Insect growth regulators as potential insecticides to control olive fruit fly (Bactrocera oleae Rossi): insect toxicity bioassays and molecular docking approach

BACKGROUND: Olive fruit fly, Bactrocera oleae (Rossi), is a key pest in olive orchards, causing serious economic damage. To date, the pest has already developed resistance to the insecticides commonly applied to control it. Thus, in searching for new products for an accurate resistance management programme, targeting the ecdysone receptor (EcR) might provide alternative compounds for use in such programmes. RESULTS: Residual contact and oral exposure in the laboratory of B. oleae adults to the dibenzoylhydrazine‐based compounds methoxyfenozide, tebufenozide and RH‐5849 showed different results. Methoxyfenozide and tebufenozide did not provoke any negative effects on the adults, but RH‐5849 killed 98‐100% of the treated insects 15 days after treatment. The ligand‐binding domain (LBD) of the EcR of B. oleae (BoEcR‐LBD) was sequenced, and a homology protein model was constructed. Owing to a restricted extent of the ligand‐binding cavity of the BoEcR‐LBD, docking experiments with the three tested insecticides showed a severe steric clash in the case of methoxyfenozide and tebufenozide, while this was not the case with RH‐5849. CONCLUSION: IGR molecules similar to the RH‐5849 molecule, and different from methoxyfenozide and tebufenozide, might have potential in controlling this pest. Copyright © 2012 Society of Chemical Industry     

Spinosad bait sprays against the olive fruit fly (Bactrocera oleae (Rossi)): effect on the canopy non-target arthropod fauna

Abundance and diversity of arthropods were compared in olive trees treated against the olive fruit fly with spinosad bait sprays and an untreated control, paying special attention to predators and parasitoids. Spinosad bait sprays did not reduce the abundance and diversity of arthropods as a whole in the canopy. However, principal response curve analysis revealed a significant deleterious effect of the treatments on natural enemies in the last of the three years of study. The most affected taxa were Anthocoridae (especially Orius spp.) and Aphelinidae.     

Organophosphate resistance in olive fruit fly, Bactrocera oleae, populations in Greece and Cyprus

The olive fruit fly Bactrocera oleae (Gmelin) (Diptera: Tephritidae) is the most important pest of olives in countries around the Mediterranean basin. Its control has been based mostly on bait sprays with organophosphate insecticides (usually dimethoate or fenthion) for about 40 years. In the present study, the resistance status of olive fruit fly populations to dimethoate was examined in Greece and Cyprus over 2 years. Thirty-one populations from various regions of Greece, nine from Cyprus and one laboratory susceptible strain, which served as a control, were assayed by topical application of dimethoate. Considerable variation in the resistance levels to dimethoate was recorded in the populations of B. oleae, with resistance ratios ranging from 6.3 to 64.4 (ED(50) values 12.5-128.7 ng dimethoate per insect). The highest resistance ratios were found in populations from Crete, and the lowest in those from Cyprus. This variation could be attributed to different selection pressures from insecticidal applications among populations from the various regions. Migration of resistant genotypes, either autonomous or via commerce, may also be involved.     

Spinosad resistance development in wild olive fruit fly Bactrocera oleae (Diptera: Tephritidae) populations in California

BACKGROUND: Among target pests of the insecticide spinosad is the olive fruit fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae). In Cyprus, spinosad has been sporadically used since its registration in 2002, whereas in Greece its use has been very limited since its registration in 2004, particularly in biological olive cultivars in Crete. By contrast, in California it has been the only insecticide used against the olive fruit fly since its registration in 2004. This study aimed at examining the resistance status of the olive fruit fly to spinosad. RESULTS: Populations from California, Greece and Cyprus, plus a laboratory population, were tested. Bioassays were performed by oral or topical application of different concentrations of the insecticide. Cypriot populations demonstrated no resistance as compared with that of the laboratory population. Among the Greek populations, only one from Crete demonstrated a fourfold increase in resistance, whereas five populations from California demonstrated a 9–13‐fold increase. CONCLUSION: The observed resistance increase was associated with spinosad applications in the respective areas. These values are relatively low and do not yet pose a serious control problem in the field. However, the observed variation documents that spinosad tolerance has increased in areas where the insecticide has been more extensively used. Copyright © 2010 Society of Chemical Industry     

Evaluation of commercial traps of various designs for capturing the olive fruit fly Bactrocera oleae (Diptera: Tephritidae)

Abstract

The attractiveness of six different traps, one hand-made and five commercially available, on olive fruit fly adults, was compared in the field. Experiments were undertaken at three different localities of Messinia Co., SW Greece, with varying conditions of fruit load and pest population density. The Glass-Plastic Elkofon Trap attracted more adult flies than any other type of trap. Satisfactory catches were also given by the Glass McPhail trap, the Plastic McPhail trap and the Plastic Elkofon trap, whereas low attractiveness was demonstrated by the Bottle trap and the Pouch trap. It is clear from the findings of this study that trap captures of the olive fruit fly are significantly influenced by trap design (e.g. shape, materials, special features), especially during the period of the high population peak (mid-September – early November) as well as in olive orchards with a high pest population density. In olive orchards with a low pest population density no significant differences were recorded among captures of different trap types. We discuss ways of improving the mass-trapping technique as a control method against olive fruit fly.     

