The fall armyworm (Spodoptera frugiperda) (J. E. Smith) (Lepidoptera: Noctuidae), a major agricul... more The fall armyworm (Spodoptera frugiperda) (J. E. Smith) (Lepidoptera: Noctuidae), a major agricultural pest in the Western Hemisphere, has recently become established in Africa and Asia. This highly polyphagous species has potential to economically harm multiple crops. Contributing to this host range are two fall armyworm populations historically called ‘host strains’ that differ in host specificity. Understanding behaviors of the two strains is crucial to effective management of this pest. A major difficulty in such studies is that strains have long been considered morphologically indistinguishable, with molecular markers the only reliable means of identification. However, studies of fall armyworm in Colombia reported strain differences in wing morphology sufficiently large to potentially provide a more economical alternative method to determine strain. This study tested whether a similar phenotypic difference was present in Florida populations using geometric morphometric analysis...
Phytophagous insects, including Asian citrus psyllids (Diaphorina citri Kuwayama), use multiple s... more Phytophagous insects, including Asian citrus psyllids (Diaphorina citri Kuwayama), use multiple sensory modalities (vision, olfaction, and gustation,) to locate and accept host plants. We explored incorporation of several sensory cues into a multi-modal attract-and-kill device (AK device) using a three-dimensional shape to increase visibility, as well as elements of color, attractant, phagostimulant, UV reflectant, and toxicant. Attraction of adult D. citri to the device was mediated by a combination of a highly reflective yellow cylinder, a UV reflectant compound (magnesium oxide), and an odorant blend as a short-range attractant. The device surface was coated with a slow-release wax matrix (SPLAT™) augmented with a phagostimulant consisting of a 3-component blend (formic acid, acetic acid, and para-cymene) and an insecticide (β-cyfluthrin). Psyllids landing on the device attempted to feed from the wax matrix, became intoxicated, died, and fell from the device. The device remained ...
The African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae), is one of th... more The African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae), is one of the most devastating pest of citrus with a well-known role as a vector of the phloem-limited bacteria [Candidatus Liberibacter africanus] associated with huanglongbing (HLB; citrus greening disease), currently considered the world's most serious disease of citrus. Although the pest can successfully develop and reproduce on non-citrus host plants, there is no documented information on geometric morphometry of ACT. We determine the effect of host plants on ACT morphometry under controlled laboratory conditions using traditional and geometric analysis. ACT reared on C. limon and Citroncirus spp. were significantly larger than those reared on the other host plant species. ACT reared on C. anisata and C. tangelo were consistently smaller than those from M. koenigii and C. sinensis. Based on warped outline drawings, ACT reared on Citroncirus spp. and Murraya koenigii had narrower wings than ...
Mosquito larvicides provide a source-reduction strategy to diminish adult females that bite and p... more Mosquito larvicides provide a source-reduction strategy to diminish adult females that bite and potentially spread pathogens. Demands are mounting for new and innovative effective biorational larvicides, due to the development of resistance to some currently utilized mosquito larvicides, undesirable non-target effects, and U.S. Environmental Protection Agency (EPA) restrictions. Methionine is a human nutrient essential amino acid that unexpectedly has been shown to be a valuable safe pest management tool against select insect pests that possess alkaline gut physiology. The present study evaluated larvicidal toxicity of methionine in several pestiferous mosquito (Diptera: Culicidae) genera. Concentration-dependent DL-methionine kinetics assays of survival and pupation were conducted in larvae of Aedes albopictus Skuse, Anopheles quadrimaculatus Say, and Culex tarsalis Coquillett in glass jars. Higher concentrations of DL-methionine yielded 100% mortality for all test species and prev...
