Entomopathogenic Fungus Metarhizium Anisopliae Research Articles

Susceptibility of Atta sexdens rubropilosa (Forel) (Hymenoptera: Formicidae) to Metarhizium anisopliae (Metsch.) Sorokin in laboratory conditions

This study aimed to evaluate the pathogenicity of the entomopathogenic fungus Metarhizium anisopliae on leaf-cutting ants Atta sexdens rubropilosa, under laboratory conditions. It was inoculated suspensions containing different concentrations of conidia on specimens of soldiers and workers, kept under controlled conditions. The mortality was verified daily until 15 days after inoculation. The experimental delineation was entirely random. Sporulation data were submitted to variance analysis and the average of the treatments were compared to each other by the Scott-Knott test. Probit analysis was performed to obtain the values of LT50 (in days). All isolates were pathogenic to A. sexdens rubropilosa, being more virulent for workers than for soldiers. Isolates IBCB 348, IBCB 410 and IBCB 425 were the most efficient in the mortality of the ants. Isolates IBCB 425 and UFGD 03 caused high percentages of confirmed mortality. The results showed that the tested isolates have the potential for using them as control agents of A. sexdens rubropilosa.

Genetics and immunity of Anopheles response to the entomopathogenic fungus Metarhizium anisopliae overlap with immunity to Plasmodium

Entomopathogenic fungi have been explored as a potential biopesticide to counteract the insecticide resistance issue in mosquitoes. However, little is known about the possibility that genetic resistance to fungal biopesticides could evolve in mosquito populations. Here, we detected an important genetic component underlying Anopheles coluzzii survival after exposure to the entomopathogenic fungus Metarhizium anisopliae. A familiality study detected variation for survival among wild mosquito isofemale pedigrees, and genetic mapping identified two loci that significantly influence mosquito survival after fungus exposure. One locus overlaps with a previously reported locus for Anopheles susceptibility to the human malaria parasite Plasmodium falciparum. Candidate gene studies revealed that two LRR proteins encoded by APL1C and LRIM1 genes in this newly mapped locus are required for protection of female A. coluzzii from M. anisopliae, as is the complement-like factor Tep1. These results indicate that natural Anopheles populations already segregate frequent genetic variation for differential mosquito survival after fungal challenge and suggest a similarity in Anopheles protective responses against fungus and Plasmodium. However, this immune similarity raises the possibility that fungus-resistant mosquitoes could also display enhanced resistance to Plasmodium, suggesting an advantage of selecting for fungus resistance in vector populations to promote naturally diminished malaria vector competence.

Behavioural alterations in female Aedes aegypti mosquito in response to entomopathogenic fungal infections.

Due to the rapid rise in arboviral disease cases, there is a need for alternative methods of vector control since fast growing insecticides resistance is a matter of great concern. Recent studies have shown the potential of entomopathogenic fungi in controlling mosquito vectors, but behavioural responses of the mosquitoes encountering with entomopathogenic fungi are still unclear. In this study, behavioural responses induced by the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin in adult female Aedes aegypti mosquito were evaluated. The survival of female mosquitoes was significantly reduced after exposure to medium and high concentrations of fungal conidia. A significant increase in frequencies and durations of different self-grooming types was observed in mosquitoes exposed to medium or high concentrations of fungal conidia. Mosquitoes were able to differentiate between active and inactive fungal conidia as application of inactive conidia showed non-significant effect on survival and self-grooming parameters. A concentration-specific reduction in flight locomotor activity of the female mosquitoes was found after fungal treatments. Fungal-exposed mosquitoes showed significantly higher antifungal activity 72 h post-application. These findings provide greater understanding of behavioural responses of the mosquitoes to resist fungal infections and suggest that mosquitoes can remove the lower amounts of fungal conidia through self-grooming behaviour, which they encounter within natural field conditions.

