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Papers by Carl Childers

Experimental and Applied Acarology, 2003

The genus Brevipalpus includes most of the economically important species of Tenuipalpidae. Many ... more The genus Brevipalpus includes most of the economically important species of Tenuipalpidae. Many Brevipalpus species reproduce by theletokous parthenogenesis while other species reproduce by male fertilization of female eggs. Previous researchers have determined that Brevipalpus californicus (Banks), B. obovatus Donnadieu, and B. phoenicis (Geijskes) females were haploid with two chromosomes. The life cycle and developmental times for these three species are reviewed. Longevity of each Brevipalpus species is two to three times greater than corresponding longevities of various tetranychid mites. Brevipalpus mites inject toxic saliva into fruits, leaves, stems, twigs, and bud tissues of numerous plants including citrus. Feeding injury symptoms on selected plants include: chlorosis, blistering, bronzing, or necrotic areas on leaves by one or more Brevipalpus mites. Premature leaf drop occurred on ‘Robinson’ tangerine leaves in Florida (USA). Leaf drop was observed in several sweet orange and grapefruit orchards in Texas (USA) that were heavily infested with Brevipalpus mites feeding on the twigs, leaves, and fruit. Initial circular chlorotic areas appear on both sweet orange and grapefruit varieties in association with developing populations of Brevipalpus mites in Texas. These feeding sites become progressively necrotic, darker in color, and eventually develop into irregular scab-like lesions on affected fruit. Russeting and cracking of the fruits of other plant hosts are reported. Stunting of leaves and the development of Brevipalpus galls on terminal buds were recorded on sour orange, Citrus aurantium L., seedlings heavily infested with B. californicus in an insectary. The most significant threat posed by these mites is as vectors of a potentially invasive viral disease called citrus leprosis.

Experimental & applied acarology, 2013

Multi-directional interactions occur among plant hosts, Brevipalpus mites and the plant viruses t... more Multi-directional interactions occur among plant hosts, Brevipalpus mites and the plant viruses they transmit. Such interactions should be considered when evaluating the severity of a disease such as citrus leprosis. The current understanding of Brevipalpustransmitted viruses relies on the capability of the vector to transmit the disease, the persistence of the virus in the host plant and the ability of the disease to spread. Previously, we discussed the Citrus leprosis virus (CiLV) and its importance and spread over the past decade into new areas of South and Central America, most recently into southern Mexico and Belize. Here, we address key questions to better understand the biology of the mite vector, fitness costs, and the peculiarities of Brevipalpus mite reproduction, virus survival, transmissibility and spread, and the expansion of the host plant range of Brevipalpus species vectoring the disease.

Journal of Economic Entomology, 2007

Binomial sampling based on the proportion of samples infested was investigated for estimating mea... more Binomial sampling based on the proportion of samples infested was investigated for estimating mean densities of citrus rust mite, Phyllocoptruta oleivora (Ashmead), and Aculops pelekassi (Keifer) (Acari: Eriophyidae), on oranges, Citrus sinensis (L.) Osbeck. Data for the investigation were obtained by counting the number of motile mites within 600 sample units (each unit a 1-cm 2 surface area per fruit) across a 4-ha block of trees (32 blocks total): Þve areas per 4 ha, Þve trees per area, 12 fruit per tree, and two samples per fruit. A signiÞcant (r 2 ϭ 0.89), linear relationship was found between ln(Ϫln(1 ϪP 0 )) and ln(mean), where P 0 is the proportion of samples with more than zero mites. The Þtted binomial parameters adequately described a validation data set from a sampling plan consisting of 192 samples. Projections indicated the Þtted parameters would apply to sampling plans with as few as 48 samples, but reducing sample size resulted in an increase of bootstrap estimates falling outside expected conÞdence limits. Although mite count data Þt the binomial model, conÞdence limits for mean arithmetic predictions increased dramatically as proportion of samples infested increased. Binomial sampling using a tally threshold of 0 therefore has less value when proportions of samples infested are large. Increasing the tally threshold to two mites marginally improved estimates at larger densities. Overall, binomial sampling for a general estimate of mite densities seemed to be a viable alternative to absolute counts of mites per sample for a grower using a low management threshold such as two or three mites per sample.

