bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenology and Parasitism of Harlequin Bugs, Murgantia histrionica (Hahn) (Hemiptera: Pentatomidae), in Southwest Virginia
Authors: Ludwig S. W. , Kok L. T.
Published: September 2017

Field plots containing broccoli, mustard, and rape were sampled weekly between June and October in 1994 and 1995 to determine parasitism and phenology of the harlequin bug, Murgantia histrionica (Hahn) (Hemiptera: Pentatomidae). Naturally-occurring wild turnips also were sampled in early spring 1995 for harlequin bugs before cultivated crops were planted. Weekly samples of harlequin bug adults, egg masses, and nymphs were field collected and returned to the laboratory. They were maintained in the laboratory until emergence to recover parasitoids and to determine the parasitization rates. No adult or nymphal parasitoids were recovered. Two species, Trissolcus murgantiae Ashmead (Hymenoptera: Scelionidae) and Ooencyrtus johnsoni Howard (Hymenoptera: Encyrtidae), were identified as egg parasitoids. The overall parasitization rates for 1994 and 1995 were 8% and 37%, respectively. Trissolcus murgantiae was more common than O. johnsoni and accounted for 87% and 96% of the parasitization, respectively. This is the first record of T. murgantiae in Virginia. The harlequin bugs had two and a partial third generation a year. Overwintered adults oviposited on wild turnips, where the first generation completed development. The subsequent generation migrated to cultivated plants in June and July. The second generation completed development on cultivated crops producing the adults which overwinter.
Thysanoptera Collected during Bloom on White and Colored Disposable Sticky Cards in Florida Citrus Groves
Authors: Childers C. C. , Nakahara S. , Beshear R. J.
Published: September 2017

During February through April between 1990 and 1993, 86 species of thrips (Thysanoptera: Terebrantia and Tubulifera) were identified from disposable colored sticky cards in navel orange groves in Polk and Osceola counties (46 species) and Hendry and Lee counties (75 species) in central and southwestern Florida, respectively. Only 33 species were collected in both central and southwestern Florida. Of the 86 species identified, 37 are phytophagous of which 12 feed on plants of the Graminae, 17 are known predators or species belonging in genera that include predators, 28 species are fungivorous or saprophytic and the feeding habits of the remaining 4 species are unknown. Frankliniella bispinosa (Morgan) (Thysanoptera: Thripidae) was the most prevalent species on sticky cards during 1990 with frequencies of 82 and 79% of slide-mounted specimens identified from the Hendry Co. sites, respectively. During 1991, F. bispinosa accounted for 91 and 96%, respectively, of the slide-mounted specimens from the Chain-O-Lakes and Raley sites in central Florida. During 1992, F. bispinosa accounted for 95% of the identified Frankliniella species from the southwest Florida site compared with 5% of F. kelliae Sakimura. During 1993, F. bispinosa accounted for 96 and 98% of the slide-mounted thrips identified from two series of experiments using different colored cards in southwest and central Florida, respectively.

During 1990 in southwest Florida, other thrips species collected from sticky cards with frequencies of 1% or more included: Arorathrips spiniceps (Hood) (3%), Microcephalothrips abdominalis (Crawford, D. L.) (1%), Adraneothrips pallidus (Watson) (1%), Gastrothrips callipus Hood (3%), Hoplandrothrips raptor (Crawford) (4%), Leptothrips cassiae Watson (1%), L. macroocellatus Watson (2%), and Neurothrips magnafemoralis (Hinds) (1%).

During 1991 in central Florida, other thrips species collected from sticky cards with frequencies of 1% or more included: A. spiniceps (2%) and M. abdominalis (1%). In 1992, thrips species collected in Hendry Co. included: A. spiniceps (2%), F. insularis (Franklin) (10%), F. kelliae Sakimura (4%), M. abdominalis (3%), and Adraneothrips pallidus (4%).
Population Dynamics of Citrus Leafminer (Lepidoptera: Gracillariidae) as Measured by Interception Traps and Egg and Larva Sampling in Lime
Authors: Peña Jorge E.
Published: September 2017

Apical leaf sampling and interception sticky traps were used to assess seasonal density for the citrus leafminer, Phyllocnistis citrella Stainton, adults and eggs plus early-instar larvae, respectively, in lime orchards. Traps intercepted greater numbers of adults when placed in the middle or top of the tree canopy than in the lower canopy. Citrus leafminer was most abundant in the spring, summer and fall, and numbers were reduced between November 1994 and January 1995. In 1994, adult capture and egg and larval density were higher than in 1995. The development of an efficient means to estimate citrus leafminer egg density or, alternatively, develop techniques to aid in prioritizing egg sampling was attempted. The probability of finding eggs in the vicinity of a passive interception trap was determined. A linear relationship was found between cumulative number of moths captured and citrus leafminer egg density (r2 = 0.52). A lower variability was recorded for adult traps than for egg densities.
Efficacy and Persistence of Beauveria bassiana and Other Fungi for Control of Diamondback Moth (Lepidoptera: Plutellidae) on Cabbage Seedlings1
Authors: Shelton A. M. , Vandenberg J. D. , Ramos M. , Wilsey W. T.
Published: September 2017

