Tephritid flies threaten the production of fruits around the world.In the Americas,populations of the genus Anastrepha are monitored with trapping networks as part of pest management programs.Here,we report the formul...Tephritid flies threaten the production of fruits around the world.In the Americas,populations of the genus Anastrepha are monitored with trapping networks as part of pest management programs.Here,we report the formulation of male Anastrepha suspensa(Loew)pheromones,(±)-anastrephin and(±)-epianastrephin,into a poly(vinyl chloride)(PVC)polymer-based lure ready for trap deployment.The PVC polymer disks(100 mg)contain 10%by weight of(±)-epianastrephin and(±)-anastrephin in a naturally occurring 7:3 diastereomeric ratio,respectively.Emission of the pheromones from the disks into an airstream was evaluated as a function of the abiotic environmental parameters,absolute humidity and temperature.Kinetic data supports a diffusion-controlled mechanism of release from the matrix with first-order rate constants that decreased about ten-fold as the temperature was lowered from 30 to 15C.As such,the emission of volatile pheromones from the disks is suitable to last for several weeks in the field.This kinetic approach,which can be easily extended to the diffusion-controlled release of other attractants from polymeric matrices,yields laboratory predictions of the potential for environmental loss prior to conducting field bioassays.展开更多
Detection of the presence of Anastrepha striata and Anastrepha ludens in guava cultures is presently done in Mexico by actually catching the flies in strategically located traps. The objective of this study is to show...Detection of the presence of Anastrepha striata and Anastrepha ludens in guava cultures is presently done in Mexico by actually catching the flies in strategically located traps. The objective of this study is to show that it is possible to locate areas with the presence or absence of flies by remote sensing means, thereby simplifying the traditional way of detection of these plagues. In the field, groups of traps were selected where flies had been captured, as well as areas in which there was no capture in the traps. The radiometric signatures of whole trees and leaves were obtained, showing measurable differences between those specimens affected by the plague and those unaffected. Next we selected a SPOT5 image of 2007 corresponding to the study area in Calvillo, State of Aguascalientes, in Mexico, one of the major areas of guava cultures in the country. A supervised classification of the image allowed for the location of guava cultures in it. The guava culture areas obtained from this classification were validated comparing them to available maps of the cultured areas. Spectral signatures for the classes were derived from the image data. The separability of pairs of classes was also evaluated in order to maximize it. The IR/R （infrared to red ratio） ratio of the image bands was evaluated in 80 × 80 pixels around the locations of five traps where flies had been captured, and around five locations where the traps had not captured flies. Only the pixels where guava cultures were present were included in the analysis, other types of vegetation and soil coverage were rejected. We found that the index distributions with flies captured and those without flies captured cluster in two well-separated groups. We note that plotting the whole distribution of pixels around a trap yields a diagnostic view of the area, and individual index values do not provide such a view, since values with the flies＇ presence and without these overlap to some extent. Further analyses of other trap locations confirmed this separation and also revealed a third group of intermediate values between the two above, that are interpreted as locations in which the guava cultures are affected by the plague at an early stage of development, where the flies are not captured by the traps since they do not yet hatch. We concluded that it is possible to use remote sensing techniques to identify the presence ofAnastrepha striata and Anastrepha ludens in cultures of Psidium guajava L., even probably at early stages of development of the plague.展开更多
Among tephritid fruit flies,hybridization has been found to produce local adaptation and speciation,and in the case of pest species,induce behavioral and ecological alterations that can adversely impact efficient pest...Among tephritid fruit flies,hybridization has been found to produce local adaptation and speciation,and in the case of pest species,induce behavioral and ecological alterations that can adversely impact efficient pest management.Thefraterculus species group within Anastrepha (Diptera:Tephritidae),is a rapidly radiating aggregate,which includes cryptic species complexes,numerous sister species,and several pest species. Molecular studies have highlighted the possibility of introgression between A.fraterculus and A.obliqua.Reproductive isolation has been studied among morphotypes of the A. fraterculus species complex as a tool for species delimitation.Here we examined the exis- tence and strength of prezygotic and postzygotic isolation between sympatric populations of two closely related species within the highly derivedfraterculus group (A.fraterculus and A.obliqua),coexisting in nature.Although adults of both species showed a strong tendency for assortative mating,a small proportion of hybrid pairings in both directions were observed.We also observed asymmetric postzygotic isolation,with one hybrid cross displaying a strong reduction in fecundity and F1 egg fertility.Survival was greater for the progeny of homotypic and hybrid crosses in the maternal host.There was a marked female biased sex ratio distortion for both F1 hybrid adults.Hybridization between A.fraterculus and A.obliqua in nature may be difficult but possible;these two species display stronger reproductive isolation than all pairs of species previously examined in the A.fraterculus species complex.Asymmetric postzygotie isolation is suggestive of Wolbachia mediated cytoplasmic incompatibilities that may be exploited in area-wide pest management.展开更多