Experimental and Applied Acarology, 2003

Citrus leprosis is caused by Citrus leprosis virus (CiLV) that is transmitted by mites in the gen... more Citrus leprosis is caused by Citrus leprosis virus (CiLV) that is transmitted by mites in the genus Brevipalpus (Acari: Tenuipalpidae). This disease directly reduces production and the life span of the citrus plant. The main symptoms of the disease include lesions on fruits, leaves, and twigs or small branches, causing premature fruit drop, defoliation, and death of the twigs or branches leading to serious tree decline. Leprosis is a highly destructive disease of citrus, wherever it occurs. The Brazilian citrus industry spends over 100 million US dollars annually on acaricides to control the vector, Brevipalpus phoenicis (Geijskes). This review contains information about the history of the etiology of citrus leprosis, its geographical distribution, host range, the role of the mite vectors, viral morphology and relationships with the infected cell, and transmissibility of the virus by the mite. In addition, data on the mite-virus-plant relationship, disease damage, and strategies for controlling disease spread are presented.

Experimental and Applied Acarology, 2003

According to published reports from 1906 to 1968, leprosis nearly destroyed the Florida citrus in... more According to published reports from 1906 to 1968, leprosis nearly destroyed the Florida citrus industry prior to 1925. This was supported with photographs showing typical leprosis symptoms on citrus leaves, fruit, and twigs. Support for the past occurrence of citrus leprosis in Florida includes: (1) presence of twig lesions in affected orange blocks in addition to lesions on fruits and leaves and corresponding absence of similar lesions on grapefruit; (2) yield reduction and die-back on infected trees; and (3) spread of the disease between 1906 and 1925. Transmission electron microscopy (TEM) examination of tissue samples from leprosis-like injuries to orange and grapefruit leaves from Florida in 1997, and fruits from grapefruit and sweet orange varieties from Texas in 1999 and 2000 did not contain leprosis-like viral particles or viroplasm inclusions. In contrast, leprosis viroplasm inclusions were readily identified by TEM within green non-senescent tissues surrounding leprosis lesions in two of every three orange leaf samples and half of the fruit samples obtained from Piracicaba, Brazil. Symptoms of leprosis were not seen in any of the 24,555 orange trees examined across Florida during 2001 and 2002. The authors conclude that citrus leprosis no longer exists in Florida nor occurs in Texas citrus based on: (1) lack of leprosis symptoms on leaves, fruit, and twigs of sweet orange citrus varieties surveyed in Florida; (2) failure to find virus particles or viroplasm inclusion bodies in suspect samples from both Florida and Texas examined by TEM; (3) absence of documented reports by others on the presence of characteristic leprosis symptoms in Florida; (4) lack of its documented occurrence in dooryard trees or abandoned or minimal pesticide citrus orchard sites in Florida. In view of the serious threat to citrus in the U.S., every effort must be taken to quarantine the importation of both citrus and woody ornamental plants that serve as hosts for Brevipalpus phoenicis (Geijskes), B. californicus (Banks), and B. obovatus Donnadieu (Acari: Tenuipalpidae) from countries where citrus leprosis occurs.

Experimental and Applied Acarology, 2004

Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) is recognized as the vector of citrus lep... more Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) is recognized as the vector of citrus leprosis virus that is a significant problem in several South American countries. Citrus leprosis has been reported from Florida in the past but no longer occurs on citrus in North America. The disease was recently reported in Central America, suggesting that B. phoenicis constitutes a potential threat to the citrus industries of North America and the Caribbean. Besides B. phoenicis, B. obovatus Donnadieu, and B. californicus (Banks) have been incriminated as vectors of citrus leprosis virus and each species has hundreds of host plants. In this study, Brevipalpus mite specimens were collected from different plants, especially citrus, in the States of Florida (USA) and Sa˜o Paulo (Brazil), and reared on citrus fruit under standard laboratory conditions. Mites were taken from these colonies for DNA extraction and for morphological species identification. One hundred and two Random Amplified Polymorphic DNA (RAPD) markers were scored along with amplification and sequencing of a mitochondrial cytochrome oxidase subunit I gene fragment (374 bp). Variability among the colonies was detected with consistent congruence between both molecular data sets. The mites from the Florida and Brazilian colonies were morphologically identified as belonging to B. phoenicis, and comprise a monophyletic group. These colonies could be further diagnosed and subdivided geographically by mitochondrial DNA analysis.

