Insect Growth Regulator Diflubenzuron Research Articles

Efficacy Evaluation of Oregano Essential Oil Mixed with Bacillus thuringiensis israelensis and Diflubenzuron against Culex pipiens and Aedes albopictus in Road Drains of Italy.

Mosquito management programs in the urban environment of Italian cities mainly rely on larval control with conventional insecticides, primarily targeting the road drains that constitute the principal mosquito breeding sites encountered in public. The repeated utilization of synthetic insecticides may have adverse effects on non-targets and lead to resistance development issues, while the performance of biopesticides encounters limitations in field use. Botanical insecticides as single larval control agents or in binary mixtures with conventional insecticides have been extensively studied in the laboratory as an effective and eco-friendly alternative mosquito control method with promising results. The study herein concerns the investigation, for the first time under realistic conditions in the field, of the joint action of a carvacrol-rich oregano Essential Oil (EO) with two conventional insecticides, namely, the insect growth regulator diflubenzuron and the bio-insecticide Bacillus thuringiensis israelensis (B.t.i.), in road drains in Crevalcore city, Italy, against Culex pipiens and Aedes albopictus. According to the obtained results, the application of both plain EO and its mixtures with diflubenzuron and B.t.i. exerted very high efficacy in terms of immature mosquito population reduction over a two-week period. Three weeks after treatment, the performance of the oil and its mixtures diminished but remained high, while the addition of diflubenzuron potentiated the persistent action of the oil against Cx. pipiens. These findings are indicative of the potential of mixing carvacrol-rich EO with diflubenzuron and B.t.i. as an efficient eco-friendly alternative to mono-insecticide applications in road drains against Cx. pipiens and Ae. albopictus larvae.

Impact of Diflubenzuron on Bombus impatiens (Hymenoptera: Apidae) Microcolony Development.

Reliance on the honey bee as a surrogate organism for risk assessment performed on other bees is widely challenged due to differences in phenology, life history, and sensitivity to pesticides between bee species. Consequently, there is a need to develop validated methods for assessing toxicity in non-Apis bees including bumble bees. The usefulness of small-scale, queenless colonies, termed microcolonies, has not been fully investigated for hazard assessment. Using the insect growth regulator diflubenzuron as a reference toxicant, we monitored microcolony development from egg laying to drone emergence using the Eastern bumble bee Bombus impatiens (C.), a non-Apis species native to North America. Microcolonies were monitored following dietary exposure to diflubenzuron (nominal concentrations: 0.1, 1, 10, 100, and 1,000 µg/liter). Microcolony syrup and pollen consumption was significantly reduced by diflubenzuron exposure. Pupal cell production was also significantly decreased at the highest diflubenzuron concentration assessed. Ultimately, diflubenzuron inhibited drone production in a concentration-dependent manner and a 42-d 50% inhibitory concentration (IC50) was determined. None of the dietary concentrations of diflubenzuron tested affected adult worker survival, or average drone weight. These data strengthen the foundation for use of this methodology, and provide valuable information for B. impatiens; however, more work is required to better understand the utility of the bumble bee microcolony model for pesticide hazard assessment.

Effect of the combined application of microencapsulated synthetic oviposition pheromone (MSP) with different larvicidal agents on the oviposition of Culex pipiens biotype molestus.

Attract-and-kill strategies, in which a behavior-modifying stimulus (e.g. a pheromone) is integrated with a pest control agent, have lately attracted increased interest for mosquito control. Previously, it was demonstrated that the polyurea microencapsulated synthetic oviposition pheromone 6-acetoxy-5-hexadecanolide (MSP) was sufficiently attractive to gravid females of Culex pipiens L. biotype molestus Førskal (Diptera: Culicidae) for a period of 40 days. Furthermore, it was shown that MSP could be effectively combined with the organophosphate temephos to achieve efficient mosquito control. In the present study, the effect of the combined application of MSP with commonly used larvicides on the oviposition response of Cx. p. biotype molestus females over time was investigated in two-choice oviposition bioassays. As larvicides, the insect growth regulator diflubenzuron and the bacterial insecticide spinosad were evaluated at their lowest recommended label dose, whereas temephos was used as a control. When MSP was applied in combination with diflubenzuron, the attractancy of MSP to gravid females was in all cases negatively affected, as fewer egg rafts were laid in pots treated with MSP and diflubenzuron compared with MSP alone. Spinosad did not reduce, but rather increased, the attractive effect of the oviposition pheromone at the beginning of the bioassay (at 2 days of ageing) when co-applied; however, the observed attractive effect was significantly reduced after 7 days of ageing and remained stable at the same level until the termination of the bioassay. Finally, the oviposition pattern of egg rafts laid on the pot with MSP and temephos was similar to that of egg rafts laid on the pot with MSP alone, showing that temephos did not significantly affect MSP activity. The results of the present study highlight the effects of the combined application of MSP with spinosad and diflubenzuron on the oviposition of gravid Cx. p. biotype molestus females, which in most cases eliminated the attractive effect of MSP. © 2017 Society of Chemical Industry.

