Chemosterilants as control agents of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in field trials

[EN] Lufenuron is a chitin synthesis inhibitor, which is able to impede Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reproduction. In laboratory trials, following ingestion of lufenuron, the eggs laid by female Ceratitis capitata were prevented from hatching. In field trials in Valencia, Spain, lufenuron showed its effectiveness by reducing C. capitata wild populations and its continuous application to several generations of fruit fly resulted in increased pest control. This field trial was conducted in an isolated valley some 80ha in size, over a continuous four-year period. In order to maintain the sterilizing effect in the field throughout the whole year, a new lufenuron bait gel was developed. This bait gel was introduced in to delta traps suspended in trees at a density of 24 traps ha 1, and these traps were replaced once a year during the field trial. Monitoring of the adult C. capitata population was conducted to assess the effects of the chemosterilant treatment. In the first year of treatment with sterilizing traps, a reduction of the C. capitata population was observed, indicating that the traps reduce the population right from the first generation. In the second, third and fourth years, a continuous and progressive reduction of the adult Mediterranean fruit fly population was observed. Therefore, the successive application of chemosterilization treatment has a cumulative effect on reducing the fly population year after year. Aerial treatment using malathion does not produce this cumulative effect, and consequently every year it is necessary to start again with the same number of flies as the year before. The possibility of using the chemosterilant method alone or combined with the sterile insect technique is discussed.The authors thank Stephen Skillman for helpful suggestions on the first version of the manuscript, Syngenta for supplying technical grade lufenuron, and the R&D+i Linguistic Assistance Office at the Universidad Politécnica de Valencia for their help in revising and correcting this paper. This research has been supported by ‘Fundación José y Ana Royo’, ‘Conselleria d’Agricultura Peixca i Alimentacio-GVA’ and INIA project number RTA03-103-C6.Navarro Llopis, V.; Sanchis Cabanes, J.; Primo Millo, J.; Primo Yufera, E. (2007). Chemosterilants as control agents of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) in field trials. Bulletin of Entomological Research. 97(4):359-368. https://doi.org/10.1017/S0007485307005081S35936897

Improvements in Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) Trapping Systems

[EN] Improved trap efficacy is crucial for implementing control methods for red palm weevil, Rhynchophorus ferrugineus (Olivier; Coleoptera: Dryophthoridae), based on trapping systems, such as mass trapping, attract and infect or attract and sterilize techniques. Although new trap designs have been proposed and aggregation pheromone dispensers have been optimized, aspects such as the use of co-attractants (molasses) and trap placement are still not well defined and standardized. The efficacy of three concentrations of molasses and different formulations to reduce water evaporation in traps was studied in different field trials to improve trapping systems and to prolong trap servicing periods. In addition, the performance of installing groups of traps or single traps was also evaluated with the aim of improving the attracted/captured weevils ratio. Our results showed that captures increased when molasses were added at 15% to the water contained in the trap and that a thin layer of oil, created by adding 2-3% of paraffinic oil to water, was able to effectively reduce evaporation and prolong trap servicing periods. Moreover, 3.5-fold more weevils were captured when placing five traps instead of one at the same trapping point. Results obtained allow improved efficacy and may have an impact in the economic viability of trapping systems and, therefore, in integrated pest management programs.We want to thank Vicente Dalmau from Conselleria de Agricultura, Peixca i Alimentacio (GVA) and Jose Juan Lopez from TRAGSA for their help and technical assistance in field trials. Also, we want to thank Helen Warburton for English editing. The research leading to these results has received funding from the 7th European Union Framework Programme under grant agreement FP7 KBBE 2011-5-289566 (PALM PROTECT).Navarro-Llopis, V.; Primo Millo, J.; Vacas, S. (2018). Improvements in Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) Trapping Systems. Journal of Economic Entomology. 111(3):1298-1305. https://doi.org/10.1093/jee/toy065S12981305111

Influence of pheromone emission on the attraction of California red scale males in citrus orchards