桃实蝇在西藏的适生性分析

［目的］ 明确桃实蝇在西藏的适生性,为科学制定检疫措施,防止其入侵和扩散,保护西藏水果的安全生产提供依据。［方法］ 以中国760个(西藏39个)气象站点的气象数据和桃实蝇生物学数据为基础,运用CLIMEX模型和ArcGIS分析相结合的方法对桃实蝇在中国,尤其是西藏的适生性进行分析。［结果］ 桃实蝇在我国具有较高的适生性,适生范围包括34个省、市（区）,其中海南、广东的南部、福建的南部、广西、云南、四川、陕西南部、河南和湖北的北部以及台湾的大部分地区属于高度适生区。而桃实蝇在西藏有3个适生站点。［结论］ 我国很多地区是桃实蝇的适生区,并且高度和中度适生区的范围相对较大。存在桃实蝇入侵西藏并定殖危害的可能性。     

Tomato fruits as an alternative host for a laboratory strain of the olive fruit flyBactrocera oleae

In nature, oviposition and larval growth of the olive fruit flyBactrocera oleae (Rossi) (Diptera: Tephritidae) occur only in the mesocarp of fruits of the genusOlea, including the cultivated olive. Here we report on its growth in tomatoes, in the laboratory, as affected by a number of factors. Caged flies from a colony reared for more than 100 generations on an artificial diet, oviposited in intact fruits of four tomato cultivars in an unheated greenhouse and in the open. In choice tests, at 25°C, 16L:8D and 65% r.h., medium (5–6 cm diam) and large (>6 cm diam) fruits received more eggs than small (3–4 cm diam) fruits, but differences were not significant in all cases. In all cultivars, more eggs were laid in greenhouse than in open-air tomatoes of three different degrees of maturity, the differences being significant in most cases. The smaller the resistance of a cultivar’s epicarp to penetration by flat ended 0.2 and 1 mm square probes, the greater the number of eggs a cultivar received. Green (unripe) fruits proved unsuitable for larval growth. Half-ripe and fully ripe (red) fruits of cvs. ‘Isidro’, ‘204’, ‘Tobo’ and ‘Ace’ yielded pupae of acceptable weight (mean 5.6 to 6.7 mg) with a high percentage of adult emergence, yet the yield was considerably lower than that of olive fruit. Fully ripe greenhouse Isidro tomatoes yielded an average of 3.2 adults per fruit and 20.4% of the eggs laid developed into adults, whereas the other categories and cultivars yielded less. The mean percentages of pupae over eggs were higher in fully ripe Isidro and 204 fruits, than in half-ripe Tobo and Ace ones. The mean time from oviposition to pupation ranged from 16.2 to 25 days, depending on the cultivar and degree of fruit maturity. In fully ripe Isidro and 204 fruits, the fewer the eggs laid per fruit, the higher the percent yield in pupae and the longer the time from oviposition to pupation. Greenhouse fully ripe fruits of cv. 204 maintained under a low light intensity of 50 lux gave a much lower yield in pupae and slower larval growth than under 1600 lux. The usefulness of tomatoes as substitutes of artificial diets in rearing the fly is discussed. http://www.phytoparasitica.org posting May 20, 2005.     

Insecticide resistance of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in mainland China

BACKGROUND: In order to investigate the extent of resistance of oriental fruit fly, Bactrocera dorsalis (Hendel), which is a widespread pest throughout tropical, subtropical and temperate fruit crops, 25 populations of this insect were collected from 13 sites in mainland China in 2007 and 2008. In addition, resistant strains were established that showed increasing development of resistance. RESULTS: Compared with the susceptible strain, one population of B. dorsalis expressed high resistance (RR = 70.4‐fold), 16 populations expressed medium resistance (11.5‐fold < RR < 25.8‐fold) and eight populations had low resistance or remained susceptible (1.4‐fold < RR < 8.9‐fold) to trichlorphon. As regards β‐cypermethrin, one population showed high resistance (RR = 44.0‐fold), nine populations expressed medium resistance (12.2‐fold < RR < 28.4‐fold), 14 populations expressed low or minor resistance (3.0‐fold < RR < 9.7‐fold) and one population remained susceptible (RR = 1.1‐fold). As regards avermectin, five populations had developed high resistance (44.3‐fold < RR < 104‐fold), seven populations expressed medium resistance (11.4‐fold < RR < 38.6‐fold) and three populations expressed low or minor resistance (3.5‐fold < RR < 5.6‐fold). A continuous resistance selection in the laboratory strain showed that the resistance ratios to trichlorphon, β‐cypermethrin and avermectin were 71.6‐fold, 333‐fold and 70.4‐fold respectively. CONCLUSION: The data provided a comprehensive survey of insecticide resistance in Bactrocera dorsalis in mainland China. All results suggested that early resistance management programmes should be established for restoring the efficacy of pesticide‐based control measures. Copyright © 2010 Society of Chemical Industry     

