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Stephen L. Lapointe - One of the best experts on this subject based on the ideXlab platform.
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Infection of the Diaprepes Root Weevil, Diaprepes abbreviatus (Coleoptera: Curculionidae) by an Iridovirus
2015Co-Authors: Stephen L. LapointeAbstract:The Diaprepes root weevil (DRW), Diaprepes abbreviatus (L.), is now regarded as a principal threat to sustainability of the citrus industry in Florida. Since its introduction into Florida in 1964, the weevil has spread throughout the citrus producing areas of peninsular Florida. Adult females oviposit on leaves. Neonate larvae fall to the ground and burrow into the soil where they feed on progressively larger roots as the larvae grow. Tre
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Orientation of weevils to citrus volatiles or volatiles produced by males feeding on citrus.
2013Co-Authors: Fernando Otálora-luna, Stephen L. Lapointe, Joseph C. DickensAbstract:Orientation responses of Diaprepes abbreviatus adults, recorded during three consecutive 2-minute periods: A. clean air (control), air passing through headspace of citrus foliage (test) and clean air again (end-control), or C. control, air passing through headspace of 10 male weevils feeding on citrus foliage (test) and end-control, were expressed as percentage of distance covered in each of four 90° angles projected to 0°, 90°, 180° and 270°. Orientation indices (B. and D. respectively) were calculated as the proportion of distance covered during the test period minus the proportion of the distance covered during the control period in each angle. Different letters indicate significant pairwise differences across the different directions (α = 0.05, Dunn’s post-hoc test). Asterisk indicates significance (α = 0.05, Wilcoxon signed rank test). In the boxplots, bold lines indicate medians, segmented line indicate the means, lower and upper boundaries of a box indicate the 25 and 75% quartiles, respectively, whiskers below and above the box indicate the 10th and 90th percentiles, respectively, and circles represent data beyond these limits (outliers).
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Orientation of weevils to colored lights in still air.
2013Co-Authors: Fernando Otálora-luna, Stephen L. Lapointe, Joseph C. DickensAbstract:Walking response of Diaprepes abbreviatus adults exposed to colored LEDs in a multiple choice arena adapted to a servosphere expressed as percent displacement in perpendicular corridors. Relative displacement in the ‘x’ and ‘y’ corridors was compared to evaluate response during 3 minute runs when offered the choice between two different pairs of colored LED lights. Asterisks indicate significance (Wilcoxon signed rank test, α = 0.05), ‘ns’ is not significant and numbers on the horizontal axis are sample size, d = dark, y = yellow, g = green, b = blue, uv = ultraviolet, r = red, dg = dim green. Note that these experiments were performed in still air. In the boxplots, bold lines indicate medians, squares indicate the means, lower and upper boundaries of a box indicate the 25 and 75% quartiles, respectively, whiskers below and above the box indicate the 10th and 90th percentiles, respectively, and circles represent data beyond these limits (outliers).
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Turning speed of weevils elicited by different stimulus treatments.
2013Co-Authors: Fernando Otálora-luna, Stephen L. Lapointe, Joseph C. DickensAbstract:A. Average turning speeds of Diaprepes abbreviatus females and males, exposed to the different stimulus treatments , were recorded during the 3 three consecutive 2-minute periods (control, test and end-control). For treatments explanations see figure 5. B. Turning speed indices for each series were calculated as the average turning speed during the test period minus the average turning speed during the control period. Different letters indicate significant pairwise differences across the different directions (α = 0.05, Dunn’s post-hoc test). Asterisk indicates significance (α = 0.05, Wilcoxon signed rank test). In the boxplots, bold lines indicate medians, segmented line indicate the means, lower and upper boundaries of a box indicate the 25 and 75% quartiles, respectively, whiskers below and above the box indicate the 10th and 90th percentiles, respectively, and circles represent data beyond these limits (outliers).
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Path striaghtness of weevils elicited by different stimulus treatments.
2013Co-Authors: Fernando Otálora-luna, Stephen L. Lapointe, Joseph C. DickensAbstract:A. Path straightness of Diaprepes abbreviatus females and males, exposed to different stimulus treatments , were recorded during the 3 three consecutive 2-minute periods (control, test and end-control). For treatments explanations see figure 5. B. Path straightness indices for each series were calculated as the average path straightness during the test period minus the average path straightness during the control period. Different letters indicate significant pairwise differences across the different directions (α = 0.05, Dunn’s post-hoc test). Asterisk indicates significance (α = 0.05, Wilcoxon signed rank test). In the boxplots, bold lines indicate medians, segmented line indicate the means, lower and upper boundaries of a box indicate the 25 and 75% quartiles, respectively, whiskers below and above the box indicate the 10th and 90th percentiles, respectively, and circles represent data beyond these limits (outliers).
