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J H Frank - One of the best experts on this subject based on the ideXlab platform.
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Biological Control of Mole Crickets
2014Co-Authors: J H Frank, Entomology NematologyAbstract:This report summarizes the current status of biological control of Scapteriscus mole crickets in Florida. Scapteriscus mole crickets (tawny mole cricket, southern mole cricket, and short-winge
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Zoogeography of mole crickets (Orthoptera: Gryllotalpidae)in the West Indies
2014Co-Authors: J H Frank, Earl D. MccoyAbstract:Four species of mole crickets (Orthoptera: Gryllotalpidae) are known from the West Indies: Neocurtilla hexadactyla (Perty), Scapteriscus abbreviatus Scudder, S. didactylus (Latreille), and S. imitatus Nickle and Castner. All are adventive (not native). We document their distributions in West Indian islands/countries by use of records from the literature and examination of specimens. Scapteriscus abbreviatus has been suggested to have arrived in, and been transported about the West Indies in ship ballast (immigration). Based on records of arrival in various parts of the West Indies and the species’ inability to fly, this suggestion seems reasonable. Scapteriscus imitatus apparently was released in Puerto Rico as a result of mistaken identification (introduction – arriving with assistance from humans – although inadvertent), and has not expanded its range in the West Indies. Although the principal mode of dispersal for the other two species also has been suggested to be ship ballast, we present an alternative based on flight which would seem at least equally as plausible. We suggest that S. didactylus could have dispersed by flight from South America through the Lesser Antilles; likewise N. hexadactyla probably from the Yucatan Peninsula to Cuba, and from South America northward through the Lesser Antilles, in at least some localities assisted by wind. Our zoogeographical alternative, if correct, means that the natural range expansions of these latter two species began very long ago and without human assistance – they were not introduced recently to the West Indies.
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0004. A history of mole crickets (Orthoptera: Gryllotalpidae) in Puerto Rico
2007Co-Authors: J H Frank, N. E. Vicente, Norman C. LepplaAbstract:Published claims in 1887-1903 that the mole cricket Neocurtilla hexadactyla (Perty) occurs in Puerto Rico all seem to be derived from a misidentification made by Agustin Stahl, a medical practitioner and collector of natural history objects, published in 1882. That species does not seem now to occur in Puerto Rico and almost certainly never did. However, the opportunity still exists for it to colonize by wind-assisted flight from islands to the southeast just as we believe did the mole cricket Scapteriscus didactylus (Latreille) as an immigrant. Stahl evidently mistook the latter for the former. According to some subsequent authors, he also stated that it (the mole cricket now believed to be S. didactylus) arrived in the port of Mayaguez in a cargo of guano about 1850 from Peru and thus colonized Puerto Rico. We found no verification for that story, and we doubt it. The first detection of the presence of S. didactylus in Puerto Rico may have been by a French expedition in 1797, but this species may have been present much earlier. Two other species of Scapteriscus were later detected in Puerto Rico. One, S. abbreviatus Scudder, was detected in 1917 and likely arrived as a contaminant of ship ballast some time earlier, perhaps at the port of Mayaguez. The other, S. imitatus Nickle and Castner, was detected about 1940 and seems to have been introduced inadvertently, as a result of mistaken identity. In broad terms, S. didactylus, S. abbreviatus, and S. imitatus are adventive species (meaning they arrived from somewhere else and are not native) in Puerto Rico. The vernacular name changa in Puerto Rico is owned by S. didactylus, which is called West Indian mole cricket in the English-speaking Caribbean. Historical accounts suggest that populations of S. didactylus and of two pest Phyllophaga spp. (Coleoptera: Scarabaeidae) surged after 1876/1877 and declined after 1920. This coincidence suggests that the cause may have been the same. The cause of the rise might conceivably have been introduction of the mongoose Herpestes javanicus (E. Geoffroy St. Hilaire) in 1877 (because it may have destroyed vertebrate predators) and the cause of the decline might conceivably have been introduction of the toad Bufo marinus L. in 1920, because it is a predator of Phyllophaga and Scapteriscus.
