D. Blumberg | Ben Gurion University of the Negev (original) (raw)
Papers by D. Blumberg
WIT Transactions on Ecology and the Environment, 2006
In Turkmenistan the most prominent cause for desertification is inappropriate land use practices.... more In Turkmenistan the most prominent cause for desertification is inappropriate land use practices. The natural arid pastures have limited carrying capacity and any changes of the fragile balance can lead to the destruction of this valuable resource. One of the most appropriate tools for monitoring these processes is change detection through remote sensing imagery. Accurate monitoring of changes on the Earth's surface is important to understand the relationship between man and nature and to provide decision makers with relevant information. The information on vegetation change is the most important of these relationships. Vegetation cover is also a useful indicator of the magnitude of land degradation that is easily assessed by multispectral remote sensing. The reduced vegetation cover causes an increase in albedo, which can also be monitored by remote sensing. The combination of these two parameters can give us a better map of the pasture status and its degradation rate. Landsat TM and ETM+ images were processed to maps of land use/land cover changes in northern Turkmenistan. The data were further processed in GIS and revealed the shrinking and the degradation of the pasture area. From the 1970s a total of ~4000km 2 of pasture were transformed into agricultural land, increasing the grazing pressure in the remaining areas. By applying advanced techniques for image based end-member retrieval and spectral mixture analysis a sub-pixel fraction was obtained for each end-member. The fractions of soil and vegetation emphasize the most degraded/rehabilitated sectors of the study area. Our results indicate the reduction of vegetation in specific areas while most of the desert experiences an increase in the vegetation cover. Our current study focuses on combining the spectral mixture analysis products with other degradation criteria such as change detection using albedo and vegetation indices to produce a more detailed assessment and understanding of the processes leading to these changes.
Among the pests of greenhouse roses in Israel, theEgyptian cotton leaf worm, Spodoptera littorali... more Among the pests of greenhouse roses in Israel, theEgyptian cotton leaf worm, Spodoptera littoralis Boisd. (= Prodenia litura F.), is of great importance.
Phytoparasitica, 1974
A description is given of efforts to develop an integrated control program for successful pest ma... more A description is given of efforts to develop an integrated control program for successful pest management of date palms in Israel. Work has been concentrated on biological control of the key pest P. blanehardi, and on alternative control operations for the remaining pests. The fact that date fruit is concentrated in bunches was used successfully to enable elficient control of fruit pests with only little interference with the biological control of P. blanchardi. The integrated control program has resulted in a drastic decline of the P. blanehardi population and in successful and easy control of the other pests.
Phytoparasitica, 1976
The extent of fruit drop and damage inflicted to date fruit by Coccotrypes and nitidulids was est... more The extent of fruit drop and damage inflicted to date fruit by Coccotrypes and nitidulids was estimated and control measures were investigated. Fruit drop, which occurred mainly in July and resulted in a 30-40% yield loss, was due mainly to Coccotrypes, which attacked unripe fruit. Fruit which dropped and started to rot was infested by nitidulid beetles throughout the summer. Green fruit was not damaged by nitidulids while on the bunches, but only as ripening progressed. Protecting the bunches with dense netting coverings prevented penetration of both pests and greatly reduced fruit drop and infestation. Although the organophosphorus insecticides pirimiphos-methyl and azinphos-methyl were efficient in controlling nitidulids, the mechanical control method was preferable.
Phytoparasitica, 1987
The corn species occurring in Israel are: Sesamia nonagrioides Lef., S. cretica Ld., Ostrinia nub... more The corn species occurring in Israel are: Sesamia nonagrioides Lef., S. cretica Ld., Ostrinia nubilalis Hb. (the European corn borer, ECB) and Chilo agamemnon Bles. Changes in cultivation methods and introduction of new varieties of corn resulted in Jaotable changes in the corn borer populations. The numbers of C. agamemnon, which was the main pest in the 1960s, decreased and since 1972 the populations of S. nonagrioides increased. In the course of the last 15 years the populations of the ECB were very low, but in 1981 an increase was observed. At present the ECB and S. nonagrioides are the main corn pests in Israel.