Rita E Duncan - One of the best experts on this subject based on the ideXlab platform.
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the role of brachyufens osborni hymenoptera trichogrammatidae in the classical biological control program against Diaprepes abbreviatus coleoptera curculionidae in florida
Biological Control, 2010Co-Authors: Josep A Jacas, Bryan J Ulmer, Rita E Duncan, Jorge E PenaAbstract:Abstract Brachyufens osborni is an indigenous egg parasitoid of weevil species laying concealed eggs in Florida. Diaprepes abbreviatus , an exotic weevil pest of different crops in the southern USA, has been reported as a host for B. osborni . In this study we investigated the interaction between B. osborni and D. abbreviatus as well as other hosts including Pachnaeus litus and Artipus floridanus . The thermal requirements of B. osborni and the interaction between this species and three other weevil parasitoids introduced in a classical biological control program against D. abbreviatus ( Aprostocetus vaquitarum , Haeckeliania sperata and Quadrastichus haitiensis ) were also examined in laboratory studies. Although B. osborni attacked eggs of all weevil species tested, it could not complete development on D. abbreviatus . The three exotic parasitoids did successfully develop on both P. litus and D. abbreviatus eggs, though our results showed that P. litus should not be considered as an alternative host for the introduced parasitoids during winter in central Florida. Because B. osborni cannot complete development on D. abbreviatus , it has never been recovered from field collected hosts, and its effect on D. abbreviatus in the field remains ignored. This study demonstrates that although B. osborni could not successfully develop in D. abbreviatus , it can inflict important mortality to it and suggests that B. osborni could impact the establishment of introduced D. abbreviatus egg parasitoids.
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reproductive biology of fidiobia dominica hymenoptera platygastridae an egg parasitoid of Diaprepes abbreviatus coleoptera curculionidae
Environmental Entomology, 2007Co-Authors: Rita E Duncan, Bryan J Ulmer, Jorge E Pena, Stephen L. LapointeAbstract:The reproductive biology of Fidiobia dominica Evans (Hymenoptera: Platygastridae) was studied in the laboratory (25.6 ± 1°C) using host eggs of Diaprepes abbreviatus L. (Coleoptera: Curculionidae). F. dominica readily parasitized D. abbreviatus eggs on both host plant and wax paper substrates. The number of egg masses parasitized and the number of offspring produced were higher when females were offered more than one host egg mass but did not differ when either two or three egg masses were offered. Female parasitoids that were provided with host eggs and a honey food source lived significantly longer than those that were not provided a food source; however, they did not parasitize more D. abbreviatus eggs. Oviposition occurred in host eggs from 0 to 7 d old, and host mortality was relatively consistent for eggs 0–5 d old and lower for eggs 6–7 d old. Successful parasitoid emergence seldom occurred after host eggs were 4 d old, and by 7 d, no adults successfully emerged. Developmental time from egg to adult was 19.3 ± 0.2 d for males, significantly more rapid than the females (20.4 ± 0.1 d). The mean longevity of adult females was 8.0 ± 0.4 d, with a mean oviposition period of 2.7 ± 0.3 d; males survived 8.1 ± 0.4 d. The demographic parameters including intrinsic rate of increase (rm), generation time (T), and net reproduction (Ro) were 0.142/d, 22 d, and 22.4 female eggs/d, respectively.
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effect of temperature on life history of aprostocetus vaquitarum hymenoptera eulophidae an egg parasitoid of Diaprepes abbreviatus coleoptera curculionidae
Biological Control, 2006Co-Authors: Bryan J Ulmer, J. E. Peña, Josep A Jacas, Rita E Duncan, J CastilloAbstract:Abstract The effect of temperatures ranging from 5 to 40 °C on Aprostocetus vaquitarum Wolcott (Hymenoptera: Eulophidae) oviposition and development were investigated. There were significant differences in the rate of development among the temperatures for all life stages. The egg stage lasted approximately 7 times longer at 15 than at 25 or 30 °C and the larval stage, consisting of 4 instars, took significantly less time at each increasing temperature from 15 to 30 °C. A. vaquitarum development from egg to adult took 16.3 days at 30 °C, significantly faster than the other temperatures tested. At 15 °C A. vaquitarum reached the pupal stage after a mean of 41.6 days but did not successfully complete pupation. A. vaquitarum eggs hatched on 66% of the parasitized egg masses at 35 °C but did not survive past the first instar. A. vaquitarum did not develop past the egg stage at 5 or 40 °C. Host Diaprepes abbreviatus L. (Coleoptera: Curculionidae) eggs also did not survive at temperatures of 35 and 40 °C on live plants. Upper and lower temperature thresholds for A. vaquitarum development were calculated to be 33.0 and 16.0 °C, respectively. Maximum development rate occurred at 30.9 °C and a thermal constant of 494.2 DD was calculated. Photoperiods ranging from 10L:14D to 16L:8D did not significantly affect development time from egg to adult at 25 °C. Oviposition was significantly higher at 30 °C than at the other temperatures tested; oviposition was also relatively high at 25 and 35 °C and several eggs were laid at 20 °C. Relatively cool winter temperatures in central Florida may be contributing to the limited range of A. vaquitarum in the state.