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MANAGEMENT OF PEST MOLE CRICKETS IN FLORIDA AND PUERTO RICO WITH A NEMATODE AND PARASITIC WASP
Florida Entomologist, 2007Co-Authors: Norman C. Leppla, J H Frank, M. B. Adjei, N. E. VicenteAbstract:Abstract Non-indigenous invasive mole crickets, Scapteriscus vicinus Scudder (Orthoptera: Gryllotalpidae) in Florida and S. didactylus (Latreille) (the “changa”) in Puerto Rico, are being managed with an entomopathogenic nematode, Steinernema scapterisci (Nguyen and Smart) (Rhabditida: Steinernematidae), and a parasitic wasp, Larra bicolor L. (Hymenoptera: Sphecidae). Pest mole cricket populations have declined by 95% in north central Florida since these specialist natural enemies were released and established in the 1980s. Commercial production of the nematode was initiated, nearly 70 billion were applied in 34 Florida counties, and their establishment, spread, and impact on mole crickets were monitored. The infected mole crickets dispersed the nematode rapidly, so that within 6 months these parasites were present in most of the insects trapped in experimental pastures. Three years later, mole cricket populations were reduced to acceptable levels and the bahiagrass had recovered. The nematode was release...
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Use of a beneficial nematode against pest mole crickets in Puerto Rico
2006Co-Authors: N. E. Vicente, J H Frank, Norman C. LepplaAbstract:A beneficial nematode, Steinemema scapterisci (Rhabditida: Steinernematidae), has been researched at the University of Florida and is now marketed as a biopesticide. Its primary target is the mole cricket, Scapteriscus vicinus Scudder (Orthoptera: Gryllotalpidae), which has been a pest in Florida for about 100 years. The nematode survives so well in Florida's sandy, low-organic soils that it serves as a classical biological control agent to provide permanent suppression of pest mole cricket populations in places to which it has spread. In Puerto Rico and islands of the Lesser Antilles, where there is a much wider range of soils, the primary mole cricket pest is Scapteriscus didactylus (Latreille). Our research evaluates the use of the nematode to control Scapteriscus didactylus. Our earlier results in the field showed establishment and survival for up to seven months in a sandy loam with mole crickets, but no establishment in a highly organic sandy soil with mole crickets. A laboratory bioassay in sterilized sand showed 100% survival of controls, but up to 100% mortality of mole crickets within 168 h dependent upon number of nematodes applied (dose or 'rate'). Laboratory survival of nematodes was poorer in non-sterilized soils than in sterilized soils.
Marc Girondot - One of the best experts on this subject based on the ideXlab platform.
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Evidence of the exploitation of marine resource by the terrestrial insect Scapteriscus didactylus through stable isotope analyzes of its cuticle
BMC Ecology, 2006Co-Authors: Alexandra Maros, Alain Louveaux, Caroline Lelarge, Marc GirondotAbstract:Background About 4 × 10^5 eggs in more than 5000 marine turtle nests are deposited every year on a 3.6 km long beach in French Guiana (South America). The dry biomass of eggs is estimated to be 5 × 10^3 kg, yet only 25% of this organic matter will return to the ocean in the form of hatchlings. Such amounts of organic matter are supposed to drive the functioning of the beach ecosystem. Previous studies have shown that egg predators and detritivorous organisms dominate the trophic relationships and the dynamics of the system. The role of a terrestrial insect Scapteriscus didactylus (Latreille), which damages up to 40% of the eggs of the marine turtle ( Dermochelys coriacea ), was unexpected. However it was impossible from direct observations to prove that the mole cricket consumed a significant amount of these eggs. Therefore, the precise place of the mole cricket in the nitrogen and carbon cycles of the beach ecosystem could not be determined. In order to answer this question, we looked for a marine signature of carbon and nitrogen source metabolized by the mole cricket. Results This study estimated the individual variability of δ^13C and δ^15N in the cuticle of Scapteriscus didactylus . The isotopic signature was compared between individuals collected at two sites: a village where mole crickets fed on human food scraps and the nearby Awala-Yalimapo beach, where food availability depends seasonally on the nesting sea turtles. The mole crickets collected near the habitations garbage showed no significant variations in the stable isotopic signature, within-and between age groups. On the contrary, isotopic values shifted from a signature of a terrestrial herbivorous diet in the mole crickets during early developmental stages, to isotopic values in adults in accordance with the exploitation of marine animal resources. Conclusion The heterogeneity of individual signatures during the year is due to a selective exploitation of the food sources, differing in space and time. Some individuals, from the beach sample consumed a sufficient quantity of turtle eggs to induce the increase of isotopic enrichment observed in the cuticle. Scapteriscus didactylus is an opportunist feeder and plays a role in the turn over of the beach organic matter.