The West Indian fruit fly, Anastrepha obliqua （Macquart）, is one of the most important pests throughout the Americas. CLIMEX 3.0 and ArcGIS 9.3 were used to model the current and future potential geographical distri...The West Indian fruit fly, Anastrepha obliqua （Macquart）, is one of the most important pests throughout the Americas. CLIMEX 3.0 and ArcGIS 9.3 were used to model the current and future potential geographical distribution of this pest. Under current climatic conditions, A. obliqua is predicted to be able to establish throughout much of the tropics and subtropics, including not only North and South America, where it has been reported, but also southern Asia, northeastern Australia and Sub-Saharan Africa. The main factors limiting the pest＇s range expansion may be cold stress. Climate change expands the potential distribution of A. obliqua poleward as cold stress boundaries recede, but the predicted distribution in northwestern Australia and northern parts of Sub-Saharan Africa will decrease because of heat stress. Considering the widely suitable range for A. obliqua globally and in China, enhanced quarantine and monitoring measures should be implemented in areas that are projected to be suitable for the establishment of the pest under current and future climatic conditions.展开更多
The behavioral responses of virgin and mated female Anastrepha striata Schiner （Diptera： Tephritidae） to guava （Psidium guajava L.） or sweet orange （Citrus sinensis L.） were evaluated separately using multilure...The behavioral responses of virgin and mated female Anastrepha striata Schiner （Diptera： Tephritidae） to guava （Psidium guajava L.） or sweet orange （Citrus sinensis L.） were evaluated separately using multilure traps in two-choice tests in field cages. The results showed that flies were more attracted to guava and sweet orange volatiles than to control （unbaited trap）. The physiological state （virgin or mated） of females did not affect their attraction to the fruit volatiles. Combined analysis of gas chromatography coupled with electroantennography （GC-EAD） of volatile extracts of both fruits showed that 1 and 6 compounds from orange and guava, respectively elicited repeatable antennal responses from mated females. The EAD active compounds in guava volatile extracts were identified by gas chromatography-mass spectrometry （GC-MS） as ethyl butyrate, （Z）-3-hexenol, hexanol, ethyl hexanoate, hexyl acetate, and ethyl octanoate. Linalool was identified as the only antennal active compound in sweet orange extracts. In field cage tests, there were no significant differences between the number of mated flies captured by the traps baited with guava extracts and the number caught by traps baited with the 6-component blend that was formulated according to the relative proportions in the guava extracts. Similar results occurred when synthetic linalool was evaluated against orange extracts. From a practical point of view, the compounds identified in this study could be used for monitoring A. striata populations.展开更多
Aging in all organisms is inevitable. Male age can have profound effects on mating success and female reproduction, yet relatively little is known on the effects of male age on different components of the ejaculate. F...Aging in all organisms is inevitable. Male age can have profound effects on mating success and female reproduction, yet relatively little is known on the effects of male age on different components of the ejaculate. Furthermore, in mass-reared insects used for the Sterile Insect Technique, there are often behavioral differences between mass-reared and wild males, while differences in the ejaculate have been less studied. The ejaculate in insects is composed mainly of sperm and accessory gland proteins. Here, we studied how male age and strain affected （i） protein quantity of testes and accessory glands, （ii） the biological activity of accessory gland products injected into females, （iii） sperm viability, and （iv） sperm quantity stored by females in wild and mass-reared Anastrepha ludens （Diptera： Tephritidae）. We found lower protein content in testes of old wild males and lower sperm viability in females mated with old wild males. Females stored more sperm when mated to young wild males than with young mass-reared males. Accessory gland injections of old or young males did not inhibit female remating. Knowledge of how male age affects different ejaculate components will aid our understanding on investment of the ejaculate and possible postcopulatory consequences on female behavior.展开更多
基金This research was funded by the USDA-Agricultural Research Service and the Cooperative Research and Development Agreement(#58-3K95-4-1665)with Betterworld Manufacturing(Fresno,USA).