The diamondback moth, Plutella xylostella (L.), is a key pest of crucifers worldwide. Resistance by diamondback moths to chemical insecticides and Bacillus thuringiensis Berliner toxins highlights the need for alternative controls. Crucifer growers often depend on seedlings produced in screenhouses and later transplanted to the field. Commercial seedlings can be contaminated with pesticide-resistant P. xylostella, leading to control problems in the field. We evaluated the efficacy of Beauveria bassiana (Balsamo) Vuillemin applied as conidia in Mycotrol ® WP in three experiments by evaluating insect control, damage reduction, and fungus persistence on treated leaves of cabbage seedlings. In one experiment, we also evaluated Metarhizium anisopliae Metschnikoff (Sorokin) applied as conidia in Bio-blast® and Paecilomyces fumosoroseus (Wize) Brown & Smith applied as freshly-cultivated unformulated blastospores. We observed significant reductions, compared to controls, in insect populations and damage ratings when Mycotrol was applied once- or twice-weekly. Mycotrol treatments were as effective as a B. thuringiensis product in preventing damage when three spray nozzles were used to insure adequate pesticide coverage. Mycotrol persisted on treated leaves in screen-houses for more than 2 wks, and mycosis of larvae reared on these leaves was >50% 7 d after a single application of fungus. Treatment with either M. anisopliae or P. fumosoroseus resulted in no significant reduction in insect numbers or damage, but each fungus persisted on leaves and caused mycosis in lab-reared larvae more than 2 wks after treatment. Mycotrol can provide an option for control of P. xylostella larvae on seedlings, and may be especially useful in a resistance management program.
Infectivity of Steinernema carpocapsae (Rhabditida: Steinernematidae) in Sterilized and Herbicide-Treated Soil
Authors: Gibb Timothy J. , Buhler Wayne G.
Published: September 2017

The infectivity of the entomopathogenic nematode, Steinernema carpocapsae (Weiser), against larvae of the greater wax moth, Galleria mellonella (L.), was investigated in sterile, nonsterile, and glyphosate-treated soil cores from a stand of bentgrass, Agrostis palustris Hudson. Soil cores were sterilized by high-pressure steam or methyl bromide fumigation. Another set of soil cores was treated with the herbicide, glyphosate. Nematode infectivity was significantly greater in sterile soil than in nonsterile and glyphosate-treated soil on days 3 and 8 after nematode application. No significant differences were detected by day 15 after nematode treatment. Results suggest the presence of a biotic factor(s) that limits the persistence of insect control provided by entomopathogenic nematodes in bentgrass.
Evaluation of Trichogramma spp. (Hymenoptera: Trichogrammatidae) Against Two Pyralid Stemborers of Texas Sugarcane
Authors: Greenberg S. M. , Legaspi J. C. , Nordlund Donald A. , Wu Z. X. , Legaspi B. , Saldana R.
Published: September 2017

The role of Trichogramma minutum Riley (reared on Helicoverpa zea [Boddie] eggs or on an artificial diet) and T. pretiosum Riley (reared on H. zea eggs) as parasitoids of the Mexican rice borer, Eoreuma loftini (Dyar) and sugarcane borer, Diatraea saccharalis (F.), was assessed under laboratory and greenhouse conditions. The laboratory results showed that T. minutum reared on H. zea eggs parasitized 52.5% of Mexican rice borer eggs, compared to 50.3% for T. pretiosum. Parasitization of Mexican rice borer eggs by T. minutum reared on the artificial diet (62.6%) was not significantly different compared to those reared on H. zea eggs (52.5%). Trichogramma minutum reared on H. zea eggs parasitized 42.0% of sugarcane borer eggs, compared to only 12.6% by T. pretiosum. About 43.4% of sugarcane borer eggs were desiccated, despite 80 to 85% RH. Percentages of emergence (83.0%), female progeny (67.0%), deformed females (3.3%), and development time (8.2 d) in T. pretiosum reared from Mexican rice borer eggs did not differ significantly from those reared on H. zea eggs (91.3%, 72.5%, 2.5%, 8.3 d, respectively). However, T. pretiosum females reared from Mexican rice borer had greater longevity (2.5 d) and body length (0.385 mm) than females reared on H. zea (1.6 d, 0.326 mm, respectively). In the greenhouse, T. pretiosum parasitized an average of 55.3% of the Mexican rice borer eggs (egg masses were distributed on the sugarcane plants). About 21.0% of the eggs were dessicated, probably due to puncturing by the parasitoid, compared with 4.5% in the control, where egg masses were distributed on the plants without release of Trichogramma. Our results show the potential for use of Trichogramma spp. to control sugarcane stalk borers in a field IPM program.
Multiple Mating Potential in a Pteromalid Wasp Determined By Using an Insecticide Resistance Marker1
Authors: Baker J. E. , Perez-Mendoza J. , Beeman R. W.
Published: September 2017