Identification of entomopathogenic fungi Metarhizium anisopliae and Purpureocillium lilacinum from oil palm plantation soils in Universiti Putra Malaysia

Identification of entomopathogenic fungi Metarhizium anisopliae and Purpureocillium lilacinum from oil palm plantation soils in Universiti Putra Malaysia

In vitro Compatibility and Efficacy Studies of Entomopathogenic Fungi Metarhizium anisopliae (Metsh.) with Commonly used Biorational and Chemical Pesticides against Spodoptera litura (Fabricius)

In vitro compatibility of selected entomopathogenic fungi with botanicals and chemical insecticides at field recommended concentrations Indoxacarb 14.5 SC, Spinosad 45 SC, neem oil and NSKE were non-toxic to the test strain M.anisopliae (Ma-L-1) as they did not show significant reduction in radial growth. The insecticide dichlorvos 76 EC (DDVP) recorded 100 per cent reduction in radial growth of test strains at field recommended concentration. The joint action of microbial agents (bacteria, viruses and fungi) revealed that the combination of pathogens did not prove superior to individual effect. All the combination of entomopathogenic fungi M. anisopliae (Ma-L-1) strain with microbial agents were within the critical limits of additive effect and combination with insecticides viz., Spinosad 45 SC @0.009%, neem oil 5% and NSKE 5%, which produced the synergism reaction.

Compatibility between Chemical Insecticides and Metarhizium anisopliae var. acridum

The entomopathogenic fungus Metarhizium anisopliae var. acridum has been studied in different countries as mycoinsecticide against grasshoppers. One of the utilization strategies considered is the association between entomopathogenic fungi and sublethal dosages of chemical insecticides compatible with the biological control agent. The effect of different chemical insecticides at concentrations varying from 5 to 5000 ppm on the conidial germination and growth of the fungus M. anisopliae var. acridum (CG 423) was assessed for compatibility evalution. The best results with inhibitory concentration (IC50) on germination (liquid medium) and radial colonial growth (solid medium) of Metarhizium anisopliae var. acridum at 28°C was obtained with Teflubenzuron.

Lethal and sub-lethal toxicity of Verticillium lecanii on the biology of Mealybug (Pseudococcidae; Homoptera) under laboratory conditions

Abstract: The Mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae) is a polyphagous pest of Citrus, grapevine, coffee and ornamental plants. The entomopathogenic fungus Beauveria bassiana, Metarhizium anisopliae, Verticillium lecanii and Isaria fumosorosea are very effective and commonly used as a biopesticide against various insect pests of different crops. The present study was conducted to check the lethal and sub-lethal effects of V. lecanii on mortality and life period of adult mealybug. Firstly LC50 value for nymph and adult was calculated by applying four different concentrations 1×105 , 1×106 , 1×107 and 1×108 CFU/ml. For nymphs, the median lethal concentration was 5.57×106 CFU/ ml, and for adults, 2.66×107 CFU/ml. After this, two lethal, 3.99×107 and 2.66×107 CFU/ml, and two sub-lethal concentrations, 1.33×107 and 6.65×106 CFU/ml, was prepared and tested against adult mealybug. Dose-dependent mortality was observed, and the highest mortality was due to the highest concentration of V. lecanii. The percentage mortality was 72.23, 52.78, 27.78 and 19.45% due to 3.99×107 , 2.66×107 , 1.33×107 and 6.65×106 CFU/ml, respectively, after 10 days of application. The weight of adult females was highest in the control treatment while lowest in high concentration, and it was gradually decreased after every day in the first three concentrations. The fecundity of mealybug also had an inverse relation with concentrations of V. lecanii, and the numbers of eggs were more in the control treatment than the other four treatments. The fecundity in lethal concentrations was reduced after the 8 th day of application. The life duration was most extended due to control treatment, 27 days, while the lowest period was due to the highest concentration, 13 days. Keywords: Verticillium lecanii, mealybug, mortality, weight, fecundity, life duration

Lethal and sublethal effects of synthetic and bio-insecticides on Trichogramma brassicae parasitizing Tuta absoluta.

