The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Zvi Mendel - One of the best experts on this subject based on the ideXlab platform.
-
Diversity of Ooencyrtus spp. (Hymenoptera: Encyrtidae) parasitizing the eggs of Stenozygum coloratum (Klug) (Hemiptera: Pentatomidae) with description of two new species
2018Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Pasquale Cascone, Emilio Guerrieri, John Noyes, Zvi MendelAbstract:Ooencyrtus spp. (Hymenoptera, Chalcidoidea, Encyrtidae) are important natural enemies of agricultural and forest insect pests, and are distributed worldwide. Their reduced dimensions, highly variable morphological characters and possible effect of wide host range and abiotic factors, make correct identification at the species level particularly difficult. This paper combined molecular, morphological, and biological data to characterize a group of Ooencyrtus spp. emerging from the eggs of the variegated caper bug, Stenozygum coloratum in the east Mediterranean area. COI and ITS2 sequencing revealed the presence of six and five divergent clades, respectively. Three clades were identified as Ooencyrtus telenomicida, Ooencyrtus pityocampae and O. pistaciae. Two clades represent new species which are here described and named Ooencyrtus zoeae and Ooencyrtus mevalbelus. These features were combined with reliable morphological characters to facilitate the separation of these species. A dichotomous key and a new synonymy are proposed. Ooencyrtus pistaciae had two distinct COI clades but only one ITS2 clade. Crossbreeding trials that included Ooencyrtus telenomicida, Ooencyrtus melvabelus sp. nov. and Ooencyrtus zoeae sp. nov. confirmed their reproductive isolation. COI sequences showed 0–0.8% and 4–9% within and between-species genetic differences, respectively. ITS2 showed 0.4–5.9% genetic differences between species, with no genetic differences within species. Haplotype diversity of Israeli and Turkish populations of the various species was 0–0.98 and was particularly low in Ooencyrtus pityocampae, whose Israeli population showed no diversity. The discovery of the Ooencyrtus spp. on the eggs of the caper bug, and their abundance support the idea that the bug can be used as an alternative host for augmentation of populations of these parasitoids in agricultural and forestry systems.
-
comparative study of development parameters of four Ooencyrtus spp hymenoptera encyrtidae on natural and factitious hosts
Journal of Applied Entomology, 2016Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:Biological control approaches such as seeding and augmentation releases of populations of natural enemies mostly rely on the indoor production of predator or parasitoid species, often with the use of alternative prey/host species. In this study, we investigated several development parameters of four egg parasitoid species: Ooencyrtus fecundus, O. near fecundus, O. pityocampae and O. telenomicida, and compared their performance on their natural host, the variegated caper bug (CB) Stenozygum coloratum, and on an alternative, factitious host, the silk moth (SM) Bombyx mori. Survival was higher and development duration shorter in CB eggs, making the CB a better host for these congeners. However, adult longevity was generally longer for individuals that developed in SM eggs. Moreover, O. fecundus and O. pityocampae females that had developed in SM eggs displayed higher fecundity than all other female/host combinations. Survival also varied according to the age of the SM eggs: parasitoid survival rates were significantly higher in 9- to 12-month-old (post-diapausing) eggs than in young (about 1 month old) ones. These results were probably influenced by differences among the egg sizes of the studied hosts. The number of non-laying females and self-superparasitism rates were exceptionally high in O. near fecundus. These findings suggest that SM eggs, and especially those which are being utilized after a long storage, could serve for mass rearing of the studied Ooencyrtus spp.
-
seasonal history plant interactions and egg parasitism of the variegated caper bug stenozygum coloratum klug heteroptera pentatomidae
Agricultural and Forest Entomology, 2016Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:The variegated caper bug Stenozygum coloratum Klug is common in the Middle East, where it is a minor agricultural pest. Recently, it was found that S. coloratum is an alternative host for the egg parasitoid Ooencyrtus pityocampae Mercet, an important natural enemy of the pine processionary moth Thaumetopoea wilkinsoni Tams, a major pest of pines. This discovery, coupled with the general lack of knowledge of S. coloratum, prompted the present study, which focused on seasonal activity of S. coloratum in Israeli pine forests, bidirectional interactions between the bug and its host the caper plant Capparis spp., and parasitism of its eggs. Stenozygum coloratum activity lasted mainly from May to October, and was followed by an adult winter diapause. Individuals formed large aggregations, causing early withering of plants and a shortening their annual growth periods. Reproductive activity peaked in August and ended in September. Egg parasitism rates increased throughout this period. Several Ooencyrtus spp., including known natural enemies of various pests, parasitized the eggs of S. coloratum and other associated pentatomids found on the caper plants. Thus, capers probably serve as a refuge for these potentially important egg parasitoids. The potential of caper plants and their fauna for biological control programmes is discussed.
