Phenacoccus Manihoti Matile-Ferrero Research Articles

Development of recombinase polymerase amplification-based colorimetric detection assay for rapid identification of invasive cassava mealybug, Phenacoccus manihoti Matile-Ferrero

Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), is an economically important invasive cassava pest responsible for the massive devastation of cassava in Asia and African continent. Initially, identifying this invasive pest posed challenges because it closely resembled native mealybug species. Additionally, the traditional morphological identification process is labor-intensive and time-consuming. Detecting invasive pests at an early stage is crucial, hence development of a rapid detection assay is essential. In the current study, we have developed a simple, rapid, sensitive, and efficient molecular detection assay for P. manihoti based on Recombinase Polymerase Amplification (RPA). The primers for the RPA assay were designed using unique nucleic acid sequences of P. manihoti, and the protocol was standardized. Specificity test demonstrated that the RPA assay could amplify DNA of P. manihoti only, and no amplification was observed in six other mealybug species. The specificity of assay was confirmed using SYBR green-based colorimetric detection and gel electrophoresis where positive samples showed 195 bp amplicon size in P. manihoti samples. The assay successfully amplified P. manihoti DNA in thirty minutes at an annealing temperature of 41° C in a water bath and displayed a sensitivity of 72.5 picograms per microliter. The assay's simplicity, rapidity, and high sensitivity make it a valuable tool for detecting and monitoring P. manihoti in quarantine stations and facilitating in development of a portable diagnostic kit.

Efficacy of the extract from pongam (Pongamia pinnata) leaves against the cassava pink mealybug (Phenacoccus manihoti Matile-Ferrero) under laboratory conditions

The cassava pink mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), a native of South America, have been one of the most serious pests of cassava (Manihot esculenta Crantz) in the world. Conventional control of this pest is dependent on synthetic chemical insecticides. This study was carried out at Entomology Laboratory, Faculty of Agronomy, University of Agriculture and Forestry, Hue University, Vietnam during 2020 - 2021 to determine the efficacy of leaf extract from Progamia pinnata against the cassava pink mealybug. The efficacy of pongam leaf extract was more efficacious against the first instar than the second instar of P. manihoti, and was according to the evaluation time. After ten days treatment, the efficacy of the leaf extract against first and second instars of P. manihoti was 100% and 50.0, 73.3, 66.7% at concentrations of 2.0, 1.8 and 1.4%, respectively. Therefore, pongam leaf extract can be recommended for protection of the cassava pink mealybug.

The Fungus Metarhizium sp. BCC 4849 Is an Effective and Safe Mycoinsecticide for the Management of Spider Mites and Other Insect Pests.

Simple SummaryThe spider mite is a destructive pest of various crops during warm and dry conditions in tropical countries, including Thailand. The pest is difficult to control despite synthetic acaricide use. In the field, insect populations gradually develop resistance to synthetic pesticides over long-term use. The use of entomopathogenic fungi is more human- and environmentally friendly. We searched and identified a potential fungal isolate from a culture collection, focusing on the genus Metarhizium. Metarhizium sp. BCC 4849 not only controls the spider mite but also plays a significant role as a natural regulator of other insect pests. Here, we investigated its infection process on the mite, optimized a conidial formulation for extended shelf life, and conducted toxicological assays in animals to assess its biosafety in humans. The fungal genome has been sequenced. The genomic data indicated that oxidoreduction proteins; zinc-, heme-, and iron-binding proteins; and transmembrane transporters are abundant in the genome.Five isolates of Metarhizium sp. were evaluated for their pathogenicity against the spider mite (Tetranychus truncatus Ehara) (Acari: Tetranychidae) and Metarhizium sp. BCC 4849 resulted in the highest mortality (82%) on the 5th day post-inoculation (DPI). Subsequent insect bioassay data indicated similar high virulence against five other insects: African red mites (Eutetranychus africanus Tucker) (Acari: Tetranychidae), bean aphid (Aphis craccivora Koch) (Hemiptera: Aphididae), cassava mealybug (Phenacoccus manihoti Matile-Ferrero) (Hemiptera: Pseudococcidae), sweet potato weevil (Cylas formicarius Fabricius) (Coleoptera: Brentidae), and oriental fruit fly (Bactrocera dorsalis Hendel) (Diptera: Tephritidae), at mortalities of 92–99%, on 3rd–6th DPI, and in laboratory conditions. The pathogenicity assay against E. africanus in hemp plants under greenhouse conditions indicated 85–100% insect mortality on 10th DPI using the fungus alone or in combination with synthetic acaricide. Genome sequencing of Metarhizium sp. BCC 4849 revealed the high abundance of proteins associated with zinc-, heme-, and iron-binding; oxidation-reduction; and transmembrane transport, implicating its versatile mode of interaction with the environment and adaptation to various ion homeostasis. The light and scanning electron microscopy indicated that at 24 h post inoculation (PI), adhesion and appressorial formation occurred, notably near the setae. Most infected mites had stopped moving and started dying by 48–72 h PI. Elongated hyphal bodies and oval blastospores were detected in the legs. At 96–120 h PI or longer, dense mycelia and conidial mass had colonized the interior and exterior of dead mites, primarily at the bottom than the upper part. The shelf-life study also indicated that conidial formulation combined with an oxygen-moisture absorber markedly enhanced the viability and germination after storage at 35 °C for four months. The fungus was tested as safe for humans and animals, according to our toxicological assays.