International Journal of Acarology, 2015

Eryngiopus audreae n. sp. is described and illustrated based on female specimens collected from c... more Eryngiopus audreae n. sp. is described and illustrated based on female specimens collected from citrus trees in Florida, USA. The new species is easily distinguished by the small size of its prodorsal shields, each with two setae; the presence of long and ventro-lateral seta c 2 , and most significantly with its smooth suranal shield and two pairs of smooth and distally forked setae.

Environmental Entomology, 2008

Six Alabama Satsuma mandarin orchards (four conventionally sprayed and two unsprayed) were survey... more Six Alabama Satsuma mandarin orchards (four conventionally sprayed and two unsprayed) were surveyed during 2005 and 2006 to determine the population dynamics of arthropod pests and their natural enemies. Twenty-eight arthropod pest species were encoun- tered; the major foliage pests were citrus whiteßy, Dialeurodes citri (Ashmead); purple scale, Lepidosaphesbeckii (Newman); Glover scale,L.gloveri (Packard); and citrus red mite,Panonychus citri (McGregor). Two

Annals of The Entomological Society of America, 2009

Nine Satsuma citrus orchards (seven conventionally sprayed and two unsprayed) in southern Alabama... more Nine Satsuma citrus orchards (seven conventionally sprayed and two unsprayed) in southern Alabama were sampled (mainly leaf samples) for predacious mites at eight different sampling dates from March 2005 to February 2006. At least 29 species of predacious mites from nine families (Anystidae, Ascidae, Bdellidae, Cheyletidae, Cunaxidae, Erythraeidae, Eupalopsellidae, Phytoseiidae, and Stigmaeidae) were identiÞed. In addition, six primarily fungivorous species

Florida Entomologist, 2006

A BSTRACT Larvae of two undescribed species of Cecidomyiidae (Diptera) were found preying upon Ph... more A BSTRACT Larvae of two undescribed species of Cecidomyiidae (Diptera) were found preying upon Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae) on Florida citrus. Identifications to genus were made from adults reared in the laboratory. The two species had distinctive larval coloration. One larval type was completely yellow and was identified as Feltiella n. sp., while the second larval type had an orange color with a transverse white band close to the mouthparts. The latter cecidomyiid was identified as belonging to a genus near Lestodiplosis in the broad sense. Feltiella n. sp. ( n = 17) and the species near the genus Lestodiplosis ( n = 12) consumed 33.8 ± 4.6 (mean ± SEM) and 43.0 ± 6.4 citrus rust mite eggs; 14.2 ± 1.4 and 15.0 ± 2.0 citrus rust mite nymphs, and 3.0 ± 0.4 and 5.6 ± 0.9 citrus rust mite adults/10 min., respectively. There were no significant differences ( P > 0.05) in the consumption rates of either predator on any rust mite life stage. These data indicate that Feltiella n. sp. and the species near the genus Lestodiplosis are both efficient predators of P. oleivora eggs, larvae, and nymphs.

Experimental and Applied Acarology, 2005

The orange bagworm (OBW), Cryptothelea gloverii (Packard) (Lepidoptera: Psychidae) was previously... more The orange bagworm (OBW), Cryptothelea gloverii (Packard) (Lepidoptera: Psychidae) was previously reported feeding on citrus fruit and foliage and preying upon the camphor scale Pseudaonidia duplex (Cockerell) (Homoptera: Coccidae). In this study using laboratory assays, OBW preyed upon citrus rust mite, Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae) and consumed eggs and adults of both P. oleivora and Panonychus citri (McGregor) (Acari:

Plant Disease, 2001

... 700 Experiment Station Road., Lake Alfred 33850-2299; and Elliot W. Kitajima, Departamentode ... more ... 700 Experiment Station Road., Lake Alfred 33850-2299; and Elliot W. Kitajima, Departamentode Entomologia, Fitopatologia e Zoologia Agrícola, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Caixa Postal 9, 13418-900 Piracicaba, SP, Brazil. ...

