Nest construction is a common form of parental care in soil organisms. However, it is unknown whe... more Nest construction is a common form of parental care in soil organisms. However, it is unknown whether the tropical earthwormPontoscolex corethrurusproduces nests in soils with low nutritional quality habitat. Here we studied the reproductive behaviour and nest site selection ofP. corethrurus, and tested the hypothesis whetherP. corethrurusproduces more cocoons in habitats with low nutritional quality. In bidimensional terrariums we evaluated the combined effect of the nutritional quality of habitat: (Poor Quality Habitat = PQH, Medium Quality Habitat = MQH, High Quality Habitat = HQH) and soil depth (Shallow, Intermediate, Deep) in a factorial 32design. The number and biomass of cocoons, progeny and the production of internal and external excreta were evaluated. The quality habitat and depth of soil and their interaction had a significant effect on nest site construction and the deposition of internal excreta. Pontoscolex corethrurus built a higher amount of nests in the PQH-Interme...
Annals of the Entomological Society of America, 2016
Abstract The mahogany shoot borer Hypsipyla grandella (Zeller) is one of the worst neotropical fo... more Abstract The mahogany shoot borer Hypsipyla grandella (Zeller) is one of the worst neotropical forest pests. Currently there is no control method that effectively reduces levels of infestation to an economically acceptable threshold. Basic knowledge on the sexual behavior of this pest is required to develop control methods. However, so far reproduction in this species has only been achieved in captivity and studied using outdoor mating cages. Here we describe for the first time, as far as we know, the precopulatory and copulatory behavior of H. grandella under controlled conditions. We found males and females performed a short and long wing-fanning behavior. Furthermore, we evaluated each behavior at three different sex ratios (3♂:1♀, 2♂:2♀, and 1♂:3♀), and studied the effect of male and female adult size on copulatory success. We observed 50% of copulations in the equal sex ratio, but found no significant effect of male or female size on the probability of mating. Copulations under laboratory conditions lasted almost two hours. These results are comparable to studies in outdoor cages. Detailed observations on the mating behavior under controlled conditions, and what factors affect mating success, can contribute toward a better understanding of H. grandella to expedite development of control methods.
Anastrepha ludens (Diptera: Tephritidae), is a damaging agricultural pest. Currently, the Sterile... more Anastrepha ludens (Diptera: Tephritidae), is a damaging agricultural pest. Currently, the Sterile Insect Technique (SIT) is used as part of its control. The SIT consists of the mass-rearing, sterilization, and release of insects in target areas. Sterile males mate with wild females, and prevent them from laying fertile eggs. However, even if females mate with sterile males, they can then remate with a second male. If this second male is wild, then this could reduce the efficiency of the SIT by producing viable offspring. The amount of progeny produced by second males (P2 values) for A. ludens is unknown. Here, we evaluated the biological attributes, mating competitiveness, and the proportion of male paternity gained by the second male, using strains that carry fluorescent marker genes and can be potentially used to develop transgenic sexing strains. Furthermore, the transgenic strains were irradiated, to test their ability to induce sterility in females. We found that the 443-G stra...
Aging in all organisms is inevitable. Male age can have profound effects on mating success and fe... more 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.
Species that exhibit broad ranges of distribution may successfully navigate environmental changes... more Species that exhibit broad ranges of distribution may successfully navigate environmental changes by modifying some of their life-history traits. Environmental humidity imposes a critical stress that organisms may overcome by increasing their resistance to desiccation. We used experimental evolution to investigate adaptation to desiccation in the tephritid Anastrepha ludens, a species with high fecundity, late maturation, and long lifespan. We measured morphological, physiological, developmental as well as demographic changes involved in the adaptation to desiccation. Notwithstanding a low heritability (h(2) = 0.237), desiccation resistance evolved extremely rapidly and few negative trade-offs were detected. Selected flies exhibited correlated increases in longevity, body size, the amount of body lipids, and bulk water content, and in the duration of the pupal stage. Females further delayed sexual maturation, decreased daily fecundity but retained high lifetime reproductive potential. No differences in male mating competitiveness were found. Selected and control lines differed in longevity but not in total female fecundity, demonstrating that A. ludens flies have the capability for fast adaptation to desiccation without loosing their reproductive capability. Thus, it seems that a rapid evolutionary response to desiccation in this polyphagous insect works as a buffer for environmental variation and reduces the strength of selection on reproductive traits.
