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Donald A Nordlund - One of the best experts on this subject based on the ideXlab platform.

Apodaca Sánchez, Miguel Angel - One of the best experts on this subject based on the ideXlab platform.

  • Primer reporte de enemigos naturales y parasitismo sobre Diaphorina citri Kuwayama en Sinaloa, México | First report of natural enemies and parasitism of Diaphorina citri Kuwayama en Sinaloa, México
    UDO Agrícola, 2018
    Co-Authors: Cortez Mondaca Edgardo, Lugo Angulo, Noraya Ely, Pérez Márquez Jesús, Apodaca Sánchez, Miguel Angel
    Abstract:

    El psílido asiático de los cítricos Diaphorina citri Kuwayama (Hemiptera: Psyllidae) es un insecto plaga de importancia cuarentenaria, vector de la proteobacteria Candidatus Liberibacter que causa la enfermedad huanglongbing. La búsqueda de enemigos naturales de D. citri se hizo en los municipios de Ahome, Guasave, Salvador Alvarado y Culiacán, Sinaloa. Se realizaron muestreos a intervalos de 3 a 7 días de junio a noviembre de 2007, en plantas de cítricos y de limonaria Murraya paniculata (L.) Jack. Se identificaron seis enemigos naturales de D. citri: Chrysoperla comanche (Banks), Chrysoperla rufilabris (Burmeister), Cycloneda sanguinea (L.), Olla v-nigrum (Mulsant), Diaphorencyrtus sp., y Tamarixia radiata (Waterston). Este último causo parasitismo natural de 0 a 59,6% y su abundancia relativa fue 95,5%. La abundancia relativa de las catarinitas C. sanguinea y O. v-nigrum fue 30,8% superior a la de las especies de crisopa. Los resultados presentados en este estudio son el primer reporte formal de enemigos naturales del psílido asiático de los cítricos en Sinaloa, México, algunos de los cuales pueden ser considerados para implementar su control biológico. Palabras clave: Enemigos naturales, depredadores, parasitoides, psílido, huanglongbing, México ABSTRACT The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an insect pest of quarantine, vector of Candidatus Liberibacter proteobacteria that cause disease huanglongbing. The search for natural enemies of D. citri was done in the municipalities of Ahome, Guasave, Salvador Alvarado and Culiacan, Sinaloa. Samplings were made at intervals of 3 to 7 days, from June to November 2007, in citrus plants and lemon grass Murraya paniculata (L.) Jack. We identified six natural enemies of D. citri: Chrysoperla comanche (Banks), Chrysoperla rufilabris (Burmeister), Cycloneda sanguinea (L.), Olla v-nigrum (Mulsant), Diaphorencyrtus sp., and Tamarixia radiata (Waterston). The last specie caused natural parasitism from 0 to 59.6% and their relative abundance was 95.5%. The relative abundance of beetles C. sanguinea and O. v-nigrum was 30.8% higher than in lacewing species. The results presented in this study are the first formal report of natural enemies of the Asian citrus psyllid in Sinaloa, Mexico, some of which can be used to implement biological control. Key words: Natural enemies, predators, parasitoids, psyllid, huanglongbing, Méxic

  • Primer reporte de enemigos naturales y parasitismo sobre Diaphorina citri Kuwayama en Sinaloa, México
    Universidad de Oriente Press, 2013
    Co-Authors: Cortez Mondaca Edgardo, Lugo Angulo, Noraya Ely, Pérez Márquez Jesús, Apodaca Sánchez, Miguel Angel
    Abstract:

    The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an insect pest of quarantine, vector of Candidatus Liberibacter proteobacteria that cause disease huanglongbing. The search for natural enemies of D. citri was done in the municipalities of Ahome, Guasave, Salvador Alvarado and Culiacan, Sinaloa. Samplings were made at intervals of 3 to 7 days, from June to November 2007, in citrus plants and lemon grass Murraya paniculata (L.) Jack. We identified six natural enemies of D. citri: Chrysoperla comanche (Banks), Chrysoperla rufilabris (Burmeister), Cycloneda sanguinea (L.), Olla v-nigrum (Mulsant), Diaphorencyrtus sp., and Diaphorencyrtus sp., y Tamarixia radiata (Waterston). The last specie caused natural parasitism from 0 to 59.6% and their relative abundance was 95.5%. The relative abundance of beetles C. sanguinea and O. v-nigrum was 30.8% higher than in lacewing species. The results presented in this study are the first formal report of natural enemies of the Asian citrus psyllid in Sinaloa, Mexico, some of which can be used to implement biological control.El psílido asiático de los cítricos Diaphorina citri Kuwayama (Hemiptera: Psyllidae) es un insecto plaga de importancia cuarentenaria, vector de la proteobacteria Candidatus Liberibacter que causa la enfermedad huanglongbing. La búsqueda de enemigos naturales de D. citri se hizo en los municipios de Ahome, Guasave, Salvador Alvarado y Culiacán, Sinaloa. Se realizaron muestreos a intervalos de 3 a 7 días de junio a noviembre de 2007, en plantas de cítricos y de limonaria Murraya paniculata (L.) Jack. Se identificaron seis enemigos naturales de D. citri: Chrysoperla comanche (Banks), Chrysoperla rufilabris (Burmeister), Cycloneda sanguinea (L.), Olla v-nigrum (Mulsant), Diaphorencyrtus sp., y Tamarixia radiata (Waterston). Este último causo parasitismo natural de 0 a 59,6% y su abundancia relativa fue 95,5%. La abundancia relativa de las catarinitas C. sanguinea y O. v-nigrum fue 30,8% superior a la de las especies de crisopa. Los resultados presentados en este estudio son el primer reporte formal de enemigos naturales del psílido asiático de los cítricos en Sinaloa, México, algunos de los cuales pueden ser considerados para implementar su control biológico

  • Primer reporte de enemigos naturales y parasitismo sobre Diaphorina citri Kuwayama en Sinaloa, México
    Universidad de Oriente, 2011
    Co-Authors: Cortez Mondaca Edgardo, Lugo Angulo, Noraya Ely, Pérez Márquez Jesús, Apodaca Sánchez, Miguel Angel
    Abstract:

    The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an insect pest of quarantine, vector of Candidatus Liberibacter proteobacteria that cause disease huanglongbing. The search for natural enemies of D. citri was done in the municipalities of Ahome, Guasave, Salvador Alvarado and Culiacan, Sinaloa. Samplings were made at intervals of 3 to 7 days, from June to November 2007, in citrus plants and lemon grass Murraya paniculata (L.) Jack. We identified six natural enemies of D. citri: Chrysoperla comanche (Banks), Chrysoperla rufilabris (Burmeister), Cycloneda sanguinea (L.), Olla v-nigrum (Mulsant), Diaphorencyrtus sp., and Tamarixia radiata (Waterston). The last specie caused natural parasitism from 0 to 59.6% and their relative abundance was 95.5%. The relative abundance of beetles C. sanguinea and O. v-nigrum was 30.8% higher than in lacewing species. The results presented in this study are the first formal report of natural enemies of the Asian citrus psyllid in Sinaloa, Mexico, some of which can be used to implement biological control.El psílido asiático de los cítricos Diaphorina citri Kuwayama (Hemiptera: Psyllidae) es un insecto plaga de importancia cuarentenaria, vector de la proteobacteria Candidatus Liberibacter que causa la enfermedad huanglongbing. La búsqueda de enemigos naturales de D. citri se hizo en los municipios de Ahome, Guasave, Salvador Alvarado y Culiacán, Sinaloa. Se realizaron muestreos a intervalos de 3 a 7 días de junio a noviembre de 2007, en plantas de cítricos y de limonaria Murraya paniculata (L.) Jack. Se identificaron seis enemigos naturales de D. citri: Chrysoperla comanche (Banks), Chrysoperla rufilabris (Burmeister), Cycloneda sanguinea (L.), Olla v-nigrum (Mulsant), Diaphorencyrtus sp., y Tamarixia radiata (Waterston). Este último causo parasitismo natural de 0 a 59,6% y su abundancia relativa fue 95,5%. La abundancia relativa de las catarinitas C. sanguinea y O. v-nigrum fue 30,8% superior a la de las especies de crisopa. Los resultados presentados en este estudio son el primer reporte formal de enemigos naturales del psílido asiático de los cítricos en Sinaloa, México, algunos de los cuales pueden ser considerados para implementar su control biológico

González Carrillo, Jesús Ascención - One of the best experts on this subject based on the ideXlab platform.