A malathion-resistance gene was used as a marker to determine if multiple mating occurs in the haplo-diploid wasp, Anisopteromalus calandrae (Howard). Results of bioassays of F1 progeny of virgin females from a malathion-susceptible strain paired sequentially with susceptible and resistant males provided evidence that multiple mating can occur. Of 35 parent females tested in this manner, 14 produced a small number of resistant F1 female progeny. Sperm from the initial mating was precedent and fertilized about 92% of the eggs in these females. When susceptible females were paired with susceptible males and allowed to parasitize weevils for 4 d prior to re-pairing, second matings with virgin resistant males did not occur. Male A. calandrae were polygynous and could successfully inseminate 10 virgin females within a 24-h period.
Attractancy and Ovipositional Response of Adult Bemisia argentifolii (Homoptera: Aleyrodidae) to Type IV Trichome Density on Leaves of Lycopersicon hirsutum Grown in Three Day-Length Regimes
Authors: Snyder John C. , Simmons Alvin M. , Thacker Richard R.
Published: September 2017

Clonal plants of six accessions of Lycopersicon hirsutum Humb. and Bonpl., a wild relative of tomato, were grown in three day-length regimes. Clones of an accession grown in different day-length regimes were genetically identical but differed in density of type IV and type VI trichomes on their leaves. Leaves on these plants were then evaluated for resistance to whiteflies (Bemisia argentifolii Bellows and Perring) in choice and non-choice bioassays. Plants grown under short days had elevated type IV density, reduced type VI trichome density, and were less attractive to whiteflies. Correlation and covariance analysis supported the hypothesis that high type IV trichome density resulted in reduced attractancy, especially on plants grown under short days.
Efficacy of Malathion Against Coleopteran Populations in Newly-Harvested Versus Year-Old Stored Corn2
Authors: Sedlacek John D. , Barney Robert J. , Weston Paul A. , Price Bryan D.
Published: September 2017

The impact of malathion treatment and duration of storage prior to treatment on species composition and relative abundance of beetle pests was investigated in shelled corn in newly-constructed galvanized steel bins. Corn was sampled monthly for insects with plastic probe traps from January through September 1989. Red and confused flour beetles, Tribolium spp., hairy fungus beetle, Typhaea stercorea (L.), flat and rusty grain and flour mill beetles, Cryptolestes spp., and foreign grain beetle, Ahasverus advena (Waltl), were most abundant in traps, but plaster beetle, Cartodere constricta (Gyllenhal), minute brown fungus beetle, Corticaria pubescens (Gyllenhal), antlike flower beetle, Anthicus spp., and larger black flour beetle, Cynaeus angustus (LeConte), also were trapped. Greater numbers of the four major beetle species were trapped in older corn and in corn that was not treated with malathion and, depending on species, trap catch peaked in August or September. Information gathered during this investigation adds to our knowledge of insect infestation and insecticide application to on-farm stored corn and confirmed earlier reports that T. stercorea and A. advena potentially are pests of stored shelled corn. Thorough inspection and sampling should be conducted throughout the storage period, but especially after grain temperatures warm above 20°C.
Stage-Dependent Bendiocarb Tolerance in the German Cockroach (Dictyoptera: Blattellidae)
Authors: Valles Steven M.
Published: September 2017

Topical insecticide bioassays revealed that last-instar German cockroach, Blattella germanica (L.), nymphs were up to 19.8-fold more tolerant of bendiocarb than adult males. Pretreatment with the cytochrome P450 monooxygenase inhibitor, piperonyl butoxide, eliminated this difference. Acetylcholinesterase activity was equally inhibited by bendiocarb in both the last-instar nymphal and adult male stages. The bimolecular rate constant (ki) for adult males was 3.58 × 105 ± 1.0 M−1min−1, which was not statistically different from nymphs at 3.33 × 105 ± 1.1 M−1min−1. Similar ki values indicate that altered acetylcholinesterase does not contribute to the increased nymphal tolerance to bendiocarb. These results indicate that increased detoxification catalyzed by microsomal oxidases is responsible for the enhanced nymphal tolerance to bendiocarb in the Village Green strain.
Revision of a Timing Model for Chemical Control of the Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) in the Southeastern Coastal Plain
Authors: Fettig Christopher J. , Berisford C. Wayne , Dalusky Mark J.
Published: September 2017

The Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), is a common pest of Christmas tree and commercial pine plantations in the eastern United States (Yates et al. 1981). During the mid-1980's, a spray timing model for contact insecticides was developed to predict optimal spray dates for controlling R. frustrana in the southeastern Coastal Plain (Gargiullo et al. 1985). Although the model provided for generally acceptable control, analysis of the original degree-day predictions revealed that some errors occur in degree-day accumulation values used to predict insecticide spray dates. We report here the corrected values for both within-generation and cumulative year-long spray date predictions to control R. frustrana in locations where four generations occur annually in the southeastern United States. A similar model for the Piedmont region of Georgia where three generations occur annually accurately predicts spray dates in its current version (Gargiullo et al. 1983).
Treatment Thresholds for European Corn Borer (Lepidoptera: Pyralidae) Infestations in Early-Season Fresh Market Sweet Corn
Authors: Riggs Dale I. M. , Hoffmann Michael P. , Thetford Larry C.
Published: September 2017

We examined the effect of varying thresholds for treatment of first generation European corn borer, Ostrinia nubilalis (Hübner), infestations in early-season fresh market sweet corn in eastern New York over a 3-year period. Seven treatment thresholds were compared: (1) 15% infested plants at whorl stage, 5% infested plants at tassel and silk stage, (2) 15% at whorl stage, 15% at tassel and silk stage, (3) 30% at whorl stage, 5% at tassel and silk stage, (4) 30% at whorl stage, 15% at tassel and silk, (5) 5% at tassel and silk stage, (6) 15% at tassel and silk stage, and (7) control (untreated). When thresholds were reached, permethrin was applied using an air-blast sprayer. Results indicated little difference in percentage marketable ears whether plants were treated or not at whorl stage, and the tassel stage threshold could be raised to 15% infested plants with no significant effect on percentage marketable ears. We found no difference in marketable yield among plots treated from one side or both sides with an air-blast sprayer.
Insecticidal Mixture Interactions Against B-strain Sweetpotato Whitefly (Homoptera: Aleyrodidae)
Authors: Loera-Gallardo Jesus , Wolfenbarger Dan A. , Riley David G.
Published: September 2017

During 1992–1993, nine insecticides and eight mixtures of these insecticides at a 1:1 ratio were tested for their toxicity to adults of the B-strain whitefly, Bemisia tabaci (Gennadius), collected from cotton plants in a greenhouse in the Lower Rio Grande Valley of Texas. Synergistic, additive, or antagonistic properties of the mixtures were determined in a glass vial bio-assay. Endosulfan+bifenthrin was the most toxic mixture tested and was synergistic with a median lethal concentration (LC50) that was significantly less than the LC50s of either insecticide tested alone. Acephate+bifenthrin and amitraz+bifenthrin provided additive toxicity while amitraz+buprofezin and endosulfan+methyl parathion were antagonistic in their effect on adult whiteflies.
tert-Pentyl 4 (and 5)-chloro-trans-2-methylcyclohexanecarboxylate, a Highly Effective and Persistent Male Specific Attractant for the Mediterranean Fruit Fly (Diptera: Tephritidae)2
Authors: DeMilo Albert B. , Cunningham Roy T. , McGovern Terrence P.
Published: September 2017

The attraction of male Ceratitis capitata (Wiedemann) to tert-pentyl 4(and 5)-chloro-trans-2-methylcyclohexanecarboxylate (or pentamedlure) was compared to its attraction to trimedlure to establish the suitability of pentamedlure as a possible alternate for trimedlure in applications that use a cotton dental-roll wick dispenser. Results from field tests with released sterile C. capitata showed that pentamedlure, applied to cotton dental roll wicks, was not only comparable to trimedlure in attractiveness but was more persistent. Batch to batch variations in isomer distribution of pentamedlure appeared to have little effect on attraction. Dose-response data showed that pentamedlure, applied at 0.02 and 0.16 ml/wick, initially caught more flies than trimedlure at comparable doses. Moreover, initial catches for pentamedlure for most dosages tested exceeded, but not significantly, initial catches for trimedlure despite a much higher load (2 ml/wick). Trimedlure initial catches within a natural population of wild C. capitata were significantly higher than pentamedlure catches at a comparable dosage (0.2 ml lure/wick). However, pentamedlure-treated wicks were 2 to 3 times more persistent than wicks treated with trimedlure.
Survival of Different Life Stages of the Southern Chinch Bug (Hemiptera: Lygaeidae) Following Insecticidal Applications
Authors: Nagata Russell T. , Cherry Ron H.
Published: September 2017