文摘Tephritid flies threaten the production of fruits around the world.In the Americas,populations of the genus Anastrepha are monitored with trapping networks as part of pest management programs.Here,we report the formulation of male Anastrepha suspensa(Loew)pheromones,(±)-anastrephin and(±)-epianastrephin,into a poly(vinyl chloride)(PVC)polymer-based lure ready for trap deployment.The PVC polymer disks(100 mg)contain 10%by weight of(±)-epianastrephin and(±)-anastrephin in a naturally occurring 7:3 diastereomeric ratio,respectively.Emission of the pheromones from the disks into an airstream was evaluated as a function of the abiotic environmental parameters,absolute humidity and temperature.Kinetic data supports a diffusion-controlled mechanism of release from the matrix with first-order rate constants that decreased about ten-fold as the temperature was lowered from 30 to 15C.As such,the emission of volatile pheromones from the disks is suitable to last for several weeks in the field.This kinetic approach,which can be easily extended to the diffusion-controlled release of other attractants from polymeric matrices,yields laboratory predictions of the potential for environmental loss prior to conducting field bioassays.
文摘Detection of the presence of Anastrepha striata and Anastrepha ludens in guava cultures is presently done in Mexico by actually catching the flies in strategically located traps. The objective of this study is to show that it is possible to locate areas with the presence or absence of flies by remote sensing means, thereby simplifying the traditional way of detection of these plagues. In the field, groups of traps were selected where flies had been captured, as well as areas in which there was no capture in the traps. The radiometric signatures of whole trees and leaves were obtained, showing measurable differences between those specimens affected by the plague and those unaffected. Next we selected a SPOT5 image of 2007 corresponding to the study area in Calvillo, State of Aguascalientes, in Mexico, one of the major areas of guava cultures in the country. A supervised classification of the image allowed for the location of guava cultures in it. The guava culture areas obtained from this classification were validated comparing them to available maps of the cultured areas. Spectral signatures for the classes were derived from the image data. The separability of pairs of classes was also evaluated in order to maximize it. The IR/R （infrared to red ratio） ratio of the image bands was evaluated in 80 × 80 pixels around the locations of five traps where flies had been captured, and around five locations where the traps had not captured flies. Only the pixels where guava cultures were present were included in the analysis, other types of vegetation and soil coverage were rejected. We found that the index distributions with flies captured and those without flies captured cluster in two well-separated groups. We note that plotting the whole distribution of pixels around a trap yields a diagnostic view of the area, and individual index values do not provide such a view, since values with the flies＇ presence and without these overlap to some extent. Further analyses of other trap locations confirmed this separation and also revealed a third group of intermediate values between the two above, that are interpreted as locations in which the guava cultures are affected by the plague at an early stage of development, where the flies are not captured by the traps since they do not yet hatch. We concluded that it is possible to use remote sensing techniques to identify the presence ofAnastrepha striata and Anastrepha ludens in cultures of Psidium guajava L., even probably at early stages of development of the plague.