-
spatial distribution and niche partitioning in the Ooencyrtus spp complex parasitizing the eggs of stenozygum coloratum
Biocontrol, 2015Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:The way in which species coexist is an important ecological question. Often, several parasitoid species may share a common host species. Five species of Ooencyrtus Ashmead (Hymenoptera: Encyrtidae) co-inhabit the egg clusters of Stenozygum coloratum Klug (Hemiptera: Pentatomidae), in the East Mediterranean region. Their relative abundance and spatial and seasonal occurrence were investigated. Parasitism and parasitoid male ratios gradually increased to about 50 and 26.8 %, respectively, from May to October. O. telenomicida Vassiliev was dominant in Mediterranean climatic regions and absent from arid areas, O. fecundus Ferriere and Voegele dominated semi-arid areas, and O. near nigerrimus was the commonest in hot-arid areas. O. near fecundus occurred everywhere but was most abundant in the more extreme weather conditions. O. pityocampae Mercet was uncommon in most areas and absent from arid ones. O. telenomicida abundance was positively, and that of O. fecundus negatively, correlated with annual rainfall. O. near fecundus and O. near nigerrimus abundance was positively correlated with temperature extremes. The results display a clear picture for climatic based spatial niche partitioning, although there is evidence that interspecific competition also plays a significant role in the frequency of occurrence of the studied Ooencyrtus spp.
-
genetic diversity and host alternation of the egg parasitoid Ooencyrtus pityocampae between the pine processionary moth and the caper bug
PLOS ONE, 2015Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Manuela Branco, Zvi MendelAbstract:The increased use of molecular tools for species identification in recent decades revealed that each of many apparently generalist parasitoids are actually a complex of morphologically similar congeners, most of which have a rather narrow host range. Ooencyrtus pityocampae (OP), an important egg parasitoid of the pine processionary moth (PPM), is considered a generalist parasitoid. OP emerges from PPM eggs after winter hibernation, mainly in spring and early summer, long before the eggs of the next PPM generation occurs. The occurrence of OP in eggs of the variegated caper bug (CB) Stenozygum coloratum in spring and summer suggests that OP populations alternate seasonally between PPM and CB. However, the identity of OP population on CB eggs seemed uncertain; unlike OP-PPM populations, the former displayed apparently high male/female ratios and lack of attraction to the PPM sex pheromone. We studied the molecular identities of the two populations since the morphological identification of the genus Ooencyrtus, and OP in particular, is difficult. Sequencing of COI and ITS2 DNA fragments and AFLP analysis of individuals from both hosts revealed no apparent differences between the OP-PPM and the OP-CB populations for both the Israeli and the Turkish OPs, which therefore supported the possibility of host alternation. Sequencing data extended our knowledge of the genetic structure of OP populations in the Mediterranean area, and revealed clear separation between East and West Mediterranean populations. The overall level of genetic diversity was rather small, with the Israeli population much less diverse than all others; possible explanations for this finding are discussed. The findings support the possibility of utilizing the CB and other hosts for enhancing biological control of the PPM.
Shahar Samra - One of the best experts on this subject based on the ideXlab platform.
-
Diversity of Ooencyrtus spp. (Hymenoptera: Encyrtidae) parasitizing the eggs of Stenozygum coloratum (Klug) (Hemiptera: Pentatomidae) with description of two new species
2018Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Pasquale Cascone, Emilio Guerrieri, John Noyes, Zvi MendelAbstract:Ooencyrtus spp. (Hymenoptera, Chalcidoidea, Encyrtidae) are important natural enemies of agricultural and forest insect pests, and are distributed worldwide. Their reduced dimensions, highly variable morphological characters and possible effect of wide host range and abiotic factors, make correct identification at the species level particularly difficult. This paper combined molecular, morphological, and biological data to characterize a group of Ooencyrtus spp. emerging from the eggs of the variegated caper bug, Stenozygum coloratum in the east Mediterranean area. COI and ITS2 sequencing revealed the presence of six and five divergent clades, respectively. Three clades were identified as Ooencyrtus telenomicida, Ooencyrtus pityocampae and O. pistaciae. Two clades represent new species which are here described and named Ooencyrtus zoeae and Ooencyrtus mevalbelus. These features were combined with reliable morphological characters to facilitate the separation of these species. A dichotomous key and a new synonymy are proposed. Ooencyrtus pistaciae had two distinct COI clades but only one ITS2 clade. Crossbreeding trials that included Ooencyrtus telenomicida, Ooencyrtus melvabelus sp. nov. and Ooencyrtus zoeae sp. nov. confirmed their reproductive isolation. COI sequences showed 0–0.8% and 4–9% within and between-species genetic differences, respectively. ITS2 showed 0.4–5.9% genetic differences between species, with no genetic differences within species. Haplotype diversity of Israeli and Turkish populations of the various species was 0–0.98 and was particularly low in Ooencyrtus pityocampae, whose Israeli population showed no diversity. The discovery of the Ooencyrtus spp. on the eggs of the caper bug, and their abundance support the idea that the bug can be used as an alternative host for augmentation of populations of these parasitoids in agricultural and forestry systems.