Journal of Economic Entomology, 2007

Binomial sampling based on the proportion of samples infested was investigated for estimating mea... more Binomial sampling based on the proportion of samples infested was investigated for estimating mean densities of citrus rust mite, Phyllocoptruta oleivora (Ashmead), and Aculops pelekassi (Keifer) (Acari: Eriophyidae), on oranges, Citrus sinensis (L.) Osbeck. Data for the investigation were obtained by counting the number of motile mites within 600 sample units (each unit a 1-cm 2 surface area per fruit) across a 4-ha block of trees (32 blocks total): Þve areas per 4 ha, Þve trees per area, 12 fruit per tree, and two samples per fruit. A signiÞcant (r 2 ϭ 0.89), linear relationship was found between ln(Ϫln(1 ϪP 0 )) and ln(mean), where P 0 is the proportion of samples with more than zero mites. The Þtted binomial parameters adequately described a validation data set from a sampling plan consisting of 192 samples. Projections indicated the Þtted parameters would apply to sampling plans with as few as 48 samples, but reducing sample size resulted in an increase of bootstrap estimates falling outside expected conÞdence limits. Although mite count data Þt the binomial model, conÞdence limits for mean arithmetic predictions increased dramatically as proportion of samples infested increased. Binomial sampling using a tally threshold of 0 therefore has less value when proportions of samples infested are large. Increasing the tally threshold to two mites marginally improved estimates at larger densities. Overall, binomial sampling for a general estimate of mite densities seemed to be a viable alternative to absolute counts of mites per sample for a grower using a low management threshold such as two or three mites per sample.

Journal of Economic Entomology, 2005

The consequence of reducing sample size on the accuracy and precision of estimates of citrus rust... more The consequence of reducing sample size on the accuracy and precision of estimates of citrus rust mite, Phyllocoptruta oleivora (Ashmead), densities on oranges was investigated. The sample unit was a 1-cm 2 surface area on fruit. Sampling plans consisting of 360, 300, 200, 160, 80, 48, 36, or 20 samples per 4 ha were evaluated through computer simulations by using real count data from 32 data sets of 600 sample units per 4 ha. The original and reduced sampling plans were hierarchical with different numbers of sample areas per 4 ha, trees per area, fruit per tree, and samples per fruit. Individual estimates (n ϭ 100 simulations per data set) using each plan were sometimes considerably below or above target densities. In an original set of count data with a mean of six mites per cm 2 , simulations of 36 samples per 4 ha produced individual estimates ranging from one to 16 mites per cm 2 , whereas 80 samples per 4 ha produced estimates ranging from two to 10 mites per cm 2 . The plans consisting of 36 or more samples were projected to provide precision levels of 0.25 (SEM/mean) or better at densities of Þve or more mites per cm 2 based on log-data, a projection that needs to be veriÞed under real-grove situations. Each plan consistently provided mite detection in these sampling simulations except those consisting of 20 or 36 samples, which sometimes failed to detect mites when the target density was less than Þve mites per cm 2 . The study provided insight into the probable precision, accuracy and detection thresholds for eight candidate sampling plans varying from relatively low to high resource input.

International Journal of Acarology, 2002

International Journal of Acarology, 2001

ABSTRACT - Low temperature scanning electron microscopy (LTSEM) is an effective technique for stu... more ABSTRACT - Low temperature scanning electron microscopy (LTSEM) is an effective technique for studying the morphology of Acari. This study evaluates results from two approaches: ambient temperature scanning electron microscopy (ATSEM) and LTSEM. Four preparation ...