Assessing adverse impact of the native biological control disruptors in the colonies of the recent invasive pest Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) in India

New challenges appear with every biological invasion and presses need to probe their ecological interactions. In the comprehensive yet complicated food web associated with the niche of the recently invaded cassava mealybug (CMB) Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), there was a multitrophic interaction structured vertically as well as horizontally. Altogether 45 species: thirty four species of insects from six orders (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, and Neuroptera) and eleven species of spiders (Araneae) were grouped under four trophic levels into 11 guilds. The analysis of trophic guild structure and interaction indicated that many indigenous parasitoid species, which qualified to be placed under the fourth trophic level, actively parasitized the potential native predators of cassava mealybug (CMB) and thereby negatively impacted the natural biological control of CMB. Most of these resident hyperparasitoid species were recorded for the first time, to be associated directly or indirectly with CMB. The species diversity at fourth trophic level could be viewed as a bioindicator and one of the most important determinant factors on the success rate of any biological control program. No indigenous primary parasitoids were documented on CMB from any of the sites sampled. In the absence of any indigenous parasitoids and high level of parasitization of the potential CMB predators, the long-term and indirect ecosystem risks will be significant until the introduction and establishment of the proven classical biological control agent, Anagyrus lopezi (De Santis) (Encyrtidae: Hymenoptera) from other countries. • First comprehensive study involving multitrophic interactions in the niche of invasive pest Phenacoccus manihoti. • Many indigenous parasitoid species actively parasitized the potential native predators of CMB. • Negatively impact on the natural biological control of CMB. • No indigenous primary parasitoids documented. • We assess the long-term and indirect ecosystem risks due to CMB and spread to other countries.

Uji Pemangsaan dan Tanggap Fungsional Predator Chysoperla carnea Stephens (Neuroptera: Crysopidae) Terhadap Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae)

Predation and Functional Response Test of Predator Chysoperla carnea Stephens (Neuroptera: Crysopidae) Against Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). This study aims to evaluate the predatory capacity of C. carnea by measuring the rate of searching capacity and handling-time of one prey and its functional response to the population density of P. manihoti. The research was conducted at the Integrated Pest Management Laboratory (IPMLab), Faculty of Agriculture, Udayana University. The study was conducted from February to May 2019. Testing of functional responses used a randomized block design with 5 treatments (3, 6, 9, 12, 15 nymphs-3) each of which was repeated 10 times. The results showed that the prey searching-capacity when the population was low (3 nymphs-3) took longer (10.37 minutes), while when the population was high it took a short time (6.23 minutes). The length of time for handling one prey in the low population was 6.08 minutes, while in the high population it was 5.48 minutes. Predator C. carnea has a tpe-2 functional response to an increase in the population of P. manihoti nymphs with the equation Y = 4.32x / 1 + 1.973x (R2 = 0.980). The rate of predation increases sharply when the population of low increases, and decreases when the increase of prey population increases. C. carnea has the potential to be developed as a control agent for P. manihoti.