  • Toxicidad de insecticidas sobre tres especies de depredadores de Diaphorina Citri (Hemíptera: Liviidae).
    Colegio de Postgraduados (COLPOS), 2014
    Co-Authors: González Carrillo, Jesús Ascención
    Abstract:

    El psílido asiático de los cítricos, Diaphorina citri (Hemiptera: Liviidae), es el principal vector del agente causal del Huanglongbing (HLB) en cítricos en el mundo. El control de esta plaga se realiza principalmente con insecticidas a pesar de la presencia de sus enemigos naturales. La integración de los enemigos naturales debe ser considerada dentro de un programa de manejo integrado de esta plaga en cultivos de cítricos, por lo que en este trabajo se evaluó la toxicidad de tres insecticidas sobre tres de los depredadores más comunes en cítricos, los crisópidos Ceraeochrysa valida y Chrysoperla rufilabris, y el coccinélido Olla v-nigrum. Se utilizaron dos insecticidas de contacto (bifentrina y spirotetramat) y un sistémico (thiamethoxam) bajo dos métodos de exposición: a) exposición directa a los insecticidas y b) exposición a superficies y ninfas contaminadas. Discos de hoja de limón mexicano se utilizaron para insecticidas de contacto y brotes de Murraya paniculata para el sistémico. Los crisópidos fueron más tolerantes a todos los insecticidas; la mortalidad a las 48h no excedió el 36% con bifentrina y fue menor a 18% con spirotetramat. Para O. v-nigrum la mortalidad con ambos productos fue más del doble de lo observada para crisópidos. El thiamethoxam fue el producto más tóxico para todos los depredadores en exposición directa, pues causó 100% de mortalidad en O. v-nigrum y 66% en los crisópidos comparado con 60% al aplicarlo vía sistémica en O. v-nigrum y 4% en crisópidos. En el documento se discuten posibles causas de la diferencia en tolerancia a los insecticidas entre estos depredadores. _______________ TOXICITY OF INSECTICIDES TO THREE PREDATOR SPECIES OF DIAPHORINA CITRI (HEMIPTERA: LIVIIDAE). ABSTRACT: Diaphorina citri (Hemiptera: Liviidae), the Asian Citrus Psyllid, is the most important vector of the Huanglongbing disease agent (HLB) worldwide. The control of this insect pest relies mainly on the use of chemical insecticides despite the natural enemies’ occurrence. The integration of those natural enemies under an IPM program must be considered a goal on citrus orchards, thus the aim of this paper was to assess the toxicity of three insecticides on three common insect predators of D. citri. The predators were the green lacewings Ceraeochrysa valida and Chrysoperla rufilabris, and the ladybug Olla v-nigrum. Two contact (bifentrina and spirotetramat) and one systemic (thiamethoxam) insecticides were evaluated using two exposition methods: a) direct exposition, and b) surface and nymphs contaminated by the insecticide. Lime leave disks for the contact products and Murraya paniculata flushes for the systemic product were used as experimental units. Green lacewings were more tolerant to all products compared to O. v-nigrum. Bifentrina provided less than 36% mortality and spirotetramat less than 18% mortality on green lacewings, whereas both pesticides produced twice this mortality on O. v-nigrum. Thiamethoxam was more toxic to all predators in direct exposition than in systemic exposition, causing 100% in O. v-nigrum and 66% in green lacewings, compared to 60% in O. v-nigrum and 4% in green lacewings in systemic exposition. Possible reasons causing these differences in insecticide tolerance among the predators tested are discussed

  • Toxicidad de insecticidas sobre tres especies de depredadores de Diaphorina Citri (Hemíptera: Liviidae).
    Colegio de Postgraduados (COLPOS), 2014
    Co-Authors: González Carrillo, Jesús Ascención
    Abstract:

    El psílido asiático de los cítricos, Diaphorina citri (Hemiptera: Liviidae), es el principal vector del agente causal del Huanglongbing (HLB) en cítricos en el mundo. El control de esta plaga se realiza principalmente con insecticidas a pesar de la presencia de sus enemigos naturales. La integración de los enemigos naturales debe ser considerada dentro de un programa de manejo integrado de esta plaga en cultivos de cítricos, por lo que en este trabajo se evaluó la toxicidad de tres insecticidas sobre tres de los depredadores más comunes en cítricos, los crisópidos Ceraeochrysa valida y Chrysoperla rufilabris, y el coccinélido Olla v-nigrum. Se utilizaron dos insecticidas de contacto (bifentrina y spirotetramat) y un sistémico (thiamethoxam) bajo dos métodos de exposición: a) exposición directa a los insecticidas y b) exposición a superficies y ninfas contaminadas. Discos de hoja de limón mexicano se utilizaron para insecticidas de contacto y brotes de Murraya paniculata para el sistémico. Los crisópidos fueron más tolerantes a todos los insecticidas; la mortalidad a las 48h no excedió el 36% con bifentrina y fue menor a 18% con spirotetramat. Para O. v-nigrum la mortalidad con ambos productos fue más del doble de lo observada para crisópidos. El thiamethoxam fue el producto más tóxico para todos los depredadores en exposición directa, pues causó 100% de mortalidad en O. v-nigrum y 66% en los crisópidos comparado con 60% al aplicarlo vía sistémica en O. v-nigrum y 4% en crisópidos. En el documento se discuten posibles causas de la diferencia en tolerancia a los insecticidas entre estos depredadores. _______________ TOXICITY OF INSECTICIDES TO THREE PREDATOR SPECIES OF DIAPHORINA CITRI (HEMIPTERA: LIVIIDAE). ABSTRACT: Diaphorina citri (Hemiptera: Liviidae), the Asian Citrus Psyllid, is the most important vector of the Huanglongbing disease agent (HLB) worldwide. The control of this insect pest relies mainly on the use of chemical insecticides despite the natural enemies’ occurrence. The integration of those natural enemies under an IPM program must be considered a goal on citrus orchards, thus the aim of this paper was to assess the toxicity of three insecticides on three common insect predators of D. citri. The predators were the green lacewings Ceraeochrysa valida and Chrysoperla rufilabris, and the ladybug Olla v-nigrum. Two contact (bifentrina and spirotetramat) and one systemic (thiamethoxam) insecticides were evaluated using two exposition methods: a) direct exposition, and b) surface and nymphs contaminated by the insecticide. Lime leave disks for the contact products and Murraya paniculata flushes for the systemic product were used as experimental units. Green lacewings were more tolerant to all products compared to O. v-nigrum. Bifentrina provided less than 36% mortality and spirotetramat less than 18% mortality on green lacewings, whereas both pesticides produced twice this mortality on O. v-nigrum. Thiamethoxam was more toxic to all predators in direct exposition than in systemic exposition, causing 100% in O. v-nigrum and 66% in green lacewings, compared to 60% in O. v-nigrum and 4% in green lacewings in systemic exposition. Possible reasons causing these differences in insecticide tolerance among the predators tested are discussed.Tesis (Maestría en Ciencias, especialista en Entomología y Acarología).- Colegio de Postgraduados, 2014.Consejo Nacional de Ciencia y Tecnología (CONACYT)

Daniel Coderre - One of the best experts on this subject based on the ideXlab platform.

  • Chrysoperla rufilabris neuroptera chrysopidae females do not avoid ovipositing in the presence of conspecific eggs
    Biological Control, 2006
    Co-Authors: Bruno Frechette, Daniel Coderre, Éric Lucas
    Abstract:

    Previous experiments have demonstrated that green lacewing (Neuroptera: Chrysopidae) adults could be attracted to Weld crops using artiWcial honeydew. To be eVective as a biological control method, such a technique would require that the increase in female abundance translate in an increase egg deposition. An experiment was conducted to evaluate whether the honeydew-feeding females of the green lacewing Chrysoperla ruWlabris (Burmeister) avoid laying eggs in the presence of conspeciWc eggs. The potential risk associated with oviposition in a site already occupied by conspeciWc eggs was also studied. The preference of C. ruWlabris larvae for kin and non-kin eggs and the susceptibility of C. ruWlabris eggs to cannibalism relative to their age was determined. The results demonstrate that females are not reluctant to oviposit in the presence of conspeciWc eggs. Larvae show no preference for kin or non-kin eggs, and lacewing eggs become less susceptible to cannibalism as they age. This indicates that the risk of egg cannibalism by neonate in the Weld may be low. The results are discussed from ecological and biological control points of view.