-
comparative study of development parameters of four Ooencyrtus spp hymenoptera encyrtidae on natural and factitious hosts
Journal of Applied Entomology, 2016Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:Biological control approaches such as seeding and augmentation releases of populations of natural enemies mostly rely on the indoor production of predator or parasitoid species, often with the use of alternative prey/host species. In this study, we investigated several development parameters of four egg parasitoid species: Ooencyrtus fecundus, O. near fecundus, O. pityocampae and O. telenomicida, and compared their performance on their natural host, the variegated caper bug (CB) Stenozygum coloratum, and on an alternative, factitious host, the silk moth (SM) Bombyx mori. Survival was higher and development duration shorter in CB eggs, making the CB a better host for these congeners. However, adult longevity was generally longer for individuals that developed in SM eggs. Moreover, O. fecundus and O. pityocampae females that had developed in SM eggs displayed higher fecundity than all other female/host combinations. Survival also varied according to the age of the SM eggs: parasitoid survival rates were significantly higher in 9- to 12-month-old (post-diapausing) eggs than in young (about 1 month old) ones. These results were probably influenced by differences among the egg sizes of the studied hosts. The number of non-laying females and self-superparasitism rates were exceptionally high in O. near fecundus. These findings suggest that SM eggs, and especially those which are being utilized after a long storage, could serve for mass rearing of the studied Ooencyrtus spp.
-
seasonal history plant interactions and egg parasitism of the variegated caper bug stenozygum coloratum klug heteroptera pentatomidae
Agricultural and Forest Entomology, 2016Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:The variegated caper bug Stenozygum coloratum Klug is common in the Middle East, where it is a minor agricultural pest. Recently, it was found that S. coloratum is an alternative host for the egg parasitoid Ooencyrtus pityocampae Mercet, an important natural enemy of the pine processionary moth Thaumetopoea wilkinsoni Tams, a major pest of pines. This discovery, coupled with the general lack of knowledge of S. coloratum, prompted the present study, which focused on seasonal activity of S. coloratum in Israeli pine forests, bidirectional interactions between the bug and its host the caper plant Capparis spp., and parasitism of its eggs. Stenozygum coloratum activity lasted mainly from May to October, and was followed by an adult winter diapause. Individuals formed large aggregations, causing early withering of plants and a shortening their annual growth periods. Reproductive activity peaked in August and ended in September. Egg parasitism rates increased throughout this period. Several Ooencyrtus spp., including known natural enemies of various pests, parasitized the eggs of S. coloratum and other associated pentatomids found on the caper plants. Thus, capers probably serve as a refuge for these potentially important egg parasitoids. The potential of caper plants and their fauna for biological control programmes is discussed.
-
spatial distribution and niche partitioning in the Ooencyrtus spp complex parasitizing the eggs of stenozygum coloratum
Biocontrol, 2015Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:The way in which species coexist is an important ecological question. Often, several parasitoid species may share a common host species. Five species of Ooencyrtus Ashmead (Hymenoptera: Encyrtidae) co-inhabit the egg clusters of Stenozygum coloratum Klug (Hemiptera: Pentatomidae), in the East Mediterranean region. Their relative abundance and spatial and seasonal occurrence were investigated. Parasitism and parasitoid male ratios gradually increased to about 50 and 26.8 %, respectively, from May to October. O. telenomicida Vassiliev was dominant in Mediterranean climatic regions and absent from arid areas, O. fecundus Ferriere and Voegele dominated semi-arid areas, and O. near nigerrimus was the commonest in hot-arid areas. O. near fecundus occurred everywhere but was most abundant in the more extreme weather conditions. O. pityocampae Mercet was uncommon in most areas and absent from arid ones. O. telenomicida abundance was positively, and that of O. fecundus negatively, correlated with annual rainfall. O. near fecundus and O. near nigerrimus abundance was positively correlated with temperature extremes. The results display a clear picture for climatic based spatial niche partitioning, although there is evidence that interspecific competition also plays a significant role in the frequency of occurrence of the studied Ooencyrtus spp.
-
genetic diversity and host alternation of the egg parasitoid Ooencyrtus pityocampae between the pine processionary moth and the caper bug
PLOS ONE, 2015Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Manuela Branco, Zvi MendelAbstract:The increased use of molecular tools for species identification in recent decades revealed that each of many apparently generalist parasitoids are actually a complex of morphologically similar congeners, most of which have a rather narrow host range. Ooencyrtus pityocampae (OP), an important egg parasitoid of the pine processionary moth (PPM), is considered a generalist parasitoid. OP emerges from PPM eggs after winter hibernation, mainly in spring and early summer, long before the eggs of the next PPM generation occurs. The occurrence of OP in eggs of the variegated caper bug (CB) Stenozygum coloratum in spring and summer suggests that OP populations alternate seasonally between PPM and CB. However, the identity of OP population on CB eggs seemed uncertain; unlike OP-PPM populations, the former displayed apparently high male/female ratios and lack of attraction to the PPM sex pheromone. We studied the molecular identities of the two populations since the morphological identification of the genus Ooencyrtus, and OP in particular, is difficult. Sequencing of COI and ITS2 DNA fragments and AFLP analysis of individuals from both hosts revealed no apparent differences between the OP-PPM and the OP-CB populations for both the Israeli and the Turkish OPs, which therefore supported the possibility of host alternation. Sequencing data extended our knowledge of the genetic structure of OP populations in the Mediterranean area, and revealed clear separation between East and West Mediterranean populations. The overall level of genetic diversity was rather small, with the Israeli population much less diverse than all others; possible explanations for this finding are discussed. The findings support the possibility of utilizing the CB and other hosts for enhancing biological control of the PPM.
