Control Of Mediterranean Fruit Fly Research Articles

Nanoformulations with exopolysaccharides from cyanobacteria: enhancing the efficacy of bioactive molecules in the Mediterranean fruit fly control

The increasing demand for food has required intensive use of pesticides which are hazardous to the ecosystem. A valid alternative is represented by biopesticides; however, these molecules are often insoluble in water, and poorly bioavailable. Nanopesticides can be engineered to reach a selected target with controlled release of the active principle. In this work, capsaicin, an irritant alkaloid from hot chili peppers, and hydroxytyrosol, a phenolic compound obtained from extra-virgin olive oil by-products, were loaded into innovative nanocarriers. These were designed ad hoc combining exopolysaccharides from the cyanobacteria Neocyanospira capsulata, and a lipid component, i.e., egg phosphatidylcholine. The polysaccharide was chosen for chemical affinity with the chitin of insect exoskeleton, while the lipids were introduced to modulate the carrier rigidity. The newly formed nanosystems were characterized by physico-chemical techniques and tested for their possible use in pest control programs. The Mediterranean Fruit Fly Ceratitis capitata Wiedemann, 1824 (Diptera, Tephriditae), a pest of the Mediterranean Region causing high economic losses, was used as a model insect. We found that the nanoformulations nanocarriers prepared in this work, were able to increase the ovicidal effect of hydroxytyrosol. Moreover, the formulation encapsulating either hydroxytyrosol or capsaicin were able to reduce the number of females landing on treated apricots.Graphical

Efficacy and residual activity of commercially available entomopathogenic nematode strains for Mediterranean fruit fly control and their ability to infect infested fruits.

BACKGROUNDEntomopathogenic nematodes (EPN) show potential in controlling larvae of the Mediterranean fruit fly (medfly) Ceratitis capitate, but previous studies mainly concern species and strains that are not commercially available. The use of EPN for control of Mediterranean fruit fly is further hampered by the cost of using nematodes. In this study, the efficacy and residual activity of commercial strains of three EPN species, Steinernema carpοcapsae, S. feltiae and Heterοrhabditis bacteriοphοra medfly) C. capitata, in the soil substrate and inside fruits were evaluated.RESULTSSuspensions of these species were applied at a dose of 1.5 mi m−2 on a soil substrate wherein medfly larvae were added sequentially for a period of 4 weeks post application at 20 °C. S. feltiae provided the highest suppression up to 50% as assessed by adult medfly emergence because it had the highest immediate activity and long residual activity. Furthermore, S. feltiae, and to a lesser degree S. carpocapsae, were able to move and infect medfly larvae inside infested apples and oranges left in the surface of the substrate wherein EPN were applied, reducing significantly adult medfly emergence (60–78%).CONCLUSIONThese results support the efficacy and feasibility of applying a single, relatively low dose of S. feltiae in autumn, off‐season, targeting overwintering medfly larvae with the scope of reducing the number of adult medflies emerging later in the new season.

The Mediterranean Fruit Fly (Diptera: Tephritidae), a Key Pest of Citrus in Egypt

Abstract The Mediterranean fruit fly (Mediterranean fruit fly), Ceratitis capitata (Wiedemann), is a key pest of citrus fruit (Sapindales: Rutaceae), and can infect over 300 other economically important fruit-bearing plant species globally. The Mediterranean fruit fly moves to different hosts continuously and has 8–10 overlapping generations a year in Egypt. The female lays the eggs under the fruit peel and hatched larvae use anterior mouth hooks to vigorously feed on fruit flesh until they reach the third and last instar. As tens of eggs are often deposited in a single spot, the fruit becomes juicy and inedible. Larval infection and feeding also facilitate the entry of fungi and microbes that can rot the fruit. Infestation of citrus orchards can result in significant annual losses in crop size and quality. As a quarantine pest with high reproductive potential and dispersive ability, the Mediterranean fruit fly is difficult to manage and poses a major threat to Egyptian citrus export because of concerns over infection or pesticide residues. This review discusses the current state of research on Mediterranean fruit fly biology and ecology as well as host fruit production practices from the standpoint of pest management. Integrated pest management programs consisting of regulatory, cultural, chemical, genetic, and biological control methods that are currently the most effective strategies for Mediterranean fruit fly control are also described.