Phytoparasitica, 1985
Cellular and genetic engineering depends on the possibility to grow whole plants from single prot... more Cellular and genetic engineering depends on the possibility to grow whole plants from single protoplasts. Protoplast fusion allows crosses of distant species and also mixing of cytoplasms of two different cells into a single fused protoplast.
Phytoparasitica, 1992
Field tests were carried out to determine whether pheromone traps, baited with (Z,E)-9,12-tetrade... more Field tests were carried out to determine whether pheromone traps, baited with (Z,E)-9,12-tetradecadienyl acetate (Z9,E12-14:Ac) impregnated in rubber septa (Maavit, Israel), could provide a reliable tool for monitoring the raisin moth, Cadra figulilella (Gregson), in date palm plantations. No significant differences were detected between captures of males in traps baited with 1 or 10 mg pheromone/dispenser. However, traps baited with 1 mg pheromone captured significantly more males than those baited with 0.l mg pheromone/dispenser. No differences were found between captures of males in traps hung at a height of 8 m (near the bunches) or 2-3 m (on palm trunks). Two peaks of male capture were detected, one in May-June and the other during September-October (ripening period). Results indicate a positive relationship between captures in traps and infestation levels by larvae. Pheromone traps baited with 1 mg Z9,E12-14:Ac impregnated in rubber septa and hung on palm trunks (at a height of 2-3 m), were very useful for monitoring C. figulilella populations and for determining the accurate timing of insecticide applications.
Phytoparasitica, 1986
The Japanese bayberry whitefly, Parabernisia myricae (Kuwana), was discovered in Israel on citrus... more The Japanese bayberry whitefly, Parabernisia myricae (Kuwana), was discovered in Israel on citrus and avocado trees in 1978. In order to clarify its mode of overwintering, observations and counts were carried out during the winters of 1979/80, 1982/83 and 1983/84, with the following findings. Larvae and adults were detected on citrus and avocado trees throughout the winter; only females were found. The oviposition rate of P. myricae in winter was low, and rose steeply in spring. The density of larvae on the lower side of leaves was higher than on the upper side. Substantial numbers of larvae survived the winter on avocado trees. Emergence of adults became intensified at the end of February, reached a peak in early March, and ceased at the end of March or beginning of April.
Phytoparasitica, 2005
The red palm weevil Rhynchophorus ferrugineus (Olivier) (RPW) is the most serious pest of date pa... more The red palm weevil Rhynchophorus ferrugineus (Olivier) (RPW) is the most serious pest of date palms in the Middle East. Weevil infestation was first detected in Israel in the summer of 1999 in date plantations in the Jordan Valley, on the west bank of the Jordan River and in the northern area of the Dead Sea. For 2 years following the discovery of the pest, prophylactic insecticide chemical treatments as well as adult weevil trapping were carried out over 450 ha of date palm plantations. Traps loaded with a commercial aggregation pheromone, ferrugineol, supplemented with ethyl acetate and a fermenting mixture of dates and sugarcane molasses, were posted in high trap density (approx. ten traps per ha) in order to monitor weevil infestation and reduce the RPW population by mass trapping. A significant decrease in number of trapped beetles and infested trees was observed in 2001 and continued in the following years. No infested trees have been found since 2002, indicating a decrease in RPW population. The sex ratio of trapped adults during 3 years of study was significantly female-biased (,~2.5:1). Therefore, mass trapping might have played a significant role in the suppression of RPW populations in date plantations.