Alex Protasov - One of the best experts on this subject based on the ideXlab platform.
-
Diversity of Ooencyrtus spp. (Hymenoptera: Encyrtidae) parasitizing the eggs of Stenozygum coloratum (Klug) (Hemiptera: Pentatomidae) with description of two new species
2018Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Pasquale Cascone, Emilio Guerrieri, John Noyes, Zvi MendelAbstract:Ooencyrtus spp. (Hymenoptera, Chalcidoidea, Encyrtidae) are important natural enemies of agricultural and forest insect pests, and are distributed worldwide. Their reduced dimensions, highly variable morphological characters and possible effect of wide host range and abiotic factors, make correct identification at the species level particularly difficult. This paper combined molecular, morphological, and biological data to characterize a group of Ooencyrtus spp. emerging from the eggs of the variegated caper bug, Stenozygum coloratum in the east Mediterranean area. COI and ITS2 sequencing revealed the presence of six and five divergent clades, respectively. Three clades were identified as Ooencyrtus telenomicida, Ooencyrtus pityocampae and O. pistaciae. Two clades represent new species which are here described and named Ooencyrtus zoeae and Ooencyrtus mevalbelus. These features were combined with reliable morphological characters to facilitate the separation of these species. A dichotomous key and a new synonymy are proposed. Ooencyrtus pistaciae had two distinct COI clades but only one ITS2 clade. Crossbreeding trials that included Ooencyrtus telenomicida, Ooencyrtus melvabelus sp. nov. and Ooencyrtus zoeae sp. nov. confirmed their reproductive isolation. COI sequences showed 0–0.8% and 4–9% within and between-species genetic differences, respectively. ITS2 showed 0.4–5.9% genetic differences between species, with no genetic differences within species. Haplotype diversity of Israeli and Turkish populations of the various species was 0–0.98 and was particularly low in Ooencyrtus pityocampae, whose Israeli population showed no diversity. The discovery of the Ooencyrtus spp. on the eggs of the caper bug, and their abundance support the idea that the bug can be used as an alternative host for augmentation of populations of these parasitoids in agricultural and forestry systems.
-
comparative study of development parameters of four Ooencyrtus spp hymenoptera encyrtidae on natural and factitious hosts
Journal of Applied Entomology, 2016Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:Biological control approaches such as seeding and augmentation releases of populations of natural enemies mostly rely on the indoor production of predator or parasitoid species, often with the use of alternative prey/host species. In this study, we investigated several development parameters of four egg parasitoid species: Ooencyrtus fecundus, O. near fecundus, O. pityocampae and O. telenomicida, and compared their performance on their natural host, the variegated caper bug (CB) Stenozygum coloratum, and on an alternative, factitious host, the silk moth (SM) Bombyx mori. Survival was higher and development duration shorter in CB eggs, making the CB a better host for these congeners. However, adult longevity was generally longer for individuals that developed in SM eggs. Moreover, O. fecundus and O. pityocampae females that had developed in SM eggs displayed higher fecundity than all other female/host combinations. Survival also varied according to the age of the SM eggs: parasitoid survival rates were significantly higher in 9- to 12-month-old (post-diapausing) eggs than in young (about 1 month old) ones. These results were probably influenced by differences among the egg sizes of the studied hosts. The number of non-laying females and self-superparasitism rates were exceptionally high in O. near fecundus. These findings suggest that SM eggs, and especially those which are being utilized after a long storage, could serve for mass rearing of the studied Ooencyrtus spp.
-
seasonal history plant interactions and egg parasitism of the variegated caper bug stenozygum coloratum klug heteroptera pentatomidae
Agricultural and Forest Entomology, 2016Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:The variegated caper bug Stenozygum coloratum Klug is common in the Middle East, where it is a minor agricultural pest. Recently, it was found that S. coloratum is an alternative host for the egg parasitoid Ooencyrtus pityocampae Mercet, an important natural enemy of the pine processionary moth Thaumetopoea wilkinsoni Tams, a major pest of pines. This discovery, coupled with the general lack of knowledge of S. coloratum, prompted the present study, which focused on seasonal activity of S. coloratum in Israeli pine forests, bidirectional interactions between the bug and its host the caper plant Capparis spp., and parasitism of its eggs. Stenozygum coloratum activity lasted mainly from May to October, and was followed by an adult winter diapause. Individuals formed large aggregations, causing early withering of plants and a shortening their annual growth periods. Reproductive activity peaked in August and ended in September. Egg parasitism rates increased throughout this period. Several Ooencyrtus spp., including known natural enemies of various pests, parasitized the eggs of S. coloratum and other associated pentatomids found on the caper plants. Thus, capers probably serve as a refuge for these potentially important egg parasitoids. The potential of caper plants and their fauna for biological control programmes is discussed.