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toxicity of pesticides used in citrus to aprostocetus vaquitarum hymenoptera eulophidae an egg parasitoid of Diaprepes abbreviatus coleoptera curculionidae
Florida Entomologist, 2006Co-Authors: Bryan J Ulmer, Stephen L. Lapointe, Jorge E Pena, Rita E DuncanAbstract:Abstract Twelve pesticides used in citrus were tested for their contact toxicity to Aprostocetus vaquitarum Wolcott (Hymenoptera: Eulophidae) a parasitoid of Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae). Sevin® 80 WSP, Malathion 5 EC, and Imidan® 70 WSB resulted in the most rapid death of A. vaquitarum adults. Admire® 2F, Danitol® 2.4EC, and Surround® WP were also very detrimental. Kocide® 101 WP, Citrus Soluble Oil, Micromite® 80 WGS, Acramite® 50 WS, Micromite® 80 WGS + Citrus Soluble Oil, Aliette WDG, and Agrimek® 0.15 EC + Citrus Soluble Oil were slightly to non-toxic to A. vaquitarum. The relative toxicity of the pesticides was consistent up to four weeks after application. Significantly fewer adult A. vaquitarum emerged from D. abbreviatus eggs laid on foliage treated in the field with Sevin® XLR and Imidan® 70 WSB than emerged from the water treated control. Field residues of Sevin® XLR remained toxic for seven days while the effects of Imidan® 70 WSB were no longer significant after one ...
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Successful oviposition and reproductive biology of Aprostocetus vaquitarum (Hymenoptera: Eulophidae): A predator of Diaprepes abbreviatus (Coleoptera: Curculionidae)
Biological Control, 2005Co-Authors: Josep A Jacas, J. E. Peña, Rita E DuncanAbstract:Abstract Aprostocetus vaquitarum (Wolcott) causes 78–91 percent mortality to eggs of Diaprepes abbreviatus (L.), under field conditions in southern Florida. In the laboratory, A. vaquitarum was reared on D. abbreviatus eggs at 25 °C, a photoperiod of 12:12 (L:D) and with abundant hosts, A. vaquitarum adult females lived around 15 days. Oviposition was significantly affected by the age of the host egg mass. Egg masses aged 0- to 3-day-old were accepted significantly better than those aged 4–6 days. The mean number of eggs deposited per female was around 53, with extreme values of 124 and 19 eggs per female. Using these data in combination with the sex ratio observed in the field (0.16) and the duration of the preimaginal stages, r m (0.168–0142 day −1 ), T (22.39–22.89 days), and R 0 (43.03–25.81 females per female) were calculated.
Clayton W. Mccoy - One of the best experts on this subject based on the ideXlab platform.
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virulence of new and mixed strains of the entomopathogenic nematode steinernema riobrave to larvae of the citrus root weevil Diaprepes abbreviatus
Biological Control, 2004Co-Authors: Robin J. Stuart, Khuong B Nguyen, David I Shapiroilan, Rosalind R James, Clayton W. MccoyAbstract:Steinernema riobrave ranks as the most efficacious entomopathogenic nematode for inundative biological control (biopesticide) applications against larvae of the root weevil Diaprepes abbreviatus in Florida citrus groves and has been commercially available for several years. However, only one strain is known, and others could be more effective. Therefore, we used two soil sampling techniques (cores and shovel/bucket samples) and collected soil samples at 10 sites near the type locality of Weslaco, Texas. Soil samples were baited with either Galleria mellonella or D. abbreviatus larvae and produced 10 new isolates of S. riobrave from five sites, and an undescribed species of entomopathogenic nematode in the genus Heterorhabditis from one site. All new isolates were from G. mellonella larvae, and eight of the S. riobrave isolates were from soil cores. In virulence assays comparing the new S. riobrave strains, the commercial strain, and a mixed strain (formed by pooling the new strains), average larval mortality for five strains (including the mixed strain) was significantly greater than for the commercial strain. Larval mortality for the 12 strains ranged from 57.7 to 84.1% with the commercial strain and the mixed strain being the extremes, and the mixed strain killing 45.7% more than the commercial strain. Among the 10 new strains, larval mortality ranged from 65.8 to 79.3%, with two strains from the same site being the extremes and the only strains significantly different from one another. Thus, these strains have potential for improved biological control of D. abbreviatus and further comparisons are warranted. 2003 Elsevier Inc. All rights reserved.
