A new bioassay method reveals pathogenicity of Metarhizium anisopliae and Beauveria bassiana against early stages of Capnodis tenebrionis (Coleoptera; Buprestidae)

We used a newly developed bioassay method to demonstrate for the first time the potential of the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae to be used for the control of neonate larvae of Capnodis tenebrionis, a major threat to stone-fruit orchards in several countries. Four B. bassiana and four M. anisopliae isolates were all pathogenic for neonate larvae of C. tenebrionis; mortality rates 10 days after inoculation by dipping in a suspension with 10(8)conidia/ml varied from 23.5% to 100%. Three of the four M. anisopliae isolates caused 100% mortality. In most cases, postmortem hyphal growth and sporulation of M. anisopliae or B. bassiana was observed covering the larvae in their galleries. The eight isolates were also evaluated for pathogenicity to C. tenebrionis eggs at the same dosage. Only two B. bassiana isolates caused significant egg hatching reduction of 84.5% and 94.5%. Our results indicate that M. anisopliae and B. bassiana may be considered as promising for a new approach to prevent larval infestations by C. tenebrionis.     

Pine processionary moth (Thaumetopoea pityocampa,Lepidoptera: Thaumetopoeidae) larvae are highly susceptible to the entomopathogenic fungi Metarhizium brunneum and Beauveria bassiana

The larvae of the pine processionary moth (PPM), Thaumetopoea pityocampa, feed on the needles of pine and cedar. The urticating hairs of older instars pose a threat to human and animal health. Strains of the entomopathogenic fungi, Metarhizium brunneum (V275, ARSEF 4556) and Beauveria bassiana (KTU-24), were assayed against first to fourth instar T. pityocampa using doses ranging from 1?×?10⁵ to 1?×?10⁸ conidia mL^?1. The three strains differed slightly in their virulence but caused 100% mortality of all instars at the highest dose. The newly emerged or first instar larvae were extremely susceptible with 100% mortality being achieved 2–4 days post inoculation with V275 at all but the lowest dose. The fourth instar larvae appeared to be less susceptible than earlier instars. There was good horizontal transmission of conidia from treated to un-inoculated larvae. However, mortality was higher in third and fourth instars and where the ratio of inoculated versus untreated larvae was high. This we presume is due to spores being more readily trapped by the urticating hairs found on third and older instar larvae. Injection of the nests offers a simple and environmentally friendly way of controlling the pest with reduced risk to operators.     

Entomopathogenic fungi-mediated biological control of the red palm weevil Rhynchophorus ferrugineus

The red palm weevil (RPW), Rhynchophorus ferrugineus, is an important pest of palms, and difficult to control by conventional methods. Therefore, microbial control is an alternative strategy for controlling RPW. Herein, a total of 15 entomopathogenic fungi (EPFs) were subjected to primary pathogenicity screening against last stage of RPW larvae. The preliminary data showed that four Beauveria bassiana isolates (JEF-484, 158, 462 and 507) and one Isaria fumosorosea isolate (JEF-014) resulted in 100 % mortality within 5–10 days post inoculation (d.p.i.), respectively. According to the time required for RPW mortality, JEF-484, 158, 462 and 014 were further subjected to bioassays using 10⁷ conidia/ml suspensions by spraying method. Based on the results, JEF-484 showed the highest mortality and shortest LT₅₀ on the last stage of RPW larvae, followed by JEF-158. The two isolates also showed good conidial production and high thermal stability compared to the other isolates. Therefore, JEF-484 and JEF-158 were selected for bioassays against RPW egg and the last larval stage with different concentrations of 10⁵, 10⁶ and 10⁷ conidia/ml conidial suspensions by spraying method. For the bioassay at the egg stage, JEF-158 showed a significantly higher ovicidal effect than JEF-484. In the larval bioassay, both EPF isolates showed a dosage-dependent effect on the RPW larvae. JEF-484 caused higher mortality in RPW larvae than JEF-158. In summary, the combination of the 2 promising EPF isolates might provide an opportunity for the practical microbial control of RPW at different life stages in palm tree fields.     