Experimental and Applied Acarology, 2003

The genus Brevipalpus includes most of the economically important species of Tenuipalpidae. Many ... more The genus Brevipalpus includes most of the economically important species of Tenuipalpidae. Many Brevipalpus species reproduce by theletokous parthenogenesis while other species reproduce by male fertilization of female eggs. Previous researchers have determined that Brevipalpus californicus (Banks), B. obovatus Donnadieu, and B. phoenicis (Geijskes) females were haploid with two chromosomes. The life cycle and developmental times for these three species are reviewed. Longevity of each Brevipalpus species is two to three times greater than corresponding longevities of various tetranychid mites. Brevipalpus mites inject toxic saliva into fruits, leaves, stems, twigs, and bud tissues of numerous plants including citrus. Feeding injury symptoms on selected plants include: chlorosis, blistering, bronzing, or necrotic areas on leaves by one or more Brevipalpus mites. Premature leaf drop occurred on ‘Robinson’ tangerine leaves in Florida (USA). Leaf drop was observed in several sweet orange and grapefruit orchards in Texas (USA) that were heavily infested with Brevipalpus mites feeding on the twigs, leaves, and fruit. Initial circular chlorotic areas appear on both sweet orange and grapefruit varieties in association with developing populations of Brevipalpus mites in Texas. These feeding sites become progressively necrotic, darker in color, and eventually develop into irregular scab-like lesions on affected fruit. Russeting and cracking of the fruits of other plant hosts are reported. Stunting of leaves and the development of Brevipalpus galls on terminal buds were recorded on sour orange, Citrus aurantium L., seedlings heavily infested with B. californicus in an insectary. The most significant threat posed by these mites is as vectors of a potentially invasive viral disease called citrus leprosis.

Experimental & applied acarology, 2013

Multi-directional interactions occur among plant hosts, Brevipalpus mites and the plant viruses t... more Multi-directional interactions occur among plant hosts, Brevipalpus mites and the plant viruses they transmit. Such interactions should be considered when evaluating the severity of a disease such as citrus leprosis. The current understanding of Brevipalpustransmitted viruses relies on the capability of the vector to transmit the disease, the persistence of the virus in the host plant and the ability of the disease to spread. Previously, we discussed the Citrus leprosis virus (CiLV) and its importance and spread over the past decade into new areas of South and Central America, most recently into southern Mexico and Belize. Here, we address key questions to better understand the biology of the mite vector, fitness costs, and the peculiarities of Brevipalpus mite reproduction, virus survival, transmissibility and spread, and the expansion of the host plant range of Brevipalpus species vectoring the disease.

Journal of Economic Entomology, 2007

Binomial sampling based on the proportion of samples infested was investigated for estimating mea... more Binomial sampling based on the proportion of samples infested was investigated for estimating mean densities of citrus rust mite, Phyllocoptruta oleivora (Ashmead), and Aculops pelekassi (Keifer) (Acari: Eriophyidae), on oranges, Citrus sinensis (L.) Osbeck. Data for the investigation were obtained by counting the number of motile mites within 600 sample units (each unit a 1-cm 2 surface area per fruit) across a 4-ha block of trees (32 blocks total): Þve areas per 4 ha, Þve trees per area, 12 fruit per tree, and two samples per fruit. A signiÞcant (r 2 ϭ 0.89), linear relationship was found between ln(Ϫln(1 ϪP 0 )) and ln(mean), where P 0 is the proportion of samples with more than zero mites. The Þtted binomial parameters adequately described a validation data set from a sampling plan consisting of 192 samples. Projections indicated the Þtted parameters would apply to sampling plans with as few as 48 samples, but reducing sample size resulted in an increase of bootstrap estimates falling outside expected conÞdence limits. Although mite count data Þt the binomial model, conÞdence limits for mean arithmetic predictions increased dramatically as proportion of samples infested increased. Binomial sampling using a tally threshold of 0 therefore has less value when proportions of samples infested are large. Increasing the tally threshold to two mites marginally improved estimates at larger densities. Overall, binomial sampling for a general estimate of mite densities seemed to be a viable alternative to absolute counts of mites per sample for a grower using a low management threshold such as two or three mites per sample.