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BMC Ecology BioMed Central
2006Co-Authors: Ra Maros, Alain Louveaux, Caroline Lelarge, Marc GirondotAbstract:Research article Evidence of the exploitation of marine resource by the terrestrial insect Scapteriscus didactylus through stable isotope analyzes of its cuticl
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Identifying Characteristics of Scapteriscus spp. (Orthoptera: Gryllotalpidae) Apparent Predators of Marine Turtle Eggs
Environmental Entomology, 2005Co-Authors: Alexandra Maros, Alain Louveaux, Elodie Liot, Julie Marmet, Marc GirondotAbstract:Abstract The leatherback turtle (Dermochelys coriacea) (Vandelli, 1761) is classified by the IUCN (The World Conservation Union) as a critically endangered species. Hatching success is as low as 35% in French Guiana, which hosts ≈40% of the worldwide nesting activity. It has recently been shown that mole crickets contribute to the destruction of the leatherbacks at the Amana Natural Reserve. The aim of this paper is to document our observations about these potential predators of marine turtles. Identification keys and sound recordings are provided for Scapteriscus didactylus (Latreille, 1804) and Scapteriscus borellii (Giglio-Tos, 1894), mole cricket species that live in French Guiana. An abundance index of the presence of juveniles and adults was developed to study mole cricket populations in turtle rookeries and promote new observations.
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Scapteriscus didactylus (Orthoptera, Gryllotalpidae), predator of leatherback turtle eggs in French Guiana
Marine Ecology Progress Series, 2003Co-Authors: Alexandra Maros, Alain Louveaux, Matthew H. Godfrey, Marc GirondotAbstract:The present study describes the potential role of the insect Scapteriscus didactylus in egg mortality in nests of the leatherback sea turtle Dermochelys coriacea found in the Amana natural reserve in French Guiana. Out of the 3 mole cricket species (Scapteriscus didactylus (Latreille), S. borellii Giglio-Tos, Neocurtilla hexadactyla Perty) observed in the natural reserve, only S. didactylus was encountered on the sandy beaches where 4 species of marine turtles nest. Controlled experi- ments, in which S. didactylus individuals of various age classes and leatherbacks eggs were placed together, revealed that only the last instar nymphs of S. didactylus preyed on the eggs, making a characteristic round hole underneath the eggs in the sand. This same distinctive damage to eggs was seen in natural leatherback nests at Awala-Yalimapo beach in the Amana natural reserve. The pre- dation affected on average 18% (range: 3.6 to 40.0%) of all yolked eggs in the nests. Juvenile S. di- dactylus were present on the beach throughout the nesting season of leatherback turtles, while adult S. didactylus were observed when the nest density on the beach reached its seasonal maximum at the end of July.
Grover C Smart - One of the best experts on this subject based on the ideXlab platform.