The tomato leaf miner (TLM), Tuta absoluta (Meyrick), is an invasive tomato pest found worldwide. Sustainable control strategies aimed at increasing biological control approaches and decreasing chemical inputs are required, due to the tendency to develop insecticide resistance. In this study, the lethal and sublethal effects of four chemical insecticides (abamectin, indoxacarb, chlorantraniliprole, and spinosad) and the sublethal effects of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) on a widespread TLM egg parasitoid, Trichogramma brassicae Bezdenko, were estimated. Concentration mortality response bioassays enabled the estimation of lethal concentrations of the tested insecticides for the parasitoids, with chlorantraniliprole having the lowest LC50 and indoxacarb the highest. The LC25 and LC50 of the tested insecticides on the TLM were sprayed on eggs and then offered at three time intervals to the parasitoids. The fertility and other life table parameters of the individuals emerging from the treated eggs were estimated. All of the chemical insecticides, but not the fungus, had harmful effects on T. brassicae. The insecticide applications caused a 3.84–5.17 times reduction in the net reproductive rate (R0) compared with the control. No parameters were affected by spraying the fungus in the 0h treatment, but effects were recorded at 24 and/or 48h, except for the gross reproduction rate (GRR). The value of the intrinsic rate of increase (rm) also decreased to 0.528–0.617 after the insecticide treatments. The doubling time (DT) increased in all treatments compared to the control. Nevertheless, the generation time (T) was only very slightly affected. In addition, in the combination experiments, M. anisopliae showed a remarkable synergism with T. brassicae in controlling TLM eggs. These results indicate that low levels of lethal effects on key biological control agents should be considered in the choice of insecticides to be included in sustainable TLM control packages.

Destruxin A Interacts with Aminoacyl tRNA Synthases in Bombyx mori.

Destruxin A (DA), a hexa-cyclodepsipeptidic mycotoxin produced by the entomopathogenic fungus Metarhizium anisopliae, exhibits insecticidal activities in a wide range of pests and is known as an innate immunity inhibitor. However, its mechanism of action requires further investigation. In this research, the interactions of DA with the six aminoacyl tRNA synthetases (ARSs) of Bombyx mori, BmAlaRS, BmCysRS, BmMetRS, BmValRS, BmIleRS, and BmGluProRS, were analyzed. The six ARSs were expressed and purified. The BLI (biolayer interferometry) results indicated that DA binds these ARSs with the affinity indices (KD) of 10−4 to 10−5 M. The molecular docking suggested a similar interaction mode of DA with ARSs, whereby DA settled into a pocket through hydrogen bonds with Asn, Arg, His, Lys, and Tyr of ARSs. Furthermore, DA treatments decreased the contents of soluble protein and free amino acids in Bm12 cells, which suggested that DA impedes protein synthesis. Lastly, the ARSs in Bm12 cells were all downregulated by DA stress. This study sheds light on exploring and answering the molecular target of DA against target insects.

The mortality of green planthoppers Nephotettix virescens (Homoptera: Cicadellidae) by Metarhizium anisopliae Metchn and Beauveria bassiana (Bals.) Vuill

The green planthopper Nephotettix virescens Distant (Homoptera: Cicadellidae) is one of the important pests of rice plants in South and Southeast Asia. N. virescens caused damages to rice plants by sucking rice fresh fluid and vector virus of tungro disease. The purpose of research is to determine the effectiveness of two types, entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana, in suppressing the population level of N. virescens on rice plants. The research activities were held at the Laboratory of Plant Pests and Diseases, Faculty of Agriculture, Hasanuddin University, Makassar, from September 2018 to June 2019. The research used a Factorial, Completely Randomized Design with eight treatments and five replications. Each treatment used ten individual nymphs of N. virescens. The research started from the collection and mass rearing of N. virescens, prepared the rice plants, cultured of M. anisopliae and B. bassiana, application of the entomopathogenic fungi M. anisopliae and B. bassiana. The application of M. anisopliae and B. bassiana on the green planthoppers nymph was showed the average mortality of N. virescens by spraying (89.6%), watering (89.6%), and dipping (89.6%) not significantly. However, the mortality was higher compared to the control (0.50%). Watering treatment used the solution of B. bassiana showed very high average mortality compared dipping used M. anisopliae. The application of M. anisopliae in the spraying and watering treatments showed the average mortality not significantly different compared to the spraying treatment used entomopathogenic B. bassiana.