Dual attractant toxic sugar baits (D-ATSB) containing two host kairomones, L-lactic (LA) and 1-oc... more Dual attractant toxic sugar baits (D-ATSB) containing two host kairomones, L-lactic (LA) and 1-octen-3-ol (O), and fruit-based attractants were evaluated through olfactory, consumption and mortality, and semi-field experiments to determine if host kairomones could first, enhance attraction of a fruit-based (attractant) toxic sugar bait (ATSB), and second, increase the efficacy of a fruit based attractive toxic sugar bait (ATSB). Four combinations of LA and O were incorporated into the ATSB and evaluated in an olfactometer to determine if these combinations could enhance attraction of Aedes aegypti (L.) to the bait. Ae. albopictus (Skuse) and Ae. aegypti were used to determine bait consumption through excrement droplet counts and percent mortality, of the most attractive D-ATSB (1% LA and 1% O) from the olfactory study. Semi-field evaluations were conducted in screened portable field cages to determine if the D-ATSB applied to non-flowering plants controlled more mosquitoes than the ...
Phenotypic plasticity provides a mechanism by which an organism can adapt to new or changing envi... more Phenotypic plasticity provides a mechanism by which an organism can adapt to new or changing environments. Earlier studies have demonstrated the variability of Diaphorina citri Kuwayama (Asian citrus psyllid) population dynamics, but no analysis of morphological changes induced by seasonal or artificial laboratory-induced conditions has yet been documented. Such morphometric variation has been found to correspond in dispersal capabilities in several insect taxa. In this study, the effects of temperature and photoperiod on morphometric variation of D. citri were examined through laboratory rearing of psyllids under controlled temperatures (20 °C, 28 °C, and 30 °C) and under a short photoperiod of 10.5:13.5 (L:D) h and a long photoperiod of 16:8 (L:D) h. Diaphorina citri were field-collected monthly from three citrus groves in Fort Pierce, Gainesville, and Immokalee, FL, to evaluate potential field-associated environmental effects. Both traditional and geometric morphometric data were...
The Asian citrus psyllid (ACP),Diaphorina citriKuwayama, is one of the most serious citrus pests ... more The Asian citrus psyllid (ACP),Diaphorina citriKuwayama, is one of the most serious citrus pests worldwide due to its role as vector of huanglongbing or citrus greening disease. While some optimal plant species for ACP oviposition and development have been identified, little is known of the influence of host plants on ACP size and shape. Our goal was to determine how size and shape of ACP wing and body size varies when development occurs on different host plants in a controlled rearing environment. ACP were reared on six different rutaceous species;Bergera koenigii,Citrus aurantifolia,Citrus macrophylla,Citrus maxima,Citrus taiwanicaandMurraya paniculata. Adults were examined for morphometric variation using traditional and geometric analysis based on 12 traits or landmarks. ACP reared onC. taiwanicawere consistently smaller than those reared on the other plant species. Wing aspect ratio also differed betweenC. maximaandC. taiwanica. Significant differences in shape were detected wi...
New technology by ICA for chemical generation of carbon dioxide (CO2) was evaluated in olfactomet... more New technology by ICA for chemical generation of carbon dioxide (CO2) was evaluated in olfactometer and large outdoor cage tests against laboratory-reared Aedes aegypti for potential use in mosquito surveillance programs. The proprietary CO2 generation system consists of a poly-Tyvek sachet containing 2 solid ingredients. Activated sachets immediately react to generate and release predictable levels of CO2 over time. In noncompetitive olfactometer studies, a freshly activated sachet attracted an average +/- SE of 96.6 +/- 0.9% of the available mosquitoes compared with 20.2 +/- 6.5% for 5 ml/min CO2 released from a compressed gas cylinder. In competitive tests, the sachet attracted 92.4 +/- 1.2% compared with 0.9 +/- 0.5% for the compressed gas. In the olfactometer, aged sachets attracted >90% of the available mosquitoes up to 8 h and ca. 27% 1 wk after activation. In the large outdoor cages, traps baited with activated sachets captured 2.2-5.4 times as many mosquitoes as unbaited traps, depending on time of testing after activation.
Journal of the American Mosquito Control Association, Jun 1, 1994
Important information for the location by mosquitoes of a wide range of resources is provided by ... more Important information for the location by mosquitoes of a wide range of resources is provided by the visual perception of objects and the environment. Behavior of mosquitoes in the location of these resources has been well studied, yet relatively little has been reported on the physical parameters pertaining to mosquito vision. An understanding of physics relating to vision aids in an appreciation of the importance of morphology and physiology and ambient light conditions in mosquito vision.