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incidence of endemic entomopathogenic nematodes following application of steinernema riobrave for control of Diaprepes abbreviatus
Journal of Nematology, 2003Co-Authors: L W Duncan, Clayton W. Mccoy, J. Zellers, J H Graham, D Dunn, Khuong B NguyenAbstract:Control of Diaprepes abbreviatus by endemic and exotic entomopathogenic nematodes (EPN) was monitored during 2000-2001 in two citrus orchards in central Florida (Bartow and Poinciana). Caged sentinel insect larvae were buried beneath citrus trees for 7 days at 1 to 2-month intervals from April to October each year. At Bartow, the survey occurred in experimental plots that were (i) not treated with commercial EPN, (ii) treated twice annually since 1998 with commercially formulated Steinernema riobrave, or (iii) treated twice annually with S. riobrave and liquid fertilization (15 times/year) occurred in place of dry fertilizer (3 times/year) used in the other treatments. Four endemic EPN species, in addition to S. riobrave, were recovered from the sandy soil at Bartow: S. Diaprepesi, Heterorhabditis zealandica, H. indica, and H. bacteriophora. Mean insect mortality in control plots was 39.4% (range = 13% to 74%), with seasonal maxima in May to July each year. Endemic EPN were recovered from 55% (range = 22% to 81%) of the cadavers each month. Total numbers of endemic EPN recovered in all plots during 2 years were directly related to the numbers of adult weevils (D. abbreviatus and Pachnaeus litus) captured in modified Tedder's traps and inversely related to recovery of S. riobrave. Insect mortality was higher and cadavers containing endemic EPN were more numerous in untreated control plots than in S. riobrave-treated plots, except during months in which S. riobrave was applied. In treated plots, endemic EPN were recovered from cadavers at twice the rate of S. riobrave. Suppression of endemic EPN in plots treated with S. riobrave, combined with inferior persistence by the introduced species, may have attenuated the net efficacy of S. riobrave against D. abbreviatus. In contrast, H. indica was the only endemic nematode recovered from the sandy clay loam soil at Poinciana, where the average mortality of D. abbreviatus was 12% (range 3% to 20%) and incidence of H. indica did not exceed 8%. Results of these surveys suggest that the regional patterns in the abundance and damage to citrus caused by D. abbreviatus in Florida are regulated by endemic EPN and other soilborne enemies of the weevil.
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abundance of Diaprepes abbreviatus l coleoptera curculionidae neonates falling to the soil under tree canopies in florida citrus groves
Journal of Economic Entomology, 2003Co-Authors: H. N. Nigg, Clayton W. Mccoy, Robin J. Stuart, L W Duncan, S. E. Simpson, Frederick G GmitterAbstract:The purpose of these experiments was to estimate the number and distribution of Diaprepes abbreviatus (L.) neonate larvae dropping from the canopy of infested citrus trees. The number of neonates was monitored in the Þeld using passive funnel traps in two simultaneous experiments and a separate experiment for an additional year. In one experiment, traps were placed from trunk to dripline in the cardinal directions under each of Þve trees (132 traps total). In a second experiment, eight traps were placed under each tree in the cardinal directions, one trap 30 cm from the trunk and one trap 30 cm from the dripline/direction for 25 trees (200 traps total). Larvae were collected weekly for 50 wk in conical tubes containing ethylene glycol as a preservative. Traps closer to the tree trunk captured more larvae than traps nearer the dripline. The area under the tree canopy was positively correlated with the total estimated number of larvae captured per tree. The estimated number of total larvae/tree over the course of our experiments ranged from 955 to 7,290. The highest number of neonate larvae observed in 1 wk was 67 6/m 2 . There was an inverse relationship between the number of traps beneath a tree and the number of trees that needed to be sampled to estimate mean population density with a given precision. However, there was a direct relationship between number of traps/tree and the total number of traps needed for a given precision. This passive technique could be used to quantify the destructive larval stage and to assess D. abbreviatus management strategies.