Survival of different life stages of the southern chinch bug, Blissus insularis Barber, was measured after insecticidal applications of acephate, chlorpyrifos, and lambda-cyhalothrin. Adults and nymphs, but not eggs, were killed with all three insecticides sprayed at recommended field rates. Even when sprigs of St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kuntze, were sprayed to runoff (drench), eggs were not killed. In topical treatments, only chlorpyrifos killed eggs when the insecticides were applied directly to the eggs.
Field Evaluation of an Improved Formulation of Gypchek (a Nuclear Polyhedrosis Virus Product) Against the Gypsy Moth (Lepidoptera: Lymantriidae)
Authors: Webb R. E. , Thorpe K. W. , Podgwaite J. D. , Reardon R. C. , White G. B. , Talley S. E.
Published: September 2017

Prior to 1994, Gypchek® (USDA Forest Service, Washington, DC), the gypsy moth nuclear multicapsid polyhedrosis virus (LdMNPV), was used in operational programs against gypsy moth Lymantria dispar (L.) dispersed in a standard molasses-lignosulfonate tank mix and applied twice at the rate of 5 × 1011 polyhedral inclusion bodies (PIB) per ha per application in a volume of 19 liters per ha. In 1995, we evaluated a commercially-produced carrier and operational options that would make Gypchek application more efficient and less costly without reducing efficacy. Specifically, the standard tank mix formulation and application procedure was compared against a premixed commercial carrier, Carrier 038 (Novo Nordisk, Franklinton, NC) applied by three different application options. Option 1 consisted of double applications of Gypchek at the rate of 5 × 1011 PIB per ha per application in volumes of 9.5 liters per ha. Option 2 was identical to Option 1 except that application volume was reduced to 4.8 liters per ha. Option 3 consisted of a single application of Gypchek dispersed in 9.5 liters per ha at the rate of 1 × 1012 PIB per ha. There was also a fifth treatment consisting of unsprayed control plots. All treatments were evaluated in replicated 4-ha forest plots in southwestern Virginia. Levels of LdNPV-induced mortality, of larvae collected live 6 to 11 days after treatment, among treatments receiving a double application were not significantly different at α = 0.05 from such mortality resulting from the single application of Gypchek in Carrier 038. However, both of the double-application treatment options (but not the single application option) of Gypchek dispersed in Carrier 038 had significantly higher levels (α = 0.05) of LdMNPV than the double-application treatment of Gypchek dispersed in the standard tank mix. Defoliation was significantly different among the four Gypchek treatments, but all were significantly lower than the controls. These results indicated that all three options using Carrier 038 provided a level of efficacy equal to or better than the standard tank mix formulation applied twice at 19 liters/ha. Economic assessment indicated that the single application option was more efficient and/or less expensive than the other options.
Dogwood Borer (Lepidoptera: Sesiidae) Flight Activity and an Attempt to Control Damage in ‘Gala’ Apples Using Mating Disruption
Authors: Pfeiffer Douglas G. , Killian Joella C.
Published: September 2017

‘Gala’ apple trees had a high incidence of burr knots (adventitious root primordia) produced on the trunk. Dogwood borer, Synanthedon scitula (Harris), infested many of these growths. Mating disruption using a sex attractant for dogwood borer, (Z,Z)-3,13-ODDA, did not control dogwood borer injury. In addition to other variables inherent to mating disruption (dispenser release and application rate, pest density, environmental factors), one potential reason for the failure was an inadequate conception of the dogwood borer sex pheromone composition. Therefore, the composition of dogwood borer pheromone should be reexamined. Traps baited with lilac borer, Podosesia syringae (Harris), lures were more sensitive for capturing dogwood borer males than traps baited with lures for dogwood borer. This is difficult to explain because the lures purportedly are identical. This difference in trap response further supports the need for reexamination of the pheromone blend compositions for each species. A complex of seven sesiids was attracted to both dogwood borer and lilac borer traps; captures of all were almost entirely eliminated by permeation with (Z,Z)-3,13-ODDA. There was a bimodal pattern of adult activity, with an early peak trap capture in May–June, and a later peak in July–August. The hypothesis of apple producing a later period of dogwood borer emergence than from dogwood was supported. This will complicate control in ‘Gala’ using current borer insecticides (e.g., chlorpyrifos, endosulfan) because of the proximity of harvest in this early-maturing variety with the ovipositional period of dogwood borer.
Microplitis croceipes (Hymenoptera: Braconidae) Development in Tobacco Budworm (Lepidoptera: Noctuidae) Larvae Treated with Bacillus thuringiensis and Thiodicarb
Authors: Atwood D. W. , Kring T. J. , Young S. Y.
Published: September 2017