Ultra structural study on different sensory structure and some associated body parts of mango mealy bug, Drosicha mangiferae (G.) by scanning electron microscopy

Ultra structural study on different sensory structure and some associated body parts of mango mealy bug, Drosicha mangiferae (G.) by scanning electron microscopy

Record of coccinellid predator, Hyperaspis maindroni Sicard (Coleoptera: Coccinellidae) on invasive cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae)

The cassava mealybug, Phenacoccus manihoti Matile-Ferrero is one of the most serious pests of cassava worldwide, which got recently introduced into India (traced in Kerala) as a potential invasive pest. Studies were carried out to record the incidence of mealybug, P. manihoti and its natural enemies on different varieties of cassava in Namakkal dt. of Tamil Nadu during June 2020. The observations were taken in the field in situ as well in the collected mealybug infested twigs in the laboratory. Results revealed that all the three surveyed cassava varieties viz. , Mulluvadi, Thailand white and Shree Atulya were found severely infested with cassava mealybug. A huge number of coccinellid beetles were collected from the P. manihoti colonies, which were identified as Hyperaspis maindroni Sicard, 1929 (Coccinellidae:Coccinellinae:Hyperaspidini). Molecular characterization of both grub and adult beetle of H. maindroni was carried out to confirm its identity.

Parasitism of cassava mealybug by Anagyrus lopezi: Effects of varying host and parasitoid densities

Abstract. Fanani MZ, Rauf A, Maryana N, Nurmansyah A, Hindayana D. 2020. Parasitism of cassava mealybug by Anagyrus lopezi: Effects of varying host and parasitoid densities. Biodiversitas 21: 4973-4980. The solitary endoparasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was introduced into Indonesia in 2014 to control the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). The objectives of this study were to understand the influence of host and parasitoid densities on functional response and mutual interference of the parasitoid, by altering either the host or parasitoid density while keeping the other constant. The effects of host and parasitoid densities on parasitism, superparasitism, progeny production, and sex ratio were also assessed. Logistic regression was used to determine the shape of the functional response. Nonlinear least-squares regression was used to estimate the attack rate (a) and handling time (Th). Nicholson’s model and linear regression were used to determine per capita searching efficiency and interference coefficient, respectively. The logistic regression results suggested a Holling type II functional response to changing host densities, with an estimated attack rate (a) and handling time (Th) were 0.037 h-1 and 1.19 h, respectively. The estimated maximum number of mealybugs parasitized over 24-h period was 20.2 mealybugs. The wasp-mealybug ratio and offspring production increased significantly from 1:2 to 1:100 and from 1.35 to 10.45, respectively. However, the per capita number of parasitization decreased significantly from 14.20 to 4.37, with the increase in parasitoid density from 1 to 8. Searching efficiency of the parasitoid decreased significantly with increasing parasitoid density, with a mutual interference constant (m) of -0.52.

INFLUENCE OF HOST STAGE ON OVIPOSITION, DEVELOPMENT, AND SEX RATIO OF Anagyrus lopezi (DE SANTIS) (HYMENOPTERA: ENCYRTIDAE), A PARASITOID OF THE CASSAVA MEALYBUG, Phenacoccus manihoti MATILE-FERRERO (HEMIPTERA: PSEUDOCOCCIDAE)

Influence of host stage on oviposition, development, and sex ratio of Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae), a parasitoid of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). The parasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was introduced from Thailand into Indonesia in early 2014 to control the invasive cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). Because of the need to produce large numbers of high-quality females, research was conducted in the laboratory to determine host stage preference for A. lopezi on different instars of P. manihoti. Individual female wasps were exposed to first, second, third instar nymphs, and pre-reproductive adult mealybugs. In the no-choice test, the frequency of parasitized hosts and the number of eggs laid per host was significantly higher in second and third instar nymphs as well as adult mealybugs compared to first instar nymphs. In the two-choice test, third instars nymphs and adult mealybugs were the most preferred host for oviposition. Immature development of parasitoids was faster and the ratio of female to male parasitoids was higher following oviposition in second and third instar nymphs and pre-reproductive adult hosts, compared to the first instar nymphs. Our findings indicate that the use of pre-reproductive adults as hosts in a mass-rearing program would be the most productive and fastest way to produce A. lopezi populations with a female-biased sex ratio. Field release of parasitoids should be conducted when the host’s third instar nymph is the most abundant because the period during which preferred and suitable host stages are available would be the longest.