  • Oviposition strategy of the green lacewing Chrysoperla rufilabris (Neuroptera: Chrysopidae) in response to extraguild prey availability
    European Journal of Endocrinology, 2000
    Co-Authors: Bruno Frechette, Daniel Coderre
    Abstract:

    The capacity of the green lacewing Chrysoperla rufilabris (Burmeister) to modify its oviposition strategy in response to extraguild prey availability in an oviposition site was studied. Gravid females were placed in presence and absence of aphids. Fecundity, fertility, dispersion and hatching synchrony were compared. Results indicate a statistical difference in the hatching synchrony of eggs. However, no statistical differences were observed in the proportion of infertile eggs and in egg dispersion. We suggest that C. rufilabris can alter hatching synchrony of eggs in condition of food scarcity in order to favour intra-clutch egg cannibalism by newly hatched larvae and thus increase its overall reproductive success.

  • Selection of molting and pupation sites by Coleomegilla maculata (Coleoptera: Coccinellidae): avoidance of intraguild predation.
    Environmental Entomology, 2000
    Co-Authors: Éric Lucas, Daniel Coderre, Jacques Brodeur
    Abstract:

    Molting and pupating insects are especially vulnerable to natural enemies and one possible component of their defensive strategy is the selection of suitable microhabitats. We hypothesized that larvae of the lady beetle Coleomegilla maculata lengi Timberlake select molting and pupation sites that effectively reduce their susceptibility to intraguild predation. We characterized microsites on potato plants and evaluated their associated risk of predation by the lacewing Chrysoperla rufilabris Burmeister (Neuroptera: Chrysopidae), a common intraguild predator. The majority of molts (>60%) occurred on potato plants in sites similar to those used by mobile coccinellid larvae. In contrast, 90% of the larvae left the plant to pupate. Second, third, and fourth instars selected artificial shelters for both molting and pupation when these were available. Vulnerability of pupae and newly molted larvae to lacewing larvae depended on plant microsite, with leaves supporting an aphid colony as the most risky sites. Molting and pupating microhabitat selection by coccinellid larvae appears to be a trade-off between the advantages of remaining close to the aphid resource, and the costs of being exposed to intraguild predators.

  • intraguild predation among aphid predators characterization and influence of extraguild prey density
    Ecology, 1998
    Co-Authors: Éric Lucas, Daniel Coderre, Jacques Brodeur
    Abstract:

    Intraguild predation (IGP), a common interaction in invertebrates and vertebrates, affects the abundance and distribution of many species. Several parameters influence the magnitude and direction of IGP: feeding specificity, size, mobility, and aggressiveness of the protagonists, as well as extraguild prey density. Under laboratory conditions, we studied IGP among three species of aphid predators, Aphidoletes aphidimyza (Diptera: Cecidomyiidae), Chrysoperla rufilabris (Neuroptera: Chrysopidae), and Coleomegilla maculata lengi (Coleoptera: Coccinellidae), which commonly attack the potato aphid (extraguild prey) Macrosiphum euphorbiae (Homoptera: Aphididae). We characterized the levels and symmetry of IGP among the various stages of the predators in the absence of extraguild prey. The aphid specialist A. aphidimyza was more vulnerable to IGP than C. rufilabris and C. maculata, two generalist predators. The C. maculata/C. rufilabris interaction was symmetric (mutual IGP), whereas the C. maculata/A. aphidimyza and C. rufilabris/A. aphidimyza interactions were asymmetric, in favor of the coccinellid and the lacewing, respectively. Sessile and low mobility stages of all species were extremely vulnerable to IGP. Generally, the larger sized individual won confrontations. For similar sizes, lacewing larvae were superior to coccinellid larvae. We also tested whether IGP decreases when extraguild prey are introduced into the system. Data from five predator combinations revealed three types of responses: (1) an exponential decrease in IGP (lacewing instar I vs. coccinellid instar I); (2) a constant IGP (lacewing instar III vs. coccinellid instar I); (3) a constant IGP at low densities decreasing at high densities (lacewing instar III vs. gall midge old larva). Four theoretical scenarios are derived from these responses. Each is discussed according to the ecological attributes of the protagonists. This study shows that IGP is influenced by factors inherent to the predators and external factors such as extraguild prey density. The results are discussed further in the context of aphid biological control.