-
spatial distribution and niche partitioning in the Ooencyrtus spp complex parasitizing the eggs of stenozygum coloratum
Biocontrol, 2015Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:The way in which species coexist is an important ecological question. Often, several parasitoid species may share a common host species. Five species of Ooencyrtus Ashmead (Hymenoptera: Encyrtidae) co-inhabit the egg clusters of Stenozygum coloratum Klug (Hemiptera: Pentatomidae), in the East Mediterranean region. Their relative abundance and spatial and seasonal occurrence were investigated. Parasitism and parasitoid male ratios gradually increased to about 50 and 26.8 %, respectively, from May to October. O. telenomicida Vassiliev was dominant in Mediterranean climatic regions and absent from arid areas, O. fecundus Ferriere and Voegele dominated semi-arid areas, and O. near nigerrimus was the commonest in hot-arid areas. O. near fecundus occurred everywhere but was most abundant in the more extreme weather conditions. O. pityocampae Mercet was uncommon in most areas and absent from arid ones. O. telenomicida abundance was positively, and that of O. fecundus negatively, correlated with annual rainfall. O. near fecundus and O. near nigerrimus abundance was positively correlated with temperature extremes. The results display a clear picture for climatic based spatial niche partitioning, although there is evidence that interspecific competition also plays a significant role in the frequency of occurrence of the studied Ooencyrtus spp.
-
genetic diversity and host alternation of the egg parasitoid Ooencyrtus pityocampae between the pine processionary moth and the caper bug
PLOS ONE, 2015Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Manuela Branco, Zvi MendelAbstract:The increased use of molecular tools for species identification in recent decades revealed that each of many apparently generalist parasitoids are actually a complex of morphologically similar congeners, most of which have a rather narrow host range. Ooencyrtus pityocampae (OP), an important egg parasitoid of the pine processionary moth (PPM), is considered a generalist parasitoid. OP emerges from PPM eggs after winter hibernation, mainly in spring and early summer, long before the eggs of the next PPM generation occurs. The occurrence of OP in eggs of the variegated caper bug (CB) Stenozygum coloratum in spring and summer suggests that OP populations alternate seasonally between PPM and CB. However, the identity of OP population on CB eggs seemed uncertain; unlike OP-PPM populations, the former displayed apparently high male/female ratios and lack of attraction to the PPM sex pheromone. We studied the molecular identities of the two populations since the morphological identification of the genus Ooencyrtus, and OP in particular, is difficult. Sequencing of COI and ITS2 DNA fragments and AFLP analysis of individuals from both hosts revealed no apparent differences between the OP-PPM and the OP-CB populations for both the Israeli and the Turkish OPs, which therefore supported the possibility of host alternation. Sequencing data extended our knowledge of the genetic structure of OP populations in the Mediterranean area, and revealed clear separation between East and West Mediterranean populations. The overall level of genetic diversity was rather small, with the Israeli population much less diverse than all others; possible explanations for this finding are discussed. The findings support the possibility of utilizing the CB and other hosts for enhancing biological control of the PPM.
Murad Ghanim - One of the best experts on this subject based on the ideXlab platform.
-
Diversity of Ooencyrtus spp. (Hymenoptera: Encyrtidae) parasitizing the eggs of Stenozygum coloratum (Klug) (Hemiptera: Pentatomidae) with description of two new species
2018Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Pasquale Cascone, Emilio Guerrieri, John Noyes, Zvi MendelAbstract:Ooencyrtus spp. (Hymenoptera, Chalcidoidea, Encyrtidae) are important natural enemies of agricultural and forest insect pests, and are distributed worldwide. Their reduced dimensions, highly variable morphological characters and possible effect of wide host range and abiotic factors, make correct identification at the species level particularly difficult. This paper combined molecular, morphological, and biological data to characterize a group of Ooencyrtus spp. emerging from the eggs of the variegated caper bug, Stenozygum coloratum in the east Mediterranean area. COI and ITS2 sequencing revealed the presence of six and five divergent clades, respectively. Three clades were identified as Ooencyrtus telenomicida, Ooencyrtus pityocampae and O. pistaciae. Two clades represent new species which are here described and named Ooencyrtus zoeae and Ooencyrtus mevalbelus. These features were combined with reliable morphological characters to facilitate the separation of these species. A dichotomous key and a new synonymy are proposed. Ooencyrtus pistaciae had two distinct COI clades but only one ITS2 clade. Crossbreeding trials that included Ooencyrtus telenomicida, Ooencyrtus melvabelus sp. nov. and Ooencyrtus zoeae sp. nov. confirmed their reproductive isolation. COI sequences showed 0–0.8% and 4–9% within and between-species genetic differences, respectively. ITS2 showed 0.4–5.9% genetic differences between species, with no genetic differences within species. Haplotype diversity of Israeli and Turkish populations of the various species was 0–0.98 and was particularly low in Ooencyrtus pityocampae, whose Israeli population showed no diversity. The discovery of the Ooencyrtus spp. on the eggs of the caper bug, and their abundance support the idea that the bug can be used as an alternative host for augmentation of populations of these parasitoids in agricultural and forestry systems.