Exploiting Thrips Aggregation Pheromones to Develop a Lure-and-Kill Strategy for the Management of the Bean Flower Thrips

The potential of semiochemicals to lure insect pests to a trap where they can be killed with biopesticides has been demonstrated as an eco-friendly pest management alternative. In this study, we tested two recently characterized male-produced aggregation pheromones of the bean flower thrips Megalurothrips sjostedti (Trybom), namely (R)-lavandulyl 3-methylbutanoate (major) and (R)-lavandulol (minor), for their field efficacy. Moreover, compatibility of these pheromones and two other thrips attractants, Lurem-TR and neryl (S)-2-methylbutanoate, with the entomopathogenic fungus (EPF) Metarhizium anisopliae ICIPE 69 has been determined. Our study revealed that the M. sjostedti aggregation pheromones have dose-dependent antifungal effects on the EPF viability, but showed no fungistatic effect at a field-realistic dose for attraction of thrips. (R)-lavandulyl 3-methylbutanoate had similar antifungal effects as neryl (S)-2-methylbutanoate 8 days after exposure; whereas, Lurem-TR had a stronger antifungal effect than other thrips attractants. In the semi-field experiments, all autoinoculation devices maintained at least 86% viability of M. anisopliae conidia after 12 days of exposure. Field trials demonstrated for the first time that (R)-lavandulyl 3-methylbutanoate increases trap catches. Our findings pave a way for designing a lure-and-kill thrips management strategy to control bean flower thrips using autoinoculation devices or spot spray application.

The Metarhizium anisopliae Toxin, Destruxin A, Interacts with the SEC23A and TEME214 Proteins of Bombyx mori.

Destruxin A (DA), a mycotoxin isolated from the entomopathogenic fungus Metarhizium anisopliae, has good insecticidal and immune-inhibitory activity, but the action mechanism has not yet been elucidated. In order to identify the DA-binding proteins, we conducted drug affinity responsive target stability (DARTS) experiments, which indicated that the silkworm’s (Bombyx mori) transmembrane protein 214 (BmTEME214) and protein transport protein SEC23A isoform X2 (BmSEC23) are the potential DA-binding proteins. The current research was focused on validation of the interaction between DA and these two proteins via bio-layer interferometry (BLI) in vitro, insect two-hybrid (I2H) in Sf9 cells, and RNAi in the insect. The results of the BLI tests showed that DA has strong affinity to bind BmTEME214 and BmSEC23 proteins with a KD value of 0.286 and 0.291 µM, respectively. In the I2H experiments, DA inhibited (at 0.02 µg/mL) and activated (at 0.002–0.0002 µg/mL) the protein interactions of BmSEC23–BmSEC13, but it only inhibited the BmTMEM214–BmSEC13L interaction. Furthermore, in the RNAi tests, an apparent increase in the silkworm’s mortality was recorded in the joint treatment of DA with dsBmSEC23 or dsBmTMEM214 when compared with the single treatment of DA (1.5 µg/g body), 40 µg/g body dsBmSEC23, or dsBmTMEM214. This research confirmed that BmSEC23 and BmTMEM214 are the DA-binding proteins and provided new insights to understand the action mechanism of DA.

Increasing Anthonomus grandis susceptibility to Metarhizium anisopliae through RNAi-induced AgraRelish knockdown: a perspective to combine biocontrol and biotechnology.

The hemolymph and insect gut together have an essential role in the immune defense against microorganisms, including the production of antimicrobial peptides (AMP). AMPs are mainly induced by two specific signaling pathways, Toll and immune deficiency (IMD). Here, we characterize the expression profile of four genes from both pathways and describe the importance of AgraRelish in the immune defense of Anthonomus grandis against the entomopathogenic fungus Metarhizium anisopliae by RNA interference (RNAi). To characterize the pathway that is activated early during the A. grandis-M. anisopliae interaction, we assessed the expression profiles of AgraMyD88 and AgraDorsal (Toll pathway), AgraIMD and AgraRelish (IMD pathway), and several AMP genes. Interestingly, we found that IMD pathway genes are upregulated early, and Toll pathway genes are upregulated just 3 days after inoculation (DAI). Furthermore, nine AMPs were upregulated 24 h after fungus inoculation, including attacins, cecropins, coleoptericins, and defensins. AgraRelish knockdown resulted in a reduction in median lethal time (LT50 ) for M. anisopliae-treated insects of around 2 days compared to control treatments. In addition, AgraRelish remained knocked down at 3 DAI. Finally, we identified that AgraRelish knockdown increased fungal loads at 2 DAI compared to control treatments, possibly indicating a faster infection. Our data indicate the influence of the IMD pathway on the antifungal response in A. grandis. Combining biocontrol and RNAi could significantly improve cotton boll weevil management. Hence, AgraRelish is a potential target for the development of biotechnological tools aimed at improving the efficacy of M. anisopliae against A. grandis.