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predation on neonate larvae of Diaprepes abbreviatus coleoptera curculionidae in florida citrus testing for daily patterns of neonate drop ant predators and chemical repellency
Florida Entomologist, 2003Co-Authors: Robin J. Stuart, Ian Jackson, Clayton W. MccoyAbstract:Abstract The root weevil, Diaprepes abbreviatus (L.), is a major pest of Florida citrus. When neonate larvae hatch from egg masses in the citrus canopy and drop to the soil surface before burrowing down to the roots for feeding, they are vulnerable to ant predation. However, neonates are reported to produce a chemical repellent that lasts up to four days and reduces ant predation by about 40%. We assessed the daily pattern of neonate drop from egg masses under laboratory conditions (24°C, 70% RH, L:D = 12:12), examined the role of ants as predators of neonates (<48 h post hatch) on the soil surface in three citrus groves in central Florida, and tested for chemical repellency in the field by comparing predation rates on 5-day versus 1-2 h old neonates. Neonate drop was not well synchronized within or among egg masses, occurred during all hours of the light and dark phases, and extended over 5 to 23 h (mean = 11.97, SE = 0.866) for individual egg masses (n = 29). However, the drop rate was highest during th...
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FIELD EFFICACY OF TWO COMMERCIAL PREPARATIONS OF ENTOMOPATHOGENIC NEMATODES AGAINST LARVAE OF Diaprepes abbreviatus (COLEOPTERA: CURCULIONIDAE) IN ALFISOL TYPE SOIL
Florida Entomologist, 2002Co-Authors: Clayton W. Mccoy, Larry W. Duncan, Robin J. Stuart, Khuong B NguyenAbstract:Abstract Spring and fall field trials were conducted to determine the efficacy of two species of entomopathogenic nematodes for the control of larvae of Diaprepes abbreviatus in a citrus grove with alfisol type soil (sandy clay loam). Both Steinernema riobrave (Bio Vector 355) as a water-dispersible granule and Heterorhabditis indica (Grubstake™ 100) as a paste on sponge at rates from 22-108 IJ’s/cm2 failed to reduce larval populations in the tree rhizosphere at 25 d post-treatment. Larval parasitism by entomopathogenic nematodes in baited screen cages was sporadic over time, with the only significant treatment effect occurring at the highest rate (108 IJ’s/cm2) of S. riobrave in the fall at 7 d post-treatment. Possible constraints to nematode efficacy are discussed.
Jorge E Pena - One of the best experts on this subject based on the ideXlab platform.
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the role of brachyufens osborni hymenoptera trichogrammatidae in the classical biological control program against Diaprepes abbreviatus coleoptera curculionidae in florida
Biological Control, 2010Co-Authors: Josep A Jacas, Bryan J Ulmer, Rita E Duncan, Jorge E PenaAbstract:Abstract Brachyufens osborni is an indigenous egg parasitoid of weevil species laying concealed eggs in Florida. Diaprepes abbreviatus , an exotic weevil pest of different crops in the southern USA, has been reported as a host for B. osborni . In this study we investigated the interaction between B. osborni and D. abbreviatus as well as other hosts including Pachnaeus litus and Artipus floridanus . The thermal requirements of B. osborni and the interaction between this species and three other weevil parasitoids introduced in a classical biological control program against D. abbreviatus ( Aprostocetus vaquitarum , Haeckeliania sperata and Quadrastichus haitiensis ) were also examined in laboratory studies. Although B. osborni attacked eggs of all weevil species tested, it could not complete development on D. abbreviatus . The three exotic parasitoids did successfully develop on both P. litus and D. abbreviatus eggs, though our results showed that P. litus should not be considered as an alternative host for the introduced parasitoids during winter in central Florida. Because B. osborni cannot complete development on D. abbreviatus , it has never been recovered from field collected hosts, and its effect on D. abbreviatus in the field remains ignored. This study demonstrates that although B. osborni could not successfully develop in D. abbreviatus , it can inflict important mortality to it and suggests that B. osborni could impact the establishment of introduced D. abbreviatus egg parasitoids.