[EN] Attraction of California red scale males, Aonidiella aurantii (Maskell), to different release rates of the sex pheromone compound 3-methyl-6-isopropenyl-9-decen-1-yl acetate was evaluated in field trials. This study was aimed to study pheromone emission-response correlations and the existence of an optimum release rate that maximizes trapping efficacy. Release profiles of the pheromone dispensers deployed were determined by gas chromatography to estimate the various emission rates tested. The results reveal that the mean number of A. aurantii males caught correlates with the daily pheromone release rates by means of a quadratic model. The obtained model indicates the existence of a relative maximum of the captures corresponding to an optimum release rate of ca. 300 mu g/day. Higher emission rates (up to 1 g/day) resulted in lower captures. Implications for the mating disruption technique are discussed.The research leading to these results received funding from the Spanish Ministry of Science and Innovation [project number AGL2009-10725].Vacas González, S.; Primo Millo, J.; Navarro-Llopis, V. (2017). Influence of pheromone emission on the attraction of California red scale males in citrus orchards. International Journal of Pest Management. 63(1):10-17. https://doi.org/10.1080/09670874.2016.1209253S1017631Anshelevich, L., Kehat, M., Dunkelblum, E., & Greenberg, S. (1994). Sex Pheromone Traps for Monitoring the European Vine Moth,Lobesia botrana: Effect of Dispenser Type, Pheromone Dose, Field Aging of Dispenser, and Type of Trap on Male Captures. Phytoparasitica, 22(4), 281-290. doi:10.1007/bf02980529Carde, R. T., & Minks, A. K. (1995). Control of Moth Pests by Mating Disruption: Successes and Constraints. Annual Review of Entomology, 40(1), 559-585. doi:10.1146/annurev.en.40.010195.003015Domínguez-Ruiz, J., Sanchis, J., Navarro-Llopis, V., & Primo, J. (2008). A New Long-Life Trimedlure Dispenser for Mediterranean Fruit Fly. Journal of Economic Entomology, 101(4), 1325-1330. doi:10.1603/0022-0493(2008)101[1325:anltdf]2.0.co;2Gardner, P. D., Ervin, R. T., Moreno, D. S., & Baritelle, L. (1983). California Red Scale (Homoptera: Diaspididae): Cost Analysis of A Pheromone Monitoring Program1. Journal of Economic Entomology, 76(3), 601-604. doi:10.1093/jee/76.3.601Gieselmann, M. J., Henrick, C. A., Anderson, R. J., Moreno, D. S., & Roelofs, W. L. (1980). Responses of male California red scale to sex pheromone isomers. Journal of Insect Physiology, 26(3), 179-182. doi:10.1016/0022-1910(80)90078-5Grout, T. G., Toit, D. W. J., Hofmeyr, J. H., & Richards, G. I. (1989). California Red Scale (Homoptera: Diaspididae) Phenology on Citrus in South Africa. Journal of Economic Entomology, 82(3), 793-798. doi:10.1093/jee/82.3.793Grout, T. G., & Richards, G. I. (1991). Value of pheromone traps for predicting infestations of red scale, Aonidiella aurantii (Maskell) (Hom., Diaspididae), limited by natural enemy activity and insecticides used to control citrus thrips, Scirtothrips aurantii Faure (Thys., Thripidae). Journal of Applied Entomology, 111(1-5), 20-27. doi:10.1111/j.1439-0418.1991.tb00290.xJacobson, M., & Beroza, M. (1964). Insect Attractants. Scientific American, 211(2), 20-27. doi:10.1038/scientificamerican0864-20Kennett, C. E., & Hoffmann, R. W. (1985). Seasonal Development of the California Red Scale (Homoptera: Diaspididae) in San Joaquin Valley Citrus Based on Degree-Day Accumulation. Journal of Economic Entomology, 78(1), 73-79. doi:10.1093/jee/78.1.73Knutson, A. E., Harris, M. K., & Millar, J. G. (1998). Effects of Pheromone Dose, Lure Age, and Trap Design on Capture of Male Pecan Nut Casebearer (Lepidoptera: Pyralidae) in Pheromone-Baited Traps. Journal of Economic Entomology, 91(3), 715-722. doi:10.1093/jee/91.3.715McDonough, L. M., Brown, D. F., & Aller, W. C. (1989). Insect sex pheromones. Journal of Chemical Ecology, 15(3), 779-790. doi:10.1007/bf01015176McLaughlin, J. R. (1990). Behavioral response of male white peach scale to the sex pheromone, (R,Z)-3,9,-dimethyl-6-isopropenyl-3,9-decadien-1-ol propionate and corresponding alcohol. Journal of Chemical Ecology, 16(3), 749-756. doi:10.1007/bf01016486Moreno, D. S., Carman, G. E., & Bain, N. S. (1972). Extraction