A new cage was designed to study caged mosquitoes in ultra-low volume insecticide spray studies i... more A new cage was designed to study caged mosquitoes in ultra-low volume insecticide spray studies in the field. Insecticide droplets may enter the cage from any direction because all surfaces are mesh. Cages can be collapsed in seconds, and reassembly is quick and simple. A 26-cm-diam cage can be constructed for less than US$6.00.
Gravid female traps are used for surveillance of populations of Culex spp. and arboviruses such a... more Gravid female traps are used for surveillance of populations of Culex spp. and arboviruses such as West Nile virus. Field trials evaluating various attributes of gravid female traps for collection of gravid Culex were conducted in rural habitats in Alachua and Marion Counties, FL. Screened cage tests in the field were also used to compare trap models. Three trap models were evaluated: two based on the original Reiter design (Gravid CDC traps A and B) and one based on the revised Reiter design (gravid box trap). Trap model significantly affected collection of Culex quinquefasciatus and Culex nigripalpus; the greatest numbers were collected by the CDC gravid trap Aand CDC gravid trap B traps compared to the gravid box traps. There were no statistically significant differences between the collections with CDC gravid traps A and B. These patterns were similar at both sites and between early and late summer collections in Marion Co. In trials conducted in screened field cages with gravid Cx. quinquefasciatus, significantly more mosquitoes were collected in the CDC gravid trap A and B than in box gravid traps. Size of pan associated with the gravid traps was important and traps with larger pans collected more mosquitoes. Pan color was also important in efficacy of traps, and traps with darker pans (black, green) collected more mosquitoes than traps with lighter pans (tan, white). The percentages of gravid mosquitoes in trap collections of Culex females ranged from 54.0% to 89.6% with no clear differences between model of trap, size of pan, or pan color. Various attributes of gravid female traps impact the efficacy of the traps for Culex spp. and these should be considered in trapping programs.
The fall armyworm (Spodoptera frugiperda) (J. E. Smith) (Lepidoptera: Noctuidae), a major agricul... more The fall armyworm (Spodoptera frugiperda) (J. E. Smith) (Lepidoptera: Noctuidae), a major agricultural pest in the Western Hemisphere, has recently become established in Africa and Asia. This highly polyphagous species has potential to economically harm multiple crops. Contributing to this host range are two fall armyworm populations historically called ‘host strains’ that differ in host specificity. Understanding behaviors of the two strains is crucial to effective management of this pest. A major difficulty in such studies is that strains have long been considered morphologically indistinguishable, with molecular markers the only reliable means of identification. However, studies of fall armyworm in Colombia reported strain differences in wing morphology sufficiently large to potentially provide a more economical alternative method to determine strain. This study tested whether a similar phenotypic difference was present in Florida populations using geometric morphometric analysis...
Phytophagous insects, including Asian citrus psyllids (Diaphorina citri Kuwayama), use multiple s... more Phytophagous insects, including Asian citrus psyllids (Diaphorina citri Kuwayama), use multiple sensory modalities (vision, olfaction, and gustation,) to locate and accept host plants. We explored incorporation of several sensory cues into a multi-modal attract-and-kill device (AK device) using a three-dimensional shape to increase visibility, as well as elements of color, attractant, phagostimulant, UV reflectant, and toxicant. Attraction of adult D. citri to the device was mediated by a combination of a highly reflective yellow cylinder, a UV reflectant compound (magnesium oxide), and an odorant blend as a short-range attractant. The device surface was coated with a slow-release wax matrix (SPLAT™) augmented with a phagostimulant consisting of a 3-component blend (formic acid, acetic acid, and para-cymene) and an insecticide (β-cyfluthrin). Psyllids landing on the device attempted to feed from the wax matrix, became intoxicated, died, and fell from the device. The device remained ...