Ovicidal effects of entomopathogenic fungal isolates on the invasive Fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

Maize is a major staple food for over 300 million people in sub‐Saharan Africa. Sustainable productivity of this primary crop has been recently threatened by Fall armyworm (FAW), Spodoptera frugiperda invasion. Due to lack of environmentally safe management strategies, immediate responses by growers and governments to tackle FAW are based on rampant use of pesticides. Looking for efficient biopesticides, twenty entomopathogenic fungal isolates (14 Metarhizium anisopliae and 6 Beauveria bassiana) were screened for their efficacy against eggs and second instar larvae of FAW. A single discriminating concentration of 1 × 10⁸ conidia ml^?1 and four replicates per treatment were used in all experiments. Isolates were assessed for their ability to cause mortality of FAW second instar larvae, eggs and the neonate larvae that emerged from treated eggs. Among the isolates tested, only B. bassiana ICIPE 676 caused moderate mortality of 30% to second instar larvae. Metarhizium anisopliae ICIPE 78, ICIPE 40 and ICIPE 20 caused egg mortalities of 87.0%, 83.0% and 79.5%, respectively, and M. anisopliae ICIPE 41 and ICIPE 7 outperformed all the others by causing 96.5% and 93.7% mortality to the neonate larvae, respectively. The cumulated mortality of eggs and neonates was highest with M. anisopliae ICIPE 41 (97.5%), followed by M. anisopliae ICIPE 7, 655, 40, 20 and 78 with total mortality of 96.0%, 95.0%, 93.5%, 93.0% and 92.0%, respectively. These isolates with high cumulated mortality (≥92%), especially ICIPE 78 and 7, which are already commercialized for spider mites and ticks control respectively, would be good candidates for development as biopesticides for management of FAW in Africa if further evidence of their efficacy is obtained in the field.     

Significant mortality of eggs and young larvae of two pine processionary moth species due to the entomopathogenic fungus Metarhizium brunneum

Bioassays were conducted to determine the susceptibility of egg masses and young larvae of two pine processionary moth species, Thaumetopoea pityocampa and Thaumetopoea wilkinsoni, to two strains (ARSEF4556, V275) of the entomopathogenic fungus Metarhizium brunneum. Mortality of treated eggs by both strains ranged from 96% to 99% but not all of this was caused by M. brunneum since control groups also experienced egg mortality due to saprophytic fungi. Still, larvae hatched in the laboratory from eggs treated with M. brunneum were all killed by this fungus, acquiring M. brunneum conidia, whereas larval mortality was 0% in the control groups. Young larvae of both pine processionary moth species were also highly susceptible to ARSEF4556 and V275 with larval mortality ranging between 94% and 100%, 8 days post-inoculation, with the vast majority of larvae being killed within the first 2–4 days. Larval mortality was dose dependent. Results were consistent across the two pine processionary moth species, showing that the pathogenicity of M. brunneum to both eggs and young larvae might be promising for biological control of these insect pests. The study also showed that non-target parasitoids of pine processionary moth eggs were also susceptible to M. brunneum. Further work is required to understand and reduce the M. brunneum effect on non-target insects.     

Oviposition,larval survival and leaf damage by the willow leaf blotch miner,Micrurapteryx salicifoliella,in relation to leaf trichomes across 10 Salix species

1. Foliar trichomes clearly reduce chewing damage and efficiency of movement by some insect herbivores, but the effect of trichomes on insect oviposition is less well characterised. Trichomes are likely to have particularly strong, negative effects on species that require secure attachment of the egg to the leaf epidermis for successful transition to the feeding stage – a group that includes many leaf mining insects. 2. One such species, Micrurapteryx salicifoliella, must initially enter leaf cells directly from an egg adhered to the cuticle, but later instars can move between leaves and initiate new mines from the leaf exterior. 3. Natural patterns of occurrence by M. salicifoliella were quantified on 10 sympatric Salix species varying in trichome expression to test whether trichomes were associated with reduced oviposition, larval survival and leaf damage. 4. Mean egg density and leaf mining damage were negatively related to mean trichome density across Salix species. Survival of M. salicifoliella from egg to pupa was positively related to trichome density, suggesting that initiation of new mines by late‐instar larvae was not adversely affected by trichomes. There was no evidence that trichomes benefited leaf miner larvae indirectly by decreasing density‐dependent mortality; rather, the positive relationship between trichome density and larval survival may reflect less effective chemical defence by Salix species expressing high trichome density. 5. The results suggest that foliar trichomes serve as an effective defence against M. salicifoliella by deterring oviposition, but do not reduce the survivorship of those individuals that successfully transition from egg to larva.     