Joint action of Beauveria bassiana and the insect growth regulators diflubenzuron and novaluron, on the migratory locust, Locusta migratoria

Beauveria bassiana (Balsamo) Vuillemin and sublethal concentrations of the insect growth regulators (IGR) diflubenzuron and novaluron were applied simultaneously and sequentially to second-instar Locusta migratoria migratorioides (Sauss.) to determine the interaction between these materials and an entomopathogenic fungus. Nymphs were fed on corn leaf disks treated with several concentrations of each IGR, and a constant dose of B. bassiana was applied topically. Additive interaction was demonstrated in all instances when second-instar nymphs were exposed to diflubenzuron or novaluron simultaneously with B. bassiana treatment, and when the fungus was applied first and IGR after 48 h. Additive interaction was also exhibited when novaluron was applied first and B. bassiana after 48 h. Antagonism was demonstrated when nymphs were fed diflubenzuron-treated corn leaves first, then after 48 h were treated with B. bassiana. The additive interaction that was observed in our experiments could still be useful to achieve efficacious levels of acridid control at low rates of an IGR along with a biological control agent such as an entomopathogenic fungus.

Factors Influencing the Incidence of Mango Leaf Webber, <i>Orthaga euadrusalis</i> Hampson, (Pyralidae:Lepidoptera) in Mango and Their Management

Screening, seasonal activity and management studies of mango leaf webber, Orthaga euadrusalis Hampson, (Pyralidae : lepidoptera) carried out at Fruit Research Station (FRS), Entkhedi, The least susceptible varieties were Chinnarasm, Piddarasm, Bombaygreen, Malda, Sindhuri and Alphanjo. While the most susceptible varieties were Mango Glass, Dahiyar, Temuria and Langrah. Significantly higher infestation was recorded in varieties had higher and dense tree canopy (r value = 0.838). Pest remained active in mango orchard from June to December and completed different over lapping generations during this period.Mechanical removal in early part of the season spot treatment with Imidacloprid (0.02%) and application of insect growth regulator Diflubenzuron were found effective and most feasible for the management of mango leaf webber.

The Use of the First Order System Transfer Function in the Analysis of Proboscis Extension Learning of Honey Bees, Apis mellifera L., Exposed to Pesticides

No attempts have been made to apply a mathematical model to the learning curve in honey bees exposed to pesticides. We applied a standard transfer function in the form Y=B3*exp(-B2*(X-1))+B4*(1-exp(-B2*(X-1))), where X is the trial number; Y is proportion of correct responses, B2 is the learning rate, B3 is readiness to learn and B4 is ability to learn. Reanalyzing previously published data on the effect of insect growth regulators tebufenozide and diflubenzuron on the classical conditioning of proboscis extension, the model revealed additional effects not detected with standard statistical tests of significance.

Evaluation of organic, synthetic and physical insecticides for the control of horse chestnut leaf miner (Cameraria ohridella)

Two separate trials during 2007 and 2008 were conducted using containerized white flowering horse chestnut trees (Aesculus hippocastanum L.) to assess the efficacy of a range of insecticides applied at three different times during a growing season against the insect pest, horse chestnut leaf miner (Cameraria ohridella Deschka and Dimic; HCLM). Insecticides were timed to coincide with the emergence of the adult moth, the target organism. A conventional synthetic insecticide (deltamethrin) used within the UK for HCLM control was included for comparison. A marked impact of insecticide type and frequency of application on HCLM severity was recorded. The effectiveness of each insecticide on mean number of HCLM mines per leaf and percent HCLM larvae/pupae mortality increased when applied at increasing frequencies, i.e. three sprays provided a higher degree of control than two sprays while two sprays provided a higher degree of control than one spray. Limited efficacy as HCLM protectant compounds was demonstrated when the insecticides pyrethrum and soap were applied, irrespective of number of applications. The synthetic insecticide deltamethrin and insect growth regulator diflubenzuron provided the greatest degree of HCLM control. In some instances two foliar sprays provided 100% HCLM control. Efficacy of remaining insecticides based on reduction of HCLM mines per leaf after three sprays averaged across both the 2007 and 2008 trials was in the order silicon dioxide>alginate/polysaccharide combination>organic plant extract>spray oil. Results show commercially registered insecticides exist that provide growing season control of HCLM provided two sprays are applied.