Survival and mating success are traits of quality in mass-reared sterile males. Thus, studying th... more Survival and mating success are traits of quality in mass-reared sterile males. Thus, studying the trade-offs between these traits may help to improve process in the sterile insect technique (SIT). Here, we tested the hypothesis that modifying individual metabolism, especially of energetic reserves, may reduce the negative impact of an early reproduction on the survival of Anastrepha ludens flies. Appling metformin (a drug used to treat type II diabetes) that improves insects’ survival, through dietary restriction mimicry, and methoprene (a juvenile hormone analogue) that accelerates the age to reproduction in insects, we explore the dynamic of this trade-off. We fed A. ludens flies with metformin, methoprene, or a mixture of metformin–methoprene for five consecutive days. We determined the effect of these treatments on the fecundity and fertility (number of eggs and percentage of hatching) of females, on sexual maturation and mating success of males, and on the survival of both sex...
Anastrepha ludens (Loew) (Diptera: Tephritidae) is an endemic pest of Mexico, attacking several f... more Anastrepha ludens (Loew) (Diptera: Tephritidae) is an endemic pest of Mexico, attacking several fruits of economic importance. The Sterile Insect Technique (SIT), consisting of mass-rearing, irradiation and release of adults, is used to control this pest in affected areas. Currently, a genetic sexing strain (Tapachula 7, Tap-7) consisting only of A. ludens males is being released, yet we lack information on its sexual performance at the early ages when they are released and on its post copulatory behavior in terms of sperm transfer and mating inhibition. Here, sexual competitiveness at young ages and ability to inhibit female re-mating was compared between sterile Tap-7, Standard Bisexual (SB), or wild males both in laboratory and field cage conditions. Sperm stored by females mating with wild, Tap-7, or SB strain males was also compared. Six-day-old sterile Tap-7 males had low mating rates, however, by 7 d of age 80% of males had mated. Tap-7 males were just as likely as wild males...
For insect pests controlled through the Sterile Insect Technique (SIT), which consists in the mas... more For insect pests controlled through the Sterile Insect Technique (SIT), which consists in the mass production, sterilization, and release of target insects into affected areas, sterile male mating success with wild females is the key that will reduce population levels in the next generation. Male size is assumed to be important for mating success, but often without any concrete evidence or confounded by other parameters. Here, we evaluated male size and its interaction with male origin (laboratory or wild) on female choice for two lekking species controlled through SIT, Anastrepha obliqua (Macquart) and Anastrepha ludens (Loew) (Diptera: Tephritidae). In field cages, we tested wild females mating with: large wild males competing against small wild males; large wild males against small laboratory-sterile males; and large laboratory-sterile males against small wild males. We found evidence of large male advantage for A. obliqua but no effect of male size on mating competitiveness for ...
The sterile insect technique (SIT) is used in area-wide pest management programs for establishing... more The sterile insect technique (SIT) is used in area-wide pest management programs for establishing low pest prevalence and/or areas free of fruit flies (Diptera: Tephritidae). The aim of this technique is to induce high levels of sterility in the wild population, for this the released insects must have a high sexual competitiveness and field dispersal. However, radiation decreases these biological attributes that do not allow it to compete successfully with wild insects. In this study the sexual competitiveness, field survival and dispersal of Anastrepha obliqua (Macquart; Diptera: Tephritidae) irradiated at 0, 40, 50, 60, 70, and 80 Gy were evaluated in laboratory. A dose of 60 Gy produced 98% sterility, whereas doses of 70 and 80 Gy produced 99% sterility. Sexual competitiveness was assessed in field cages, comparing males irradiated at 0, 50, 60, 70, and 80 Gy against wild males for mating with wild fertile females. Males irradiated at 50 and 60 Gy achieved more matings than those...
Toxic environmental effects of most insecticides have led to a search for bio-organic insecticide... more Toxic environmental effects of most insecticides have led to a search for bio-organic insecticides. In this study, we tested the effects of lethal and sublethal exposure to two abamectin-based insecticides (VOLIAM TARGO and LUQ-THOR) on survival, mating, and oviposition of the tephritid Anastrepha ludens (Loew). Different doses of insecticides (0.001-2.00% of the commercial products) were offered mixed with the phagostimulant bait Captor commonly used in spraying and in trapping activities for the control of flies. Both insecticides exhibited 90% killing effectiveness (Abbott index) when offered in doses between 0.02 to 2.00%. The LC50 obtained from the bioassay at 72 h after treatment was 0.003% of commercial product for TARGO and 0.008% for LUQ-THOR. Sublethal exposures to insecticides (0.003%; LC50 for TARGO and LC30 for LUQ-THOR) caused a reduction in oviposition but not in mating parameters, indicating that females were more susceptible than males to reduced doses of insecticid...