Laboratory and field evaluations of the susceptibility of immature Choristoneura rosaceana (Lepidoptera: Tortricidae) to Beauveria bassiana (Hypocreales: Cordycipitaceae)

Abstract

The susceptibility of immature Choristoneura rosaceana (Harris) to Beauveria bassiana-GHA (BotaniGard® 22WP) was evaluated under laboratory and field conditions. Although egg masses ≤24 h old were susceptible to infection by topically sprayed B. bassiana spores in the laboratory and resulting mycosis significantly reduced the percent of neonates able to emerge, no significant egg mass infections resulted from orchard treatment of ≤24–48 h eggs. Exposure to high levels of the B. bassiana product on apple leaf surfaces in the laboratory caused significant dose-related mortality in first to fourth instar C. rosaceana. First instar C. rosaceana were the most susceptible of the larval stages assayed in the laboratory although only 36% of neonates introduced into the orchard prior to Beauveria treatment and 27% of the neonates emerging from orchard treated egg masses became infected. Fourth instar mortalities were similar but moderate when treated with 1×10⁸ spores mL^?1 in the orchard and on leaf surfaces in the laboratory. Beauveria bassiana-induced larval mortalities were significantly higher when the spores were applied directly to the larval integument as opposed to the leaf surface where the insect would encounter the pathogen in a treated orchard. Feeding of C. rosaceana larvae on antibiotic containing meridic diet prior to their use in trials did not impact the susceptibility of the larvae to B. bassiana. Antibiotic containing meridic diet significantly reduced larval C. rosaceana mortality when treated larvae or the spores were placed directly on the diet as opposed to leaf tissue.     

金龟甲对蓖麻叶挥发物的触角电位和行为反应

为了探明金龟甲偏爱选择有害非寄主植物蓖麻的原因,应用触角电位（EAG）仪和“Y”型嗅觉仪,分别测定了华北大黑鳃金龟、暗黑鳃金龟和铜绿丽金龟雌、雄虫对5种蓖麻叶挥发物的触角电位和选择行为反应。EAG测定结果表明,3种金龟甲雄虫对各处理挥发物的EAG反应值均比参照挥发物顺-3-己烯-1-醇强。华北大黑鳃金龟对邻苯二甲酸二丁酯和肉桂醛的EAG反应值相对较高,暗黑鳃金龟对苯甲醇的EAG反应值相对较高,铜绿丽金龟对邻苯二甲酸二丁酯和苯甲醇的EAG反应值相对较高。选择行为反应测定结果表明,当顺-3-己烯-1-醇与其他挥发物配对测试时,华北大黑鳃金龟对邻苯二甲酸二丁酯和肉桂醛2种蓖麻叶挥发物表现出明显的选择偏好,暗黑鳃金龟对蓖麻叶挥发物苯甲醇表现出明显的选择偏好,铜绿丽金龟则更偏好选择蓖麻的绿叶气味物质顺-3-己烯-1-醇。总之,蓖麻叶的挥发性物质与引诱金龟甲偏爱选择密切相关,且偏爱的挥发物因金龟甲的种类而异。     

Virulence of Metarhizium anisopliae and Beauveria bassiana isolates and the effects of fungal infection on the reproduction potential of Rhiphicephalus microplus engorged females

The aim of the study was to assess the virulence of five Metarhizium anisopliae (Ma) and three of Beauveria bassiana (Bb) isolates, and the effect of the fungal infection to the reproduction of engorged females from two colonies of Rhiphicephalus microplus; one colony was collected from naturally infested cattle (Native) and the other one from a laboratory colony (Media Joya). Virulence was evaluated using the immersion technique at a concentration of 1?×?10⁸ conidia/ml; control groups received a water suspension with Tween 80 (0.1%). The Reproductive Efficiency Index ‘REI’ (eggs laid/engorged female weight) and the Reproductive Aptitude Index ‘RAI’ (eggs hatched as larvae/engorged female weight) were calculated for both groups. This experiment shows that two entomopathogenic fungal isolates, Bb115 and Ma136, caused high mortality from 5 days post-treatment (PT), reaching mortality rates of 99–100% at 15 days PT in both R. microplus colonies. The Bb115 isolate caused 98 and 79% reduction in egg oviposition in the field and laboratory colonies, respectively, while the reduction in egg hatchability was 98 and 89% in the field and laboratories colonies, respectively. In the case of Ma136, the egg oviposition was reduced in 73% in the field colony and 64% in laboratory colony, while in the field and laboratory colonies, with a reduction in egg hatchability of 73% and 86%, respectively. These results indicate the potential of Bb115 and Ma136 isolates as possible biological control agents of R. microplus.     