Evaluation of thiacloprid and clothianidin (neonicotinoids) as alternative to fenthion (organophosphate) for control of Mediterranean fruit fly (Diptera: Tephritidae) in deciduous fruit orchards

Fenthion (organophosphate) was used in Australia to target adults, eggs and larvae of Mediterranean fruit fly (Medfly), Ceratitis capitata Wiedmann (Diptera: Tephritidae) in deciduous fruits. With its removal from use in 2015, clothianidin and thiacloprid (neonicotinoids) were evaluated for any adulticide, ovicide or larvicide (eggs, larvae) activity against Medfly in a series of laboratory and field-cage experiments in peach and nectarine. We included fenthion in all experiments as a positive control. As an adulticide, fenthion had the greatest residual toxicity on fruit, with 7 d old residues killing 44% of adults within 48 h compared to thiacloprid (17%) and clothianidin (30%). When applied as a larvicide to naturally infested peaches, none of the insecticides was 100% effective, though fewest pupae (1.18 ± 0.19 pupae/fruit) (indirect measurement of larval survival) were produced when treated with fenthion, followed by clothianidin (3.40 ± 0.33 pupae/fruit) and thiacloprid (6.88 ± 0.34 pupae/fruit); with 11.35 ± 0.30 pupae/fruit in control (water). In peaches treated 48 h post-infestation, fenthion was most effective in reducing numbers of pupae and adult emergence and with higher percentage of deformed adults, with thiacloprid=clothianidin. In nectarines treated 48 h post-infestation, fenthion was most effective in reducing numbers of pupae and adult emergence as well as with higher percentage of deformed adults, followed by clothianidin. Insecticides were least effective when applied as a preventative 24 h or 7 d prior to infestation, with fenthion more effective than clothianidin. Whilst our study shows that neither clothianidin nor thiacloprid are equivalent to fenthion, they are acceptable substitutes to growers for use for Medfly in deciduous fruits given that fenthion is no longer available to growers in Australia. We recommend that growers incorporate other controls to target the adult stage rather than rely only on new insecticides.

Suppressing Mediterranean fruit fly (Diptera: Tephritidae) with an attract-and-kill device in pome and stone fruit orchards in Western Australia

Attract-and-kill is a possible alternative to the conventional control of Mediterranean fruit fly (medfly), Ceratitis capitata Wiedemann (Diptera: Tephritidae) with bait or cover sprays of organophosphate insecticides. In this study, we determined if an attract-and-kill device (MagMED®) could be applied alone at the recommended rate (80 devices/ha), or needed to be combined with other conventional control tactics to suppress medfly in deciduous fruit orchards (apple, nectarine, peach, pear, plum). We also determined if attract-and-kill had any detrimental effects on naturally occurring beneficial insects. Based on an acceptable level of crop loss of 2–5% (the level of crop loss growers can tolerate), attract-and-kill suppressed medfly and reduced crop loss below the acceptable level in orchards with additional controls. Attract-and-kill was most effective when combined with either bait spraying, cover spraying or both. Combining attract-and-kill with cover sprays of fenthion resulted in a drop in crop loss of apples from 2.5% to 0.5%. By combining attract-and-kill with weekly bait sprays and two cover spray applications, crop loss fell from 13.7% to 4.3% in peaches, from 6.3% to 5% in nectarines and from 6.3% to 3.7% in pears. Twice weekly bait spraying was the most effective technique at suppressing medfly, providing acceptable control when applied alone, which further improved by combining with attract-and-kill. By combining attract-and-kill with twice weekly bait spraying crop loss fell from 2% to 1% in nectarines and from 4% to 2% in apples. In laboratory trials, attract-and-kill devices killed 100% of brown lacewings (Micromus tasmaniae Walker) and 94% of transverse ladybeetles (Coccinella transversalis Fabricius) 24 h after contact. However, orchard samples suggest that it may not pose any significant negative impact on naturally occurring beneficials such as Neuroptera, Hymenoptera, Coleoptera, Thysanoptera and Syrphidae in the field.

Eradication versus control of Mediterranean fruit fly in Western Australia

The primary chemicals used by Western Australia's horticultural industries with respect to field control and post-harvest disinfestation procedures for the Mediter- ranean fruit fly are soon to be withdrawn from use because of public health concerns. 2 When this occurs, the necessary switch to alternative control methods such as bait sprays and intensive fruit fly trapping will involve additional producer costs. 3 The present study demonstrates that these costs are likely to exceed the costs of eradication using the sterile insect technique. 4 Given this result, eradication cost sharing arrangements between government and industry are discussed that could produce mutual benefits in the long term.

