Nursery Management of Two Major Below-Ground Feeding Plant Pests: Root Mealybug, Rhizoecus sp. and Rice Root Aphid, Rhopalosiphum rufiabdominalis (Sasaki) (Hemiptera: Pseudococcidae and Aphididae)

Root mealybug (Rhizoecus sp.) and rice root aphid (Rhopalosiphum rufibdominalis) are below-ground feeding insects that are difficult to control and have become major pests as production of their host plants has grown. Field trials were designed to investigate the impact new insecticides and biopesticides have on root mealybugs and rice root aphids. In our first three trials, we investigated the effects of biopesticides, entomopathogenic nematodes or fungi on reflexed stonecrop (Sedum rupestre) and stonecrop (S. montanum) against root mealybug. We found that flupyradifurone (Altus), flonicamid (Aria), chlorantraniliprole (Acelepryn), pymetrozine (Endeavor), Beauveria bassiana (Mycotrol), Chromobacterium subtsugae (Grandevo), Burkholderia spp. strain A396 (Venerate), cyantraniliprole (Mainspring) and Steinernema carpocapsae (Millenium) significantly reduced root mealybug populations compared to nontreated controls when applied as drenches in a curative manner. In our fourth trial, we evaluated biopesticides and Beauveria bassiana, on rice root aphid feeding on common rush (Juncus effusus) roots. Results showed pymetrozine significantly reduced populations as early as 14 days after treatment and continued to reduce their population throughout the remainder of the trial. However, chlorantraniliprole, cyantraniliprole, Beauveria bassiana, M-306 and MBI-203 did not significantly reduce rice root aphid populations until 28 days after initial application. Predator activity on root balls of Juncus effusus plants was also noted during the trials and may provide an integrated pest management (IPM) approach in controlling populations. Index words: reflexed stonecrop, Sedum rupestre L, stonecrop, Sedum montanum Song. & Perr, common rush, Juncus effuses L, Beauveria bassiana, Mycotrol, Steinernema carpocapsae, Millenium, reduced-risk pesticides, Chromobacterium subtsugae (Grandevo), flupyradifurone, Altus, flonicamid, Aria, chlorantraniliprole, Acelepryn, pymetrozine, Endeavor, Burkholderia spp. strain A396, Venerate, cyantraniliprole, Mainspring, M-306, MBI-203. Chemicals used in this study: flupyradifurone (Altus); flonicamid (Aria); chlorantraniliprole (Acelepryn); cyantraniliprole (Mainspring); pyrometrozine (Endeavor); Burkholderia spp. strain 396 (Venerate); Chromobacterium subtsugae (Grandevo); Beauveria bassiana (Mycotrol); AMBI-203 WDG – 30% Chromobacterium subtsugae strain PRAA4-1T cells and spent fermentation media. EPA registration number 84059-27; MBI-206 EP – 94.46% Heat-killed Burkholderia spp. strain A396 cells and spent fermentation media. EPA registration number 84059-14; MBI-203 SC2 – 98% Chromobacterium subtsugae strain PRAA4-1T cells and spent fermentation media. Experimental; MBI-306 SC1 - 94.46% non-viable Burkholderia spp. strain A396 cells and spent fermentation media. Experimental. Species used in this study: Root mealybug, Rhizoecus sp; Rice root aphid, Rhopalosiphum rufiabdominalis (Sasaki); reflexed stonecrop, Sedum rupestre; stonecrop, Sedum montanum; common rush, Juncus effusus.

Capsule-C: an improved Steinernema carpocapsae capsule formulation for controlling Agrotis ipsilon Hufnagel (Lepidoptera: Noctuidae)

Background Entomopathogenic nematodes (EPNs) have long been used for controlling soil-dwelling insects. Steinernema carpocapsae HB310, previously showed a high virulence against many pests including Agrotis ipsilon Hufnagel (Lepidoptera: Noctuidae). Due to the lack of durable formulations, up until now, S. carpocapsae HB310 has thus far been prevented from use in large-scale farming. The present study aimed to get a better EPNs capsule formulation suitable for long-term storage and effective application. Results An improved EPNs capsule formulation, herein named: Capsule-C was prepared by the following composition: Solution I: 18% glycerol, 0.075% formaldehyde, 1% sodium alginate, 0.2% xanthan gum, 0.5% potassium sorbate, 9% glucose, 2% fructose, 2% sucrose, and the remainder was distilled water. The nematodes suspension was added to the alginate mixture in 2 × 104 IJs/mL; Solution II: 18% glycerol, 0.075% formaldehyde, 0.5% calcium chloride, 0.5% potassium sorbate, with the remainder being distilled water. After storage for 180 days at 16 °C and 100% RH, the survival rate of nematodes in Capsule-C was 75.68 ± 0.48% and the nematodes caused 82.33 ± 1.45% mortality in the 5th instar larvae of Galleria mellonella. A. ipsilon larvae preferred to chew and ingest Capsule-C due to the addition of the glucose compound. The feeding rate of A. ipsilon larvae on Capsule-C reached to 100% within 24 h and the larval mortality of A. ipsilon was 90.48 ± 6.35%. Conclusion EPNs-containing capsules were as effective as sprayed EPNs in water solution at killing A. ipsilon. These results will provide ideas to acquire a stable and efficient EPNs capsule formulation and further promote the application of environmental friendly biological pesticides.