Genomic and proteomic studies on the effects of the insect growth regulator diflubenzuron in the model beetle species Tribolium castaneum

Several benzoylphenyl urea-derived insecticides such as diflubenzuron (DFB, Dimilin®) are in wide use to control various insect pests. Although this class of compounds is known to disrupt molting and to affect chitin content, their precise mode of action is still not understood. To gain a broader insight into the mechanism underlying the insecticidal effects of benzoylphenyl urea compounds, we conducted a comprehensive study with the model beetle species and stored product pest Tribolium castaneum (red flour beetle) utilizing genomic and proteomic approaches. DFB was added to a wheat flour-based diet at various concentrations and fed to larvae and adults. We observed abortive molting, hatching defects and reduced chitin amounts in the larval cuticle, the peritrophic matrix and eggs. Electron microscopic examination of the larval cuticle revealed major structural changes and a loss of lamellate structure of the procuticle. We used a genomic tiling array for determining relative expression levels of about 11,000 genes predicted by the GLEAN algorithm. About 6% of all predicted genes were more than 2-fold up- or down-regulated in response to DFB treatment. Genes encoding enzymes involved in chitin metabolism were unexpectedly unaffected, but many genes encoding cuticle proteins were affected. In addition, several genes presumably involved in detoxification pathways were up-regulated. Comparative 2D gel electrophoresis of proteins extracted from the midgut revealed 388 protein spots, of which 7% were significantly affected in their levels by DFB treatment as determined by laser densitometry. Mass spectrometric identification revealed that UDP-N-acetylglucosamine pyrophosphorylase and glutathione synthetase were up-regulated. In summary, the red flour beetle turned out to be a good model organism for investigating the global effects of bioactive materials such as insect growth regulators and other insecticides. The results of this study recapitulate all of the different DFB-induced symptoms in a single model insect, which have been previously found in several different insect species, and further illustrate that DFB treatment causes a wide range of effects at the molecular level.

THE INFLUENCE OF DIFLUBENZURON TRUNK AND SCAFFOLD LIMB SPRAYS ON CONTROLLING HORSE CHESTNUT LEAF MINER (CAMERARIA OHRIDELLA)

Summary The aim of this study was to determine the usefulness of trunk and scaffold limb sprays of the insect growth regulator diflubenzuron on reducing horse chestnut leaf miner (HCLM) severity on the white flowering horse chestnut tree Aesculus hippocastanum L. One bark and scaffold limb spray applied to coincide with the emergence of the first adult moth generation reduced leaf mining severity and increased larvae/pupae mortality at week 4 after treatment, but this effect faded by the end of the growing season. Two and three repeat bark and scaffold limb diflubenzuron sprays significantly reduced leaf mining severity and increased larvae/pupae mortality rates at the end of the growing season compared to non-diflubenzuron treated controls but did not significantly differ between themselves indicating little beneficial influence of a third diflubenzuron spray. There was no significant influence of diflubenzuron sprays applied in 2007 on leaf mine number and larvae pupae survival the following year (September 2008). This suggests that the treatment would have to be re-applied on an annual basis. Consequently, the cost benefit of such trunk and scaffold limb treatments needs to be carefully considered, especially as systemic insecticides exist that provide longer term control with less frequency of application.

Effects of sublethal concentrations of diflubenzuron and methoprene on Aedes aegypti (Diptera: Culicidae) fitness

The effects of sublethal concentrations of the insect growth regulators (IGRs) diflubenzuron and methoprene on some fitness components of an Aedes aegypti (L.) population in south-eastern Brazil were investigated. The fourth instar larvae of the mosquito were exposed to 20 ppb methoprene and 3 ppb diflubenzuron, and adult survivors were evaluated for fitness parameters, including body size and biomass, fecundity, fertility, longevity and symmetry. The sublethal concentrations had negative effects on longevity, but biomass, fecundity and fertility were not affected by either IGR. In separate experiments, A. aegypti individuals' surviving concentrations of 2, 3 and 3.5 ppb diflubenzuron and 5, 10 and 20 ppb methoprene were used for morphological analyses (size and symmetry). Diflubenzuron had negative effects on the mosquito's body symmetry. The observed decreases in longevity and symmetry may have negative impacts on the population dynamics of A. aegypti.

