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John A. Byers - One of the best experts on this subject based on the ideXlab platform.
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Earwigs (Labidura riparia) mimic rotting-flesh odor to deceive vertebrate predators
The Science of Nature, 2015Co-Authors: John A. ByersAbstract:Many insects repel predators with caustic chemicals, while insects mimicking odors of wastes/dead insects to fool predators have not been documented. We found that the shore earwig, Labidura riparia (Dermaptera: Labiduridae) when bitten by anole lizards, Anolis carolinenesus , spits a rotting-flesh odor that deceives these insectivores into rejecting prey. Once a lizard attacked and rejected an earwig, the lizard did not attack another earwig during several weeks despite consuming other prey, indicating associative learning after one trial. The fetid odor was found in the head-prothorax containing salivary glands of both male and female earwigs and was comprised of ∼100 ng dimethyl disulfide and ∼600 ng dimethyl trisulfide. Nymphs had
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earwigs Labidura riparia mimic rotting flesh odor to deceive vertebrate predators
Naturwissenschaften, 2015Co-Authors: John A. ByersAbstract:Many insects repel predators with caustic chemicals, while insects mimicking odors of wastes/dead insects to fool predators have not been documented. We found that the shore earwig, Labidura riparia (Dermaptera: Labiduridae) when bitten by anole lizards, Anolis carolinenesus, spits a rotting-flesh odor that deceives these insectivores into rejecting prey. Once a lizard attacked and rejected an earwig, the lizard did not attack another earwig during several weeks despite consuming other prey, indicating associative learning after one trial. The fetid odor was found in the head-prothorax containing salivary glands of both male and female earwigs and was comprised of ∼100 ng dimethyl disulfide and ∼600 ng dimethyl trisulfide. Nymphs had <5 ng of either compound. Adults also spit odorous sulfides after prolonged attacks by harvester ants, Pogonomyrmex rugosus, who were only deterred by the earwig’s forceps. Sulfides released by the earwig are similar to odors of carrion/feces, which may be innately repulsive to some vertebrate predators. The mean initial discharge percentage (IDP) of sulfides from a cohort of earwigs was 62 %; however, IDPs of individuals were highly variable (3–99 %; mean 57 %). The discharge refill time (DRT) to refill 50 % of the earwig’s allomone reservoir was estimated at 13 h. A positive relationship in sulfide amounts with body weight was found only in females in 2009, suggesting metabolic cost tradeoffs were revealed when sulfide content was half that in 2010. This is the first report of insects releasing sulfur-containing compounds that may mimic carrion-fecal odors as a deceptive defense against vertebrate predators.
T. P. Mack - One of the best experts on this subject based on the ideXlab platform.
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Comparison of three methods for sampling arthropod pests and their natural enemies in peanut fields
Journal of Economic Entomology, 1993Co-Authors: Marwan S. Kharboutli, T. P. MackAbstract:We compared the use of beat sheets, pitfall traps, and sweep nets for sampling common arthropods in peanut fields by taking weekly samples in the 1987 to 1989 growing seasons. We used σ 2/ x ratios and number of samples needed as the criteria for comparing sampling techniques. Pitfall trap samples had the largest means for soil surface-dwelling arthropods such as Labidura riparia (Pallas) (Dermaptera: Labiduridae), Oxyopes salticus Hentz (Arachnida: Araneae: Oxyopidae), ground beetles, rove beetles, and wolf spiders. Beat sheet samples had the smallest σ 2/ x ratios for Solenopsis invicta (Buren) (Hymenoptera: Formicidae) and Peucetia viridans Hentz (Arachnida: Araneae: Oxyopidae). Samples from sweep nets had the smallest σ 2/ x ratios for Geocoris spp. (Hemiptera: Lygaeidae). All three techniques had similar σ 2/ x ratios for Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) and the Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). Sweep net samples had the smallest σ 2/ x ratios for Spissistilus festinus (Say) (Homoptera: Membracidae). None of the techniques adequately sampled all common pest and beneficial arthropods in peanuts.