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inoculative release of steinernema scapterisci rhabditida steinernematidae to suppress pest mole crickets orthoptera gryllotalpidae on golf courses
Environmental Entomology, 1994Co-Authors: J P Parkman, J H Frank, Khuong B Nguyen, Grover C SmartAbstract:Single inoculative applications of Steinernema scapterisci were made on golf courses in north central (Alachua County) and southeastern (Broward County) Florida. Nematode-infected Scapteriscus spp. mole crickets were collected from eight of nine treated plots and from five of six treated plots in Alachua and Broward counties, respectively. However, infected individuals were collected with regularity from only two courses in Alachua County where level of infection was greatest during the spring (March-June). Weekly infection levels for weeks 1–12 after treatment ranged from 0–100%. Infection of Scapteriscus spp. adults from treated plots in Alachua County, 25.2%, was significantly greater than that for nymphs, 1.2%; and infection of Scapteriscus borellii , 25.0%, was significantly greater than that of S. vicinus , 11.0%. Nematode-infected mole crickets were collected from four control plots in Alachua County and from one in Broward County during the 2nd yr after treatment. Significantly fewer mole crickets were collected in 24-h trap catches the 2nd yr after treatment on all treated plots combined and control plots combined in both counties. Mean trap catch was reduced 68, 62, and 41% the 2nd yr on treated plots where the nematode persisted; on control plots where infected crickets were collected; and on control plots where the nematode was not detected, respectively. Damage ratings and number of mole crickets soap-flushed from treated plots were significantly reduced the 2nd yr after treatment. Results indicate S. scapterisci can serve as an inoculative biological control agent for Scapteriscus spp. mole crickets on golf courses and as a biopesticide for relatively rapid suppression of pest populations.
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Establishment and Persistence of Steinernema scapterisci (Rhabditida: Steinernematidae) in Field Populations of Scapteriscus spp. Mole Crickets (Orthoptera: Gryllotalpidae)
Journal of Entomological Science, 1993Co-Authors: J P Parkman, J H Frank, Khuong B Nguyen, W. G. Hudson, Grover C SmartAbstract:The first successful inoculative releases of an entomopathogenic nematode, Steinernema scapterisci Nguyen and Smart, for the control of exotic pests, Scapteriscus spp. mole crickets, were made at three pasture sites in Alachua County, Florida in 1985. Based on the evaluation of field-collected crickets, the nematode was established at all sites and persisted for over 5 years. Mean yearly percentage of infected crickets ranged from 0 to 21.4% for individual release sites. Mean adult infection level for all years combined, 10.9%, was significantly greater than that for nymphs (2.5%) and infection levels for Scapteriscus borellii Giglio-Tos, 12.7%, was significantly greater than that for Scapteriscus vicinus Scudder (4.5%) for all years combined. Although 24 h trap catch results indicate mole cricket populations were significantly reduced, the nematode's effect on pest abundance could not be adequately assessed because of the variation in trap catch results and inadequate knowledge about the relationship between trap catch and the mole cricket field populations being sampled. Despite inadequacies in estimating pest abundance, the results indicate S. scapterisci has potential as a biological control agent for pest mole crickets in the genus Scapteriscus.
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Establishment and persistence of Steinernema scapterisci (Rhabditida: Steinernematidae) in field populations of Scapteriscus spp. mole crickets (Orthoptera: Gryllotalpidae)
Journal of Entomological Science, 1993Co-Authors: J P Parkman, J H Frank, Khuong B Nguyen, W. G. Hudson, Grover C SmartAbstract:The first successful inoculative releases of an entomopathogenic nematode, Steinernema scapterisci Nguyen and Smart, for the control of exotic pests, Scapteriscus spp. mole crickets, were made at three pasture sites in Alachua County, Florida in 1985. Based on the evaluation of field-collected crickets, the nematode was established at all sites and persisted for over 5 years. Mean yearly percentage of infected crickets ranged from 0 to 21.4% for individual release sites. Mean adult infection level for all years combined, 10.9%, was significantly greater than that for nymphs (2.5%) and infection levels for Scapteriscus borellii Giglio-Tos, 12.7%, was significantly greater than that for Scapteriscus vicinus Scudder (4.5%) for all years combined. Although 24 h trap catch results indicate mole cricket populations were significantly reduced, the nematode's effect on pest abundance could not be adequately assessed because of the variation in trap catch results and inadequate knowledge about the relationship bet...
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Mode of Entry and Sites of Development of Steinernema scapterisci in Mole Crickets.
Journal of nematology, 1991Co-Authors: Khuong B Nguyen, Grover C SmartAbstract:Key words: entomopathogenic nematode, mole cricket, Scapteriscus acletus, Steinernema scapterisci.