Biological activity of entomopathogenic nematodes on Anastrepha fraterculus (Diptera: Tephritidae)

Anastrepha fraterculus (Wiedemann) is one of the main pests of fruit farming, and entomopathogenic nematodes (EPNs) represent an important control tool of this species. Thus, the objective of this study was to evaluate the biological activity of different isolate against A. fraterculus larvae and adults. Bioassays were performed using a suspension of three isolates of Heterorhabditis amazonensis IBCB 24, Steinernema carpocapsae IBCB 02 and Steinernema feltiae IBCB 47 at six concentrations (control - without nematodes), 50, 150, 300, 500, 1000 and 1500 infective juveniles (IJs)/mL of water per 3º instar larvae. It was verified the susceptibility of larvae of A. fraterculus to isolates of EPNs and a significant increase of the pupal mortality in the function of the concentration of IJs inoculated by larva (above 75%). After the dissection of pupae and adults of A. fraterculus from infected larvae, the concentration of 1500 IJs/mL of EPNs provided the highest rate of multiplication of IJs by insect, equating to maximum concentration tested 1500 IJs/mL. Adults of A. fraterculus from larvae infected with EPNs longevity of five days, being less than adults from uninfected larvae by IJs (135 days). H. amazonensis IBCB 24, S. carpocapsae IBCB 02, and S. feltiae IBCB 47 proved to be promising as agents of biological control of A. fraterculus.

Efficacy of some native entomopathogenic nematodes against the alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), and the lucerne beetle, Gonioctena fornicata (Brüggemann) (Coleoptera: Chrysomelidae), adults under laboratory conditions

Background Entomopathogenic nematodes (EPNs) have more important role in biological control of economic insect pests. The effect of native EPNs on adults of the lucerne beetle, Gonioctena fornicata (Brüggemann, 1873) (Coleoptera: Chrysomelidae), and the alfalfa weevil, Hypera postica (Gyllenhal, 1813) (Coleoptera: Curculionidae), which are important alfalfa pests in Turkey and around the world, was investigated. Results Dose-mortality assays were carried out with 5 isolates [Steinernema carpocapsae (Weiser, 1955) (Nematoda: Steinernematidae) (Black sea isolate), S. feltiae Filipjev, 1934 (isolate 09-31), Heterorhabditis bacteriophora Poinar, 1976 (Nematoda: Heterorhabditidae) (isolate 09-43), H. bacteriophora Tokat-Songut, and S. carpocapsae Tokat-Ulas] using doses of 500, 1000, and 2000 IJs ml−1 under the laboratory conditions. Studies showed that all isolates had an effect 90% and more at 2000 IJs ml−1 and at the end of 112 h [except, H. bacteriophora (isolate 09-43) and H. bacteriophora Tokat-Songut isolates against H. postica]. In addition, LT30, LT50, and LT90 values at 1000 IJs ml−1 were determined. Conclusions According to the results, G. fornicata adults were susceptible to all isolates tested in the study and H. postica adults were susceptible to the isolates S. carpocapsae (Black sea isolate), S. feltiae (isolate 09-31), and S. carpocapsae Tokat-Ulas. This is the first study conducted in Turkey for the virulence of EPNs against G. fornicata and H. postica.

Susceptibility of Drosophila suzukii larvae to the combined administration of the entomopathogens Bacillus thuringiensis and Steinernema carpocapsae

Non-native pests are often responsible for serious crop damage. Since Drosophila suzukii has invaded North America and Europe, the global production of soft, thin-skinned fruits has suffered severe losses. The control of this dipteran by pesticides, although commonly used, is not recommended because of the negative impact on the environment and human health. A possible alternative is the use of bio-insecticides, including Bacillus thuringiensis and entomopathogenic nematodes, such as Steinernema carpocapsae. These biological control agents have a fair effectiveness when used individually on D. suzukii, but both have limits related to different environmental, methodological, and physiological factors. In this work, we tested various concentrations of B. thuringiensis and S. carpocapsae to evaluate their efficacy on D. suzukii larvae, when administered individually or in combination by using agar traps. In the combined trials, we added the nematodes after 16 h or concurrently to the bacteria, and assessed larvae lethality from 16 to 48 h. The assays demonstrated a higher efficacy of the combined administration, both time-shifted and concurrent; the obtained data also showed a relevant decrease of the time needed to kill the larvae. Particularly, the maximum mortality rate, corresponding to 79% already at 16 h, was observed with the highest concentrations (0.564 µg/mL of B. thuringiensis and 8 × 102 IJs of S. carpocapsae) in the concurrent trials. This study, conducted by laboratory tests under controlled conditions, is a good starting point to develop a further application step through field studies for the control of D. suzukii.