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Effect of temperature, humidity, and prey density on feeding rate of the striped earwig (Dermaptera: Labiduridae)
Environmental Entomology, 1993Co-Authors: Marwan S. Kharboutli, T. P. MackAbstract:We measured the feeding rate of the striped earwig, Labidura riparia (Pallas) on third-instar fall armyworm, Spodoptera frugiperda (J. E. Smith), at three constant temperatures and at three humidities. Striped earwigs ate more larvae at 30°C than at 25 or 35°C. Humidity did not affect feeding rate. Rogers' random predator equation described the effects of prey density on feeding at 30°C and 80% RH. Search rates were ≍1,127 and 4,355 cm2/d, and handling rates were 20 and 22.1 prey per day for males and females, respectively. Females consumed more prey than males. The striped earwig appears to bean excellent biological control agent for arthropod pests in row crops.
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Tolerance of the striped earwig (Dermaptera: Labiduridae) to hot and dry conditions
Environmental Entomology, 1993Co-Authors: Marwan S. Kharboutli, T. P. MackAbstract:We measured the degree of adaptation to a xeric environment of immatures and adults of the striped earwig, Labidura riparia (Pallas). All stages of the striped earwig were moderately tolerant to heat, with critical thermal maxima ranging from 45.2 to 46.1°C for small and large nymphs, respectively. Percentage body water content ranged from 58.9% for females to 75.6% for small nymphs. Cuticular permeabilities were similar for all stages and were within the range of those reported for xeric species, ranging from 8.5 μg water lost per cm2·h·mm Hg for medium-sized nymphs to 17.0 μg water lost per cm2·h·mm Hg for females. Percentage total body water lost increased linearly with desiccation time. Lethal body water loss varied among stages and ranged from 47.6 to 52.9% for small and medium nymphs. The mean hour of death ranged from 16.8 h for small nymphs to 70.7 h for large nymphs, indicating that small nymphs were the least tolerant of desiccating conditions.
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Relative and Seasonal Abundance of Predaceous Arthropods in Alabama Peanut Fields as Indexed by Pitfall Traps
Journal of Economic Entomology, 1991Co-Authors: Marwan S. Kharboutli, T. P. MackAbstract:Pitfall traps were used to monitor the seasonal abundance of predators in conventionally tilled, irrigated, and nonirrigated peanut (Arachis hypogaea L.) fields in Alabama in 1987 and 1988. A diverse fauna of predaceous arthropods was captured ; Labidura riparia (Pallas) (Dermaptera : Labiduridae) was the most abundant. Solenopsis invicta Buren (Hymenoptera : Formicidae), Geocoris spp. (Hemiptera : Lygaeidae), carabids, staphylinids, and lycosids were also common. Traps placed between plant rows and those within rows yielded similar averages. All predaceous groups were captured throughout the peanut-growing season but in varied densities. Predator abundances peaked 70-100 d after planting, depending on the group. Capture of most predators increased exponentially for part or all of the growing season
Fouad Sayah - One of the best experts on this subject based on the ideXlab platform.
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Changes in the lipid and fatty acid composition of hemolymph and ovaries during the reproductive cycle of Labidura riparia
Entomological Science, 2008Co-Authors: Fouad SayahAbstract:Lipid metabolism was investigated during the reproductive cycle of Labidura riparia (Pallas). The lipid classes and their constitutive fatty acids present in hemolymph and ovaries were measured using thin-layer chromatography and gas-liquid chromatography. In the hemolymph, total lipids increase steadily from the previtellogenic period to vitellogenic arrest. These lipids are predominantly diacylglycerols and phospholipids. In the ovaries, total lipids increase during vitellogenesis then decrease during the vitellogenesis arrest period. The major lipids are triacylglycerols, followed by phospholipids. In both hemolymph and ovaries, all lipid classes contained variable proportions of seven main fatty acids: the saturated fatty acids myristic acid (14:0), palmetic acid (16:0), and stearic acid (18:0); the monounsaturated fatty acids palmitoleic acid (16:1) and oleic acid (18:1); and the polyunsaturated fatty acids linoleic acid (18:2) and linolenic acid (18:3). Unsaturated fatty acids predominate throughout the reproductive cycle. The percentage compositions of total and triacylglycerol fatty acids do not change markedly during the reproductive cycle in hemolymph nor in ovaries, with 18:2, 18:1 and 16:0 fatty acids being the major components. However, for diacylglycerols and phospholipids, the proportions of fatty acids vary systematically. For phospholipids during the vitellogenesis period, 18:2 increases considerably whereas other fatty acids decrease; for diacylglycerols, these fatty acids vary in the reverse way.