-
comparative study of development parameters of four Ooencyrtus spp hymenoptera encyrtidae on natural and factitious hosts
Journal of Applied Entomology, 2016Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:Biological control approaches such as seeding and augmentation releases of populations of natural enemies mostly rely on the indoor production of predator or parasitoid species, often with the use of alternative prey/host species. In this study, we investigated several development parameters of four egg parasitoid species: Ooencyrtus fecundus, O. near fecundus, O. pityocampae and O. telenomicida, and compared their performance on their natural host, the variegated caper bug (CB) Stenozygum coloratum, and on an alternative, factitious host, the silk moth (SM) Bombyx mori. Survival was higher and development duration shorter in CB eggs, making the CB a better host for these congeners. However, adult longevity was generally longer for individuals that developed in SM eggs. Moreover, O. fecundus and O. pityocampae females that had developed in SM eggs displayed higher fecundity than all other female/host combinations. Survival also varied according to the age of the SM eggs: parasitoid survival rates were significantly higher in 9- to 12-month-old (post-diapausing) eggs than in young (about 1 month old) ones. These results were probably influenced by differences among the egg sizes of the studied hosts. The number of non-laying females and self-superparasitism rates were exceptionally high in O. near fecundus. These findings suggest that SM eggs, and especially those which are being utilized after a long storage, could serve for mass rearing of the studied Ooencyrtus spp.
-
seasonal history plant interactions and egg parasitism of the variegated caper bug stenozygum coloratum klug heteroptera pentatomidae
Agricultural and Forest Entomology, 2016Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:The variegated caper bug Stenozygum coloratum Klug is common in the Middle East, where it is a minor agricultural pest. Recently, it was found that S. coloratum is an alternative host for the egg parasitoid Ooencyrtus pityocampae Mercet, an important natural enemy of the pine processionary moth Thaumetopoea wilkinsoni Tams, a major pest of pines. This discovery, coupled with the general lack of knowledge of S. coloratum, prompted the present study, which focused on seasonal activity of S. coloratum in Israeli pine forests, bidirectional interactions between the bug and its host the caper plant Capparis spp., and parasitism of its eggs. Stenozygum coloratum activity lasted mainly from May to October, and was followed by an adult winter diapause. Individuals formed large aggregations, causing early withering of plants and a shortening their annual growth periods. Reproductive activity peaked in August and ended in September. Egg parasitism rates increased throughout this period. Several Ooencyrtus spp., including known natural enemies of various pests, parasitized the eggs of S. coloratum and other associated pentatomids found on the caper plants. Thus, capers probably serve as a refuge for these potentially important egg parasitoids. The potential of caper plants and their fauna for biological control programmes is discussed.
-
spatial distribution and niche partitioning in the Ooencyrtus spp complex parasitizing the eggs of stenozygum coloratum
Biocontrol, 2015Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Zvi MendelAbstract:The way in which species coexist is an important ecological question. Often, several parasitoid species may share a common host species. Five species of Ooencyrtus Ashmead (Hymenoptera: Encyrtidae) co-inhabit the egg clusters of Stenozygum coloratum Klug (Hemiptera: Pentatomidae), in the East Mediterranean region. Their relative abundance and spatial and seasonal occurrence were investigated. Parasitism and parasitoid male ratios gradually increased to about 50 and 26.8 %, respectively, from May to October. O. telenomicida Vassiliev was dominant in Mediterranean climatic regions and absent from arid areas, O. fecundus Ferriere and Voegele dominated semi-arid areas, and O. near nigerrimus was the commonest in hot-arid areas. O. near fecundus occurred everywhere but was most abundant in the more extreme weather conditions. O. pityocampae Mercet was uncommon in most areas and absent from arid ones. O. telenomicida abundance was positively, and that of O. fecundus negatively, correlated with annual rainfall. O. near fecundus and O. near nigerrimus abundance was positively correlated with temperature extremes. The results display a clear picture for climatic based spatial niche partitioning, although there is evidence that interspecific competition also plays a significant role in the frequency of occurrence of the studied Ooencyrtus spp.