  • instar specific defense of coleomegilla maculata lengi col coccinellidae influence on attack success of the intraguild predator Chrysoperla rufilabris neur chrysopidae
    Biocontrol, 1997
    Co-Authors: Éric Lucas, Daniel Coderre, Jacques Brodeur
    Abstract:

    We conducted a laboratory study of the behavioural interactions between larval stages of the lady beetleColeomegilla maculata lengi Timberlake and an intraguild predator, the lacewingChrysoperla rufilabris Burmeister. Ladybird susceptibility to predation by third instarC. rufilabris is age-specific and influenced by larval defensive strategies. First and second instars ofC. maculata were captured more consistently by chrysopid larvae than third and fourth instars. Young coccinellids generally exhibit escape reactions (dropping, fleeing, retreating) but, do not survive after being caught by lacewings. In addition to escape reactions, older larvae may actively defend themselves by wriggling or biting, even after being pierced. The proportion of physical interactions that resulted in coccinellid death was significantly lower for older instars (<2%) than for first (35%) and second (19%) instars. Capture efficiency byC. rufilabris was related to the coccinellid-chrysopid size ratio. Dropping off the leaves, the most common defensive behaviour displayed by coccinellid larvae, contributed to reduce overall mortality of first instars to a level similar to the one observed for older stages. However, lacewings were able to prevent coccinellid dropping by impaling and holding their prey in the air, or by falling with the ladybirds to the ground where they continued their attack.

Jacques Brodeur - One of the best experts on this subject based on the ideXlab platform.

  • Do furtive predators benefit from a selfish herd effect by living within their prey colony?
    Behavioral Ecology and Sociobiology, 2015
    Co-Authors: François Dumont, Éric Lucas, Jacques Brodeur
    Abstract:

    Protection from predators is a recognized benefit of group living for animals. The selfish herd effect implies that individuals in a central position within the group suffer lower predation than individuals at the edges of the group. The midge, Aphidoletes aphidimyza , is a furtive predator that lives within aphid colonies where it benefits from a dilution effect that reduces the incidence of intraguild predation. We hypothesized that the selfish herd effect also contributes to midge survival. In laboratory experiments, we examined the distribution of midge larvae within aphid ( Macrosiphum euphorbiae ) colonies and determined the susceptibility of central and peripheral individuals to lacewing, Chrysoperla rufilabris , and coccinellid, Coleomegilla maculata larvae, two common intraguild predators. The probability of observing a midge in the central zone of an aphid colony was higher than predicted after a 24-h period. During predation tests, midges and aphids in the peripheral zone were attacked first significantly more often than prey in the central zone of the colony. However, because foraging coccinellid and lacewing larvae rapidly disrupt the cohesion among aphids in the colony, midge mortality was subsequently similar in both zones. We conclude that A. aphidimyza preferentially choose the central position of their aphid prey colonies. Such a preference reduces the probability of becoming the first prey attacked by intraguild predators. The effectiveness of the selfish herd for slow-moving midge larvae would depend on the nature and foraging behavior of the predator, as well as on cohesion of the aphid colony.

  • Selection of molting and pupation sites by Coleomegilla maculata (Coleoptera: Coccinellidae): avoidance of intraguild predation.
    Environmental Entomology, 2000
    Co-Authors: Éric Lucas, Daniel Coderre, Jacques Brodeur
    Abstract:

    Molting and pupating insects are especially vulnerable to natural enemies and one possible component of their defensive strategy is the selection of suitable microhabitats. We hypothesized that larvae of the lady beetle Coleomegilla maculata lengi Timberlake select molting and pupation sites that effectively reduce their susceptibility to intraguild predation. We characterized microsites on potato plants and evaluated their associated risk of predation by the lacewing Chrysoperla rufilabris Burmeister (Neuroptera: Chrysopidae), a common intraguild predator. The majority of molts (>60%) occurred on potato plants in sites similar to those used by mobile coccinellid larvae. In contrast, 90% of the larvae left the plant to pupate. Second, third, and fourth instars selected artificial shelters for both molting and pupation when these were available. Vulnerability of pupae and newly molted larvae to lacewing larvae depended on plant microsite, with leaves supporting an aphid colony as the most risky sites. Molting and pupating microhabitat selection by coccinellid larvae appears to be a trade-off between the advantages of remaining close to the aphid resource, and the costs of being exposed to intraguild predators.

  • intraguild predation among aphid predators characterization and influence of extraguild prey density
    Ecology, 1998
    Co-Authors: Éric Lucas, Daniel Coderre, Jacques Brodeur
    Abstract:

    Intraguild predation (IGP), a common interaction in invertebrates and vertebrates, affects the abundance and distribution of many species. Several parameters influence the magnitude and direction of IGP: feeding specificity, size, mobility, and aggressiveness of the protagonists, as well as extraguild prey density. Under laboratory conditions, we studied IGP among three species of aphid predators, Aphidoletes aphidimyza (Diptera: Cecidomyiidae), Chrysoperla rufilabris (Neuroptera: Chrysopidae), and Coleomegilla maculata lengi (Coleoptera: Coccinellidae), which commonly attack the potato aphid (extraguild prey) Macrosiphum euphorbiae (Homoptera: Aphididae). We characterized the levels and symmetry of IGP among the various stages of the predators in the absence of extraguild prey. The aphid specialist A. aphidimyza was more vulnerable to IGP than C. rufilabris and C. maculata, two generalist predators. The C. maculata/C. rufilabris interaction was symmetric (mutual IGP), whereas the C. maculata/A. aphidimyza and C. rufilabris/A. aphidimyza interactions were asymmetric, in favor of the coccinellid and the lacewing, respectively. Sessile and low mobility stages of all species were extremely vulnerable to IGP. Generally, the larger sized individual won confrontations. For similar sizes, lacewing larvae were superior to coccinellid larvae. We also tested whether IGP decreases when extraguild prey are introduced into the system. Data from five predator combinations revealed three types of responses: (1) an exponential decrease in IGP (lacewing instar I vs. coccinellid instar I); (2) a constant IGP (lacewing instar III vs. coccinellid instar I); (3) a constant IGP at low densities decreasing at high densities (lacewing instar III vs. gall midge old larva). Four theoretical scenarios are derived from these responses. Each is discussed according to the ecological attributes of the protagonists. This study shows that IGP is influenced by factors inherent to the predators and external factors such as extraguild prey density. The results are discussed further in the context of aphid biological control.

  • instar specific defense of coleomegilla maculata lengi col coccinellidae influence on attack success of the intraguild predator Chrysoperla rufilabris neur chrysopidae
    Biocontrol, 1997
    Co-Authors: Éric Lucas, Daniel Coderre, Jacques Brodeur
    Abstract:

    We conducted a laboratory study of the behavioural interactions between larval stages of the lady beetleColeomegilla maculata lengi Timberlake and an intraguild predator, the lacewingChrysoperla rufilabris Burmeister. Ladybird susceptibility to predation by third instarC. rufilabris is age-specific and influenced by larval defensive strategies. First and second instars ofC. maculata were captured more consistently by chrysopid larvae than third and fourth instars. Young coccinellids generally exhibit escape reactions (dropping, fleeing, retreating) but, do not survive after being caught by lacewings. In addition to escape reactions, older larvae may actively defend themselves by wriggling or biting, even after being pierced. The proportion of physical interactions that resulted in coccinellid death was significantly lower for older instars (<2%) than for first (35%) and second (19%) instars. Capture efficiency byC. rufilabris was related to the coccinellid-chrysopid size ratio. Dropping off the leaves, the most common defensive behaviour displayed by coccinellid larvae, contributed to reduce overall mortality of first instars to a level similar to the one observed for older stages. However, lacewings were able to prevent coccinellid dropping by impaling and holding their prey in the air, or by falling with the ladybirds to the ground where they continued their attack.