scholarly journals Diachasmimorpha longicaudata Parasitism Response to Medfly Host Fruit and Fruit Infestation Age

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 211 ◽  
Author(s):  
Ahlem Harbi ◽  
Luis de Pedro ◽  
Fernando A. A. Ferrara ◽  
José Tormos ◽  
Brahim Chermiti ◽  
...  

The parasitoid Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) is increasingly being used in integrated pest management (IPM) programs as a biological control agent in order to suppress tephritid fruit flies of economic importance. Innate and acquired behavioral responses—such as pest host fruit preference—of parasitoids can modulate their efficiency in the field and should be taken into consideration prior to parasitoid species’ selection for mass-rearing. We have assessed the influence of medfly-infested (two infestation ages, 1 and 4-d-old) and uninfested fruit species on host preference and efficiency of D. longicaudata by using a multistep assay including olfactory, laboratory and semi-field trials. We found that D. longicaudata was significantly more attracted to medfly-infested apples for both infestation ages, with the oldest being the most preferred. D. longicaudata exhibited a significant preference among the four fruits tested. The implications of these behavioral responses of D. longicaudata to medfly host fruits and infestation age are discussed in relationship to its use in IPM programs in the Mediterranean basin area.

Plant Disease ◽  
2021 ◽  
Author(s):  
Leslie Amanda Holland ◽  
Renaud Travadon ◽  
Daniel P. Lawrence ◽  
Mohamed Taieb Nouri ◽  
Florent P Trouillas

Almond trunk and branch canker diseases constitute a major cause of tree mortality in California. Numerous fungal pathogens have been associated with these canker diseases and pruning wounds act as major infection courts. Prior to this study, there were no products registered in California for the management of these diseases. In this study, fungicidal products including synthetic chemistries, biocontrols, paint and a sealant were evaluated for preventing fungal pathogen infection via pruning wounds. In four field trials conducted over two dormant seasons, sixteen pruning wound treatments were tested using hand-held spray applications, against five almond canker pathogens, namely Botryosphaeria dothidea, Neofusicoccum parvum, Cytospora sorbicola, Ceratocystis destructans, and Eutypa lata. The fungicide thiophanate-methyl (Topsin M) provided 82% overall disease prevention against four fungal pathogens. The biological control agent, Trichoderma atroviride SC1 (Vintec), tested at three application rates, resulted in 90 to 93% protection of pruning wounds in field trials, and for individual pathogens ranged from 81-100% protection for the three rates. At the time of this publication, Vintec is being considered for registration as a biological control product for the prevention of almond canker diseases, while Topsin M is recommended to growers for the prevention of almond canker diseases. This research indicates that effective protection of pruning wounds from infection by almond canker pathogens can be achieved with a one-time spray application of thiophanate-methyl or the biocontrol, T. atroviride SC1 (recommended 2 g/liter) after pruning.


2021 ◽  
Author(s):  
Shuen-Huang Tsai ◽  
Yu-Ting Chen ◽  
Yu-Liang Yang ◽  
Bo-Yi Lee ◽  
Chien-Jui Huang ◽  
...  

Paenibacillus polymyxa is a beneficial bacterium for plant health. Paenibacillus polymyxa TP3 exhibits antagonistic activity toward Botrytis cinerea and alleviates gray mold symptoms on the leaves of strawberry plants. Moreover, suppression of gray mold on the flowers and fruits of strawberry plants in field trials, including vegetative cells and endospores, was demonstrated, indicating the potential of strain TP3 as a biological control agent. To examine the anti-B. cinerea compounds produced by P. polymyxa TP3, matrix‐assisted laser‐desorption/ionization time‐of‐flight mass spectrometry was performed and fusaricidin-corresponding mass spectra were detected. Moreover, fusaricidin-related signals appeared in imaging mass spectrometry of TP3 when confronted with B. cinerea. By using liquid chromatography-mass spectrometry-based molecular networking approach, several fusaricidins were identified including a new variant of m/z 917.5455 with serine in the first position of the hexapeptide. Via advanced mass spectrometry and network analysis, fusaricidin-type compounds produced by P. polymyxa TP3 were efficiently disclosed and were presumed to play roles in the antagonism against gray mold pathogen B. cinerea.


2011 ◽  
Vol 101 (1) ◽  
pp. 113-123 ◽  
Author(s):  
V. O. Stockwell ◽  
K. B. Johnson ◽  
D. Sugar ◽  
J. E. Loper

Mixtures of biological control agents can be superior to individual agents in suppressing plant disease, providing enhanced efficacy and reliability from field to field relative to single biocontrol strains. Nonetheless, the efficacy of combinations of Pseudomonas fluorescens A506, a commercial biological control agent for fire blight of pear, and Pantoea vagans strain C9-1 or Pantoea agglomerans strain Eh252 rarely exceeds that of individual strains. A506 suppresses growth of the pathogen on floral colonization and infection sites through preemptive exclusion. C9-1 and Eh252 produce peptide antibiotics that contribute to disease control. In culture, A506 produces an extracellular protease that degrades the peptide antibiotics of C9-1 and Eh252. We hypothesized that strain A506 diminishes the biological control activity of C9-1 and Eh252, thereby reducing the efficacy of biocontrol mixtures. This hypothesis was tested in five replicated field trials comparing biological control of fire blight using strain A506 and A506 aprX::Tn5, an extracellular protease-deficient mutant, as individuals and combined with C9-1 or Eh252. On average, mixtures containing A506 aprX::Tn5 were superior to those containing the wild-type strain, confirming that the extracellular protease of A506 diminished the biological control activity of C9-1 and Eh252 in situ. Mixtures of A506 aprX::Tn5 and C9-1 or Eh252 were superior to oxytetracycline or single biocontrol strains in suppressing fire blight of pear. These experiments demonstrate that certain biological control agents are mechanistically incompatible, in that one strain interferes with the mechanism by which a second strain suppresses plant disease. Mixtures composed of mechanistically compatible strains of biological control agents can suppress disease more effectively than individual biological control agents.