Susceptibility of Aedes aegypti (L) to the insect growth regulators diflubenzuron and methoprene in Uberlândia, State of Minas Gerais

Aedes aegypti (L) (Diptera: Culicidae) was reared in several concentrations of diflubenzuron and methoprene under laboratory conditions in Uberlândia, State of Minas Gerais, southeastern Brazil. Characteristics such as LC50 and LC95, the susceptibility of immature stages of different ages to these insect growth regulators and their residual effects were studied. The LC50 and LC95 of diflubenzuron and methoprene were 5.19 and 12.24 ppb; 19.95 and 72.08 ppb, respectively. While diflubenzuron caused great mortality in all larval instars, methoprene was more effective when the mosquito was exposed from the start of the fourth larval instar onwards. Commercial concentrations of these two insect growth regulators close to LC95 presented greater residual activity than did their respective technical formulations. The parameters were compared with those obtained elsewhere. The characteristics investigated here indicate that these insect growth regulators are effective alternatives for controlling the dengue vector in the Uberlândia region.

Insecticide Resistance in Potential Vector Mosquitoes for West Nile Virus in Japan

Culex pipiens complex is the significant vector mosquito of West Nile virus. To take stock of the current situation of insecticide susceptibilities and design an ideal mosquito control strategy, we collected Culex pipiens pallens Coquillet, Culex pipiens form molestus Forskal, and Culex quinquefasciatus Say from fields in Japan and conducted bioassays for five larvicides (fenitrothion, temephos, etofenprox, diflubenzuron, and pyriproxyfen) by using a larval dipping method. Among five insecticides tested, obvious reduced susceptibilities were observed for etofenprox, which is the only pyrethroid compound registered as a larvicide in Japan. Twenty-two of 56 colonies exhibited a >10% survival rate at the etofenprox concentration of 5.7 microg/ml, which is a 10 times higher concentration of the working solution. The LC50 of a colony collected from Fukuoka prefecture for etofenprox exceeded 60 microg/ml (resistance ratio >2,307), and this colony also exhibited cross-resistance to other pyrethroids, permethrin (299-fold) and phenothrin (1,200-fold). The insect growth regulators diflubenzuron and pyriproxyfen were found to be sufficiently effective enough to control Culex larvae present, but decreased sensitivities to these insecticides were slightly detected in some colonies of Cx. p. form molestus collected from urban areas. Several etofenprox-resistant colonies of Cx. p. form molestus exhibited simultaneously decreased susceptibilities to other insecticides, including temephos, diflubenzuron, and pyriproxyfen.

A selective 19F NMR spectroscopic method for determination of insecticide diflubenzuron in different media

A selective and rapid 19F NMR spectroscopic analytical procedure for insect growth regulator diflubenzuron, a phenylurea insecticide, has been developed. Optimal NMR sensitivity based upon T 1 relaxation time was investigated for diflubenzuron and 4-fluorobenzoic acid as internal standard in dimethyl sulphoxide. The method was validated through spike and recovery for diflubenzuron from apple juice and its commercial sample (Dimilin) without any interference, separation steps and lengthy instrument time. The calibration curve was linear for diflubenzuron over the range of 25–1000 μg/ml, with detection limit (S/N = 3) of 6 μg/ml. The within- and between-day repeatability coefficients of variation were lower than 6 ( n = 3) and 7 ( n = 5), respectively. Recovery of diflubenzuron from spiked apple juice samples at two fortification levels were 96% and 92% with relative standard deviation of <10% ( n = 3).

Residues of diflubenzuron on horse chestnut (Aesculus hippocastanum) leaves and their efficacy against the horse chestnut leafminer, Cameraria ohridella

Residues of the insect growth regulator diflubenzuron were quantified on horse chestnut (Aesculus hippocastanum L.) leaves treated with a diflubenzuron 480 g litre(-1) SC, Dimilin. To analyse the samples, an analytical procedure was developed involving a simple extraction step followed by high-performance liquid chromatography on an octadecyl-modified silica column with methanol + 0.01 M ammonium acetate mobile phase. The results showed diflubenzuron to be highly stable on horse chestnut leaves; more than 4 months (127 days) after application, 38% (on average) of the insecticide still remained on/in the leaves. The data confirmed biological observations showing diflubenzuron's long-term efficacy against the horse chestnut leafminer, Cameraria ohridella Deschka and Dimić, which is the most important pest of the horse chestnut in Europe. The hypothesis of possible penetration of diflubenzuron into the leaf mass is explored and discussed.