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reproductive biology of fidiobia dominica hymenoptera platygastridae an egg parasitoid of Diaprepes abbreviatus coleoptera curculionidae
Environmental Entomology, 2007Co-Authors: Rita E Duncan, Bryan J Ulmer, Jorge E Pena, Stephen L. LapointeAbstract:The reproductive biology of Fidiobia dominica Evans (Hymenoptera: Platygastridae) was studied in the laboratory (25.6 ± 1°C) using host eggs of Diaprepes abbreviatus L. (Coleoptera: Curculionidae). F. dominica readily parasitized D. abbreviatus eggs on both host plant and wax paper substrates. The number of egg masses parasitized and the number of offspring produced were higher when females were offered more than one host egg mass but did not differ when either two or three egg masses were offered. Female parasitoids that were provided with host eggs and a honey food source lived significantly longer than those that were not provided a food source; however, they did not parasitize more D. abbreviatus eggs. Oviposition occurred in host eggs from 0 to 7 d old, and host mortality was relatively consistent for eggs 0–5 d old and lower for eggs 6–7 d old. Successful parasitoid emergence seldom occurred after host eggs were 4 d old, and by 7 d, no adults successfully emerged. Developmental time from egg to adult was 19.3 ± 0.2 d for males, significantly more rapid than the females (20.4 ± 0.1 d). The mean longevity of adult females was 8.0 ± 0.4 d, with a mean oviposition period of 2.7 ± 0.3 d; males survived 8.1 ± 0.4 d. The demographic parameters including intrinsic rate of increase (rm), generation time (T), and net reproduction (Ro) were 0.142/d, 22 d, and 22.4 female eggs/d, respectively.
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toxicity of pesticides used in citrus to aprostocetus vaquitarum hymenoptera eulophidae an egg parasitoid of Diaprepes abbreviatus coleoptera curculionidae
Florida Entomologist, 2006Co-Authors: Bryan J Ulmer, Stephen L. Lapointe, Jorge E Pena, Rita E DuncanAbstract:Abstract Twelve pesticides used in citrus were tested for their contact toxicity to Aprostocetus vaquitarum Wolcott (Hymenoptera: Eulophidae) a parasitoid of Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae). Sevin® 80 WSP, Malathion 5 EC, and Imidan® 70 WSB resulted in the most rapid death of A. vaquitarum adults. Admire® 2F, Danitol® 2.4EC, and Surround® WP were also very detrimental. Kocide® 101 WP, Citrus Soluble Oil, Micromite® 80 WGS, Acramite® 50 WS, Micromite® 80 WGS + Citrus Soluble Oil, Aliette WDG, and Agrimek® 0.15 EC + Citrus Soluble Oil were slightly to non-toxic to A. vaquitarum. The relative toxicity of the pesticides was consistent up to four weeks after application. Significantly fewer adult A. vaquitarum emerged from D. abbreviatus eggs laid on foliage treated in the field with Sevin® XLR and Imidan® 70 WSB than emerged from the water treated control. Field residues of Sevin® XLR remained toxic for seven days while the effects of Imidan® 70 WSB were no longer significant after one ...
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effects of host age female parasitoid age and host plant on parasitism of ceratogramma etiennei hymenoptera trichogrammatidae
Florida Entomologist, 2005Co-Authors: Divina M Amalin, Jorge E Pena, Rita E DuncanAbstract:Abstract Parasitism of Diaprepes abbreviatus (L.) eggs by Ceratogramma etiennei Delvare as influenced by host age, age of the female parasitoid, and host plant preference was evaluated under laboratory or greenhouse tests. Percent parasitism of D. abbreviatus eggs by C. etiennei decreased as eggs matured. The optimal age of C. etiennei for successful parasitism ranged from 1-2-d old. Host plant leaf thickness, leaf pubescence, and plant strata probably played a role on the parasitism by C. etiennei. This parasitoid is diurnal and spent approximately 5 min searching for eggs laid in cryptic locations, 46 min parasitizing an egg mass and 24 min resting. This biological information is relevant in evaluating the potential of C. etiennei in the classical biological control of D. abbreviatus.