Effect of tomato fruit cultivar and ripening stage on Bactrocera tryoni (Froggatt) egg and larval survival

In studies of frugivorous tephritids, determining when offspring (i.e. egg and three larval instars) mortality occurs within the fruit can greatly improve the mechanistic understanding of the fly/host interaction. Previous research has demonstrated that the Queensland fruit fly, Bactrocera tryoni, has differential offspring performance in two tomato cultivars Cherry and Roma, but when juvenile mortality was occurring was not determined. We examined B. tryoni egg and larval survival in three different ripening stages (immature-green (IG), colour-break (CB) and fully-ripe (FR)) of Cherry and Roma tomato cultivars through destructive fruit sampling at 72 and 120 hr for eggs, and 48 (1st instar), 96 (2nd instar) and 120 hr (3rd instar) after fruit inoculation with neonates for larvae. Cultivar and ripening stage had no significant effect on egg survival, nor larval survival at 48 hr: the overall percentage of egg survival was at least 80% across all treatments, while 1st-instar larval was less than 52% across all treatments. In immature-green tomatoes of both varieties, nearly all mortality occurred during the first and second instars, but at 96 and 120 hr, there were significant interaction effects between cultivar and ripening stage on larval survival. In both colour-break Cherry and Roma tomatoes, there was significant larval mortality between 96 and 120 hr. However, in fully-ripe Cherry, no further significant larval mortality happened after 48 hr, while in fully-ripe Roma significant larval mortality occurred between the first and second larval instars but not thereafter. The difference in timing of larval mortality with ripening stage provides indirect evidence of active fruit defence which is strongest in immature-green fruit, less in colour-break fruit and absent in fully-ripe fruit.     

Preliminary life table of the spotted tortoise beetle,Aspidomorpha miliaris (Coleoptera: Chrysomelidae) in Sumatra

From December, 1981 to February, 1982, a population study of the spotted tortoise beetle, Aspidomorpha miliaris, feeding on a shrub-like morning glory, Ipomea carnea, was conducted in Padang, Sumatra with the construction of a life table.

1. Dissection of oothecae collected from the field after hatching clarified that the average egg mass size was 43.4 and hatching rate was 25.0%. Causes for egg mortality included: parasitism by a wasp, Tetrastichus sp. A(Europhidae) (49.8% of eggs laid), predation (12.8%), disappearance of egg masses (5.3%) and hatching failure (7.1%). An ant, Dolichoderus bituberculatus, visiting the extrafloral nectaries of the host plnts was responsible for predation and disappearance of the egg masses. The ants again attacked the larvae and pupae.
2. Larvae showed a gregarious habit for almost the entire larval period. Survival rates between two successive instars were low and constant, ranging from 70 to 90%, but only 1.3% of final (5th) instars become pupae (six individuals). Since the growth of host plants was extremely rapid, shortage of food was rare in larval stages. The sudden drop in numbers after 5th instar may be due to predation and/or dispersal of matured larvae from the host plants for pupation.
3. Pupae were attacked by three species of parasitic wasps:Tetrastichus sp. C, Pediobius elasmi (Eulophidae) and Cassidocida aspidomorphae (Tetracampidae). Among the six pupae, two were parasitized, one died of disease and two disappeared. Out of 4078 eggs laid, only one emerged to adult.

     

Survival of cabbage stem flea beetle larvae,Psylliodes chrysocephala,exposed to low temperatures

The cabbage stem flea beetle, Psylliodes chrysocephala (L.) (Coleoptera: Chrysomelidae), is a major pest of winter oilseed rape. The larvae live throughout winter in leaf petioles and stems. Winter temperatures might play an important role in survival during winter and hence population dynamics, yet to what degree is unknown. This study investigates the effect of exposure time, cold acclimation, and larval stage on survival at ?5 and ?10 °C. Exposure time at ?5 °C was 1, 2, 4, 8, 12, 16, and 20 days and 6, 12, 24, 36, 48, 72, 96, 120, and 144 h at ?10 °C. Mortality increased with increasing exposure time and was significantly lower for cold‐acclimated larvae. Estimated time until an expected mortality of 50% (LT₅₀) and 90% (LT₉₀) of larvae exposed to ?5 °C was 7.4 and 9.6 days (non‐acclimated) and 11.0 and 15.1 days (acclimated), respectively. Estimated LT₅₀ for non‐acclimated and acclimated larvae exposed to ?10 °C was 32.6 and 70.5 h, respectively, and estimated LT₉₀ 66.8 and 132.2 h. Significant differences in mortality between larval stages were observed only at ?5 °C. When exposed to ?5 °C for 8 days, mortality of first and second instars was 81.2 and 51.3%, respectively. When exposed to ?10 °C for 2 days, mortality of first and second instars was 70.5 and 76.1%. Data on winter temperatures in Denmark from 1990 to 2013 showed that larvae were rarely exposed to a number of continuous days at ?5 or ?10 °C causing a potential larval mortality of 50–90%.     