Experimental and Applied Acarology, 2003

Citrus leprosis is caused by Citrus leprosis virus (CiLV) that is transmitted by mites in the gen... more Citrus leprosis is caused by Citrus leprosis virus (CiLV) that is transmitted by mites in the genus Brevipalpus (Acari: Tenuipalpidae). This disease directly reduces production and the life span of the citrus plant. The main symptoms of the disease include lesions on fruits, leaves, and twigs or small branches, causing premature fruit drop, defoliation, and death of the twigs or branches leading to serious tree decline. Leprosis is a highly destructive disease of citrus, wherever it occurs. The Brazilian citrus industry spends over 100 million US dollars annually on acaricides to control the vector, Brevipalpus phoenicis (Geijskes). This review contains information about the history of the etiology of citrus leprosis, its geographical distribution, host range, the role of the mite vectors, viral morphology and relationships with the infected cell, and transmissibility of the virus by the mite. In addition, data on the mite-virus-plant relationship, disease damage, and strategies for controlling disease spread are presented.

Experimental and Applied Acarology, 2003

According to published reports from 1906 to 1968, leprosis nearly destroyed the Florida citrus in... more According to published reports from 1906 to 1968, leprosis nearly destroyed the Florida citrus industry prior to 1925. This was supported with photographs showing typical leprosis symptoms on citrus leaves, fruit, and twigs. Support for the past occurrence of citrus leprosis in Florida includes: (1) presence of twig lesions in affected orange blocks in addition to lesions on fruits and leaves and corresponding absence of similar lesions on grapefruit; (2) yield reduction and die-back on infected trees; and (3) spread of the disease between 1906 and 1925. Transmission electron microscopy (TEM) examination of tissue samples from leprosis-like injuries to orange and grapefruit leaves from Florida in 1997, and fruits from grapefruit and sweet orange varieties from Texas in 1999 and 2000 did not contain leprosis-like viral particles or viroplasm inclusions. In contrast, leprosis viroplasm inclusions were readily identified by TEM within green non-senescent tissues surrounding leprosis lesions in two of every three orange leaf samples and half of the fruit samples obtained from Piracicaba, Brazil. Symptoms of leprosis were not seen in any of the 24,555 orange trees examined across Florida during 2001 and 2002. The authors conclude that citrus leprosis no longer exists in Florida nor occurs in Texas citrus based on: (1) lack of leprosis symptoms on leaves, fruit, and twigs of sweet orange citrus varieties surveyed in Florida; (2) failure to find virus particles or viroplasm inclusion bodies in suspect samples from both Florida and Texas examined by TEM; (3) absence of documented reports by others on the presence of characteristic leprosis symptoms in Florida; (4) lack of its documented occurrence in dooryard trees or abandoned or minimal pesticide citrus orchard sites in Florida. In view of the serious threat to citrus in the U.S., every effort must be taken to quarantine the importation of both citrus and woody ornamental plants that serve as hosts for Brevipalpus phoenicis (Geijskes), B. californicus (Banks), and B. obovatus Donnadieu (Acari: Tenuipalpidae) from countries where citrus leprosis occurs.

Experimental and Applied Acarology, 2004

Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) is recognized as the vector of citrus lep... more Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) is recognized as the vector of citrus leprosis virus that is a significant problem in several South American countries. Citrus leprosis has been reported from Florida in the past but no longer occurs on citrus in North America. The disease was recently reported in Central America, suggesting that B. phoenicis constitutes a potential threat to the citrus industries of North America and the Caribbean. Besides B. phoenicis, B. obovatus Donnadieu, and B. californicus (Banks) have been incriminated as vectors of citrus leprosis virus and each species has hundreds of host plants. In this study, Brevipalpus mite specimens were collected from different plants, especially citrus, in the States of Florida (USA) and Sa˜o Paulo (Brazil), and reared on citrus fruit under standard laboratory conditions. Mites were taken from these colonies for DNA extraction and for morphological species identification. One hundred and two Random Amplified Polymorphic DNA (RAPD) markers were scored along with amplification and sequencing of a mitochondrial cytochrome oxidase subunit I gene fragment (374 bp). Variability among the colonies was detected with consistent congruence between both molecular data sets. The mites from the Florida and Brazilian colonies were morphologically identified as belonging to B. phoenicis, and comprise a monophyletic group. These colonies could be further diagnosed and subdivided geographically by mitochondrial DNA analysis.