Response of parasitoids to invasive pest Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on cassava crop in Bali, Indonesia

Abstract. Supartha IW, Yudha IKW, Wiradana PA, Susila IW. 2020. Response of parasitoids to invasive pest Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on cassava crop in Bali, Indonesia. Biodiversitas 21: 4543-4549. Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) is an invasive pest that entered Indonesia in 2010 and attacks cassava plants, especially in Bali Province. This study aimed to identify species and establish the population distribution mapping, community structures (diversity, abundance, and dominance), and parasitization rate on cassava crops in Bali. This study conducted with a field observation method by taking infested shoots of cassava plants by P. manihoti purposively in the field. The cassava mealybug that was present in the leaves or shoots were kept in the laboratory until the parasitoid appeared. The results showed that four species of parasitoids were found to respond to invasive pest, namely Anagyrus lopezi (Encyrtidae), Acerophagus sp. (Encyrtidae), Blepyrus sp. (Encyrtidae) and Encarsia sp. (Aphelinidae). Structurally the parasitoid community had a low abundance (R1 = 0.50–0.87) and low diversity index value (H'= 0.27-0.28). While the parasitoid dominance index was in the moderate category with a value D = 0.33–0.59 in Bangli, Klungkung, Badung, Tabanan, and Buleleng Districts. But it had high dominance index values in Gianyar, Denpasar, Jembrana, and Karangasem Districts with a value D = 0.62-0.72. The three species of parasitoid spread evenly in all districts and cities in Bali according to the host distribution map, namely P. manihoti on cassava crop. The four parasitoids showed varying parasitic levels in the field with the highest parasitization rate was A. lopezi followed by Acerophagus sp., Blepyrus sp., and Encarsia sp.

Parasitism disruption by ants of Anagyrus lopezi (Hymenoptera: Encyrtidae), parasitoid of cassava mealybug

Abstract. Fanani MZ, Rauf A, Maryana N, Nurmansyah A, Hindayana D. 2020. Parasitism disruption by ants of Anagyrus lopezi (Hymenoptera: Encyrtidae), parasitoid of cassava mealybug. Biodiversitas 21: 2337-2343. Parasitoid, Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was introduced into Indonesia in 2014 to control the invasive cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). Among ants associated with honeydew-producing hemipterans, there are three common species in Indonesia i.e., Anoplolepis gracilipes (Smith), Dolichoderus thoracicus (Smith), and Oecophylla smaragdina (Fabricius) (Hymenoptera: Formicidae). The objective of this research was to investigate the relative influence of the three ant species on the parasitism of A. lopezi under laboratory conditions. Experiments were carried out by allowing a number of ants and parasitoids to forage on mealybugs-infested waterleaf (Talinum triangulare (Jaqc.) Willd.). The average time spent by individual parasitoid foraging was significantly longer (27.39 minutes) on ant-excluded plants compared to ant-attended plants (2.47- 4.68 minutes). Accordingly, parasitoid spent less time in finding hosts on ant-excluded plants, while spent a longer time in handling hosts. More oviposition activities by parasitoids on mealybug were occurred on ant-excluded plants compared to those on ant-attended plants. As a result, the percentage of parasitism and the number of wasps that emerged from the hosts on ant-excluded plants were almost 2 - 3 folds higher than those on ant-attended plants.

Masa hidup imago, progeni, dan kemampuan parasitisasi Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae), parasitoid kutu putih singkong

Parasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) diintroduksikan dari Thailand ke Indonesia pada tahun 2014 untuk mengendalikan hama asing invasif, kutu putih singkong Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). Penelitian dilakukan di laboratorium dengan tujuan untuk mengetahui potensi reproduksi, pengaruh pemberian larutan madu terhadap masa hidup imago, mempelajari keperidian, progeni, dan respons A. lopezi terhadap peningkatan kerapatan inang. Penelitian dilaksanakan dengan memajankan nimfa instar-3 kutu putih pada parasitoid. Pengaruh perlakuan pakan madu terhadap masa hidup imago parasitoid dilakukan pada kondisi tanpa inang. Keperidian diukur berdasarkan banyaknya mumi yang terbentuk. Hasil penelitian menunjukkan betina hidup selama 3,7 hari dan jantan 3,2 hari bila hanya tersedia air. Masa hidup imago parasitoid berlangsung lebih lama bila tersedia madu. Parasitoid yang diberi larutan madu 50% mampu hidup 6–9 kali lipat lebih lama dibandingkan dengan yang hanya diberi air. Selama hidupnya imago betina A. lopezi memarasit 96–287 kutu putih, dengan rataan 203,7 atau tingkat parasitisasi 34,6%, serta 24,86% mengalami kematian karena kegiatan pengisapan inang. Masa perkembangan pradewasa dari telur hingga imago muncul berlangsung 17,97 dan 17,67 hari, berturut-turut untuk jantan dan betina. Rataan progeni per induk adalah 88,8 individu, dengan 56,9% berjenis kelamin betina. Pada kerapatan inang 2–100 individu, parasitoid A. lopezi memperlihatkan tanggap fungsional tipe III.

Geographic distribution of the invasive mealybug Phenacoccus manihoti and its introduced parasitoid Anagyrus lopezi in parts of Indonesia

Abstract. Fanani Z. M., Rauf A, Maryana N, Nurmansyah A, Hindayana D. 2019. Geographic distribution of the invasive mealybug Phenacoccus manihoti and its introduced parasitoid Anagyrus lopezi in parts of Indonesia. Biodiversitas 20: 3751-3757. Cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), is an invasive pest detected for the first time in Indonesia in 2010. An exotic parasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was introduced and released in 2014 to control the pest. Study was conducted with the objective to determine the geographic distribution of P. manihoti and spread of A. lopezi. Field surveys were conducted on cassava fields in various locations in Lampung, Java, and Nusa Tenggara. Our studies showed that P. manihoti was found to be widely distributed in Lampung, Banten, West Java, Central Java, East Java, West Nusa Tenggara and East Nusa Tenggara. In each location visited, symptoms of P. manihoti infestation as indicated by internode distortion and bunchy top were prominent. Three years following release, parasitoid A. lopezi has established and spread into several cassava growing areas, except East Nusa Tenggara. Parasitism rates varied from 1.50% in West Nusa Tenggara up to 59.18% in East Java. Logistic regression revealed that probability of severe damage by the cassava mealybug was significantly (P<0.05) increased with the increasing abundance of ants.

Genetic variation among the geographic population of Cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) in Indonesia inferred from mitochondrial COI gene sequence

Abstract. Nopriawansyah N, Rauf A, Kusumah YM, Nurmansyah A, Koesmaryono Y. 2019. Genetic variation among the geographic population of Cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae) in Indonesia inferred from mitochondrial COI gene sequence. Biodiversitas 20: 2685-2692. Cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) is an invasive pest native to South America. Research was conducted with the objective to study genetic variation of cassava mealybug from different geographic areas in Indonesia. Thirty-six samples of cassava mealybugs were collected from eight different population locations. Genomic DNA was extracted from individual specimens of P. manihoti using gSYNC DNA Extraction Kit from Geneaid Lot No. FB221707. PCR amplification using primary CO1 gene showed the target position as long as 518 bp. Analysis of homology from eight populations revealed eight haplotypes in Indonesia with different variable sites. Genetic distance analysis was done by calculating base pair differences in each population. The percentage of genetic distance between populations was 0.0000% -0.00409%. The results of the analyst using the Kimura-2 parameter showed that the population was divided into 2 clusters. The highest haplotype (Hd) diversity value was 0.8333, while the lowest was zero (Hd = 0). The highest nucleotide diversity (π) was 0.00225 and the lowest was 0.000000. The genetic distance and nucleotide diversity were low because P. manihoti was thelytoky parthenogenesis.