Nest construction is a common form of parental care in soil organisms. However, it is unknown whe... more Nest construction is a common form of parental care in soil organisms. However, it is unknown whether the tropical earthwormPontoscolex corethrurusproduces nests in soils with low nutritional quality habitat. Here we studied the reproductive behaviour and nest site selection ofP. corethrurus, and tested the hypothesis whetherP. corethrurusproduces more cocoons in habitats with low nutritional quality. In bidimensional terrariums we evaluated the combined effect of the nutritional quality of habitat: (Poor Quality Habitat = PQH, Medium Quality Habitat = MQH, High Quality Habitat = HQH) and soil depth (Shallow, Intermediate, Deep) in a factorial 32design. The number and biomass of cocoons, progeny and the production of internal and external excreta were evaluated. The quality habitat and depth of soil and their interaction had a significant effect on nest site construction and the deposition of internal excreta. Pontoscolex corethrurus built a higher amount of nests in the PQH-Interme...
Annals of the Entomological Society of America, 2016
Abstract The mahogany shoot borer Hypsipyla grandella (Zeller) is one of the worst neotropical fo... more Abstract The mahogany shoot borer Hypsipyla grandella (Zeller) is one of the worst neotropical forest pests. Currently there is no control method that effectively reduces levels of infestation to an economically acceptable threshold. Basic knowledge on the sexual behavior of this pest is required to develop control methods. However, so far reproduction in this species has only been achieved in captivity and studied using outdoor mating cages. Here we describe for the first time, as far as we know, the precopulatory and copulatory behavior of H. grandella under controlled conditions. We found males and females performed a short and long wing-fanning behavior. Furthermore, we evaluated each behavior at three different sex ratios (3♂:1♀, 2♂:2♀, and 1♂:3♀), and studied the effect of male and female adult size on copulatory success. We observed 50% of copulations in the equal sex ratio, but found no significant effect of male or female size on the probability of mating. Copulations under laboratory conditions lasted almost two hours. These results are comparable to studies in outdoor cages. Detailed observations on the mating behavior under controlled conditions, and what factors affect mating success, can contribute toward a better understanding of H. grandella to expedite development of control methods.
Anastrepha ludens (Diptera: Tephritidae), is a damaging agricultural pest. Currently, the Sterile... more Anastrepha ludens (Diptera: Tephritidae), is a damaging agricultural pest. Currently, the Sterile Insect Technique (SIT) is used as part of its control. The SIT consists of the mass-rearing, sterilization, and release of insects in target areas. Sterile males mate with wild females, and prevent them from laying fertile eggs. However, even if females mate with sterile males, they can then remate with a second male. If this second male is wild, then this could reduce the efficiency of the SIT by producing viable offspring. The amount of progeny produced by second males (P2 values) for A. ludens is unknown. Here, we evaluated the biological attributes, mating competitiveness, and the proportion of male paternity gained by the second male, using strains that carry fluorescent marker genes and can be potentially used to develop transgenic sexing strains. Furthermore, the transgenic strains were irradiated, to test their ability to induce sterility in females. We found that the 443-G stra...
Aging in all organisms is inevitable. Male age can have profound effects on mating success and fe... more 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.
Species that exhibit broad ranges of distribution may successfully navigate environmental changes... more Species that exhibit broad ranges of distribution may successfully navigate environmental changes by modifying some of their life-history traits. Environmental humidity imposes a critical stress that organisms may overcome by increasing their resistance to desiccation. We used experimental evolution to investigate adaptation to desiccation in the tephritid Anastrepha ludens, a species with high fecundity, late maturation, and long lifespan. We measured morphological, physiological, developmental as well as demographic changes involved in the adaptation to desiccation. Notwithstanding a low heritability (h(2) = 0.237), desiccation resistance evolved extremely rapidly and few negative trade-offs were detected. Selected flies exhibited correlated increases in longevity, body size, the amount of body lipids, and bulk water content, and in the duration of the pupal stage. Females further delayed sexual maturation, decreased daily fecundity but retained high lifetime reproductive potential. No differences in male mating competitiveness were found. Selected and control lines differed in longevity but not in total female fecundity, demonstrating that A. ludens flies have the capability for fast adaptation to desiccation without loosing their reproductive capability. Thus, it seems that a rapid evolutionary response to desiccation in this polyphagous insect works as a buffer for environmental variation and reduces the strength of selection on reproductive traits.