International Journal of Acarology, 2015

Eryngiopus audreae n. sp. is described and illustrated based on female specimens collected from c... more Eryngiopus audreae n. sp. is described and illustrated based on female specimens collected from citrus trees in Florida, USA. The new species is easily distinguished by the small size of its prodorsal shields, each with two setae; the presence of long and ventro-lateral seta c 2 , and most significantly with its smooth suranal shield and two pairs of smooth and distally forked setae.

Environmental Entomology, 2008

Six Alabama Satsuma mandarin orchards (four conventionally sprayed and two unsprayed) were survey... more Six Alabama Satsuma mandarin orchards (four conventionally sprayed and two unsprayed) were surveyed during 2005 and 2006 to determine the population dynamics of arthropod pests and their natural enemies. Twenty-eight arthropod pest species were encoun- tered; the major foliage pests were citrus whiteßy, Dialeurodes citri (Ashmead); purple scale, Lepidosaphesbeckii (Newman); Glover scale,L.gloveri (Packard); and citrus red mite,Panonychus citri (McGregor). Two

Annals of The Entomological Society of America, 2009

Nine Satsuma citrus orchards (seven conventionally sprayed and two unsprayed) in southern Alabama... more Nine Satsuma citrus orchards (seven conventionally sprayed and two unsprayed) in southern Alabama were sampled (mainly leaf samples) for predacious mites at eight different sampling dates from March 2005 to February 2006. At least 29 species of predacious mites from nine families (Anystidae, Ascidae, Bdellidae, Cheyletidae, Cunaxidae, Erythraeidae, Eupalopsellidae, Phytoseiidae, and Stigmaeidae) were identiÞed. In addition, six primarily fungivorous species

Florida Entomologist, 2006

A BSTRACT Larvae of two undescribed species of Cecidomyiidae (Diptera) were found preying upon Ph... more A BSTRACT Larvae of two undescribed species of Cecidomyiidae (Diptera) were found preying upon Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae) on Florida citrus. Identifications to genus were made from adults reared in the laboratory. The two species had distinctive larval coloration. One larval type was completely yellow and was identified as Feltiella n. sp., while the second larval type had an orange color with a transverse white band close to the mouthparts. The latter cecidomyiid was identified as belonging to a genus near Lestodiplosis in the broad sense. Feltiella n. sp. ( n = 17) and the species near the genus Lestodiplosis ( n = 12) consumed 33.8 ± 4.6 (mean ± SEM) and 43.0 ± 6.4 citrus rust mite eggs; 14.2 ± 1.4 and 15.0 ± 2.0 citrus rust mite nymphs, and 3.0 ± 0.4 and 5.6 ± 0.9 citrus rust mite adults/10 min., respectively. There were no significant differences ( P > 0.05) in the consumption rates of either predator on any rust mite life stage. These data indicate that Feltiella n. sp. and the species near the genus Lestodiplosis are both efficient predators of P. oleivora eggs, larvae, and nymphs.

Experimental and Applied Acarology, 2005

The orange bagworm (OBW), Cryptothelea gloverii (Packard) (Lepidoptera: Psychidae) was previously... more The orange bagworm (OBW), Cryptothelea gloverii (Packard) (Lepidoptera: Psychidae) was previously reported feeding on citrus fruit and foliage and preying upon the camphor scale Pseudaonidia duplex (Cockerell) (Homoptera: Coccidae). In this study using laboratory assays, OBW preyed upon citrus rust mite, Phyllocoptruta oleivora (Ashmead) (Acari: Eriophyidae) and consumed eggs and adults of both P. oleivora and Panonychus citri (McGregor) (Acari:

Plant Disease, 2001

... 700 Experiment Station Road., Lake Alfred 33850-2299; and Elliot W. Kitajima, Departamentode ... more ... 700 Experiment Station Road., Lake Alfred 33850-2299; and Elliot W. Kitajima, Departamentode Entomologia, Fitopatologia e Zoologia Agrícola, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Caixa Postal 9, 13418-900 Piracicaba, SP, Brazil. ...