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Pathogenicity of Steinernema scapterisci to Selected Invertebrates.
Journal of nematology, 1991Co-Authors: K. B. Nguyen, Grover C SmartAbstract:Steinernema scapterisci was more pathogenic to insects tested in the order Orthoptera than to those in the orders Lepidoptera or Hymenoptera; it was not pathogenic to earthworms. The nematode also infected and killed the mole crickets Scapteriscus acletus and S. vicinus when released four successive times at 10-day intervals in containers of soil infested with the nematode.
J P Parkman - One of the best experts on this subject based on the ideXlab platform.
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Classical Biological Control of Scapteriscus spp. (Orthoptera: GrylIotalpidae) in Florida
Environmental Entomology, 1996Co-Authors: J P Parkman, J H Frank, Thomas J. Walker, David J. SchusterAbstract:The effects of classical biological control on pest mole crickets, Scapteriscus spp., in Florida were examined. Incidence of infection of sound-trapped Scapteriscus spp. by the entomopathogenic nematode Steinernema scapterisci Nguyen & Smart ranged from 0 to 4.5.3% for collections made near Gainesville and Bradenton during 1991, 1992, and 1994. Twelve of 49 mole cricket collections from 15 counties made from November 1992 to April 1995 contained individuals parasitized by the tachinid Ormia depleta (Wiedemann). Parasitism levels from 0 to 25.0% and from 0 to 24.1% were observed for female and male Scapteriscus vicinus Scudder, respectively. Mean total yearly sound trap catch of S. vicinus was reduced 36 and 25% at 2 sites near Gainesville after establishment of the 2 natural enemies; catches of Scapteriscus borellii Giglio-Tos were reduced 70 and 64%. At Bradenton, catches of S. vicinus and S. boreliii were reduced 81 and 5%, respectively, since the beneficial species were established. However, catches of S. borellii have declined by 81% in the last 3 yr. Results indicate that classical biological control of pest mole crickets in Florida is succeeding.
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The Introduction, Establishment, and Spread ofOrmia depletain Florida
Biological Control, 1996Co-Authors: J H Frank, Thomas J. Walker, J P ParkmanAbstract:Abstract Ormia depleta (Wiedemann) (Diptera: Tachinidae), native to Brazil, is a parasitoid of some Scapteriscus species (Orthoptera: Gryllotalpidae). It was first cultured in a laboratory in Florida in 1987. Releases of O. depleta were made against Scapteriscus mole crickets in all regions of Florida beginning in 1988. Establishment of populations was achieved at some, but not all, of the release sites. The two earliest-established populations were monitored using traps employing synthetic calling song of male Scapteriscus mole crickets, to which gravid female flies are attracted. Additionally, progeny of the released flies were trapped between 1988 and 1993 in 32 peninsular counties, including 15 counties in which no releases had been made. The most parsimonious explanation of the pathways of spread of the current population was inferred from trapping surveys, and this yielded the probable year of colonization for peninsular counties. Reports in successive years by golf course superintendents of damage by mole crickets showed that counties with O. depleta populations had significantly less damage than did yet-uncolonized counties.
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Entomopathogenic Nematodes, a Case Study: Introduction of Steinernema scapterisci in Florida
Biocontrol Science and Technology, 1996Co-Authors: J P Parkman, G. C. SmartAbstract:Steinernema scapterisci Nguyen & Smart (Rhabditida: Steinernematidae) was established in Florida in 1985 for the control of mole crickets, Scapteriscus spp. Infected hosts were collected in sound traps 23 km from the nearest release, indicating long-distance dispersal and area-wide establishment. In a subsequent pasture study, the nematode dispersed, on average, 60 m in 20 months; dispersal in some pastures was 150 m in 1 year. Establishment was not as successful on golf-courses; however, pest populations were reduced 27% in areas where the nematode persisted. Inoculative applications were successful at 10 of 29 sites in Florida, where sound traps attracted flying Scapteriscus to relatively small numbers of S. scapterisci infective juveniles. The differences in the susceptibility to the nematode for mole cricket life stages and species were determined in laboratory and field trials. The nematode became commercially available in 1993; commercial applications facilitate the establishment of S. scapterisci i...