Species-specific COI primers for rapid identification of a globally significant invasive pest, the cassava mealybug Phenacoccus manihoti Matile-Ferrero

The globally invasive cassava mealybug Phenacoccus manihoti Matile-Ferrero is a pernicious pest of cassava, and its recent introduction into Asia has raised considerable alarm. To slow or prevent further invasion, an accurate, simple, and developmental-stage-independent detection method for P. manihoti is required. In the present study, a PCR method based on a species-specific mitochondrial DNA cytochrome oxidase I (SS-COI) marker was developed for rapid identification of P. manihoti. One pair of SS-COI primers (PMSSZW-1F and PMSSZW-1R) was designed based on sequence variations in the COI gene among P. manihoti and related mealybug species. Specificity of the primer pair was validated on 21 closely related species. Sensitivity tests were performed on four immature developmental stages and female adults. Efficacy tests demonstrated that at the relatively low concentration of (135.2±14.7) pg μL−1 resuspended DNA, the specific fragment was detected in all replicates. Furthermore, the SS-COI primer pair was assayed on three populations of P. manihoti from major exporting countries of cassava. The PCR assay was proved to be a rapid, simple, and reliable molecular measure for the identification of P. manihoti. This tool will be useful for quarantine, monitoring, and management of this invasive pest.

The early transcriptome response of cassava (Manihot esculenta Crantz) to mealybug (Phenacoccus manihoti) feeding.

The mealybug, Phenacoccus manihoti, is a leading pest of cassava (Manihot esculenta Crantz), damaging this crop globally. Although the biological control of this mealybug using natural predators has been established, resistance breeding remains an important means of control. Understanding plant responses to insect herbivory, by determining and identifying differentially expressed genes (DEGs), is a vital step towards the understanding of molecular mechanisms of defence responses in plants and the development of resistant cultivars by gene editing. Morphological and molecular analysis confirmed the mealybug identity as Phenacoccus manihoti (Matile-Ferrero). The transcriptome response of the green mite resistant cassava genotype AR23.1 was compared to P40/1 with no known resistance at 24 and 72 hours of mealybug infestation compared to non-infested mock. A total of 301 and 206 genes were differentially expressed at 24 and 72 of mealybug infestation for AR23.1 and P40/1 genotypes respectively, using a log2 fold change and P-value ≤ 0.05. Gene ontology functional classification revealed an enrichment of genes in the secondary metabolic process category in AR23.1 in comparison with P40/1, while genes in the regulation of molecular function, cellular component biogenesis and electron carrier categories were more significantly enriched in P40/1 than in AR23.1. Biological pathway analysis, based on KEGG, revealed a significant enrichment of plant-pathogen interaction and plant hormonal signal transduction pathways for a cohort of up-regulated and down-regulated DEGs in both genotypes. Defence-related genes such as 2-oxogluterate, gibberellin oxidase and terpene synthase proteins were only induced in genotype AR23.1 and not in P40/1, and subsequently validated by RT-qPCR. The study revealed a difference in response to mealybug infestation in the two genotypes studied, with AR23.1 showing a higher number of differentially expressed transcripts post mealybug infestation at 24 and 72 hours. Candidate defence-related genes that were overexpressed in the AR23.1 genotype post mealybug infestation will be useful in future functional studies towards the control of mealybugs.

KUTU PUTIH SINGKONG, PHENACOCCUS MANIHOTI MATILE-FERRERO (HEMIPTERA: PSEUDOCOCCIDAE): PERSEBARAN GEOGRAFI DI PULAU JAWA DAN RINTISAN PENGENDALIAN HAYATI

Cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae): Geographic distribution in Java and initiation of biological control. Cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Psedococcidae), is a recently introduced pest in Indonesia. Parasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was imported to control the pest. Studies were conducted to determine geographic distribution of P. manihoti throughout Java, and to evaluate the potential of the parasitoid as a biological control agent. Geographic distribution of the pest was determined through field survey, whereas evaluation of the parasitoid was studied through cage experiment and field release. Our survey revealed that the cassava mealybug has spread throughout Java. Heavy infestations caused shortened and distorted stems, complete defoliation, and stunted growth. In cages containing only mealybugs, all cassava plants (100%) died after two months. Whereas in cages containing both mealybugs and three pairs of parasitoid, rate of parasitization was 25% and plant mortality 20%. Parasitoids released in the field were able to survive, reproduce, and establish under Bogor climatic condition. These might indicate that parasitoid A. lopezi is a potential natural enemy to be used in biological control program of the cassava mealybug.