The African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae), is one of th... more The African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae), is one of the most devastating pest of citrus with a well-known role as a vector of the phloem-limited bacteria [Candidatus Liberibacter africanus] associated with huanglongbing (HLB; citrus greening disease), currently considered the world's most serious disease of citrus. Although the pest can successfully develop and reproduce on non-citrus host plants, there is no documented information on geometric morphometry of ACT. We determine the effect of host plants on ACT morphometry under controlled laboratory conditions using traditional and geometric analysis. ACT reared on C. limon and Citroncirus spp. were significantly larger than those reared on the other host plant species. ACT reared on C. anisata and C. tangelo were consistently smaller than those from M. koenigii and C. sinensis. Based on warped outline drawings, ACT reared on Citroncirus spp. and Murraya koenigii had narrower wings than ...
Mosquito larvicides provide a source-reduction strategy to diminish adult females that bite and p... more Mosquito larvicides provide a source-reduction strategy to diminish adult females that bite and potentially spread pathogens. Demands are mounting for new and innovative effective biorational larvicides, due to the development of resistance to some currently utilized mosquito larvicides, undesirable non-target effects, and U.S. Environmental Protection Agency (EPA) restrictions. Methionine is a human nutrient essential amino acid that unexpectedly has been shown to be a valuable safe pest management tool against select insect pests that possess alkaline gut physiology. The present study evaluated larvicidal toxicity of methionine in several pestiferous mosquito (Diptera: Culicidae) genera. Concentration-dependent DL-methionine kinetics assays of survival and pupation were conducted in larvae of Aedes albopictus Skuse, Anopheles quadrimaculatus Say, and Culex tarsalis Coquillett in glass jars. Higher concentrations of DL-methionine yielded 100% mortality for all test species and prev...
Dual attractant toxic sugar baits (D-ATSB) containing two host kairomones, L-lactic (LA) and 1-oc... more Dual attractant toxic sugar baits (D-ATSB) containing two host kairomones, L-lactic (LA) and 1-octen-3-ol (O), and fruit-based attractants were evaluated through olfactory, consumption and mortality, and semi-field experiments to determine if host kairomones could first, enhance attraction of a fruit-based (attractant) toxic sugar bait (ATSB), and second, increase the efficacy of a fruit based attractive toxic sugar bait (ATSB). Four combinations of LA and O were incorporated into the ATSB and evaluated in an olfactometer to determine if these combinations could enhance attraction of Aedes aegypti (L.) to the bait. Ae. albopictus (Skuse) and Ae. aegypti were used to determine bait consumption through excrement droplet counts and percent mortality, of the most attractive D-ATSB (1% LA and 1% O) from the olfactory study. Semi-field evaluations were conducted in screened portable field cages to determine if the D-ATSB applied to non-flowering plants controlled more mosquitoes than the ...
Phenotypic plasticity provides a mechanism by which an organism can adapt to new or changing envi... more Phenotypic plasticity provides a mechanism by which an organism can adapt to new or changing environments. Earlier studies have demonstrated the variability of Diaphorina citri Kuwayama (Asian citrus psyllid) population dynamics, but no analysis of morphological changes induced by seasonal or artificial laboratory-induced conditions has yet been documented. Such morphometric variation has been found to correspond in dispersal capabilities in several insect taxa. In this study, the effects of temperature and photoperiod on morphometric variation of D. citri were examined through laboratory rearing of psyllids under controlled temperatures (20 °C, 28 °C, and 30 °C) and under a short photoperiod of 10.5:13.5 (L:D) h and a long photoperiod of 16:8 (L:D) h. Diaphorina citri were field-collected monthly from three citrus groves in Fort Pierce, Gainesville, and Immokalee, FL, to evaluate potential field-associated environmental effects. Both traditional and geometric morphometric data were...