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Seasonality ofOrmia depletaand Limits to Its Spread
Biological Control, 1996Co-Authors: Thomas J. Walker, J P Parkman, J H Frank, David J. SchusterAbstract:Abstract Ormia depleta (Wiedemann) (Diptera: Tachinidae), a South American fly that homes on the calling songs of its hosts, was brought from Piracicaba, Brazil; colonized; and released in Florida for the biological control of Scapteriscus spp. mole crickets. It became established at some release sites and rapidly spread through most of peninsular Florida. The seasonal distributions of phonotactic females in Florida differed from the single summer peak recorded at Rio Claro and Piracicaba, Brazil (23° S). Near Bradenton (27° N), spring and fall peaks with a summer hiatus were quickly established and remain evident. At two sites near Gainesville (30° N), a strong fall peak and a modest-to-none spring peak developed. Peaks of phonotactic females seem to follow times of peak host availability and sometimes coincide with minima of host availability. Limits to geographical expansion of O. depleta are poorly understood. At Gainesville, the site of earliest introduction, establishment was rapid and soundtrap catches increased for the first 3 years, exceeding 1000 per year at one site. Catches then declined for 3 years, almost reaching zero in 1994. On the other hand, annual sound-trap catches of O. depleta at Bradenton exceeded 1000 in O. depleta 's increase than during its decline. Perhaps mild winters cause the flies to become active early—only to starve for lack of adequate winter nectar sources. O. depleta may yet spread to the northern limits of its Scapteriscus hosts as present populations adapt to new environments. Or farther spread may require that new strains be introduced from more southerly sites in South America.
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inoculative release of steinernema scapterisci rhabditida steinernematidae to suppress pest mole crickets orthoptera gryllotalpidae on golf courses
Environmental Entomology, 1994Co-Authors: J P Parkman, J H Frank, Khuong B Nguyen, Grover C SmartAbstract:Single inoculative applications of Steinernema scapterisci were made on golf courses in north central (Alachua County) and southeastern (Broward County) Florida. Nematode-infected Scapteriscus spp. mole crickets were collected from eight of nine treated plots and from five of six treated plots in Alachua and Broward counties, respectively. However, infected individuals were collected with regularity from only two courses in Alachua County where level of infection was greatest during the spring (March-June). Weekly infection levels for weeks 1–12 after treatment ranged from 0–100%. Infection of Scapteriscus spp. adults from treated plots in Alachua County, 25.2%, was significantly greater than that for nymphs, 1.2%; and infection of Scapteriscus borellii , 25.0%, was significantly greater than that of S. vicinus , 11.0%. Nematode-infected mole crickets were collected from four control plots in Alachua County and from one in Broward County during the 2nd yr after treatment. Significantly fewer mole crickets were collected in 24-h trap catches the 2nd yr after treatment on all treated plots combined and control plots combined in both counties. Mean trap catch was reduced 68, 62, and 41% the 2nd yr on treated plots where the nematode persisted; on control plots where infected crickets were collected; and on control plots where the nematode was not detected, respectively. Damage ratings and number of mole crickets soap-flushed from treated plots were significantly reduced the 2nd yr after treatment. Results indicate S. scapterisci can serve as an inoculative biological control agent for Scapteriscus spp. mole crickets on golf courses and as a biopesticide for relatively rapid suppression of pest populations.
Alexandra Maros - One of the best experts on this subject based on the ideXlab platform.