A literature review and new observations on the use of diflubenzuron for control of locusts and grasshoppers throughout the world

The insect growth regulator diflubenzuron (Dimilin®) is used to control locusts and grasshoppers on rangeland and croplands worldwide. Ingestion of diflubenzuron by immature insects results in disruption of chitin formation and deposition that affects the cuticle and the molting process. Symptoms of diflubenzuron intoxication include: death, physical abnormalities (such as loss of limbs), lethargy and cessation of feeding. Field trials with diflubenzuron on grasslands are reported in this paper and support previously published work showing it to be effective in broadcast treatments or alternating swaths and barriers. Affected insects were observed 3 d after application but maximum control of populations occurred by 14 d. Low grasshopper population counts the year after application suggested fewer eggs hatched from adults exposed to diflubenzuron. This bears out results of earlier laboratory and small-scale experiments. Diflubenzuron applications to rangeland did not seriously affect the populations of nontarget arthropods.

Spider fauna in apple ecosystem of western Oregon and its field susceptibility to chemical and microbial insecticides.

Twelve families, 26 genera, and 30 identifiable spider species were found in surveys conducted in apple orchards of western Oregon. The Salticidae, Linyphiidae, Clubionidae, Philodromidae, and Theridiidae comprised 85.56% ofthe total spiders collected. The most common species in order of abundance were Metaphidippus aeneolus Curtis, Spirembolus mundus Chamberlin & Ivie, Cheiracanthium inclusum (Hentz), Philodromus spectabilis Keyserling, Eris marginata (Walckenaer), and Theridion lawrencei Gertsch & Archer. Individuals of these species were collected in 50-60% of the samples and were most abundant in the month of August. The Bacillus thuringiensis-based insecticides, DiPel (100 Million International Units/100 liters) and MVP (250 ml/100 liters), summer oil (0.5-1.0 liter/100 liters), the insect growth regulator (IGR) diflubenzuron (3-12 g/100 liters), and organophosphate Phosmet (6-60 g/100 liters) were generally harmless (P > 0.05) to these spider species. Full field rates of organophosphate azinphosmethyl (25 g/100 liters) and carbamate carbaryl (60 g/100 liters) were slightly to moderately harmful (25-75% mortality). These insecticides at reduced rates (azinphosmethyl 2.5-5.0 g and carbaryl 12 g/100 liters) applied alone or in combination with DiPel and MVP, had a negligible effect. Full rates of pyrethroids esfenvalerate (2.5 g/100 liters) and permethrin (4.0 g/100 liters) were moderately to highly harmful (50-75% mortality) and their reduced rates (esfenvalerate 0.25-0.50 g and permethrin 0.4-0.8 g/100 liters) were selective to the spiders.

Utilization of diflubenzuron to controlgelechia senticetella (Stgr.) (Lepidoptera: Geiechiidae), a dangerous pest ofjuniperus excelsa M. B. (Cupressaceae) in Bulgaria

In 1992, experiments were carried out in Bulgaria to controlGelechia senticetella (Stgr.) (Lepidoptera: Geiechiidae), a mining pest on the needles and young shoots ofJuniperus excelsa M. B. by commercial products Dimilin ODC-45 and Dimilin WP-25 based on the insect growth regulator diflubenzuron. Two Ultra Low Volume (ULV) treatments were performed - on March 12th and April 16th, during the emerging of the pest larvae out of the infested shoots. Dimilin ODC-45 was applied in a dose of 60-120 ml/ha (27-54 g a.i./ha), dissolved in 5l of diesel oil, and Dimilin WP-25 - in a dose of 200 g/ha (50 g a.i./ha) dissolved in 5l of water. The effect of Dimilin ODC-45 was very high - 92.5-97.6 %. The effect of Dimilin WP-25 was unsatisfactory - 63.4-70.0 %, which was most probably due to the fact that the oil emulsions adhere to the treated plants better than the water solutions, thus ensuring a longer period of action.