Cross-Resistance to Insecticides in a Malathion-Resistant Strain of Ceratitis capitata (Diptera: Tephritidae)

Resistance to malathion has been reported in field populations of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), in areas of Spain where an intensive use of this insecticide was maintained for several years. The main goal of this study was to determine whether resistance to malathion confers cross-resistance to different types of insecticides. Susceptibility bioassays showed that the malathion-resistant W-4Km strain (176-fold more resistant to malathion than the susceptible C strain) has moderate levels of cross-resistance (three- to 16-fold) to other organophosphates (trichlorphon, diazinon, phosmet and methyl-chlorpyrifos), the carbamate carbaryl, the pyrethroid lambda-cyhalothrin, and the benzoylphenylurea derivative lufenuron, whereas cross-resistance to spinosad was below two-fold. The W-4Km strain was selected with lambda-cyhalothrin to establish the lambda-cyhalothrin-resistant W-1Klamda strain (35-fold resistant to lambda-cyhalothrin). The synergistic activity of the esterase inhibitor DEF with lambda-cyhalothrin and the increase in esterase activity in the W-1Klamda strain suggests that esterases may be involved in the development of resistance to this insecticide. Our results showed that resistance to malathion may confer some degree of cross-resistance to insecticides currently approved for the control of Mediterranean fruit fly in citrus crops (lambda-cyhalothrin, lufenuron, and methyl-chlorpyrifos). Especially relevant is the case of lambda-cyhalothrin, because we have shown that resistance to this insecticide can rapidly evolve to levels that may compromise its effectiveness in the field.

Cold treatment of table grapes infested with Mediterranean fruit fly Ceratitis capitata (Wiedemann) and Queensland fruit fly Bactrocera tryoni (Froggatt) Diptera: Tephritidae

A series of trials, using standard bioassay procedures followed by large-scale export tests, were conducted on five table grape cultivars at 1°C, 2°C and 3°C against the Mediterranean fruit fly (MFF) and the Queensland fruit fly (QFF). MFF was found to be more tolerant to cold treatment than QFF as shown in tests required to achieve complete mortality in >100,000 insects. MFF control was achieved in 16 days at 1°C, 18 days at 2°C and 20 days at 3°C. QFF control was obtained in 12 days at 1°C and 14 days at both 2°C and 3°C. These results provide flexibility for static and in-transit quarantine treatments for export and are an effective alternative to methyl bromide fumigation.

Chemical Alternatives to Malathion for Controlling <I>Ceratitis capitata</I> (Diptera: Tephritidae), and Their Side Effects on Natural Enemies in Spanish Citrus Orchards

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the most important fruit pests worldwide. Mediterranean fruit fly control in Spain has been based on organophosphate sprays, especially malathion, mixed with protein baits. However, this insecticide has recently been excluded from annex 1 of the Directive 91/414 CEE, which lists authorized active ingredients for pest control in the European Union. This article reports on the efficacy of four alternative baited insecticides on Mediterranean fruit fly and their side effects on three natural enemies [Cryptolaemus montrouzieri (Mulsant), Neoseiulus californicus (McGregor), and Aphidius colemani (Viereck)] relevant for pest control in citrus agroecosystems. A high Mediterranean fruit fly mortality was obtained for all baited insecticides (phosmet and spinosad) except lambdacyhalothrin, which caused the lowest mortality and showed a novel disabling effect on surviving Mediterranean fruit fly adults. Spinosad proved to be the most selective bait treatment for C. montrouzieri and N. californicus, whereas for A. colemani the most selective bait was phosmet and lambda-cyhalothrin. These findings would contribute to a sustainable chemical control of C. capitata populations under an integrated pest management system in Spanish citrus orchards.