Control methods of the olive leaf gall midge (Dasineura oleae Angelini,Cecidomyiidae, Diptera) and potential implementation of integrated control programs in olive orchards

Journal of Plant Diseases and Protection - The olive leaf gall midge (Dasineura oleae) is a gall-inducing insect on leaves, branches and stems of flowers of olive trees. Heavy infestation with the...     

Neem (Azadirachta indica) seed kernel extracts and azadirachtin as oviposition deterrents against the melon fly (Bactrocera cucurbitae) and the oriental fruit fly (Bactrocera dorsalis)

Neem(Azadirachta indica A. Juss.) seed kernel (NSK) extracts,viz., NSK aqueous suspension (NSKS), ethanolic extract of NSK (EtOH. NSK), hexane extract of NSK (neem oil), ethanolic extract of the hexane extract (EtOH. oil) and acetone extract of deoiled NSK powder (Acet. DNSKP) at 1.25-20% concentrations, and pure azadirachtin at 1.25-10 ppm, were evaluated as oviposition deterrents toBactrocera cucurbitae (Coq.) andB. dorsalis Hendel. NSKS at ≥5% under choice test conditions, and at all concentrations (≥1.25%) in no-choice tests significantly deterred oviposition in both species. Similarly, EtOH. NSK was significantly active at all the concentrations tested for both species in choice and no-choice tests. However, with neem oil and EtOH. oil sensitivities of the two species differed considerably. Both extracts deterred oviposition byB. cucurbitae at all the concentrations tested under both choice and no-choice test conditions. On the other hand, withB. dorsalis, neem oil was significantly deterrent only at 20% in both test regimes and at 5% and 20% for EtOH. oil under choice and no-choice test conditions, respectively. Acet. DNSKP significantly deterred oviposition by both species at all concentrations tested. Azadirachtin failed to deter oviposition in either species.     

Raspberry ketone feeding makes Queensland fruit fly,Bactrocera tryoni (Froggatt), more vulnerable to desiccation but not starvation

Background

Queensland fruit fly (Qfly) males exhibit accelerated sexual maturation when their diet is supplemented with raspberry ketone (RK) for 48 h following emergence, which is beneficial for sterile insect technique operation. The present study tests whether RK supplementation makes Qfly more vulnerable to starvation or desiccation.

Results

Flies were fed for 48 h with a yeast hydrolysate and sugar diet (1:3) that contained 0% RK (control), 1.25% RK (low dose) or 5% RK (high dose) to test subsequent vulnerability to starvation and desiccation. RK feeding decreased body weight and water content in males and increased lipid levels in both sexes before exposure to any stress treatment. Under nutritional stress, flies fed the low RK dose, but not the high RK dose, had higher survival than controls. Under desiccation stress, flies fed both the low and high RK doses had lower survival than the controls. Body weight, water content and lipid reserves at death were all affected by RK dose when under nutritional stress, but not when under desiccation stress. In the absence of stress, body weight at death was higher than controls in flies provided with the high RK dose and lipids were lower than controls in flies provided with the low RK dose.

Conclusion

Feeding with RK makes Qflies more vulnerable to desiccation but not starvation. In most conditions, it is expected that the disadvantage of increased desiccation vulnerability would be outweighed by the benefits of accelerated sexual maturation in RK-fed young adult Qflies. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

番石榴果实蝇在我国的潜在地理分布

番石榴果实蝇Bactrocera(Bactrocera)correcta(Bezzi)是一种寄主范围广、为害严重的水果果实害虫,目前已入侵我国云南和台湾两省。为了明确该虫在我国的潜在地理分布,根据其生物生态学资料及地理分布信息,采用CLIMEX的地点比较模型和DIVA-GIS的BIOCLIM模型对番石榴果实蝇的适生区进行预测,并比较了预测结果。结果表明,预测番石榴果实蝇的潜在地理分布,地点比较模型优于BIOCLIM模型;该虫在我国的中、高适生区主要包括云南、广东、广西、海南、台湾、福建、贵州以及四川省。     

橘小实蝇不能在荔枝健果上成功产卵

根据在果园和室内测定，证实橘小蝇[Bactrocera dorsalis（Hendel）]不能在健康荔枝果实上成功产卵，但可在受损伤的果实上成功产卵。