Modelling pesticide residues on greasy wool: surveys of the insect growth regulators triflumuron and diflubenzuron

Surveys have examined the relationship between louse and flystrike treatments on farms and the resulting residues of insect growth regulators on greasy wool. These results have been summarised using a model of the on-farm survey data. The model estimated the amount of chemical taken up by the wool at application. This was based on experimental breakdown rates of these insecticides on wool determined in controlled trials. The data indicated that the backliner, triflumuron, when used off-shears within 24 h of shearing, was normally applied at slightly higher than the recommended rate on-farm and left an average residue of 30 mg/kg greasy wool at the following shearing 12 months later. Diflubenzuron, applied by dipping or jetting, was usually applied at lower than the recommended rates, and left an average residue of 40 mg/kg on the wool at shearing 12 months later. When treatment was applied to very short wool (&lt;3 weeks after shearing) the residue was only about 20 mg/kg, but when applied at later times after shearing the residue at the following shearing was not closely related to the time of treatment. The model can be used to estimate the expected residue level and likely range of results from most standard insect growth regulator treatments. This will improve advice to producers so most can meet specified industry standards.

La toxicité du diflubenzuron, pyriproxyfen, imidacloprid et diafenthiuron sur le prédateurOrius laevigatus (Fieber) (Heteroptera : Anthocoridae)

The susceptibility of the predatory bugOrius laevigatus (Fieber) to the insect growth regulators diflubenzuron, pyriproxyfen, the nitroguanidine insecticide imidacloprid and the thiourea compound diafenthiuron was investigated in the laboratory. Fifth-instar nymphs were exposed to formulated materials of each compound and adults were exposed to formulated materials of diafenthiuron and imidacloprid. In each case, exposure via ingestion and residual contact was tested. Pyriproxyfen was harmless toO. laevigatus nymphs by both ways of exposure. The respective LC50-values of diflubenzuron via ingestion and residual contact were 229.9 and 391.1 mg a.i./l. Diafenthiuron did not cause significant mortality to fifth-instar nymphs and adults via ingestion but was toxic by residual contact with LC50-values of 329.4 mg a.i./l and 125.9 mg a.i./l for nymphs and adults respectively. Imidacloprid proved to be the most toxic compound with LC50-values of 1.1 and 0.04 mg a.i./l for nymphs and 2.1 and 0.3 mg a.i./l for adults, via ingestion and residual contact, respectively. The results suggest that use of pyriproxyfen in an integrated pest management programme will not cause any problems but that imidacloprid, and to a lesser extent, also diflubenzuron and diafenthiuron could be harmful to the predator.

Virulence of the entomopathogenic fungus Metarhizium flavoviride Gams and Rozsypal and toxicity of diflubenzuron, fenitrothion-esfenvalerate and profenofos-cypermethrin to nontarget arthropods in Mauritania.

Within the framework of the GTZ project, Biological and Integrated Control of Locusts and Grasshoppers, a laboratory screening fo rMetarhizium flavoviride (strain Mfl 5) blastospore pathogenicity to the nontarget arthropods Pharoscymnus anchorago F. (Coleoptera:Coccinellidae), Trachyderma hispida (Forskâl) (Coleoptera:Tenebrionidae), Palpares cf. tesselatus Rambur (Neuroptera:Myrmeleontidae) and Thanatus sp. (Araneae: Philodromidae) was conducted in Akjoujt research station, Mauritania. Various larval stages of desert locust, Schistocerca gregaria Forskâl (Orthoptera:Acrididae), were tested as positive controls. The insect growth regulator diflubenzuron was used as a reference in the bioassay with P.anchorago. In addition, two organophosphate-pyrethroid insecticide swidely used in locust control, fenitrothion-esfenvalerate (P.anchorago, T. hispida) and profenofos-cypermethrin (Thanatussp.) were tested as toxic standards. M. flavoviride was not pathogenic to nontargets, but very virulent to S. gregaria. The results provided further evidence that the host range of M.flavoviride (Mfl5), a strain isolated from migratory locust in Madagascar, is very narrow. Diflubenzuron was toxic to P. anchorago and to S. gregaria. The LD50s of both chemical insecticides tested were considerably lower than the expected initial environmental concentration. The beneficial P. anchorago, a natural enemy of scale insects in date palms, was considered most at risk in the course of chemical locust control. The use of mycopesticides to control desert locust in date palm plantations offers an environmentally safe and economically viable alternative to chemical control.