Bacillus thuringiensis Berliner var. kurstaki and thiodicarb were evaluated in laboratory and field assays to determine the effect on tobacco budworm larvae, Heliothis virescens (F.), and the parasitoid Microplitis croceipes Cresson. Laboratory trials were conducted using B. thuringiensis concentrations of 0, 10, 50 and 250 ppm and thiodicarb concentrations of 0, 12.5, 25, 50, 100, and 200 ppm in the diet. The test using field-treated cotton squares was conducted using B. thuringiensis and thiodicarb, independently and in combination, at rates recommended for resistance management in Arkansas. Laboratory tests indicated that tobacco budworm mortality was directly related to B. thuringiensis and thiodicarb concentrations, although B. thuringiensis only significantly increased tobacco budworm mortality at the highest concentration of exposure in the absence of parasitization. Parasitization increased host mortality at all B. thuringiensis experimental rates after 6 and 14 days. Although host mortality increased linearly with increasing thiodicarb concentration, parasitization did not significantly increase host mortality over thiodicarb alone until day 14. Emergence of M. croceipes was inversely related to B. thuringiensis and thiodicarb concentration. In assays using squares from field-sprayed cotton, thiodicarb and thiodicarb/B thuringiensis mixtures provided significantly greater tobacco budworm mortality than did B. thuringiensis application alone. In addition, no significant advantage was determined for tank mixtures with B. thuringiensis as compared to thiodicarb application alone. However, neither B. thuringiensis nor thiodicarb, alone or in combination, caused a high mortality of early third instar tobacco budworm in the absence of parasitization by M. croceipes.
Compatibility of Insect Growth Regulators and Beauveria bassiana (Balsamo) Vuillemin in Controlling Green Peach Aphid (Homoptera: Aphididae) on Greenhouse Chrysanthemums
Authors: Olson D. L. , Oetting R. D.
Published: September 2017

In laboratory and greenhouse studies, the compatibility of a spore suspension of Beauveria bassiana (Balsamo) with insect growth regulators (IGRs) was determined. When B. bassiana was applied over residues of 7 different IGRs, infectivity of greater wax moth larvae, Galleria mellonella (L), exposed to leaf rinsates was reduced by two of the IGRs. Azadirachtin and diflubenzuron reduced the infectivity of B. bassiana by up to 50%. Fenoxycarb, cyromazine, S-kinoprene, pyriproxyfen, and buprofezin did not significantly reduce the infectivity of B. bassiana. Under greenhouse conditions, the population levels of green peach aphid, Myzus persicae (Sulzer), on chrysanthemums, were not significantly different when Botanigard® (B. bassiana strain GHA) was used independently or in combination with the IGR S-kinoprene. In laboratory tests, 100% of wax moth larvae were infected with B. bassiana when they were exposed to leaf washes 24 h post Botanigard application to chrysanthemum foliage. Infectivity decreased rapidly with less than 15% of the larvae infected with B. bassiana when exposed to leaf washes 48 hr post Botanigard application to foliage.
Esterase Isozymes Associated with Bifenthrin Resistance in the Silverleaf Whitefly (Homoptera: Aleyrodidae)
Authors: Riley David G. , Tan Wei-Jia , Wolfenbarger Dan
Published: September 2017

Esterase isozymes associated with bifenthrin-resistant and susceptible strains of the silverleaf whitefly, Bemisia argentifolii (Bellows & Perring), were investigated using electrophoretic techniques. Samples of adults from the parent susceptible strain, parent resistant strain, F1 crosses, and backcrosses were homogenized in sodium phosphate buffer solutions and analysed using PhastSystem™ (IEF). The results showed that all of the test populations had four common esterase isozymes (E1–E4) in the crude homogenate of whitefly adults based on migration distances. However, significant differences occurred between the susceptible and bifenthrin-resistant strains in the quantity of the E3 isozyme, as measured by the band intensity. This result plus enzyme inhibition tests suggested that E3, a carboxylesterase with pi 5.04, was associated with detoxification of bifenthrin. Changes in quantity of the E3 esterase isozyme, measured with image analysis, was correlated with resistance (higher lethal concentrations) to bifenthrin. The E4 isozyme of all strains tested was inhibited by 1 μM eserine, but sensitivity to eserine was not detected in E2 and E3.
Diapause Induction in a Kentucky Population of Diprion similis (Hymenoptera: Diprionidae)
Authors: Melcher Heidi L. , Townsend Lee H.
Published: September 2017