Estimating Contact Rates Between Metarhizium anisopliae-Exposed Males With Female Aedes aegypti.

IntroductionEffective control of Aedes aegypti will reduce the frequency and severity of outbreaks of dengue, chikungunya, and Zika; however, control programs are increasingly threatened by the rapid development of insecticide resistance. Thus, there is an urgent need for novel vector control tools, such as auto-dissemination of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana. The aim of this study was to estimate contact rates of M. anisopliae-exposed males with wild female Ae. aegypti. As a control the contact rates of untreated males with wild females was contrasted.MethodsThe study was conducted in Reynosa, Mexico. The treatment and control households (n = 15 per group) were geographically separated by an arid and hot area that naturally prevented the flight of males between arms. In each control household, 40 M. anisopliae-exposed male Ae. aegypti were released per week for 8 weeks (specimens were exposed to a concentration of 5.96 × 107 conidia/cm2 for 24 h; n = 4,800 males). In each control household, 40 untreated males were released per week for 8 weeks (n = 4,800 males). All specimens were dust-marked prior to release. Mosquito abundance was monitored with human landing collections, and captured Ae. aegypti were examined for any dust-marking.ResultsIn the treatment households, the contact rate of Ae. aegypti females with marked, fungus-treated males was 14% (n = 29 females marked from 197). Where in the control households, the contact rate of females with marked, untreated males was only 6% (n = 22 marked from 365). In the treatment households the recapture rate of released males was at 5% and higher than that for the control households (which was 2%). Auto-dissemination of M. anisopliae from infected males to female Ae. aegypti was demonstrated through the recovery of an infected female from the floor of a household.ConclusionsOverall, the contact rate between M. anisopliae-infected males with the natural female population was 60% higher than for the control group of healthy males. The results provide further support to the release of fungus-exposed males as a potentially useful strategy against Ae. aegypti, though further research is required.

Alteration of Termite Locomotion and Allogrooming in Response to Infection by Pathogenic Fungi.

Termites, being vulnerable to parasitic or pathogenic infections due to large number of individuals living together in colonies, have evolved various behavioral and physiological tactics to resist the infections by those pathogens. Locomotion can help termites collect information on parasites and accordingly exhibit hygienic behaviors. Termites inevitably encounter entomopathogenic fungi during nesting and foraging. However, how these fungal pathogens influence locomotion of termites and how hygienic behavior benefits their survival remains unknown. Here, we examined locomotion alteration of the termite Reticulitermes chinensis (Isoptera: Rhinotermitidae) after infections with different concentrations of the entomopathogenic fungus Metarhizium anisopliae (Hypocreales: Clavicipitaceae). When R. chinensis was isolated, the low concentration (5 × 103 conidia/ml) significantly increased termite locomotion after 6, 12, and 24 h compared with control. However, the high concentrations (5 × 107, 5 × 109 conidia/ml) significantly decreased termite locomotion after 48 h, and termite survival was also significantly lower at 5 × 107 and 5 × 109 conidia/ml compared with the low concentrations and the control. When R. chinensis was in group, however, the locomotion significantly increased 24 h after exposure to 5 × 103 and 5 × 109 conidia/ml but was normalized after 48 h of exposure compared with the control. Allogrooming was significantly higher at 5 × 103 and 5 × 109 conidia/ml compared with the control. The fungal infection did not result in significantly higher mortality of the group termites probably owing to their allogrooming. These findings enhance our understanding on how a termite species copes with biotic stress (i.e., fungal infections) via adaptive behaviors.

Genome-Wide Identification and Analysis of Nilaparvata lugens microRNAs during Challenge with the Entomopathogenic Fungus Metarhizium anisopliae.