Worker exposure and a risk assessment of Malathion and Fenthion used in the control of Mediterranean fruit fly in South Australia

In 2001, an outbreak of Mediterranean fruit fly in Adelaide was controlled by South Australian Government workers applying organophosphorus insecticides (OPs) to domestic gardens. Residents made claims of adverse effects associated with allegations that worker application practices were poor and led to contamination of homes, residents and pets. The concerns led to a Parliamentary enquiry, the suspension of OP applications for fruit fly control, and the investigation of alternative methods of combating fruit fly in metropolitan Adelaide. The extent of exposure of workers and residents was not estimated. This paper describes a simulated application of the OPs concerned (fenthion and malathion) with measurements of potential exposure through inhalation, dermal contact and deposition of pesticides on surfaces. The data were used as part of a toxicological risk assessment to determine the likely impact of the use of these insecticides. Malathion, used as a 1% suspension in a protein bait mixture, was found to have little potential for airborne exposure, although some workers were found to have up to 0.315 μg/cm 2 malathion deposited on overalls (principally on forearms) and over 500 μg deposited on liner gloves and hats, respectively. Risks to workers and residents were low, with exposures likely to be a small fraction of the acceptable daily intake. Fenthion, used as a 0.05% foliar cover spray, was found between 0.02 and 0.23 mg/m 3 in air 10 m downwind from spray activity and was unlikely to pose a significant risk to residents, since exposures were of short durations of up to 20 min. Personal air samples of spray workers averaged 0.55 mg/m 3 (Workplace Exposure Standard 0.20 mg/m 3). Since workers were usually engaged in spraying for a large proportion of the day, this demonstrates the need for respiratory protective equipment. Maximum deposition of fenthion on workers overalls ranged from 0.06 to over 0.20 μg/cm 2, although little was found on gloves and hats, suggesting workers were skilled in avoiding the plume of overspray. Dialkyl phosphates (metabolites of OP insecticides) were not detected in urine of workers, and there were no changes observed in serum cholinesterase (SChE) enzyme activities 24 h following the simulation. These data suggest absorption of OP insecticides by workers was negligible. Deposition on surfaces 5 and 10 m downwind ranged from none detected to 145 μg/cm 2, suggesting that exposure of residents and children in contact with contaminated surfaces (such as garden furniture or play equipment) is possible. Estimates of the potential dermal intake of fenthion by children from contaminated surfaces suggested that risks of acute and chronic effects are slight, since exposures may occur for short periods at intervals of approximately 10 days during fruit fly outbreaks.

Heat treatment of ‘Oroblanco’ citrus fruit to control insect infestation

‘Oroblanco’ citrus fruit were heat treated with hot forced air at holding temperatures from 43 to 47 °C for times from 10 to 90 min. Unwaxed fruit developed heat damage at 47 °C, while waxed fruit showed heat damage at 44 °C. Thermal death kinetics of Mediterranean fruit fly, Ceratitis capitata (Wiedemann), eggs, first and third instars were tested in a hot water system for temperatures between 43 and 49 °C, and Probit 9 calculated from the data. Using first instar larvae the times needed to control the fruit fly at 43 and 44 °C were tested in infested ‘Oroblanco’ fruit. The observed lethal times in the hot water (113 min at 43 °C) were longer than what was observed in heated, infested ‘Oroblanco’ fruit (90 min). When 0.05% oxygen was added to a 43 °C heat treatment the time to completely kill first instar larvae was decreased to 30 min. Provided a fruit cooling method will prevent heat damage to the fruit, 43 °C in low oxygen, or 44 °C in air for 30 min can provide control of Mediterranean fruit fly in this citrus cultivar. These times, temperatures and atmospheres did not impair fruit quality either after shelf life alone, or following storage and shelf life.

Effects of Mediterranean Fruit Fly Malathion Bait Spray on the Longevity and Oviposition of Parasitoids of Linden and Tuliptree Aphids (Homoptera: Aphididae)

The longevity of two primary aphid parasitoids, Aphidius liriodendrii Liu and Trioxys curvicaudus (MacKauer), was severely reduced when they were exposed in the laboratory to a malathion bait spray used to eradicate the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). The longevity of several hyperparasites of A. liriodendrii and T. curvicaudus also was reduced. Oviposition of A. liriodendrii was severely reduced on plants that received field applications of malathion bait spray. The parasitoids appeared neither attracted to nor repelled by the malathion bait. Pesticide contact occurred during apparently random searching by the parasitoids. As T. curvicaudus is reportedly responsible for the biological control of its aphid host, Eucallipterus tiliae (L.), malathion bait sprays used for Mediterranean fruit fly control may cause an increase in aphid populations by reducing the effectiveness of primary parasitoids.