Journal of Economic Entomology, 2007

Binomial sampling based on the proportion of samples infested was investigated for estimating mea... more Binomial sampling based on the proportion of samples infested was investigated for estimating mean densities of citrus rust mite, Phyllocoptruta oleivora (Ashmead), and Aculops pelekassi (Keifer) (Acari: Eriophyidae), on oranges, Citrus sinensis (L.) Osbeck. Data for the investigation were obtained by counting the number of motile mites within 600 sample units (each unit a 1-cm 2 surface area per fruit) across a 4-ha block of trees (32 blocks total): Þve areas per 4 ha, Þve trees per area, 12 fruit per tree, and two samples per fruit. A signiÞcant (r 2 ϭ 0.89), linear relationship was found between ln(Ϫln(1 ϪP 0 )) and ln(mean), where P 0 is the proportion of samples with more than zero mites. The Þtted binomial parameters adequately described a validation data set from a sampling plan consisting of 192 samples. Projections indicated the Þtted parameters would apply to sampling plans with as few as 48 samples, but reducing sample size resulted in an increase of bootstrap estimates falling outside expected conÞdence limits. Although mite count data Þt the binomial model, conÞdence limits for mean arithmetic predictions increased dramatically as proportion of samples infested increased. Binomial sampling using a tally threshold of 0 therefore has less value when proportions of samples infested are large. Increasing the tally threshold to two mites marginally improved estimates at larger densities. Overall, binomial sampling for a general estimate of mite densities seemed to be a viable alternative to absolute counts of mites per sample for a grower using a low management threshold such as two or three mites per sample.

Journal of Economic Entomology, 2005

The consequence of reducing sample size on the accuracy and precision of estimates of citrus rust... more The consequence of reducing sample size on the accuracy and precision of estimates of citrus rust mite, Phyllocoptruta oleivora (Ashmead), densities on oranges was investigated. The sample unit was a 1-cm 2 surface area on fruit. Sampling plans consisting of 360, 300, 200, 160, 80, 48, 36, or 20 samples per 4 ha were evaluated through computer simulations by using real count data from 32 data sets of 600 sample units per 4 ha. The original and reduced sampling plans were hierarchical with different numbers of sample areas per 4 ha, trees per area, fruit per tree, and samples per fruit. Individual estimates (n ϭ 100 simulations per data set) using each plan were sometimes considerably below or above target densities. In an original set of count data with a mean of six mites per cm 2 , simulations of 36 samples per 4 ha produced individual estimates ranging from one to 16 mites per cm 2 , whereas 80 samples per 4 ha produced estimates ranging from two to 10 mites per cm 2 . The plans consisting of 36 or more samples were projected to provide precision levels of 0.25 (SEM/mean) or better at densities of Þve or more mites per cm 2 based on log-data, a projection that needs to be veriÞed under real-grove situations. Each plan consistently provided mite detection in these sampling simulations except those consisting of 20 or 36 samples, which sometimes failed to detect mites when the target density was less than Þve mites per cm 2 . The study provided insight into the probable precision, accuracy and detection thresholds for eight candidate sampling plans varying from relatively low to high resource input.

International Journal of Acarology, 2002

International Journal of Acarology, 2001

ABSTRACT - Low temperature scanning electron microscopy (LTSEM) is an effective technique for stu... more ABSTRACT - Low temperature scanning electron microscopy (LTSEM) is an effective technique for studying the morphology of Acari. This study evaluates results from two approaches: ambient temperature scanning electron microscopy (ATSEM) and LTSEM. Four preparation ...