文摘Among tephritid fruit flies,hybridization has been found to produce local adaptation and speciation,and in the case of pest species,induce behavioral and ecological alterations that can adversely impact efficient pest management.Thefraterculus species group within Anastrepha (Diptera:Tephritidae),is a rapidly radiating aggregate,which includes cryptic species complexes,numerous sister species,and several pest species. Molecular studies have highlighted the possibility of introgression between A.fraterculus and A.obliqua.Reproductive isolation has been studied among morphotypes of the A. fraterculus species complex as a tool for species delimitation.Here we examined the exis- tence and strength of prezygotic and postzygotic isolation between sympatric populations of two closely related species within the highly derivedfraterculus group (A.fraterculus and A.obliqua),coexisting in nature.Although adults of both species showed a strong tendency for assortative mating,a small proportion of hybrid pairings in both directions were observed.We also observed asymmetric postzygotic isolation,with one hybrid cross displaying a strong reduction in fecundity and F1 egg fertility.Survival was greater for the progeny of homotypic and hybrid crosses in the maternal host.There was a marked female biased sex ratio distortion for both F1 hybrid adults.Hybridization between A.fraterculus and A.obliqua in nature may be difficult but possible;these two species display stronger reproductive isolation than all pairs of species previously examined in the A.fraterculus species complex.Asymmetric postzygotie isolation is suggestive of Wolbachia mediated cytoplasmic incompatibilities that may be exploited in area-wide pest management.
文摘The West Indian fruit fly, Anastrepha obliqua （Macquart）, is one of the most important pests throughout the Americas. CLIMEX 3.0 and ArcGIS 9.3 were used to model the current and future potential geographical distribution of this pest. Under current climatic conditions, A. obliqua is predicted to be able to establish throughout much of the tropics and subtropics, including not only North and South America, where it has been reported, but also southern Asia, northeastern Australia and Sub-Saharan Africa. The main factors limiting the pest＇s range expansion may be cold stress. Climate change expands the potential distribution of A. obliqua poleward as cold stress boundaries recede, but the predicted distribution in northwestern Australia and northern parts of Sub-Saharan Africa will decrease because of heat stress. Considering the widely suitable range for A. obliqua globally and in China, enhanced quarantine and monitoring measures should be implemented in areas that are projected to be suitable for the establishment of the pest under current and future climatic conditions.
文摘The behavioral responses of virgin and mated female Anastrepha striata Schiner （Diptera： Tephritidae） to guava （Psidium guajava L.） or sweet orange （Citrus sinensis L.） were evaluated separately using multilure traps in two-choice tests in field cages. The results showed that flies were more attracted to guava and sweet orange volatiles than to control （unbaited trap）. The physiological state （virgin or mated） of females did not affect their attraction to the fruit volatiles. Combined analysis of gas chromatography coupled with electroantennography （GC-EAD） of volatile extracts of both fruits showed that 1 and 6 compounds from orange and guava, respectively elicited repeatable antennal responses from mated females. The EAD active compounds in guava volatile extracts were identified by gas chromatography-mass spectrometry （GC-MS） as ethyl butyrate, （Z）-3-hexenol, hexanol, ethyl hexanoate, hexyl acetate, and ethyl octanoate. Linalool was identified as the only antennal active compound in sweet orange extracts. In field cage tests, there were no significant differences between the number of mated flies captured by the traps baited with guava extracts and the number caught by traps baited with the 6-component blend that was formulated according to the relative proportions in the guava extracts. Similar results occurred when synthetic linalool was evaluated against orange extracts. From a practical point of view, the compounds identified in this study could be used for monitoring A. striata populations.
文摘Aging in all organisms is inevitable. Male age can have profound effects on mating success and female reproduction, yet relatively little is known on the effects of male age on different components of the ejaculate. Furthermore, in mass-reared insects used for the Sterile Insect Technique, there are often behavioral differences between mass-reared and wild males, while differences in the ejaculate have been less studied. The ejaculate in insects is composed mainly of sperm and accessory gland proteins. Here, we studied how male age and strain affected （i） protein quantity of testes and accessory glands, （ii） the biological activity of accessory gland products injected into females, （iii） sperm viability, and （iv） sperm quantity stored by females in wild and mass-reared Anastrepha ludens （Diptera： Tephritidae）. We found lower protein content in testes of old wild males and lower sperm viability in females mated with old wild males. Females stored more sperm when mated to young wild males than with young mass-reared males. Accessory gland injections of old or young males did not inhibit female remating. Knowledge of how male age affects different ejaculate components will aid our understanding on investment of the ejaculate and possible postcopulatory consequences on female behavior.