Critical photoperiod, sensitive stage for diapause induction, and requirements for termination of diapause were studied in a colony of the introduced pine sawfly, Diprion similis (Hartig), established from a feral Kentucky population. We investigated induction of diapause in the laboratory under photoperiods of 10:14, 11:13, 12:12, 13:11, 14:10, 15:9, and 16:8 (L:D) in the first trial, and added a photoperiod of 9:15 (L:D) in the second trial. Individuals exposed to light periods ≤12:12 (L:D) entered diapause; individuals in a photoperiod > 13:11 (L:D) bypassed diapause. The sensitive stage was determined using reciprocal switches of diapause-inducing (9:15) and non-diapause inducing (16:8) L:D regimes. Our studies indicated that late instars of the introduced pine sawfly are significantly sensitive to photoperiod. Termination of diapause in D. similis did not require a cold or chilling period. All individuals from critical photoperiod trials were kept at 22°C to determine the duration of diapause. Diapausing individuals emerged from the cocoon after 82 to 105 d, compared to 6 to 23 d for individuals not entering diapause.
Development of Oebalus ornatus (Sailer) and Oebalus insularis (Stal) (Hemiptera: Pentatomidae) on Rice
Authors: Pantoja Alberto , Daza Eugenia , Mejfa Olga I. , Garcia Cesar A. , Duque Miriam C. , Escalona Luis E.
Published: September 2017

The development and reproduction of Oebalus insularis (Stal) and O. ornatus (Sailer) were studied on rice. Both females and males of O. insularis took longer to complete development than O. ornatus. Both species complete development in five instars. No significant differences in the number of days to lay eggs, the days ovipositing, and the number of eggs were detected between species.
Comparison of Bt (Bacillus thuringiensis Berliner) Maize and Conventional Measures for Control of the European Corn Borer (Lepidoptera: Crambidae)
Authors: Clark Thomas L. , Foster J. E. , Kamble Shripat T. , Heinrichs E. A.
Published: September 2017

Field experiments were conducted in 1997 to compare the efficacy Bt (Bacillus thuringiensis Berliner) maize hybrids and two conventional measures for control of the European corn borer, Ostrinia nubilalis (Hübner). Treatments consisted of transgenic Bt maize hybrids and their non-Bt isolines, and isolines treated with a formulated Bt or permethrin insecticide. All control measures significantly reduced O. nubilalis damage in terms of tunnels per plant, length of tunneling, and larvae per plant. The following hierarchy in terms of O. nubilalis efficacy was observed: transgenic Bt > permethrin > formulated Bt > control. In most cases, transgenic Bt maize was most effective in preventing European corn borer damage to ear shanks and generally produced the highest grain yields.
Effect of Noctuidonema guyanense (Nematoda: Acugutturidae) on the Longevity of Feral Male Spodoptera frugiperda (Lepidoptera: Noctuidae) Moths2
Authors: Marti O. G. , Rogers C. E.
Published: September 2017

Noctuidonema guyanense Remillet and Silvain is an ectoparasitic nematode of certain species of adult Lepidoptera, particularly Noctuidae, in the Western Hemisphere. It is transferred to a new host when the insects mate. Survival of infested and uninfested feral adult males of Spodoptera frugiperda (J. E. Smith), the fall armyworm, was compared at three different temperature regimens (20°C, 30°C, and 30/20°C) at 14:10 L/D at 80% RH. Apparent age differences were controlled by pairing moths having the same amount of scale loss. Overall mean nematode infestations of 239.3 and 0 in infested and uninfested groups produced significantly different mean longevity of 3.7 and 6.2 days, respectively. At 20°C, survival of both groups increased to 6.2 and 13.3 days, but remained significantly different. The results demonstrate a deleterious effect of Noctuidonema infestation on longevity of feral adult male S. frugiperda.
Comparative Feeding by Three Chrysomelid (Coleoptera: Chrysomelidae) Species on Eight Soybean Genotypes
Authors: Baur M. E. , Hattier L. M. , Boethel D. J.
Published: September 2017

The feeding rates on soybean, Glycine max (L.) Merr., by three beetle species, Cerotoma trifurcata (Forster), Diabrotica balteata LeConte, and Colaspis louisianae Blake, were compared in bioassays in the laboratory. Eight soybean genotypes, including two resistant standards (PI171451 and PI229358), a resistant line (D89-9121), four resistant commercial cultivars (Lamar, Lyon, Crockett, and Shore), and a susceptible standard (Centennial) were planted on the research farm at St. Gabriel, LA. Beetles were collected from the field throughout central and south Louisiana, separated by gender, and placed in Petri dishes with leaflets of known leaf area. Feeding, mortality, and oviposition were monitored daily for 5 d. Per capita daily consumption by C. louisianae and D. balteata averaged between 3.5 and 2.5 mg dry weight, and C. trifurcata consumed 7.6 mg dry weight. Beetles of all species consumed more Centennial foliage than foliage from PI229358, PI171451, Lyon, and Shore. Consumption of other soybean genotypes varied among beetle species. Number of eggs deposited by C. trifurcata and C. louisianae did not vary significantly among soybean genotypes. Diabrotica balteata females were not observed ovipositing on leaves of any cultivar. Mortality varied significantly among beetle species, but not among soybean genotypes. Diabrotica balteata suffered the highest mortality and C. trifurcata the lowest. The results suggest cultivars resistant to C. trifurcata and D. balteata should also be effective against C. louisianae.
Insect Distribution in a Spring Pea-Winter Wheat-Spring Barley Crop Rotation System
Authors: Quisenberry S. S. , Schotzko D. J. , Lamb P. F. , Young F. L.
Published: September 2017