Survival and mating success are traits of quality in mass-reared sterile males. Thus, studying th... more Survival and mating success are traits of quality in mass-reared sterile males. Thus, studying the trade-offs between these traits may help to improve process in the sterile insect technique (SIT). Here, we tested the hypothesis that modifying individual metabolism, especially of energetic reserves, may reduce the negative impact of an early reproduction on the survival of Anastrepha ludens flies. Appling metformin (a drug used to treat type II diabetes) that improves insects’ survival, through dietary restriction mimicry, and methoprene (a juvenile hormone analogue) that accelerates the age to reproduction in insects, we explore the dynamic of this trade-off. We fed A. ludens flies with metformin, methoprene, or a mixture of metformin–methoprene for five consecutive days. We determined the effect of these treatments on the fecundity and fertility (number of eggs and percentage of hatching) of females, on sexual maturation and mating success of males, and on the survival of both sex...
Anastrepha ludens (Loew) (Diptera: Tephritidae) is an endemic pest of Mexico, attacking several f... more Anastrepha ludens (Loew) (Diptera: Tephritidae) is an endemic pest of Mexico, attacking several fruits of economic importance. The Sterile Insect Technique (SIT), consisting of mass-rearing, irradiation and release of adults, is used to control this pest in affected areas. Currently, a genetic sexing strain (Tapachula 7, Tap-7) consisting only of A. ludens males is being released, yet we lack information on its sexual performance at the early ages when they are released and on its post copulatory behavior in terms of sperm transfer and mating inhibition. Here, sexual competitiveness at young ages and ability to inhibit female re-mating was compared between sterile Tap-7, Standard Bisexual (SB), or wild males both in laboratory and field cage conditions. Sperm stored by females mating with wild, Tap-7, or SB strain males was also compared. Six-day-old sterile Tap-7 males had low mating rates, however, by 7 d of age 80% of males had mated. Tap-7 males were just as likely as wild males...
For insect pests controlled through the Sterile Insect Technique (SIT), which consists in the mas... more For insect pests controlled through the Sterile Insect Technique (SIT), which consists in the mass production, sterilization, and release of target insects into affected areas, sterile male mating success with wild females is the key that will reduce population levels in the next generation. Male size is assumed to be important for mating success, but often without any concrete evidence or confounded by other parameters. Here, we evaluated male size and its interaction with male origin (laboratory or wild) on female choice for two lekking species controlled through SIT, Anastrepha obliqua (Macquart) and Anastrepha ludens (Loew) (Diptera: Tephritidae). In field cages, we tested wild females mating with: large wild males competing against small wild males; large wild males against small laboratory-sterile males; and large laboratory-sterile males against small wild males. We found evidence of large male advantage for A. obliqua but no effect of male size on mating competitiveness for ...
The sterile insect technique (SIT) is used in area-wide pest management programs for establishing... more The sterile insect technique (SIT) is used in area-wide pest management programs for establishing low pest prevalence and/or areas free of fruit flies (Diptera: Tephritidae). The aim of this technique is to induce high levels of sterility in the wild population, for this the released insects must have a high sexual competitiveness and field dispersal. However, radiation decreases these biological attributes that do not allow it to compete successfully with wild insects. In this study the sexual competitiveness, field survival and dispersal of Anastrepha obliqua (Macquart; Diptera: Tephritidae) irradiated at 0, 40, 50, 60, 70, and 80 Gy were evaluated in laboratory. A dose of 60 Gy produced 98% sterility, whereas doses of 70 and 80 Gy produced 99% sterility. Sexual competitiveness was assessed in field cages, comparing males irradiated at 0, 50, 60, 70, and 80 Gy against wild males for mating with wild fertile females. Males irradiated at 50 and 60 Gy achieved more matings than those...
Toxic environmental effects of most insecticides have led to a search for bio-organic insecticide... more Toxic environmental effects of most insecticides have led to a search for bio-organic insecticides. In this study, we tested the effects of lethal and sublethal exposure to two abamectin-based insecticides (VOLIAM TARGO and LUQ-THOR) on survival, mating, and oviposition of the tephritid Anastrepha ludens (Loew). Different doses of insecticides (0.001-2.00% of the commercial products) were offered mixed with the phagostimulant bait Captor commonly used in spraying and in trapping activities for the control of flies. Both insecticides exhibited 90% killing effectiveness (Abbott index) when offered in doses between 0.02 to 2.00%. The LC50 obtained from the bioassay at 72 h after treatment was 0.003% of commercial product for TARGO and 0.008% for LUQ-THOR. Sublethal exposures to insecticides (0.003%; LC50 for TARGO and LC30 for LUQ-THOR) caused a reduction in oviposition but not in mating parameters, indicating that females were more susceptible than males to reduced doses of insecticid...
Uploads