Larval preference and performance of the green lacewing, Plesiochrysa ramburi (Schneider) (Neuroptera: Chrysopidae) on three species of cassava mealybugs (Hemiptera: Pseudococcidae)

The green lacewing, Plesiochrysa ramburi (Schneider) (Neuroptera: Chrysopidae), is a dominant predatory insect in cassava fields. The suitability of different cassava mealybug species as prey for Pl. ramburi is important information for mass rearing in the laboratory. Phenacoccus manihoti Matile-Ferrero, Phenacoccus madeirensis Green and Pseudococcus jackbeardsleyi (Gimpel & Miller) were compared to determine their potential as prey for Pl. ramburi larvae by testing the green lacewing's preference and performance. Non-choice tests showed that Pl. ramburi larva could feed on all three cassava mealybug species. Choice tests showed that the 1st and 2nd instars of Pl. ramburi preferred Ph. manihoti and the 3rd instars preferred Ph. madeirensis. However, life table parameters showed that the highest net reproduction number (19.1967) and gross reproductive rate (46.0156, females/female/generation) occurred when Pl. ramburi fed on Ps. jackbeardsleyi. This indicates that Ps. jackbeardsleyi is the most suitable diet for the mass rearing of Pl. ramburi to allow releases in integrated pest management programs.

Pengujian kekhususan inang parasitoid Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) pada empat spesies kutu putih yang berasosiasi dengan tanaman singkong

A parasitoid, Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was introduced from Thailand into Indonesia in early 2014 to control the cassava mealybug Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). To determine its potential uses and effect on non-target species, behavioural observation of the parasitoids were made on four species of mealybugs, i.e. P. manihoti, Paracoccus marginatus Williams-Granara de Willink, Pseudococcus jackbeardsleyi Gimpel-Miller, and Ferrisia virgata Cockerell (Hemiptera: Pseudococcidae). For that purposes, a set of tests were conducted which includes host susceptability, preference, and suitability. Tests were conducted by exposing a female parasitoid to 3rd instar nymphs of each mealybug species in a petri dish. For susceptability test, parasitoid A. lopezi encounterend P. manihoti more often (13.70 ± 7.18 visits per 30 minutes) as compared to P. marginatus (985 ± 10.24), P. jackbeardsleyi (6.60 ± 3.62), and F. virgata (5.75 ± 4.09). So did ovipositor probing occurred more on P. manihoti (8.20 ± 5.68 probes per 30 minutes) than on P. marginatus (0.70 ± 1.84), P. jackbeardsleyi (0.35 ± 0.68), and F. virgata (0.10 ± 0.45). For preference test, host encounter and ovipositor probing by the parasitoid were more common on P. manihoti as opposed to other mealybug species. Out of four mealybug species tested, P. manihoti was the only suitable host for parasitoid development, with the number of progenies emerged 7.40 ± 2.17 individuals per 3 female parasitoids exposed in 24 hour. Host specifity exhibited by parasitoid A. lopezi may prevent adverse effect to other mealybug species inhabiting cassava fields.

PARAMETER NERACA HAYATI DAN PERTUMBUHAN POPULASI KUTU PUTIH Phenacoccus manihoti Matile-Ferrero (HEMIPTERA: PSEUDOCOCCIDAE) PADA DUA VARIETAS UBI KAYU

ABSTRACTThe life history and population growth parameters of mealybug Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on two cassava varieties. The development, reproduction, and population growth parameters of the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on two cassava varieties were studied in laboratory. The varieties tested were UJ-5 with high cyanide content (>100 mg per kg) dan Adira-1 with low cyanide content (27.5 mg per kg). Our research revealed that P. manihoti performances were highly affected by cassava varieties. Incubation period of eggs of P. manihoti were 7.93 ± 0.09 and 8.33 ± 0.11 days, nymphal development periode 12.32±0.13 and 15.67 ± 0.13 days, respectively on UJ-5 and Adira-1. Fecundity averaged 386.37 ± 5.83 on UJ-5 and 318.67±2.81 eggs on Adira-1. Intrinsic rate of increase (rm) were 0.258 ± 0.001 on UJ-5 and 0.220 ± 0.001 on Adira-1. Mean generation time (T) on UJ-5 and Adira-1 were 22.795 ± 0.050 and 25.532 ± 0.047 days, repectively. Our findings showed that variety UJ-5 was more suitable for development and population growth of the cassava mealybug.