-
genetic diversity and host alternation of the egg parasitoid Ooencyrtus pityocampae between the pine processionary moth and the caper bug
PLOS ONE, 2015Co-Authors: Shahar Samra, Alex Protasov, Murad Ghanim, Manuela Branco, Zvi MendelAbstract:The increased use of molecular tools for species identification in recent decades revealed that each of many apparently generalist parasitoids are actually a complex of morphologically similar congeners, most of which have a rather narrow host range. Ooencyrtus pityocampae (OP), an important egg parasitoid of the pine processionary moth (PPM), is considered a generalist parasitoid. OP emerges from PPM eggs after winter hibernation, mainly in spring and early summer, long before the eggs of the next PPM generation occurs. The occurrence of OP in eggs of the variegated caper bug (CB) Stenozygum coloratum in spring and summer suggests that OP populations alternate seasonally between PPM and CB. However, the identity of OP population on CB eggs seemed uncertain; unlike OP-PPM populations, the former displayed apparently high male/female ratios and lack of attraction to the PPM sex pheromone. We studied the molecular identities of the two populations since the morphological identification of the genus Ooencyrtus, and OP in particular, is difficult. Sequencing of COI and ITS2 DNA fragments and AFLP analysis of individuals from both hosts revealed no apparent differences between the OP-PPM and the OP-CB populations for both the Israeli and the Turkish OPs, which therefore supported the possibility of host alternation. Sequencing data extended our knowledge of the genetic structure of OP populations in the Mediterranean area, and revealed clear separation between East and West Mediterranean populations. The overall level of genetic diversity was rather small, with the Israeli population much less diverse than all others; possible explanations for this finding are discussed. The findings support the possibility of utilizing the CB and other hosts for enhancing biological control of the PPM.
Elisabeth Tabone - One of the best experts on this subject based on the ideXlab platform.
-
etude de la performance d un parasitoide oophage Ooencyrtus pityocampae mercet hymenoptera encyrtidae pour lutter contre des ravageurs d un ecosysteme mediterraneen
Biotechnologie Agronomie Société et Environnement, 2019Co-Authors: Hilal Tunca, Marine Venard, Etty-ambre Colombel, Elisabeth TaboneAbstract:Description du sujet. Dans le cadre d’un projet de biocontrole de la processionnaire du pin, Thaumetopoea pityocampa Denis & Schiffermuller, l’utilisation de parasitoides indigenes pour lutter contre ce ravageur a ete etudiee au sein du Laboratoire Biocontrole a l’UEFM (Unite Experimentale Entomologie et Foret Mediterraneenne) a l’INRA PACA. Objectifs. Il est necessaire de rechercher le meilleur hote de substitution et de mettre au point son elevage. Plus particulierement, l'espece Ooencyrtus pityocampae (Mercet) a ete etudiee. Methode. Thaumetopoea pityocampa etant une espece allergisante, plusieurs hotes de substitution ont ete compares pour l’elevage des parasitoides : Philosamia ricini (Danovan), Nezara viridula (L.) et Halyomorpha halys (Stal). Les caracteristiques biologiques et la fitness des descendants ont ete comparees en conditions de laboratoire (25 ± 1 °C, 75 ± 5 % HR, 16L:8D). Resultats. Philosamia ricini est le meilleur hote de substitution pour l’elevage d’O. pityocampae pour ce qui est de la quantite et de la qualite des individus produits. Conclusions. Cette etude servira de base a une reflexion sur les possibilites d’utiliser ce parasitoide dans le cadre de la lutte biologique contre certains ravageurs mediterraneens.
-
Ooencyrtus pityocampae Mercet rearing on three substitute hosts in laboratory to implement a biocontrol of Thaumetopoea pityocampa Den. & Schiff.
2018Co-Authors: Elisabeth Tabone, Hilal Tunca, Etty Colombel, Thomas Defferier, Marine Venard, Anne-sophie Brinquin, Maurane Buradino, Estelle Morel, Jean Claude MartinAbstract:Egg parasitoids are considered as efficient biological control agents and are used worldwide for control of several pests in many crops. Ooencyrtus pityocampae Mercet (Hymenoptera: Encyrtidae) is a polyphagous egg parasitoid which parasitises Thaumetopoea pityocampa Denis & Schiffermüller (Lepidoptera: Notodontidae) eggs. To implement a biocontrol of pine processionary moth with these parasitoids, it is first necessary to rear O. pityocampae. Because of allergy risks and problems of long life cycle and behavior, Thaumetopoea pityocampa is not easy to rear so the use of substitute host is unavoidable. In this project, Philosamia ricini Danovan (Lepidoptera: Saturniidae), Halyomorpha halys Stål (Hemiptera: Pentatomidae) and Nezara viridula L. (Hemiptera: Pentatomidae) were evaluated all three as substitute hosts. Different biological characteristics of O. pityocampae were determined for each one at 25 ± 1°C, 65 ± 5% RH, and a photoperiod of 16:8 h (L: D): development time, emergence rate, longevity, parasitism rate and fecundity. Results show that all three can be used to rear O. pityocampae.