The Asian citrus psyllid (ACP),Diaphorina citriKuwayama, is one of the most serious citrus pests ... more The Asian citrus psyllid (ACP),Diaphorina citriKuwayama, is one of the most serious citrus pests worldwide due to its role as vector of huanglongbing or citrus greening disease. While some optimal plant species for ACP oviposition and development have been identified, little is known of the influence of host plants on ACP size and shape. Our goal was to determine how size and shape of ACP wing and body size varies when development occurs on different host plants in a controlled rearing environment. ACP were reared on six different rutaceous species;Bergera koenigii,Citrus aurantifolia,Citrus macrophylla,Citrus maxima,Citrus taiwanicaandMurraya paniculata. Adults were examined for morphometric variation using traditional and geometric analysis based on 12 traits or landmarks. ACP reared onC. taiwanicawere consistently smaller than those reared on the other plant species. Wing aspect ratio also differed betweenC. maximaandC. taiwanica. Significant differences in shape were detected wi...
New technology by ICA for chemical generation of carbon dioxide (CO2) was evaluated in olfactomet... more New technology by ICA for chemical generation of carbon dioxide (CO2) was evaluated in olfactometer and large outdoor cage tests against laboratory-reared Aedes aegypti for potential use in mosquito surveillance programs. The proprietary CO2 generation system consists of a poly-Tyvek sachet containing 2 solid ingredients. Activated sachets immediately react to generate and release predictable levels of CO2 over time. In noncompetitive olfactometer studies, a freshly activated sachet attracted an average +/- SE of 96.6 +/- 0.9% of the available mosquitoes compared with 20.2 +/- 6.5% for 5 ml/min CO2 released from a compressed gas cylinder. In competitive tests, the sachet attracted 92.4 +/- 1.2% compared with 0.9 +/- 0.5% for the compressed gas. In the olfactometer, aged sachets attracted >90% of the available mosquitoes up to 8 h and ca. 27% 1 wk after activation. In the large outdoor cages, traps baited with activated sachets captured 2.2-5.4 times as many mosquitoes as unbaited traps, depending on time of testing after activation.
Journal of the American Mosquito Control Association, Jun 1, 1994
Important information for the location by mosquitoes of a wide range of resources is provided by ... more Important information for the location by mosquitoes of a wide range of resources is provided by the visual perception of objects and the environment. Behavior of mosquitoes in the location of these resources has been well studied, yet relatively little has been reported on the physical parameters pertaining to mosquito vision. An understanding of physics relating to vision aids in an appreciation of the importance of morphology and physiology and ambient light conditions in mosquito vision.
A new cage was designed to study caged mosquitoes in ultra-low volume insecticide spray studies i... more A new cage was designed to study caged mosquitoes in ultra-low volume insecticide spray studies in the field. Insecticide droplets may enter the cage from any direction because all surfaces are mesh. Cages can be collapsed in seconds, and reassembly is quick and simple. A 26-cm-diam cage can be constructed for less than US$6.00.
Gravid female traps are used for surveillance of populations of Culex spp. and arboviruses such a... more Gravid female traps are used for surveillance of populations of Culex spp. and arboviruses such as West Nile virus. Field trials evaluating various attributes of gravid female traps for collection of gravid Culex were conducted in rural habitats in Alachua and Marion Counties, FL. Screened cage tests in the field were also used to compare trap models. Three trap models were evaluated: two based on the original Reiter design (Gravid CDC traps A and B) and one based on the revised Reiter design (gravid box trap). Trap model significantly affected collection of Culex quinquefasciatus and Culex nigripalpus; the greatest numbers were collected by the CDC gravid trap Aand CDC gravid trap B traps compared to the gravid box traps. There were no statistically significant differences between the collections with CDC gravid traps A and B. These patterns were similar at both sites and between early and late summer collections in Marion Co. In trials conducted in screened field cages with gravid Cx. quinquefasciatus, significantly more mosquitoes were collected in the CDC gravid trap A and B than in box gravid traps. Size of pan associated with the gravid traps was important and traps with larger pans collected more mosquitoes. Pan color was also important in efficacy of traps, and traps with darker pans (black, green) collected more mosquitoes than traps with lighter pans (tan, white). The percentages of gravid mosquitoes in trap collections of Culex females ranged from 54.0% to 89.6% with no clear differences between model of trap, size of pan, or pan color. Various attributes of gravid female traps impact the efficacy of the traps for Culex spp. and these should be considered in trapping programs.
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