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Ultrastructural changes in the corpus allatum after azadirachtin and 20-hydroxyecdysone treatment in adult females of Labidura riparia (Dermaptera).
Tissue & cell, 2002Co-Authors: Fouad SayahAbstract:In previous reports, we have shown that the injection of azadirachtin (AZA) as well as 20-hydroxyecdysone (20E) into vitellogenic females of Labidura riparia induces inhibition of vitellogenin synthesis and ovarian development. Juvenile hormone (JH) treatment rescues vitellogenin synthesis and ovarian growth (Sayah et al., 1995, 1996). In this work, we have studied ultrastructural changes of corpus allatum (CA) after injection of 200, 400, and 600 ng of 20E or 1, 3, and 5 μg of AZA. CA cells exhibit signs of inactivity in both AZA and females treated with 20E at doses of 3 μg and 400 ng, respectively. Conspicuous cytological effects consisting of multivesicular bodies with dense contents, abnormally large intercellular spaces comprising myelinic structures, and rare smooth endoplasmic reticula occured in cytoplasm of CA glandular cells in both experimental females. However, the CA ultrastructure of females injected with 20E differs from CA cells of females injected with AZA in having a cytoplasm containing numerous electron-lucent intracellular areas and marked glycogen zones. They also differ in having abundant microtubules and well-developed junctional membranes. At a dose of 600 ng of 20E or 5 μg of AZA, the intensity of the cytotoxic effects is more apparent. CA cells display pycnotic nuclei, spherical mitochondria, large multivesicular bodies, and vacuolization of the cytoplasm. These results are discussed and compared with observations made on other insect species.
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Immunohistochemical localization of a bombyxin-like peptide in the brain-retrocerebral complex of the insect Labidura riparia
Invertebrate Reproduction & Development, 2001Co-Authors: Fouad Sayah, Anne-marie LaverdureAbstract:Summary Changes of bombyxin-like material in the brain-retrocerebral complex throughout the reproductive cycle of experimental Labidura riparia adult females have been examined with a monoclonal antibody raised against a synthetic decapeptide corresponding to the N-terminus of the bombyxin A-chain. In adult females immunostaining was detected in numerous intrinsic secretory cells of the corpora cardiaca (CC) and in six median protocerebral neurosecretory cells. During the previtellogenic period, a weak immunoreactivity was observed in a few cells of the CC and six median cells of the protocerebrum. Immunoreactivity gradually increased during vitellogenesis and disappeared after egg laying and during the following vitellogenesis arrest period. In pars lateralis -cauterized females, known to display continuous vitellogenesis but lower ecdysteroid levels than in normal vitellogenic females, a slight immunoactivity was present in a few CC cells only. Based on its cyclic variations in the brain-retrocerebral c...
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endocrine and neuroendocrine effects of azadirachtin in adult females of the earwig Labidura riparia
Tissue & Cell, 1998Co-Authors: Fouad Sayah, M. Idaomar, L Soranzo, A. KarlinskyAbstract:In previous studies we have shown that injection of the insect growth regulator Azadirachtin (AZA) into young vitellogenic females induces inhibition of vitellogenesis in a dose-dependent manner. Juvenile hormone treatment rescues vitellogenin synthesis and ovarian growth. The cytopathological effects on ovaries and fat body are not linked to an inhibition of feeding. In this work we investigated the effects of AZA on the endocrine and neuroendocrine system. Enzyme immunoassay reveals that ovarian ecdysteroid levels are drastically reduced, in a dose-dependent fashion, by AZA. Ultrastructural study indicates that corpus allatum cells exhibit signs of inactivity and degenerative changes after AZA exposure. Using an antibody against allastostatin-3 of Blatella germanica (BLAST-3), we show the appearance of strong immunoreactivity of numerous cells and axons in the brain of AZA-injected females. We conclude that vitellogenesis inhibition by AZA consists of a direct cytotoxic effect as well as a generalized disruption of endocrine and neuroendocrine functions.