-
a new substitute host and its effects on some biological properties of Ooencyrtus kuvanae
Bulletin of Entomological Research, 2017Co-Authors: Hilal Tunca, Marine Venard, Etty-ambre Colombel, Elisabeth TaboneAbstract:Lymantia dispar (L.) (Lepidoptera: Lymantriidae), commonly known as the gypsy moth, is a serious forest pest, and beneficial insects are particularly important for reducing its population numbers. Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae) is an arrhenotokous, solitary egg parasitoid of L. dispar. In this study, we evaluated a new substitute host, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae) for O. kuvanae. We investigated some of the biological effects of O. kuvanae on P. ricini eggs. In this context, the importance of the age of the female parasitoid (1, 3 or 5 days old), host age (1-2 and 3-4 days old) and host number (40, 60 and 80 host eggs) were examined under laboratory conditions (25 ± 1 °C, 65 ± 5% relative humidity and a 16 : 8 h photoperiod [light : dark]). The highest rate of offspring production (89.90%) occurred with 40 (1-2-day-old) host eggs and 5-day-old females. The mean developmental period ranged from 16.5 ± 0.08 days to 18.7 ± 0.08 days. The mean lifespan of the parasitoid was 51.10 ± 1.1 (n = 60) days with bio-honey and 3.92 ± 0.14 (n = 60) days without food. The mean fecundity was 68.88 ± 3.22 offspring/female. Peak adult emergence occurred between 2 and 9 days. The mean oviposition and mean post-oviposition periods of the female parasitoid were 22.76 ± 1.37 days and 13.64 ± 1.40 days, respectively. O. kuvanae was reared for more than ten generations on the eggs of P. ricini. Based on our findings, P. ricini can be used to rear O. kuvanae for the biological control of L. dispar.
-
Incidence of superparasitism in the egg parasitoid, Ooencyrtus kuvanae Howard (Hymenoptera: Encyrtidae)
Biocontrol Science and Technology, 2017Co-Authors: Hilal Tunca, Etty Colombel, Marine Venard, Elisabeth TaboneAbstract:The encyrtid Ooencyrtus kuvanae is a solitary parasitoid of the gypsy moth, Lymantria dispar L. (Lepidoptera-Lymantridae) that is used in biological control programmes and whose mass rearing is influenced by superparasitism. The purpose of this study was to investigate the effect of the self-superparasitism of O. kuvanae at different host densities (5, 10, 15 and 20), female ages (3 and 5 days) and durations of exposure (1 and 5 days) under various laboratory conditions (25°C ± 1°C, RH 60 ± 5% and a 16:8 h light: dark photoperiod) as well as in a new laboratory host, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae) of O. kuvanae. In this study, we determined the rate of egg superparasitism and adult emergence and recorded development time, longevity and body weight. Superparasitism increased with female age and the duration of exposure to parasitoids when females had access to five host eggs. Superparasitism increased the number of parasitoid offspring, but it resulted in male-biased (56.90%) progeny. Furthermore, superparasitism caused deleterious effects to the fitness of the progeny by prolonging the developmental process, and decreasing longevity. For example, we found that when four adults can emerge from one superparasitised host egg, the body size of the parasitoid offspring decreases significantly. Hence, superparasitism should be avoided when mass rearing O. kuvanae.
-
vers une production de masse d i Ooencyrtus pityocampae i et i Ooencyrtus kuvanae i hymenoptera encyrtidae pour le developpement d un biocontrole en foret
10. Rencontres Annuelles du Groupe des Entomologistes Forestiers Francophones (GEFF), 2016Co-Authors: Tunca Hilal, Etty Colombel, Marine Venard, Jean Claude Martin, Maurane Buradino, Estelle Morel, Elisabeth TaboneAbstract:[i]Thaumetopoea pityocampa[/i] (Lepidoptera: Thaumetopoeidae) et [i]Lymantria dispar[/i] (Lepidoptera: Lymantriidae) sont deux especes defoliatrices qui s’attaquent aux forets de resineux et de feuillus. Peu de traitements existent contre ces deux ravageurs. Notre objectif est de rechercher une methode de biocontrole visant a reduire l'utilisation des produits phytosanitaires, dans le respect de l'environnement. [i]Ooencyrtus pityocampae[/i] et [i]Ooencyrtus kuvanae[/i] (Hymenoptera: Encyrtidae) sont deux parasitoides oophages naturels de [i]T. pityocampa[/i] et [i]L. dispar[/i]. Ils jouent un role reel mais insuffisant dans la regulation naturelle des populations de ravageurs ainsi que dans la dynamique de repartition de la processionnaire du pin et de Bombyx disparate. Afin d’ameliorer la production de masse de ces ennemis naturels, il est necessaire de rechercher le meilleur hote de substitution et de mettre au point son elevage. L’objectif est d’ameliorer l’efficacite des parasitoides oophages produits et d’en diminuer les couts. Pour cela, plusieurs caracteristiques biologiques des deux parasitoides oophages [i]O. pityocampae[/i] et [i]O. kuvanae[/i] ont ete etudiees avec le nouvel hote de substitution [i]Philosamia ricini[/i] (Lepidoptera: Saturniidae). Les essais ont ete realises dans le laboratoire BioControle de l’UEFM INRA-PACA. Les bons resultats obtenus ont permis d’optimiser la technique d’elevage de masse de ces deux entomophages. A terme, la strategie des lâchers sera mise au point, respectivement pour les auxiliaires les plus performants, et adaptee aux conditions environnementales.