The resistance of the notorious rice pest Nilaparvata lugens to many insecticides has caused significant concerns. Our previous study demonstrated that the fungus Metarhizium anisopliae CQMa421 shows great potential for the control of this pest, but the interactions between them are still unclear. Thus, we further investigated fungal infection-related microRNAs (miRNAs) in N. lugens during M. anisopliae CQMa421 challenge using Illumina sequencing. In this study, we constructed twenty-four small RNA libraries over different time courses (i.e., 4 h, 8 h, 16 h, and 24 h). A total of 478.62 M clean reads were collected, with each sample producing more than 13.37 M reads, after the removal of low-quality reads. We identified 2324 miRNAs and their 11,076 target genes within the twenty-four libraries by bioinformatics analysis. Differentially expressed miRNAs (DEmiRNAs), including 58 (32 upregulated vs. 26 downregulated), 62 (30 upregulated vs. 32 downregulated), 126 (71 upregulated vs. 55 downregulated), and 109 (40 upregulated vs. 69 downregulated) DEmiRNAs were identified at 4 h, 8 h, 16 h, and 24 h post-infection, respectively. We further conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to predict the functions of all target genes of DEmiRNAs. These DEmiRNAs targets identified during 24 h of infection were primarily involved in energy metabolism, lysine degradation, the FoxO signaling pathway, ubiquitin-mediated proteolysis, the mRNA surveillance pathway, and the MAPK signaling pathway. Taken together, our results provide essential information for further study of the interactions between the entomopathogenic fungus M. anisopliae and N. lugens at the posttranscriptional level.

Silencing of selenium-binding protein disrupted the active immunization of the termite Reticulitermes chinensis and improved the lethal effect of the entomopathogenic fungus Metarhizium anisopliae

Active immunization is a process by which naïve termites receive sublethal doses of pathogenic spores from infected termites through social contact to enhance their immune responses; this process significantly diminishes the termite biocontrol effect of commercial entomopathogenic products, such as Metarhizium anisopliae. We found that the expression of selenium-binding protein (SeBP) was significantly increased by active immunization of the nestmates of fungus-contaminated termites, suggesting a close relationship between SeBP and active immunization in termites. To elucidate this relationship, we used the fungus M. anisopliae to contaminate the termite Reticulitermes chinensis and then measured the changes in the grooming behavior, antifungal activity, immune gene expression and survival of the double-stranded SeBP (dsSeBP)-injected nestmates of these fungus-contaminated termites. Our results showed that there was no significant change in the grooming behavior of the dsSeBP-injected nestmates of the fungus-contaminated termites, but the antifungal activity and expression of the immune gene Gram-negative bacteria-binding protein 2 (GNBP2) were significantly reduced. Moreover, the survival of the dsSeBP-injected nestmates of the fungus-contaminated termites was significantly decreased. These findings showed that SeBP knockdown disrupted the active immunization of R. chinensis and improved the lethal effect of M. anisopliae, which suggested that enhancing immune dysregulation by targeting SeBP was a sound strategy for the biological control of termites.

Compatibility of Entomopathogenic Fungi with Neonicotinoids for the Management of Brown Plant Hopper of Rice, Nilaparvata lugens stal. (Delphacidae: Hemiptera)

Background: Rice is the staple food of Indians and it is attacked by more than 100 species of insects. Among all, brown planthopper (BPH), Nilaparvata lugens (Stal) (Hemiptera: Delphacidae) is one of the major sucking insects, which can cause appreciable damage by sucking sap on other hand transmitting viral diseases. Farming community using several insecticides for managing the BPH. However, continuous use of these insecticides causes health hazards and environmental pollution and also leads to development of insecticide resistance. Keeping this view in mind, the present investigation has been planned with combined use of fungal formulations and commonly used neonicotinoid insecticides in rice eco system for managing BPH. Methods: This experiment was carried out in two parts, one is studied the compatibility between neonicotinoids (Thiamethoxam 25 SG and Dinotefuran 20 SG) and entomopathogenic fungi (Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii =Verticillium lecanii) by following the standard poison food technique. Second one is after studied the compatibility between neonicotinoids and entomopathogenic fungal agents, inhibitory studies were conducted under glasshouse conditions.Result: The study revealed that two tested insecticides affected the radial growth of fungi partially at all the three concentrations (0.5RC, RC and 1.5RC). At recommended concentration (RC), dinotefuran 20 SG @0.4 g/l was found to be slightly harmful to all three fungi (20% - 35% reduction of the growth of the fungus) and thiamethoxam 25 SG @ 0.25g/l appeared to be slightly harmful to B. bassiana and M. anisopliae and moderately harmful to L. lecanii (35-50% reduction of the growth of the fungus). Thiamethoxam 25SG alone recorded 65.0% mortality of BPH and when mixed with B. bassiana and M. anisopliae gave 86.25% and 81.25% mortality of BPH respectively under glass house conditions. Similarly, Dinotefuron 20 SG alone could gave 98.75% mortality of BPH.

Biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) by Entomopathogenic fungi and their side effects on natural enemies

BackgroundThe Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) is an insect pest species responsible for damages of citrus fruit quality and tree health. This insect is a vector of bacteria ‘Candidatus Liberibacter’ spp. a putative causal agent of citrus greening disease known as Huanglongbing (HLB), considered one of the most destructive diseases of citrus orchards worldwide. Disease management is mainly based on vector control using pesticides which can affect natural enemies that play an important role in pest control. The entomopathogenic fungi (EPF) Beauveria bassiana (2067 and 2121) and Metarhizium anisopliae (2411) were achieved by applying a suspension of 1 × 107 spores against D. citri nymphs and artificially infected the citrus seedlings under controlled and semi-field conditions. Also, the activity of these EPFs on the coccinellid and lacewing predators was evaluated. The effects of the main chemicals used in citrus plantations on the selected fungi for possible combined use was also investigated.ResultsThe obtained results showed that under controlled conditions, the percentage of insect mortality produced by EPF varied between 82.8 and 85.9%. Under semi-field conditions, the infection and mortality of D. citri caused by the M. anisopliae 2411 strain was significantly higher than that of B. bassiana 2067, 78.9 and 51%, respectively. Non-significant effect of EPF on the natural enemies of D. citri was observed, suggesting that EPF and predators had compatible effects.ConclusionThis study clearly demonstrated that EPF were able to kill D. citri and can be explored as a promissory biocontrol candidate. Simultaneous use in an integrated pest management program could be possible by applying EPF combined with pesticides.

ГАЖ-технологияларды қолдана отырып зиянды шегірткелердің табын түрлерін биологиялық бақылау

In 2018-2020, domestic and foreign biological insecticides were tested against three species of herd locusts; Dociostaurus maroccanus Thunb., Locusta migratoria migratoria L. and Calliptamus italicus L. Scientific research was carried out in the main regional locust foci in Almaty, Zhambyl, Turkestan and Kyzylorda regions. The spring-autumn examination of locust pods was carried out according to generally accepted methods in entomology. The examined deposits of pods were recorded by a GPS device. Tested drugs: 1) Actarophyte 1% is a complex of natural avermectins, 2) Actarophyte 1.8% is produced from the same soil fungus, DV - Bifenazate. 3) Green barrier, S.P. is developed on the basis of the fungus Beauveria bassiana, 108 CFU/g. 4) Mikolar B, Mikolar M. are based on strains of entomopathogenic fungi of boveria and metarizium from the collection of the biotechnology laboratory of Kazniizikr LLP. 5) Novacrid is a drug manufactured by Elephant Vert. The drug is pure spores of the entomopathogenic fungus Metarhizium anisopliae. 6) Greene gold, 0.3% by weight (azadirakhtin, 0.3%). In general, all the tested means have shown one or another effectiveness in the fight against locust larvae. The most rapid and strong toxic effect was shown by the drug actofit based on avermectins - up to 90-99% mortality on day 1-3, up to 100% mortality on day 10. The herbal preparation Greene Gold showed a slightly smaller effect on all three types of locusts. Mycola B and Mycola M did not show high efficacy, which is due to the lack of preparation forms. In experiments on the use of the So-450 sprayer and the Gaia 160 AG UAV as a treatment technique against locust larvae, identical results were obtained in all experiments, which will further simplify the test procedure using only one of the types of equipment, depending on the circumstances.