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ALLATOSTATIN-LIKE PEPTIDE IN THE BRAIN-RETROCEREBRAL COMPLEX OF THE EARWIGLabidura riparia : CYCLIC VARIATIONS RELATED TO THE REPRODUCTIVE CYCLE
Invertebrate Reproduction & Development, 1998Co-Authors: Fouad Sayah, Claire Fayet, Anne-marie La VerdureAbstract:Summary A polyclonal antibody raised against allatostatin-3 of Blattella germanica (BLAST-3) has been used to immunolocalize allatostatin-like peptides in the brain-retrocerebral complex of Labidura riparia adult females. Strongly stained immunoreactive cells are observed in the pars intercerebralis (14 cells) and mainly in the pars lateralis (32 cells). Fibres leading to the corpus allatum are also stained. In the deutocerebrum, one cell is immunostained at the root of each antennal nerve. In the tritocerebmm two cells in each brain hemisphere are weakly immunostained. During the reproductive cycle, these cells and their axons show immunoreactivity at previtellogenic, ovulation and ovarian arrest periods. During vitellogenesis, immunoreactivity is restricted to only four perikarya in the pars intercerebralis. When young vitellogenic females are injected with 20-hydroxyecdysone (20E), which inhibits vitellogenesis, full immunoreactivity reappears, suggesting sensibility of these cells to 20E as is expecte...
Marwan S. Kharboutli - One of the best experts on this subject based on the ideXlab platform.
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Comparison of three methods for sampling arthropod pests and their natural enemies in peanut fields
Journal of Economic Entomology, 1993Co-Authors: Marwan S. Kharboutli, T. P. MackAbstract:We compared the use of beat sheets, pitfall traps, and sweep nets for sampling common arthropods in peanut fields by taking weekly samples in the 1987 to 1989 growing seasons. We used σ 2/ x ratios and number of samples needed as the criteria for comparing sampling techniques. Pitfall trap samples had the largest means for soil surface-dwelling arthropods such as Labidura riparia (Pallas) (Dermaptera: Labiduridae), Oxyopes salticus Hentz (Arachnida: Araneae: Oxyopidae), ground beetles, rove beetles, and wolf spiders. Beat sheet samples had the smallest σ 2/ x ratios for Solenopsis invicta (Buren) (Hymenoptera: Formicidae) and Peucetia viridans Hentz (Arachnida: Araneae: Oxyopidae). Samples from sweep nets had the smallest σ 2/ x ratios for Geocoris spp. (Hemiptera: Lygaeidae). All three techniques had similar σ 2/ x ratios for Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) and the Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). Sweep net samples had the smallest σ 2/ x ratios for Spissistilus festinus (Say) (Homoptera: Membracidae). None of the techniques adequately sampled all common pest and beneficial arthropods in peanuts.
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Effect of temperature, humidity, and prey density on feeding rate of the striped earwig (Dermaptera: Labiduridae)
Environmental Entomology, 1993Co-Authors: Marwan S. Kharboutli, T. P. MackAbstract:We measured the feeding rate of the striped earwig, Labidura riparia (Pallas) on third-instar fall armyworm, Spodoptera frugiperda (J. E. Smith), at three constant temperatures and at three humidities. Striped earwigs ate more larvae at 30°C than at 25 or 35°C. Humidity did not affect feeding rate. Rogers' random predator equation described the effects of prey density on feeding at 30°C and 80% RH. Search rates were ≍1,127 and 4,355 cm2/d, and handling rates were 20 and 22.1 prey per day for males and females, respectively. Females consumed more prey than males. The striped earwig appears to bean excellent biological control agent for arthropod pests in row crops.
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Tolerance of the striped earwig (Dermaptera: Labiduridae) to hot and dry conditions
Environmental Entomology, 1993Co-Authors: Marwan S. Kharboutli, T. P. MackAbstract:We measured the degree of adaptation to a xeric environment of immatures and adults of the striped earwig, Labidura riparia (Pallas). All stages of the striped earwig were moderately tolerant to heat, with critical thermal maxima ranging from 45.2 to 46.1°C for small and large nymphs, respectively. Percentage body water content ranged from 58.9% for females to 75.6% for small nymphs. Cuticular permeabilities were similar for all stages and were within the range of those reported for xeric species, ranging from 8.5 μg water lost per cm2·h·mm Hg for medium-sized nymphs to 17.0 μg water lost per cm2·h·mm Hg for females. Percentage total body water lost increased linearly with desiccation time. Lethal body water loss varied among stages and ranged from 47.6 to 52.9% for small and medium nymphs. The mean hour of death ranged from 16.8 h for small nymphs to 70.7 h for large nymphs, indicating that small nymphs were the least tolerant of desiccating conditions.