Keefektifan Patogenesitas Steirmema Carpocapsae (all strain) terhadap Hama Plutella xylostella L.

The utilization of entomopathogenic nematodes is an example of the uses of an environmentally friendly biological agent. Entomopathogenic nematodes of the family Steinernematidae and Hetrorhabditidae are very potential to control insect pests. The purpose of this study was to study the pathogenicity of the entomopathogenic nematode Steinernema carpocapsae (all strains) as a biological control against Plutella xylostella. This research includes 2 stages, namely the preparation stage and laboratory experiments. The experimental design in this study was a completely randomized design (CRD) consisting of six treatments and three replications. The treatments tested were entomopathogenic nematode concentrations consisting of six levels: 0, 8, 16, 32, 64 and 128 infective juvenile per ml. The LC50 and LT50 values were calculated using Probit analysis. The results of observations of nematodes that enter the insect body and pest mortality were analyzed using analysis of variance (ANOVA), once showing a significant difference, it was then continued to the DMRT test at 5% level. Based on the results of the study, the highest pathogenicity against Plutella xylostella was Steinernema carpocapsae (all strains) when compared to Steinernema glaseri (NC) and Steinernema sp. local isolates. Resistance to Steinernema carpocapsae (all strains) and the LC50 value were determined by the age of Plutella xylostella larvae. The bigger and older the larvae, the more its resistance to Steinernema carpocapsae (All strains) and the LC50 value. The number of entomopathogenic nematodes that enter the body of Plutella xylostella increased with increasing length of contact time.Penggunaan nematoda entomopatogen merupakan salah satu pemanfaatan agensia hayati yang ramah lingkungan. Nematoda entomopatogen dari famili Steinernematidae dan Hetrorhabditidae sangat potensial untuk mengendalikan serangga hama. Tujuan dari penelitian ini adalah mempelajari patogenisitas nematoda entomopatogen Steinernema carpocapsae (all strain) sebagai pengendali hayati terhadap hama Plutella xylostella. Penelitian ini meliputi 2 tahap yaitu tahap persiapan dan percobaan laboratorium. Rancangan percobaan pada penelitian ini adalah Rancangan Acak Lengkap (RAL) yang terdiri enam perlakuan dan tiga ulangan. Perlakuan yang diujikan adalah konsentrasi nematoda entomopatogen yang terdiri enam taraf: 0, 8, 16, 32, 64 dan 128 infektif juvenile/ml. Nilai LC50 dan LT50 dihitung menggunakan analisis probit. Hasil pengamatan nematoda yang masuk dalam tubuh serangga dan mortalitas hama dianalisis menggunakan analisis sidik ragam (ANOVA), apabila menunjukkan beda nyata dilanjutkan uji DMRT taraf 5%. Berdasarkan hasil penelitian, patogenisitas tertinggi terhadap Plutella xylostella adalah Steinernema carpocapsae (all strain) bila dibandingkan dengan Steinernema glaseri (NC) dan Steinernema sp. isolat lokal. Ketahanan terhadap Steinernema carpocapsae (All strain) dan nilai LC50 ditentukan umur larva Plutella xylostella. Semakin besar dan tua umur larva, ketahanan terhadap Steinernema carpocapsae (All strain) dan nilai LC50 juga semakin meningkat. Jumlah nematoda entomopatogen yang masuk kedalam tubuh Plutella xylostella semakin banyak seiring dengan bertambah lamanya waktu kontak.

PERFORMANCE OF ENTOMOPATHOGENIC NEMATODES ON NEOLEUCINODES ELEGANTALIS (GUENÉE) (LEPIDOPTERA: CRAMBIDAE)

The use of entomopathogenic nematodes in pest management is an alternative to reduce the yield and/or damage losses caused by pests in several crops. The present study aimed to evaluate the performance of Heterorhabditis indica (Nemata: Rhabditida) and Steinernema carpocapsae (Nemata: Rhabditida), in pre-pupae of Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) and determine the temporal viability of the pathogenicity of S. carpocapsae applied to soil. The nematode species were diluted in distilled water to 50, 65, 83, 107, 138, 178, 229, 295, 380 and 500 infective juveniles per pre-pupae (IJs insect-1) of N. elegantalis. The mortality of pre-pupa of N. elegantalis was higher as the concentrations of both studied species increased. The nematode S. carpocapsae was the most effective, causing mortality of 82.93% in the concentration of 65 IJs insect-1 and an LC50 of 24.32 IJs insect-1. In the pathogenicity test, S. carpocapsae was applied in the concentration of 100 JI/cm² in pots previously planted with tomato seedlings. As positive control was used tomato seedlings treated with distilled water. S. carpocapse presented soil viability of 24 days. Thus, S. carpocapsae can be an important tool in the integrated pest management (IPM) of N. elegantalis.