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oviposition and larval survival of Diaprepes abbreviatus coleoptera curculionidae on select host plants
Florida Entomologist, 2003Co-Authors: Catharine Mannion, Jorge E Pena, Adrian G B Hunsberger, Lance S OsborneAbstract:In a preliminary survey in four commercial ornamental nurseries in south Florida (1998), Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae) egg masses, feeding damage, or adults occurred on numerous field-grown ornamental plant species. Live oak (Quercus virginiana Mill.), silver buttonwood (Conocarpus erectus L. variety sericeus Fors. Ex DC), and black olive (Bucida buseras L.) had the highest percentage of plants with egg masses. Adult feeding damage was found on all examined plants of dahoon holly (Ilex cassine L.), cocoplum (Chrysobalanus icaco L.), black olive, live oak, Bauhinia sp., and Cassia sp. Oviposition of D. abbreviatus was evaluated in no-choice, two-choice, three-choice and multiple-choice caged tests. In no-choice tests, silver buttonwood had the highest mean number of egg masses. In two-choice tests, egg masses were laid on all plant species tested but there were significantly more egg masses on silver buttonwood than the alternate choice. The number of egg masses in the three-choice tests was low and there were no significant differences among the plant species tested. As in the no-choice and two-choice tests, significantly more egg masses were found on silver buttonwood in multiple-choice tests. Survival of larvae and their effect on plant growth was examined on several commonly grown plant species in southern Florida. Larval survival was highest on silver buttonwood and Sorghum sudanense Pers (sorghum-sudan) compared with other plant species. Root and/or total biomass was significantly reduced on green bean (Phaseolus vulgaris), silver buttonwood, Tahiti lime (Citrus aurantifolia), and sorghum-sudan.
Bryan J Ulmer - One of the best experts on this subject based on the ideXlab platform.
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the role of brachyufens osborni hymenoptera trichogrammatidae in the classical biological control program against Diaprepes abbreviatus coleoptera curculionidae in florida
Biological Control, 2010Co-Authors: Josep A Jacas, Bryan J Ulmer, Rita E Duncan, Jorge E PenaAbstract:Abstract Brachyufens osborni is an indigenous egg parasitoid of weevil species laying concealed eggs in Florida. Diaprepes abbreviatus , an exotic weevil pest of different crops in the southern USA, has been reported as a host for B. osborni . In this study we investigated the interaction between B. osborni and D. abbreviatus as well as other hosts including Pachnaeus litus and Artipus floridanus . The thermal requirements of B. osborni and the interaction between this species and three other weevil parasitoids introduced in a classical biological control program against D. abbreviatus ( Aprostocetus vaquitarum , Haeckeliania sperata and Quadrastichus haitiensis ) were also examined in laboratory studies. Although B. osborni attacked eggs of all weevil species tested, it could not complete development on D. abbreviatus . The three exotic parasitoids did successfully develop on both P. litus and D. abbreviatus eggs, though our results showed that P. litus should not be considered as an alternative host for the introduced parasitoids during winter in central Florida. Because B. osborni cannot complete development on D. abbreviatus , it has never been recovered from field collected hosts, and its effect on D. abbreviatus in the field remains ignored. This study demonstrates that although B. osborni could not successfully develop in D. abbreviatus , it can inflict important mortality to it and suggests that B. osborni could impact the establishment of introduced D. abbreviatus egg parasitoids.
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reproductive biology of fidiobia dominica hymenoptera platygastridae an egg parasitoid of Diaprepes abbreviatus coleoptera curculionidae
Environmental Entomology, 2007Co-Authors: Rita E Duncan, Bryan J Ulmer, Jorge E Pena, Stephen L. LapointeAbstract:The reproductive biology of Fidiobia dominica Evans (Hymenoptera: Platygastridae) was studied in the laboratory (25.6 ± 1°C) using host eggs of Diaprepes abbreviatus L. (Coleoptera: Curculionidae). F. dominica readily parasitized D. abbreviatus eggs on both host plant and wax paper substrates. The number of egg masses parasitized and the number of offspring produced were higher when females were offered more than one host egg mass but did not differ when either two or three egg masses were offered. Female parasitoids that were provided with host eggs and a honey food source lived significantly longer than those that were not provided a food source; however, they did not parasitize more D. abbreviatus eggs. Oviposition occurred in host eggs from 0 to 7 d old, and host mortality was relatively consistent for eggs 0–5 d old and lower for eggs 6–7 d old. Successful parasitoid emergence seldom occurred after host eggs were 4 d old, and by 7 d, no adults successfully emerged. Developmental time from egg to adult was 19.3 ± 0.2 d for males, significantly more rapid than the females (20.4 ± 0.1 d). The mean longevity of adult females was 8.0 ± 0.4 d, with a mean oviposition period of 2.7 ± 0.3 d; males survived 8.1 ± 0.4 d. The demographic parameters including intrinsic rate of increase (rm), generation time (T), and net reproduction (Ro) were 0.142/d, 22 d, and 22.4 female eggs/d, respectively.