2021 ◽  
Vol 285 ◽  
pp. 03010
Author(s):  
Irina Agasyeva

Ectoparasite Habrobracon hebetor Say is one of the most widely used biological controllers in biological plant protection against a number of harmful lepidopterans, including especially dangerous pests of corn, soy, fruit and vegetable crops. As a result of research conducted in 2017, food specialization and parasitic activity of three different populations of H.hebetor were studied. Two races have been identified for mass rearing and application: pyralid and leaf roller (against corn moth, bean pod borer, apple and plum moths), and pyralid owl-moth (against cotton moth, corn borer, bean pod borer and boxwood moth). As a result of studies of biological features and trophic needs, it has been determined that caterpillars of mill moth (Ephestia cuhniellia Zella) should be used as a host insect for laboratory cultivation of the stock population of the Habrobracon pyralid and leaf roller race (race No. 1). For the introduced from South Kazakhstan the H.hebetor pyralid and noctuid race the most productive rearing is on the caterpillars of large bee moth (Galleria mellonela L.). Optimal temperature for rearing of both races is 26-28 ° C, relative air humidity is 70% and photoperiod is not less than 16 hours. It has been noticed that before laying eggs on the host’s caterpillars, the Habrobracon female preliminarily paralyzes the victim, piercing the sheath with ovipositor. As a result, the caterpillar stops eating and is immobilized. In 3-4 days larvae hatch out of the laid on the caterpillar eggs. The larvae feed on the contents of the caterpillars for 4-5 days, then pupate and after 6-8 days an adult insect leaves the cocoon. The development of one generation lasts 13-16 days, one cocoon includes one parasite. 1,000 large bee moth caterpillars used for infection provide on average 5.8-6.0 thousand cocoons, of which an average of 4.5-4.7 thousand parasites fly out.


2016 ◽  
Vol 69 ◽  
pp. 258-262
Author(s):  
B. Smith ◽  
S.G. Casonato ◽  
A. Noble ◽  
G. Bourd?t

Californian thistle (Cirsium arvense) is a problematic weed particularly in permanent pastures The fungus Sclerotinia sclerotiorum has potential as a bioherbicide to control this weed but its variable efficacy in historical field trials suggest that there are differences in susceptibility to S sclerotiorum within the species To test this hypothesis the responses of 32 New Zealand provenances of C arvense to a foliageapplied myceliumonbarley preparation of S sclerotiorum were compared under common conditions Significant differences between provenances were found supporting the hypothesis that there is variation within C arvense in New Zealand in its susceptibility to S sclerotiorum Further work will examine differences in the efficacy of fungal isolates against different C arvense provenances


2021 ◽  
Vol 11 (20) ◽  
pp. 9445
Author(s):  
Maria Zottele ◽  
Johanna Mayerhofer ◽  
Hannah Embleton ◽  
Katharina Wechselberger ◽  
Jürg Enkerli ◽  
...  

Inundative mass application of Metarhizium brunneum BIPESCO 5 (Hypocreales, Clavicipitaceae) is used for the biological control of Diabrotica v. virgifera (Coleoptera, Chrysomelidae). Long-term field trials were performed in three Austrian maize fields—with different cultivation techniques and infestation rates—in order to evaluate the efficacy of the treatment to control the pest larvae. In addition, the indigenous Metarhizium spp. population structure was assessed to compare the different field sites with BIPESCO 5 mass application. Annual application of the product Granmet-PTM (Metarhizium colonized barley kernels) significantly increased the density of Metarhizium spp. in the treated soil above the upper natural background level of 1000 colony forming units per gram dry weight soil. Although a decrease in the pest population over time was not achieved in heavily infested areas, less damage occurred in treated field sites in comparison to control sites. The Metarhizium population structure was significantly different between the treated field sites. Results showed that inundative mass application should be repeated regularly to achieve good persistence of the biological control agent, and indicated that despite intensive applications, indigenous populations of Metarhizium spp. can coexist in these habitats. To date, crop rotation remains the method of choice for pest reduction in Europe, however continuous and preventive application of M. brunneum may also present an alternative for the successful biological control of Diabrotica.


Author(s):  
Júlia Gabriela Aleixo Vieira ◽  
Alexandra Peter Krüger ◽  
Tiago Scheuneumann ◽  
Maíra Chagas Morais ◽  
Hugo Julio Speriogin ◽  
...  

Abstract Spotted-wing Drosophila, Drosophila suzukii (Matsumura, 1931), is an economic pest of thin-skinned fruit crops. Its control has commonly been carried out through chemical methods. However, given the need to develop safer and environmentally friendly management alternatives, the pupal endoparasitoid Trichopria anastrephae Lima stands out as a potential biological control agent. However, the lack of information on the mass rearing of this parasitoid limits its use. Thus, the objective of our study was to provide information that is useful for rearing T. anastrephae using D. suzukii as a host. The effects of pupal age, exposure time, and pupal density on the parasitism rate were examined, as was the effect of honey provision for extending adult parasitoid longevity. Exposing 15 12-h-old pupae per female for 24 h resulted in higher parasitism rates and a greater number of emerged parasitoids. Males and females of T. anastrephae fed with pure honey (100%) or honey diluted to 50% in water lived longer compared to those fed 10% honey, no food, or only water.


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