Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood borer and the primary vec... more Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood borer and the primary vector of Raffaelea lauricola, a symbiotic fungus that causes laurel wilt. This lethal disease has decimated native redbay [Persea borbonia (L.) Sprengel] and swampbay [Persea palustris (Rafinesque) Sargent] throughout southeastern U.S. forests, and currently threatens avocado (Persea americana Miller) in Florida. To curtail the spread of laurel wilt, effective attractants are needed for early detection of the vector. Phoebe oil lures were the best known attractant for X. glabratus, but they are no longer available. The current detection system uses manuka oil lures, but previous research indicated that manuka lures have a short field life in Florida. Recently, cubeb oil was identified as a new attractant for X. glabratus, and cubeb bubble lures are now available commercially. This study compared trapping efficacy and field longevity of cubeb and manuka lures with phoebe lures that had been...
We investigated the eVect of exogenously administered 20-hydroxyecdysone (20E) on sexual behavior... more We investigated the eVect of exogenously administered 20-hydroxyecdysone (20E) on sexual behavior and on contact sex signals of adult females of the spider Tegenaria atrica. In untreated or control females cannibalism occurred in 36-47% of encounters, whereas no cannibalism at all was observed with 20E-treated females. The frequency of sexual receptivity was low (42%) in untreated or control females and
The redbay ambrosia beetle Xyleborus glabratus Eichhoff is an exotic wood-boring pest native to s... more The redbay ambrosia beetle Xyleborus glabratus Eichhoff is an exotic wood-boring pest native to southeastern Asia. It carries a symbiotic fungus (Raffaelea lauricola) that causes laurel wilt, a lethal vascular disease of trees in the Lauraceae. First detected in Georgia in 2002, the beetle has spread south through Florida causing high mortality in redbay and swampbay, and threatening commercial avocado production. There is a critical need for effective attractants to detect and control the spread of this invasive pest. Previous reports showed that manuka and phoebe oils (essential oil extracts from Leptospermum scoparium and Phoebe porosa trees, respectively) were attractive baits for monitoring X. glabratus. The suspected attractants from those oils were two volatile sesquiterpenes, α-copaene and calamenene. We report here a combination of field trapping studies and chemical analysis evaluating attraction of redbay ambrosia beetle to commercial phoebe and manuka lures in relation t...
The level of an organisms investment in defences against natural enemies depends on the fitness c... more The level of an organisms investment in defences against natural enemies depends on the fitness costs of resisting parasitism and on the costs of maintaining defences in the absence of infection. Heritable variation in resistance suggests that costs exist, but very little is known about the nature or magnitude of these costs in natural populations of animals. A powerful technique for identifying trade-offs between fitness components is the study of correlated responses to artificial selection.We selected for increased resistance in the Indian meal moth, Plodia interpunctella, following parasitism by the koinobiont parasitoid, Venturia canescens, and measured the cost of resistance to parasitism and the cost of maintaining resistance in the absence of immune challenge during the next generation. Parasitism decreased larval host size, growth, and developmental time and was significantly negatively correlated with the size of surviving host adults. Larvae of the next generation also ha...
Review of the phoretic association between coprophilous insects and macrochelid mites (Acari: Mes... more Review of the phoretic association between coprophilous insects and macrochelid mites (Acari: Mesostigmata) in France. This study updates the catalogue of the phoretic mites (Macrochelidae family) associated with insects in France. Twenty one macrochelid species belonging to 3 genera were collected on 31 hosts, both on dung beetles and flies. Aphodius and Onthophagus species were the most commonly hosted. Macrochelids of the glaber-group appeared the most widely distributed mites. Mites-insects associations can be influenced by ecological conditions, e.g. host availability, climate, soil conditions. An identification key of French macrochelid species is given.
Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood borer and the primary vec... more Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood borer and the primary vector of Raffaelea lauricola, a symbiotic fungus that causes laurel wilt. This lethal disease has decimated native redbay [Persea borbonia (L.) Sprengel] and swampbay [Persea palustris (Rafinesque) Sargent] throughout southeastern U.S. forests, and currently threatens avocado (Persea americana Miller) in Florida. To curtail the spread of laurel wilt, effective attractants are needed for early detection of the vector. Phoebe oil lures were the best known attractant for X. glabratus, but they are no longer available. The current detection system uses manuka oil lures, but previous research indicated that manuka lures have a short field life in Florida. Recently, cubeb oil was identified as a new attractant for X. glabratus, and cubeb bubble lures are now available commercially. This study compared trapping efficacy and field longevity of cubeb and manuka lures with phoebe lures that had been...
We investigated the eVect of exogenously administered 20-hydroxyecdysone (20E) on sexual behavior... more We investigated the eVect of exogenously administered 20-hydroxyecdysone (20E) on sexual behavior and on contact sex signals of adult females of the spider Tegenaria atrica. In untreated or control females cannibalism occurred in 36-47% of encounters, whereas no cannibalism at all was observed with 20E-treated females. The frequency of sexual receptivity was low (42%) in untreated or control females and
The redbay ambrosia beetle Xyleborus glabratus Eichhoff is an exotic wood-boring pest native to s... more The redbay ambrosia beetle Xyleborus glabratus Eichhoff is an exotic wood-boring pest native to southeastern Asia. It carries a symbiotic fungus (Raffaelea lauricola) that causes laurel wilt, a lethal vascular disease of trees in the Lauraceae. First detected in Georgia in 2002, the beetle has spread south through Florida causing high mortality in redbay and swampbay, and threatening commercial avocado production. There is a critical need for effective attractants to detect and control the spread of this invasive pest. Previous reports showed that manuka and phoebe oils (essential oil extracts from Leptospermum scoparium and Phoebe porosa trees, respectively) were attractive baits for monitoring X. glabratus. The suspected attractants from those oils were two volatile sesquiterpenes, α-copaene and calamenene. We report here a combination of field trapping studies and chemical analysis evaluating attraction of redbay ambrosia beetle to commercial phoebe and manuka lures in relation t...
The level of an organisms investment in defences against natural enemies depends on the fitness c... more The level of an organisms investment in defences against natural enemies depends on the fitness costs of resisting parasitism and on the costs of maintaining defences in the absence of infection. Heritable variation in resistance suggests that costs exist, but very little is known about the nature or magnitude of these costs in natural populations of animals. A powerful technique for identifying trade-offs between fitness components is the study of correlated responses to artificial selection.We selected for increased resistance in the Indian meal moth, Plodia interpunctella, following parasitism by the koinobiont parasitoid, Venturia canescens, and measured the cost of resistance to parasitism and the cost of maintaining resistance in the absence of immune challenge during the next generation. Parasitism decreased larval host size, growth, and developmental time and was significantly negatively correlated with the size of surviving host adults. Larvae of the next generation also ha...
Review of the phoretic association between coprophilous insects and macrochelid mites (Acari: Mes... more Review of the phoretic association between coprophilous insects and macrochelid mites (Acari: Mesostigmata) in France. This study updates the catalogue of the phoretic mites (Macrochelidae family) associated with insects in France. Twenty one macrochelid species belonging to 3 genera were collected on 31 hosts, both on dung beetles and flies. Aphodius and Onthophagus species were the most commonly hosted. Macrochelids of the glaber-group appeared the most widely distributed mites. Mites-insects associations can be influenced by ecological conditions, e.g. host availability, climate, soil conditions. An identification key of French macrochelid species is given.
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Papers by Jerome Niogret