Phytoparasitica, 1996
Avocados in New Zealand are damaged by six leafroller species (Lepidoptera: Tortricidae), all but... more Avocados in New Zealand are damaged by six leafroller species (Lepidoptera: Tortricidae), all but one of which are native to New Zealand. The most important species are Ctenopseustis obliquana (Walker) and Ctenopseustis herana (Felder and Rogenhofer), which account for 90% of all caterpillars collected from fruit. The other species found occasionally are Cnephasia jactatana (Walker), Planotortrix octo (Dugdale), Planotortrix excessana (Walker) and the Australian Epiphyas postvittana (Walker). Caterpillars of Stathmopoda spp. are also sometimes observed damaging fruit. Other insects that can sometimes cause problems include the armoured scale species Hemiberlesia lataniae (Signoret) and H. rapax (Comstock), and the greenhouse thrips, Heliothrips haemorrhoidalis (Bouch6); further problems are due to mites.
Phytoparasitica, 1977
During 1972-1976 four species of African encyrtid wasps were introduced into Israel and released ... more During 1972-1976 four species of African encyrtid wasps were introduced into Israel and released against the Mediterranean black scale, Saissetia oleae (Olivier), in citrus and olive groves. Metaphycus helvolus (Compere) and M. aft. stanleyi Compete were recovered in small numbers. M. bartletti Annecke and Mynhardt and M. lounsburyi (Howard), which were found in large numbers on citrus during the release season, seem to be promising for the biological control of the black scale.
Phytoparasitica, 2007
Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae), an invasive species in the Mediterranean ... more Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae), an invasive species in the Mediterranean area that occurs naturally on Eucalyptus camaldulensis at Wagga Wagga in New South Wales, was studied in Israel on the same host plant. The most distinctive characteristic of O. maskelli as compared with other congeners is the presence of only a single seta on the submarginal vein. O. maskelli shows a clear tendency to oviposit in developed, immature leaves, and it prefers to oviposit on an area of the leaf blade near the petiole. The female lays an average of 109 eggs when maintained on water alone. The egglaying distribution tended towards aggregation, and the same tendency has also been observed within and among trees. The wasp prefers to attack the lower canopy. The gall diameter ranged from 1.2 to 0.9 mm, and gall density from 11.5 to 36.0 galls cm -2, respectively. The typical color of the gall appeared as soon as third instar larva developed. Galls on shaded leaves remained green or greenish-yellow, whereas those that were exposed to the sun were reddish. O. maskelli produces three generations per year in Israel. High flight occurs among the spring generations, starting in early March. The wasps were attracted to green sticky plates much more than to the other tested colors. Heavy galling by O. maskelli results in premature shedding of the leaves, soon after the emergence of the wasps. Among the 84 eucalyptus species tested, the following 14 species were found to be suitable hosts: and E. viminalis. This study focused on morphological and development characters that can clearly distinguish O. maskelli from Ophelimus eucalypti Gahan, and on examining the effect of crossing between eucalyptus species on the development possibilities of the wasps. Also considered were the effect of the food on adult survival, the competition between the eulophid gall maker Leptocybe invasa Fisher & LaSalle and O. maskelli, the heavy damage inflicted on eucalyptus, and the health problems and nuisance to people caused by the wasp near heavily infested trees during the mass emergence of adults.
Phytoparasitica, 1992
Biological control of four phloem-feeding homopterans on citrus and avocado is discussed. Example... more Biological control of four phloem-feeding homopterans on citrus and avocado is discussed. Examples of successful control are those achieved with Parabemisia myricae and lcerya purchasi; only partial control was obtained with Protopulvinaria pyriformis (nonspecitic parasitoid complex) and with Planococcus citri (climatic conditions unfavourable for its natural enemies).
Phytoparasitica, 2007
Four parasitoids emerged from leaves galled by the wasp Ophelimus maskelli (Ashmead) that were co... more Four parasitoids emerged from leaves galled by the wasp Ophelimus maskelli (Ashmead) that were collected in Wagga Wagga, NSW, Australia: Closterocerus chamaeleon (Girault) and an unidentified Tetrastichinae species (Eulophidae); and Stethynium ophelimi Huber and Stethynium breviovipositor Huber (Mymaridae). C. chamaeleon and S. ophelimi were released in eucalyptus plantations infested with O. maskelli in Israel. The recovery of the parasitoids, as well as several aspects of their possible role in control of the galls, were studied. In view of the parasitism of the galler in Wagga Wagga, we suggest that the proportion of S. ophelimi in the Israeli population of O. maskelli will increase markedly as soon as the gall wasp population density reaches a very low level.