and Bioassay of, and Effect of Solvents on, the Sex Pheromone of the Yellow Scale1, 2. Annals of the Entomological Society of America, 65(5), 1061-1064. doi:10.1093/aesa/65.5.1061Moreno, D. S., Fargerlund, J., & Shaw, J. G. (1973). California Red Scale: Captures of Males in Modified Pheromone Traps13. Journal of Economic Entomology, 66(6), 1333-1333. doi:10.1093/jee/66.6.1333Moreno, D. S., & Kennett, C. E. (1985). Predictive Year-end California Red Scale (Homoptera: Diaspididae) Orange Fruit Infestations Based on Catches of Males in the San Joaquin Valley. Journal of Economic Entomology, 78(1), 1-9. doi:10.1093/jee/78.1.1Navarro-Llopis, V., Sanchis, J., Primo-Millo, J., & Primo-Yúfera, E. (2007). Chemosterilants as control agents of Ceratitis capitata (Diptera: Tephritidae) in field trials. Bulletin of Entomological Research, 97(4), 359-368. doi:10.1017/s0007485307005081Rice, R. E., & Moreno, D. S. (1970). Flight of Male California Red Scale1,2,3. Annals of the Entomological Society of America, 63(1), 91-96. doi:10.1093/aesa/63.1.91Rice, R. E., & Moreno, D. S. (1969). Marking and Recapture of California Red Scale1 for Field Studies3,4. Annals of the Entomological Society of America, 62(3), 558-560. doi:10.1093/aesa/62.3.558Rice, R. E., & Hoyt, S. C. (1980). Response of San Jose Scale 1 to Natural and Synthetic Sex Pheromones. Environmental Entomology, 9(2), 190-194. doi:10.1093/ee/9.2.190ROELOFS, W. L., GIESELMANN, M. J., CARDÉ, A. M., TASHIRO, H., MORENO, D. S., HENRICK, C. A., & ANDERSON, R. J. (1977). Sex pheromone of the California red scale, Aonidiella aurantii. Nature, 267(5613), 698-699. doi:10.1038/267698a0Roelofs, W., Gieselmann, M., Card�, A., Tashiro, H., Moreno, D. S., Henrick, C. A., & Anderson, R. J. (1978). Identification of the California red scale sex pheromone. Journal of Chemical Ecology, 4(2), 211-224. doi:10.1007/bf00988056Samways, M. J. (1988). Comparative monitoring of red scaleAonidiella aurantii(Mask.) (Hom., Diaspididae) and itsAphytisspp. (Hym., Aphelinidae) parasitoids. Journal of Applied Entomology, 105(1-5), 483-489. doi:10.1111/j.1439-0418.1988.tb00214.xShaw, J. G., Moreno, D. S., & Fargerlund, J. (1971). Virgin Female California Red Scales Used to Detect Infestations13. Journal of Economic Entomology, 64(5), 1305-1306. doi:10.1093/jee/64.5.1305Tashiro, H., & Chambers, D. L. (1967). Reproduction in the California Red Scale, Aonidiella aurantii (Homoptera: Diaspididae). I. Discovery and Extraction of a Female Sex Pheromone1,2. Annals of the Entomological Society of America, 60(6), 1166-1170. doi:10.1093/aesa/60.6.1166Vacas, S., Alfaro, C., Navarro-Llopis, V., & Primo, J. (2009). The first account of the mating disruption technique for the control of California red scale, Aonidiella aurantii Maskell (Homoptera: Diaspididae) using new biodegradable dispensers. Bulletin of Entomological Research, 99(4), 415-423. doi:10.1017/s0007485308006470Vacas, S., Alfaro, C., Navarro-Llopis, V., Zarzo, M., & Primo, J. (2009). Study on the Optimum Pheromone Release Rate for Attraction of Chilo suppressalis (Lepidoptera: Pyralidae). Journal of Economic Entomology, 102(3), 1094-1100. doi:10.1603/029.102.0330Vacas, S., Alfaro, C., Navarro-Llopis, V., & Primo, J. (2010). Mating disruption of California red scale, Aonidiella aurantii Maskell (Homoptera: Diaspididae), using biodegradable mesoporous pheromone dispensers. Pest Management Science, 66(7), 745-751. doi:10.1002/ps.1937Vacas, S., Alfaro, C., Primo, J., & Navarro-Llopis, V. (2014). Deployment of mating disruption dispensers before and after first seasonal male flights for the control of Aonidiella aurantii in citrus. Journal of Pest Science, 88(2), 321-329. doi:10.1007/s10340-014-0623-1Vacas, S., Miñarro, M., Bosch, M. D., Primo, J., & Navarro-Llopis, V. (2013). Studies on the Codling Moth (Lepidoptera: Tortricidae) Response to Different Codlemone Release Rates. Environmental Entomology, 42(6), 1383-1389. doi:10.1603/en13114Zhang, A., & Amalin, D. (2005). Sex Pheromone of the Female Pink Hibiscus Mealybug,Maconellicoccus hirsutus(Green) (Homoptera: Pseudococcidae): Biological Activity Evaluation. Environmental Entomology, 34(2), 264-270. doi:10.1603/0046-225x-34.2.26