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Evidence of the exploitation of marine resource by the terrestrial insect Scapteriscus didactylus through stable isotope analyzes of its cuticle
BMC Ecology, 2006Co-Authors: Alexandra Maros, Alain Louveaux, Caroline Lelarge, Marc GirondotAbstract:Background About 4 × 10^5 eggs in more than 5000 marine turtle nests are deposited every year on a 3.6 km long beach in French Guiana (South America). The dry biomass of eggs is estimated to be 5 × 10^3 kg, yet only 25% of this organic matter will return to the ocean in the form of hatchlings. Such amounts of organic matter are supposed to drive the functioning of the beach ecosystem. Previous studies have shown that egg predators and detritivorous organisms dominate the trophic relationships and the dynamics of the system. The role of a terrestrial insect Scapteriscus didactylus (Latreille), which damages up to 40% of the eggs of the marine turtle ( Dermochelys coriacea ), was unexpected. However it was impossible from direct observations to prove that the mole cricket consumed a significant amount of these eggs. Therefore, the precise place of the mole cricket in the nitrogen and carbon cycles of the beach ecosystem could not be determined. In order to answer this question, we looked for a marine signature of carbon and nitrogen source metabolized by the mole cricket. Results This study estimated the individual variability of δ^13C and δ^15N in the cuticle of Scapteriscus didactylus . The isotopic signature was compared between individuals collected at two sites: a village where mole crickets fed on human food scraps and the nearby Awala-Yalimapo beach, where food availability depends seasonally on the nesting sea turtles. The mole crickets collected near the habitations garbage showed no significant variations in the stable isotopic signature, within-and between age groups. On the contrary, isotopic values shifted from a signature of a terrestrial herbivorous diet in the mole crickets during early developmental stages, to isotopic values in adults in accordance with the exploitation of marine animal resources. Conclusion The heterogeneity of individual signatures during the year is due to a selective exploitation of the food sources, differing in space and time. Some individuals, from the beach sample consumed a sufficient quantity of turtle eggs to induce the increase of isotopic enrichment observed in the cuticle. Scapteriscus didactylus is an opportunist feeder and plays a role in the turn over of the beach organic matter.
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Identifying Characteristics of Scapteriscus spp. (Orthoptera: Gryllotalpidae) Apparent Predators of Marine Turtle Eggs
Environmental Entomology, 2005Co-Authors: Alexandra Maros, Alain Louveaux, Elodie Liot, Julie Marmet, Marc GirondotAbstract:Abstract The leatherback turtle (Dermochelys coriacea) (Vandelli, 1761) is classified by the IUCN (The World Conservation Union) as a critically endangered species. Hatching success is as low as 35% in French Guiana, which hosts ≈40% of the worldwide nesting activity. It has recently been shown that mole crickets contribute to the destruction of the leatherbacks at the Amana Natural Reserve. The aim of this paper is to document our observations about these potential predators of marine turtles. Identification keys and sound recordings are provided for Scapteriscus didactylus (Latreille, 1804) and Scapteriscus borellii (Giglio-Tos, 1894), mole cricket species that live in French Guiana. An abundance index of the presence of juveniles and adults was developed to study mole cricket populations in turtle rookeries and promote new observations.
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Scapteriscus didactylus (Orthoptera, Gryllotalpidae), predator of leatherback turtle eggs in French Guiana
Marine Ecology Progress Series, 2003Co-Authors: Alexandra Maros, Alain Louveaux, Matthew H. Godfrey, Marc GirondotAbstract:The present study describes the potential role of the insect Scapteriscus didactylus in egg mortality in nests of the leatherback sea turtle Dermochelys coriacea found in the Amana natural reserve in French Guiana. Out of the 3 mole cricket species (Scapteriscus didactylus (Latreille), S. borellii Giglio-Tos, Neocurtilla hexadactyla Perty) observed in the natural reserve, only S. didactylus was encountered on the sandy beaches where 4 species of marine turtles nest. Controlled experi- ments, in which S. didactylus individuals of various age classes and leatherbacks eggs were placed together, revealed that only the last instar nymphs of S. didactylus preyed on the eggs, making a characteristic round hole underneath the eggs in the sand. This same distinctive damage to eggs was seen in natural leatherback nests at Awala-Yalimapo beach in the Amana natural reserve. The pre- dation affected on average 18% (range: 3.6 to 40.0%) of all yolked eggs in the nests. Juvenile S. di- dactylus were present on the beach throughout the nesting season of leatherback turtles, while adult S. didactylus were observed when the nest density on the beach reached its seasonal maximum at the end of July.