Biological Control, 2007
Closterocerus chamaeleon (Girault) (Hymenoptera; Eulophidae) was introduced into Israel for biolo... more Closterocerus chamaeleon (Girault) (Hymenoptera; Eulophidae) was introduced into Israel for biological control of its family member, a gall-inducing pest Ophelimus maskelli (Ashmead). Closterocerus chamaeleon appears to be a widespread species in Australia, ranging from northern Queensland to Victoria and Western Australia. It was reared from galls on Eucalyptus camaldulensis Dehnh., E. tereticornis (=umbellata Smith.), E. amplifolia Naudin, E. cloziana F.Muell.
Agriculture, Ecosystems & Environment, 1989
ABSTRACT Since 1980 the pyriform scale, Protopulvinaria pyriformis (Cockerell) (Homoptera: Coccid... more ABSTRACT Since 1980 the pyriform scale, Protopulvinaria pyriformis (Cockerell) (Homoptera: Coccidae), has been an important pest of avocado in Israel.Field evaluation showed differences in the susceptibility of avocado cultivars to P. pyriforms; Nabal were the most infested, followed by Hass and Fuerte, whereas Ettinger was sometimes attacked when located close to infested Nabal or Hass trees.In a laboratory experiment P. pyriformis was able to develop and to reproduce on Nabal, Ein Vered and, to a lesser extent, on Hass. Survival of P. pyriformis populations was very low on Fuerte, Horshim and Wurz cultivars, whereas P. pyriformis settled more successfully on Ettinger, Pinkerton and Reed. Results from the laboratory experiment confirmed the actual infestation rates in avocado orchards.
WIT Transactions on Ecology and the Environment, 2006
In Turkmenistan the most prominent cause for desertification is inappropriate land use practices.... more In Turkmenistan the most prominent cause for desertification is inappropriate land use practices. The natural arid pastures have limited carrying capacity and any changes of the fragile balance can lead to the destruction of this valuable resource. One of the most appropriate tools for monitoring these processes is change detection through remote sensing imagery. Accurate monitoring of changes on the Earth's surface is important to understand the relationship between man and nature and to provide decision makers with relevant information. The information on vegetation change is the most important of these relationships. Vegetation cover is also a useful indicator of the magnitude of land degradation that is easily assessed by multispectral remote sensing. The reduced vegetation cover causes an increase in albedo, which can also be monitored by remote sensing. The combination of these two parameters can give us a better map of the pasture status and its degradation rate. Landsat TM and ETM+ images were processed to maps of land use/land cover changes in northern Turkmenistan. The data were further processed in GIS and revealed the shrinking and the degradation of the pasture area. From the 1970s a total of ~4000km 2 of pasture were transformed into agricultural land, increasing the grazing pressure in the remaining areas. By applying advanced techniques for image based end-member retrieval and spectral mixture analysis a sub-pixel fraction was obtained for each end-member. The fractions of soil and vegetation emphasize the most degraded/rehabilitated sectors of the study area. Our results indicate the reduction of vegetation in specific areas while most of the desert experiences an increase in the vegetation cover. Our current study focuses on combining the spectral mixture analysis products with other degradation criteria such as change detection using albedo and vegetation indices to produce a more detailed assessment and understanding of the processes leading to these changes.
Among the pests of greenhouse roses in Israel, theEgyptian cotton leaf worm, Spodoptera littorali... more Among the pests of greenhouse roses in Israel, theEgyptian cotton leaf worm, Spodoptera littoralis Boisd. (= Prodenia litura F.), is of great importance.