Isolation of N-(2-Methyl-3-oxodecanoyl)pyrrole and N-(2-Methyl-3-oxodec-8-enoyl)pyrrole, Two New Natural Products from Penicillium brevicompactum, and Synthesis of Analogues with Insecticiidal and Fungicidal Activity

[EN] Two new natural products have been isolated from culture broth of Penicillium brevicompactum Dierckx. The structures have be en assigned as N-(2-methyl-3-oxodecanoyl)pyrrole and N-(2-methyl-3-oxodec-8-enoyl)pyrrole on the basis of spectral data. Synthesis of analogues has been carried out by acylation of the pyrrole ring at Ct with different acylated Meldrum's acids. Two analogues (6b and 7b) have shown interesting insecticidal activities, and three other ones (6a, 6c, and 7a) have exhibited significant broad-spectrum fungicidal activities. These synthetic products might be considered as a starting point in the search for new pesticides.Cantin Sanz, A.; Moya, P.; Miranda Alonso, MÁ.; Primo Millo, J.; Primo Yufera, E. (1998). Isolation of N-(2-Methyl-3-oxodecanoyl)pyrrole and N-(2-Methyl-3-oxodec-8-enoyl)pyrrole, Two New Natural Products from Penicillium brevicompactum, and Synthesis of Analogues with Insecticiidal and Fungicidal Activity. Journal of Agricultural and Food Chemistry. 46(11):4748-4753. doi:10.1021/jf9800763S47484753461

Influence of weather conditions on Lobesia botrana (Lepidoptera: Tortricidae) mating disruption dispensers' emission rates and efficacy

[EN] Passive dispensers are the most widely used dispensers to control the European grapevine moth, Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae), by mating disruption (MD). Although their efficacy is well-proven, efforts are needed to reduce the use of pheromone without compromising efficacy and to allow lower MD costs. For this purpose, two different widely employed dispenser types in Europe against this pest (Ampoule and Rope dispensers) were evaluated in the field to verify their performance (emission rates and efficacy) in relation to weather conditions. Their release profiles were studied by extracting and quantifying the residual pheromone load over time by gas chromatography. Dispensers' performance in relation to weather conditions was then assessed by correlating the daily emission rates with the mean daily values of several of these variables. Although both dispenser types were efficient in controlling L. botrana populations and reducing fruit damage, their pheromone content and their release rates differed at the end of the crop cycle. The Ampoule dispensers emitted lower amounts of pheromone throughout the study period, whereas the Rope dispensers¿ emissions were weather-dependent, with higher emission rates at higher mean temperatures and wind speeds. Our results showed that the current commercial MD dispensers could be improved by adjusting their release rates to better reflect actual pheromone requirements.Authors would like to thank Celler del Roure winery (Mogente, Valencia) and Emilio Giménez (Venta del Moro) for providing field study vineyards. This research received funding from Conselleria de Agricultura, Desarrollo Rural, Emergencia Climática y Transicion Ecologica (Generalitat Valenciana) under grant agreement S8456000. We are also grateful to Ana Castellar and Helen Warburton for language editing. Funding for open access charge: CRUE-Universitat Politécnica de Valéncia.Gavara, A.; Navarro-Llopis, V.; Primo Millo, J.; Vacas, S. (2022). Influence of weather conditions on Lobesia botrana (Lepidoptera: Tortricidae) mating disruption dispensers' emission rates and efficacy. Crop Protection. 155:1-8. https://doi.org/10.1016/j.cropro.2022.105926S1815