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effect of temperature on life history of aprostocetus vaquitarum hymenoptera eulophidae an egg parasitoid of Diaprepes abbreviatus coleoptera curculionidae
Biological Control, 2006Co-Authors: Bryan J Ulmer, J. E. Peña, Josep A Jacas, Rita E Duncan, J CastilloAbstract:Abstract The effect of temperatures ranging from 5 to 40 °C on Aprostocetus vaquitarum Wolcott (Hymenoptera: Eulophidae) oviposition and development were investigated. There were significant differences in the rate of development among the temperatures for all life stages. The egg stage lasted approximately 7 times longer at 15 than at 25 or 30 °C and the larval stage, consisting of 4 instars, took significantly less time at each increasing temperature from 15 to 30 °C. A. vaquitarum development from egg to adult took 16.3 days at 30 °C, significantly faster than the other temperatures tested. At 15 °C A. vaquitarum reached the pupal stage after a mean of 41.6 days but did not successfully complete pupation. A. vaquitarum eggs hatched on 66% of the parasitized egg masses at 35 °C but did not survive past the first instar. A. vaquitarum did not develop past the egg stage at 5 or 40 °C. Host Diaprepes abbreviatus L. (Coleoptera: Curculionidae) eggs also did not survive at temperatures of 35 and 40 °C on live plants. Upper and lower temperature thresholds for A. vaquitarum development were calculated to be 33.0 and 16.0 °C, respectively. Maximum development rate occurred at 30.9 °C and a thermal constant of 494.2 DD was calculated. Photoperiods ranging from 10L:14D to 16L:8D did not significantly affect development time from egg to adult at 25 °C. Oviposition was significantly higher at 30 °C than at the other temperatures tested; oviposition was also relatively high at 25 and 35 °C and several eggs were laid at 20 °C. Relatively cool winter temperatures in central Florida may be contributing to the limited range of A. vaquitarum in the state.
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toxicity of pesticides used in citrus to aprostocetus vaquitarum hymenoptera eulophidae an egg parasitoid of Diaprepes abbreviatus coleoptera curculionidae
Florida Entomologist, 2006Co-Authors: Bryan J Ulmer, Stephen L. Lapointe, Jorge E Pena, Rita E DuncanAbstract:Abstract Twelve pesticides used in citrus were tested for their contact toxicity to Aprostocetus vaquitarum Wolcott (Hymenoptera: Eulophidae) a parasitoid of Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae). Sevin® 80 WSP, Malathion 5 EC, and Imidan® 70 WSB resulted in the most rapid death of A. vaquitarum adults. Admire® 2F, Danitol® 2.4EC, and Surround® WP were also very detrimental. Kocide® 101 WP, Citrus Soluble Oil, Micromite® 80 WGS, Acramite® 50 WS, Micromite® 80 WGS + Citrus Soluble Oil, Aliette WDG, and Agrimek® 0.15 EC + Citrus Soluble Oil were slightly to non-toxic to A. vaquitarum. The relative toxicity of the pesticides was consistent up to four weeks after application. Significantly fewer adult A. vaquitarum emerged from D. abbreviatus eggs laid on foliage treated in the field with Sevin® XLR and Imidan® 70 WSB than emerged from the water treated control. Field residues of Sevin® XLR remained toxic for seven days while the effects of Imidan® 70 WSB were no longer significant after one ...
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effect of temperature on life history of quadrastichus haitiensis hymenoptera eulophidae an endoparasitoid of Diaprepes abbreviatus coleoptera curculionidae
Biological Control, 2006Co-Authors: J Castillo, J. E. Peña, Josep A Jacas, Bryan J Ulmer, D G HallAbstract:Abstract The influence of temperature on life history traits of the egg parasitoid Quadrastichus haitiensis (Gahan) (Hymenoptera: Eulophidae) was investigated in the laboratory on eggs of the root weevil Diaprepes abbreviatus (L.) (Coleoptera: Curculionidae). Duration of development from egg to adult decreased from 39.99 ± 0.27 days to 13.57 ± 0.07 days (mean ± SE) as temperature increased from 20 to 33 °C, respectively. No development was observed at 5–15 °C. Fecundity was highest at 25 and 30 °C (70–73 eggs per female) but was reduced at 33 °C (21.5 eggs per female). Oviposition rate was also reduced at 33 °C. Q. haitiensis accepted host eggs from 0 to 7 days old for oviposition but was most prolific when parasitizing 1- to 4-day-old eggs. Very few adult Q. haitiensis emerged from host eggs that were 5–7 days old, however, D. abbreviatus egg mortality was similar for eggs 0–7 days old. A brief description of the parasitoid egg, larva, prepupae, and pupa is provided.