Behavioral Response to Larval Tracks and the Influence of Tracks on Intraguild Scavenging by Coccinellid Larvae

A paired design was used to determine that Harmonia axyridis 4th instars were not influenced by the presence of conspecific larval tracks, but well-fed H. axyridis 4th instars spent less time on plants that contained tracks left by Coleomegilla maculata 4th instars. To determine if the presence of larval tracks influences intraguild scavenging by H. axyridis 4th instars, dead 4th instars were placed in Petri dishes that contained or did not contain larval tracks. The presence of larval tracks did not influence the feeding frequency or the amount of time before feeding. However, larvae dragged their pygopod on dish surfaces more frequently if the dish contained larval tracks. In addition, starved H. axyridis larvae were more likely to feed on the prey and dragged their pygopod less frequently than well-fed larvae.     

Pathogenicity of hyphomycetous fungi against <Emphasis Type="Italic">Cyclocephala signaticollis</Emphasis>

Susceptibility of the white grub Cyclocephala signaticollis Burmeister (Coleoptera: Scarabaeidae: Dynastinae) larvae to seven isolates of Beauveria bassiana (Balsamo) Vuillemin, five of Metarhizium anisopliae (Metschnikoff) Sorokin and two of Paecilomyces lilacinus (Thom) Samson (Deuteromycotina: Hyphomycetes) was investigated. Among 14 fungal isolates screened the most virulent was a B. bassiana isolate (Bb 53) that caused 70% mortality of third instar larvae in 40 days after inoculation at 1 × 10⁸ conida/ml. Strains of M. anisopliae and P. lilacinus showed low efficacy or no virulence to the target host.     

Microplitis croceipes teratocytes cause developmental arrest of Heliothis virescens larvae

Microplitis croceipes teratocytes placed into nonparasitized Heliothis virescens larvae survived in the absence of a parasitoid larva and caused developmental changes in the host. Expressions of these changes included delayed larval mortality, incomplete larval-pupal ecdysis, or delayed pupation. Two day old 4th stadium H. virescens larvae were more sensitive to injected teratocytes than were 5th stadium larvae. Three day old teratocytes were more effective than were 6 day old teratocytes. The degree of response was related to the number of injected teratocytes. For example, 750 three day old teratocytes (the approximate number from a single parasitoid egg) caused delayed larval mortality in 96% of the treated larvae whereas 175 three day old teratocytes caused delayed larval mortality in only 33% of the treated larvae. Even a dose of 80 teratocytes resulted in 15% incomplete larval-pupal ecdysis compared to 0% for controls. Treatment with hemocyte-and teratocyte-free hemolymph from parasitized larvae, hemocytes from nonparasitized H. virescens, unfertilized M. croceipes eggs, Cotesia congregata teratocytes, or Micrococcus lysodeikticus cells all had very little effect either on larval growth or development time.     

Virulence of entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae against red palm weevil,Rhynchophorus ferrugineus (Olivier)

Nineteen different isolates of the entomopathogenic fungi Beauveria bassiana sensu lato (s.l.) and Metarhizium anisopliae s.l. (Ascomycota: Hypocreales), recovered from different soil samples (field crops, fruit orchards, vegetable fields and forests) and insect cadavers were tested against Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) at two different spore concentrations (1 × 10⁷ and 1 × 10⁸ conidia mL^?1). Three isolates of B. bassiana and two of M. anisopliae gave >88 % larval and >75 % adult mortality of R. ferrugineus on their highest dose rate respectively. More sporulating cadavers (mycosis) resulted from a high dose rate compared to low dose on both life stages of R. ferrugineus. The current study confirmed the lethal action of B. bassiana and M. anisopliae isolates with mortality levels usually directly proportional to the conidial concentration. This study further confirmed that the isolates recovered from R. ferrugineus dead cadavers gave more mortality compared to the other sources. In the virulence assay two isolates of B. bassiana caused the highest percentage of both larval and adult mortality at all exposure intervals which suggest that they may be the most promising for use in sustainable management programs aimed at microbial control in date palm orchards.     

