensis Blanchard (Diptera: Agromyzidae), Liriomyza chinensis Kato (Diptera: Agromyzidae), and Liriomyza trifolii Burgess (Diptera: Agromyzidae). Asteraceae species were the most common host plants attacked by leaf miners in the field. The same...

Biodiversitas Journal of Biological Diversity, 2022

The beet armyworm, Spodoptera exigua Hubner (Lepidoptera: Noctuidae), is a polyphagous insect tha... more The beet armyworm, Spodoptera exigua Hubner (Lepidoptera: Noctuidae), is a polyphagous insect that is the main pest and is responsible for the decline in shallot production in Indonesia. This study aims to (i) analyze preferences; (ii) colonization time; (iii) population development; (iv) attack of armyworms according to plant phenology in the shallot cultivars; and (v) identification species of armyworms. The research was conducted in Bangli Village, Tabanan Regency, Bali Province, Indonesia. The research design used was a randomized block design with the treatment of five shallot cultivars and five replications. Molecular analysis of armyworm larvae was carried out using the Polymerase Chain Reaction (PCR) method using forward Lep_F1 and reverse Lep_R1 primers at the Cytochrome Oxidase Subunit I (COI) gene. Our results indicate that the period of adult pest infestation has been seen since the emergence of plants, namely 7 days after planting (dap). The colonization period begins at 21 (dap), when plants and larvae begin to grow. The development of the egg and larva population was seen when the plants totaled 21 (dap) (for eggs) and 28 dap (for larvae). The most preferred shallot cultivars are "Bali Karet" and "Bima Brebes". Armyworm larvae, including S. exigua, were identified as related to the same group as isolate larvae from China, India, Pakistan, Thailand, and Japan. These findings indicated that S. exigua preferred the two cultivars of shallots in the fields and emerged at 21 dap. This shows that insect management activities must be carried out systematically both when the shallots plants are young, pre-and post-harvest. Control with natural enemies can also be done for further research.

Biodiversitas Journal of Biological Diversity

The black fig fly (Silba adipata) is newly emerging pests that attack cayenne pepper (Capsicum fr... more The black fig fly (Silba adipata) is newly emerging pests that attack cayenne pepper (Capsicum frutescens L.) plants in Bali Province, Indonesia. This study aimed to determine the parasitoid type, community structure, distribution, and parasitization rate of the parasitoids of S. adipata on cayenne pepper in Bali. The sampling method employed in this study involves purposive sampling techniques on 100-150 pieces of cayenne pepper infested with S. adipata at each location point, with the emerging parasitoids identified morphologically. Three types of parasitoid species were associated with S. adipata, which include Asobara japonica Belokobylskij, Fopius arisanus (Sonan), and Diachasmimorpha longicaudata (Ashmead). The parasitoid community structure associated with S. adipata had a low abundance index, low diversity index, and a moderate dominance index. Based on the distribution of the three parasitoids, D. longicaudata is distributed evenly in Bali, whereas F. arisanus was not found in Jembrana. Conversely, A. japonica was only found in Badung, Bangli, Gianyar, and Klungkung. As summary, D. laungicaudata had the highest parasitization rate compared to the F. arisanus and A. japonica. D. longicaudata is a potential parasitoid, which can be studied for the future biological control of S. adipata.