Phytoparasitica, 1974
A description is given of efforts to develop an integrated control program for successful pest ma... more A description is given of efforts to develop an integrated control program for successful pest management of date palms in Israel. Work has been concentrated on biological control of the key pest P. blanehardi, and on alternative control operations for the remaining pests. The fact that date fruit is concentrated in bunches was used successfully to enable elficient control of fruit pests with only little interference with the biological control of P. blanchardi. The integrated control program has resulted in a drastic decline of the P. blanehardi population and in successful and easy control of the other pests.
Phytoparasitica, 1976
The extent of fruit drop and damage inflicted to date fruit by Coccotrypes and nitidulids was est... more The extent of fruit drop and damage inflicted to date fruit by Coccotrypes and nitidulids was estimated and control measures were investigated. Fruit drop, which occurred mainly in July and resulted in a 30-40% yield loss, was due mainly to Coccotrypes, which attacked unripe fruit. Fruit which dropped and started to rot was infested by nitidulid beetles throughout the summer. Green fruit was not damaged by nitidulids while on the bunches, but only as ripening progressed. Protecting the bunches with dense netting coverings prevented penetration of both pests and greatly reduced fruit drop and infestation. Although the organophosphorus insecticides pirimiphos-methyl and azinphos-methyl were efficient in controlling nitidulids, the mechanical control method was preferable.
Phytoparasitica, 1987
The corn species occurring in Israel are: Sesamia nonagrioides Lef., S. cretica Ld., Ostrinia nub... more The corn species occurring in Israel are: Sesamia nonagrioides Lef., S. cretica Ld., Ostrinia nubilalis Hb. (the European corn borer, ECB) and Chilo agamemnon Bles. Changes in cultivation methods and introduction of new varieties of corn resulted in Jaotable changes in the corn borer populations. The numbers of C. agamemnon, which was the main pest in the 1960s, decreased and since 1972 the populations of S. nonagrioides increased. In the course of the last 15 years the populations of the ECB were very low, but in 1981 an increase was observed. At present the ECB and S. nonagrioides are the main corn pests in Israel.
Phytoparasitica, 1985
Cellular and genetic engineering depends on the possibility to grow whole plants from single prot... more Cellular and genetic engineering depends on the possibility to grow whole plants from single protoplasts. Protoplast fusion allows crosses of distant species and also mixing of cytoplasms of two different cells into a single fused protoplast.
Phytoparasitica, 1992
Field tests were carried out to determine whether pheromone traps, baited with (Z,E)-9,12-tetrade... more Field tests were carried out to determine whether pheromone traps, baited with (Z,E)-9,12-tetradecadienyl acetate (Z9,E12-14:Ac) impregnated in rubber septa (Maavit, Israel), could provide a reliable tool for monitoring the raisin moth, Cadra figulilella (Gregson), in date palm plantations. No significant differences were detected between captures of males in traps baited with 1 or 10 mg pheromone/dispenser. However, traps baited with 1 mg pheromone captured significantly more males than those baited with 0.l mg pheromone/dispenser. No differences were found between captures of males in traps hung at a height of 8 m (near the bunches) or 2-3 m (on palm trunks). Two peaks of male capture were detected, one in May-June and the other during September-October (ripening period). Results indicate a positive relationship between captures in traps and infestation levels by larvae. Pheromone traps baited with 1 mg Z9,E12-14:Ac impregnated in rubber septa and hung on palm trunks (at a height of 2-3 m), were very useful for monitoring C. figulilella populations and for determining the accurate timing of insecticide applications.
Phytoparasitica, 1986
The Japanese bayberry whitefly, Parabernisia myricae (Kuwana), was discovered in Israel on citrus... more The Japanese bayberry whitefly, Parabernisia myricae (Kuwana), was discovered in Israel on citrus and avocado trees in 1978. In order to clarify its mode of overwintering, observations and counts were carried out during the winters of 1979/80, 1982/83 and 1983/84, with the following findings. Larvae and adults were detected on citrus and avocado trees throughout the winter; only females were found. The oviposition rate of P. myricae in winter was low, and rose steeply in spring. The density of larvae on the lower side of leaves was higher than on the upper side. Substantial numbers of larvae survived the winter on avocado trees. Emergence of adults became intensified at the end of February, reached a peak in early March, and ceased at the end of March or beginning of April.