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Relative and Seasonal Abundance of Predaceous Arthropods in Alabama Peanut Fields as Indexed by Pitfall Traps
Journal of Economic Entomology, 1991Co-Authors: Marwan S. Kharboutli, T. P. MackAbstract:Pitfall traps were used to monitor the seasonal abundance of predators in conventionally tilled, irrigated, and nonirrigated peanut (Arachis hypogaea L.) fields in Alabama in 1987 and 1988. A diverse fauna of predaceous arthropods was captured ; Labidura riparia (Pallas) (Dermaptera : Labiduridae) was the most abundant. Solenopsis invicta Buren (Hymenoptera : Formicidae), Geocoris spp. (Hemiptera : Lygaeidae), carabids, staphylinids, and lycosids were also common. Traps placed between plant rows and those within rows yielded similar averages. All predaceous groups were captured throughout the peanut-growing season but in varied densities. Predator abundances peaked 70-100 d after planting, depending on the group. Capture of most predators increased exponentially for part or all of the growing season
Konrad Dettner - One of the best experts on this subject based on the ideXlab platform.
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Abdominal gland secretion ofBledius rove beetles as an effective defence against predators
Entomologia Experimentalis et Applicata, 1995Co-Authors: Johannes L. M. Steidle, Konrad DettnerAbstract:The biological function of the abdominal gland of the rove beetle genus Bledius (Coleoptera: Staphylinidae: Oxytelinae) was examined using behavioural criteria. The attractant effect of the abdominal secretion on the Bledius predators Dyschirius obscurus and D. thoracicus (Carabidae), described in the literature, was identified as artificial. In choice experiments the secretion showed repellent effects on natural predators of Bledius furcatus, B. spectabilis and B. arenarius . In predator-prey encounters with Cataglyphis bicolor (Formicidae) and Labidura riparia (Dermaptera) the gland secretion of B. furcatus induced cleaning behaviour. When attacked by C. bicolor the chance of survival for B. furcatus was increased by the presence of the abdominal gland secretion. This clearly shows that the abdominal gland of the genus Bledius is used for defensive purposes.
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Abdominal gland secretion of Bledius rove beetles as an effective defence against predators
Entomologia Experimentalis et Applicata, 1995Co-Authors: Johannes L. M. Steidle, Konrad DettnerAbstract:The biological function of the abdominal gland of the rove beetle genus Bledius (Coleoptera: Staphylinidae: Oxytelinae) was examined using behavioural criteria. The attractant effect of the abdominal secretion on the Bledius predators Dyschirius obscurus and D. thoracicus (Carabidae), described in the literature, was identified as artificial. In choice experiments the secretion showed repellent effects on natural predators of Bledius furcatus, B. spectabilis and B. arenarius. In predator-prey encounters with Cataglyphis bicolor (Formicidae) and Labidura riparia (Dermaptera) the gland secretion of B. furcatus induced cleaning behaviour. When attacked by C. bicolor the chance of survival for B. furcatus was increased by the presence of the abdominal gland secretion. This clearly shows that the abdominal gland of the genus Bledius is used for defensive purposes.
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Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators
CHEMOECOLOGY, 1993Co-Authors: Johannes L. M. Steidle, Konrad DettnerAbstract:The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions of Bledius furcatus, B. spectabilis and B. arenarius. Therefore the target organisms of the secretion of these Bledius species ( i.e. their predators) had to be identified. At the collection sites examined these were the earwig Labidura riparia , the ant Cataglyphis bicolor , the fly Lispe candicans , different carabids of the genera Pogonus, Dichirotrichus, Dyschirius, Bembidion and Calathus and the wading birds Haematopus ostralegus and Calidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either γ -dodecalactone and 1-undecene ( B. furcatus and B. spectabilis ) or in octanoic acid and octyloctanoate ( B. arenarius ). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators ( L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius ) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.