Seasonal phenology and stage-specific parasitism of the apple ermine moth, Yponomeuta malinellus Zeller, in Korea

The apple ermine moth, Yponomeuta malinellus Zeller (Lepidoptera: Yponomeutidae), is a tent caterpillar that feeds on Malus spp. in Korea. Populations of the moth in native areas appeared to be regulated by the assemblage of parasitoids. Phenological associations between host stages and parasitoids, susceptible stage(s) of the host for each parasitoid, and stage‐specific parasitism were studied. The egg larval parasitoid Ageniaspis fuscicollis (Dalman) had highest parasitism of first instar larvae (24%), with 14% parasitism of other larval stages. Dolichogenidea delecta (Haliday) was recovered from all larval instars with the highest parasitism rate of second instar larvae (20.1%), followed by 19.9% parasitism of mid‐larval hosts. Herpestomus brunicornis Gravenhorst was reared from second instar larvae through to pupal collection, and had the highest parasitism rate (29.9%) at the pupal stage. The larval pupal parasitoid Zenillia dolosa (Meigen) was recovered from mid‐larval to pupal stages with the highest parasitism rate (5.5%) occurring in third to fourth instar larvae. The host stages for developing A. fuscicollis completely overlap with those of D. delecta, and with those of H. brunicornis to some degree. A statistically significant negative correlation exists between A. fuscicollis and these dominant parasitoids, indicating competitive interaction within the host.     

Effects of the IGRs compounds,lufenuron and fenoxycarb on Leptinotarsa decemlineata (Say) (Col.: Chrysomelidae)

In this research work, the susceptibility of egg and four larval instars of Leptinotarsa decemlineata (Say) (Col.: Chrysomelidae) to Insect Growth Regulators (IGRs) compounds (lufenuron 25% EC and fenoxycarb 25% WP) was determined. Different larval instar groups were separated by measuring the head capsule width and were used in all bioassays. The data were analysed with log-probit transformation using the SPSS software. The LC₅₀ for egg was determined by dipping egg masses in different concentration of either compound for 10 s, and LC₅₀ values for each group of larvae was estimated by using treated potato plants. The LC₅₀ values of lufenuron on egg, first, second and third instars of larvae were 682.65, 40.58, 47.83 and 261.38 ppm, respectively, and for fenoxycarb, these were estimated as 897.50, 35.60, 57.91 and 355.23 ppm, respectively. The LD₅₀ values of lufenuron and fenoxycarb on second instar larvae were 139.56 and 228.42 ppm, respectively.     

The efficacy of high and low volume spray applications of Mimic® (tebufenozide) for managing autumn gum moth larvae Mnesampela privata (Lepidoptera: Geometridae) in eucalypt plantations

Abstract 1 The autumn gum moth Mnesampela privata (Guenée) (Lepidoptera: Geometridae, Ennominae) is a native moth that can outbreak, resulting in significant defoliation of plantation eucalypts in southern Australia. 2 Laboratory trials tested M. privata larvae for their dose–response to the ecdysone agonist, Mimic® 700 WP (a.i. 700 g/kg tebufenozide); ground and aerial field trials also tested its efficacy in eucalypt plantations. 3 The laboratory trials showed that there was no significant difference in mortality between larvae treated with 172 g Mimic® (120 g a.i)/ha and those sprayed with doses ranging from 86 to 3340 g Mimic®/ha. 4 Laboratory and field trials demonstrated that second instars were the most susceptible, with the most rapid response. However, second to fourth instars all reached 100% and fifth instars 90% mortality 3 weeks after aerial spraying at 120 g a.i./ha. 5 Aerial spraying an Eucalyptus globulus plantation with 120 g a.i. Mimic® at 20 L/ha caused 95% mortality of instars two to five, and 100% for instars two to four within 3 weeks after spraying. 6 Ground spraying to run‐off with 120 g a.i. Mimic®/ha reduced defoliation of E. grandis from between 67% to 80% for unsprayed trees to 0% defoliation for sprayed trees. 7 The window for effective management of M. privata larvae is 3–5 weeks, during first to third instar development. 8 Replacement of broad‐spectrum insecticides with the more target‐specific Mimic® should increase the biodiversity of plantations and therefore would be more environmentally friendly.