Phytoparasitica, 2005
The red palm weevil Rhynchophorus ferrugineus (Olivier) (RPW) is the most serious pest of date pa... more The red palm weevil Rhynchophorus ferrugineus (Olivier) (RPW) is the most serious pest of date palms in the Middle East. Weevil infestation was first detected in Israel in the summer of 1999 in date plantations in the Jordan Valley, on the west bank of the Jordan River and in the northern area of the Dead Sea. For 2 years following the discovery of the pest, prophylactic insecticide chemical treatments as well as adult weevil trapping were carried out over 450 ha of date palm plantations. Traps loaded with a commercial aggregation pheromone, ferrugineol, supplemented with ethyl acetate and a fermenting mixture of dates and sugarcane molasses, were posted in high trap density (approx. ten traps per ha) in order to monitor weevil infestation and reduce the RPW population by mass trapping. A significant decrease in number of trapped beetles and infested trees was observed in 2001 and continued in the following years. No infested trees have been found since 2002, indicating a decrease in RPW population. The sex ratio of trapped adults during 3 years of study was significantly female-biased (,~2.5:1). Therefore, mass trapping might have played a significant role in the suppression of RPW populations in date plantations.
Phytoparasitica, 1996
Avocados in New Zealand are damaged by six leafroller species (Lepidoptera: Tortricidae), all but... more Avocados in New Zealand are damaged by six leafroller species (Lepidoptera: Tortricidae), all but one of which are native to New Zealand. The most important species are Ctenopseustis obliquana (Walker) and Ctenopseustis herana (Felder and Rogenhofer), which account for 90% of all caterpillars collected from fruit. The other species found occasionally are Cnephasia jactatana (Walker), Planotortrix octo (Dugdale), Planotortrix excessana (Walker) and the Australian Epiphyas postvittana (Walker). Caterpillars of Stathmopoda spp. are also sometimes observed damaging fruit. Other insects that can sometimes cause problems include the armoured scale species Hemiberlesia lataniae (Signoret) and H. rapax (Comstock), and the greenhouse thrips, Heliothrips haemorrhoidalis (Bouch6); further problems are due to mites.
Phytoparasitica, 1977
During 1972-1976 four species of African encyrtid wasps were introduced into Israel and released ... more During 1972-1976 four species of African encyrtid wasps were introduced into Israel and released against the Mediterranean black scale, Saissetia oleae (Olivier), in citrus and olive groves. Metaphycus helvolus (Compere) and M. aft. stanleyi Compete were recovered in small numbers. M. bartletti Annecke and Mynhardt and M. lounsburyi (Howard), which were found in large numbers on citrus during the release season, seem to be promising for the biological control of the black scale.
Phytoparasitica, 2007
Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae), an invasive species in the Mediterranean ... more Ophelimus maskelli (Ashmead) (Hymenoptera: Eulophidae), an invasive species in the Mediterranean area that occurs naturally on Eucalyptus camaldulensis at Wagga Wagga in New South Wales, was studied in Israel on the same host plant. The most distinctive characteristic of O. maskelli as compared with other congeners is the presence of only a single seta on the submarginal vein. O. maskelli shows a clear tendency to oviposit in developed, immature leaves, and it prefers to oviposit on an area of the leaf blade near the petiole. The female lays an average of 109 eggs when maintained on water alone. The egglaying distribution tended towards aggregation, and the same tendency has also been observed within and among trees. The wasp prefers to attack the lower canopy. The gall diameter ranged from 1.2 to 0.9 mm, and gall density from 11.5 to 36.0 galls cm -2, respectively. The typical color of the gall appeared as soon as third instar larva developed. Galls on shaded leaves remained green or greenish-yellow, whereas those that were exposed to the sun were reddish. O. maskelli produces three generations per year in Israel. High flight occurs among the spring generations, starting in early March. The wasps were attracted to green sticky plates much more than to the other tested colors. Heavy galling by O. maskelli results in premature shedding of the leaves, soon after the emergence of the wasps. Among the 84 eucalyptus species tested, the following 14 species were found to be suitable hosts: and E. viminalis. This study focused on morphological and development characters that can clearly distinguish O. maskelli from Ophelimus eucalypti Gahan, and on examining the effect of crossing between eucalyptus species on the development possibilities of the wasps. Also considered were the effect of the food on adult survival, the competition between the eulophid gall maker Leptocybe invasa Fisher & LaSalle and O. maskelli, the heavy damage inflicted on eucalyptus, and the health problems and nuisance to people caused by the wasp near heavily infested trees during the mass emergence of adults.
Phytoparasitica, 1992
Biological control of four phloem-feeding homopterans on citrus and avocado is discussed. Example... more Biological control of four phloem-feeding homopterans on citrus and avocado is discussed. Examples of successful control are those achieved with Parabemisia myricae and lcerya purchasi; only partial control was obtained with Protopulvinaria pyriformis (nonspecitic parasitoid complex) and with Planococcus citri (climatic conditions unfavourable for its natural enemies).
Phytoparasitica, 2007
Four parasitoids emerged from leaves galled by the wasp Ophelimus maskelli (Ashmead) that were co... more Four parasitoids emerged from leaves galled by the wasp Ophelimus maskelli (Ashmead) that were collected in Wagga Wagga, NSW, Australia: Closterocerus chamaeleon (Girault) and an unidentified Tetrastichinae species (Eulophidae); and Stethynium ophelimi Huber and Stethynium breviovipositor Huber (Mymaridae). C. chamaeleon and S. ophelimi were released in eucalyptus plantations infested with O. maskelli in Israel. The recovery of the parasitoids, as well as several aspects of their possible role in control of the galls, were studied. In view of the parasitism of the galler in Wagga Wagga, we suggest that the proportion of S. ophelimi in the Israeli population of O. maskelli will increase markedly as soon as the gall wasp population density reaches a very low level.
Biological Control, 2007
Closterocerus chamaeleon (Girault) (Hymenoptera; Eulophidae) was introduced into Israel for biolo... more Closterocerus chamaeleon (Girault) (Hymenoptera; Eulophidae) was introduced into Israel for biological control of its family member, a gall-inducing pest Ophelimus maskelli (Ashmead). Closterocerus chamaeleon appears to be a widespread species in Australia, ranging from northern Queensland to Victoria and Western Australia. It was reared from galls on Eucalyptus camaldulensis Dehnh., E. tereticornis (=umbellata Smith.), E. amplifolia Naudin, E. cloziana F.Muell.
Agriculture, Ecosystems & Environment, 1989
ABSTRACT Since 1980 the pyriform scale, Protopulvinaria pyriformis (Cockerell) (Homoptera: Coccid... more ABSTRACT Since 1980 the pyriform scale, Protopulvinaria pyriformis (Cockerell) (Homoptera: Coccidae), has been an important pest of avocado in Israel.Field evaluation showed differences in the susceptibility of avocado cultivars to P. pyriforms; Nabal were the most infested, followed by Hass and Fuerte, whereas Ettinger was sometimes attacked when located close to infested Nabal or Hass trees.In a laboratory experiment P. pyriformis was able to develop and to reproduce on Nabal, Ein Vered and, to a lesser extent, on Hass. Survival of P. pyriformis populations was very low on Fuerte, Horshim and Wurz cultivars, whereas P. pyriformis settled more successfully on Ettinger, Pinkerton and Reed. Results from the laboratory experiment confirmed the actual infestation rates in avocado orchards.