The effects of tillage method (conventional or conservative) and weed management level (recommended or minimum) on insect distribution in a wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and pea (Pisum sativum L.) rotation were studied. Aphids were the major insect species on winter wheat and spring barley, but were not of economic importance. Beneficial species impacted aphid population levels by maintaining their numbers below economic thresholds. Tillage method and weed management level had limited impact on aphid and beneficial insect populations. Pea leaf weevil (Sitonia lineatus [L.]) and pea weevil (Bruchus pisorum [L.]) populations reached economic injury levels in 1992; two insecticide applications were needed. Pea leaf weevil populations did not reach economic levels in 1993; however, pea weevil populations reached an economic level at flowering stage and an insecticide was applied. Pea leaf weevil populations were higher in conventional tillage plots compared with conservation tillage plots. Early-season insecticide applications suppressed beneficial insects in the pea plots.
Development of Spodoptera exigua and Helicoverpa zea (Lepidoptera: Noctuidae) on Transgenic Cotton Containing CrylAc Insecticidal Protein
Authors: Ashfaq Muhammad , Young S. Y. , McNew R. W.
Published: September 2017

The effects of transgenic Bacillus thuringiensis (Bt)-cotton on three instars of Spodoptera exigua (Hübner) and Helicoverpa zea (Boddie) were studied. First, third and fifth instars were fed field-collected Bt-cotton leaves for 1, 2, 3, 4 and 7 d or until pupation, and then transferred to artificial diet. Larval mortality at pupation, length of larval and pupal periods, pupal weights and survival time from hatch to adult were recorded for regular and Bt-cotton. Larval mortality at pupation in S. exigua fed Bt-cotton was low for all instars exposed and feeding periods on Bt-cotton. The mortality in H. zea was high for first and third instars and significantly increased with the increase in feeding period on Bt-cotton (P < 0.05). The length of larval period increased in both species when first and third instars but not fifth instars were fed Bt-cotton. In H. zea, the larval period increased when larvae were on Bt-cotton leaves for only 2 d. Pupal weight was reduced with an increase in feeding time on Bt-cotton in all three instars in both species. An increase in length of feeding time on Bt-cotton reduced survival to adults in both species on Bt-cotton in first and third instars but not in fifth instars. Survival to adults was much lower in H. zea than S. exigua for all instars exposed and feeding periods on Bt-cotton. These results demonstrate the large differences in effectiveness of Bt-cotton against lepidopteran cotton pests, as well as the adverse effects on larvae developing on Bt-cotton.
Managing Colorado Potato Beetles (Coleoptera: Chrysomelidae) and European Corn Borers (Lepidoptera: Pyralidae) in Potato with Foliar Applications of Bacillus thuringiensis Berliner
Authors: Nault Brian A. , Speese John
Published: September 2017

Application timing and rate combinations of Bacillus thuringiensis Berliner used for protecting Irish potato, Solanum tuberosum L., from defoliation by the Colorado potato beetle, Leptinotarsa decemlineata (Say), and stem injury by the European corn borer, Ostrinia nubilalis (Hübner), were investigated. Significant reductions in defoliation levels during bloom, populations of first-generation potato beetle adults, and the percentage of stems injured by corn borers at the end of the season in B. thuringiensis-treated potato were considered criteria for a successful management strategy. Although Colorado potato beetle infestations were managed effectively with B. thuringiensis, European corn borer populations were not reduced to a commercially acceptable level. In each of 3 yrs, neither an increase in the number of applications (from 1 to 4) nor an increase in rate (from 0.9 to 3.8 liters/ha) of B. thuringiensis subsp. kurstaki improved the level of corn borer control. In contrast, results indicated that 1 application of B. thuringiensis subsp. tenebrionis, timed when there was >1 large potato beetle larva per stem, using a 4.7 liters/ha rate protected the potato crop during the bloom stage. However, this strategy may not be sufficient to prevent significant levels of defoliation by first-generation potato beetle adults during post-bloom or reduce the size of this population, which will infest next season's crop. For this reason, the B. thuringiensis subsp. tenebrionis timing and rate regimen described above may be most effective in fields where the overwintering potato beetle population is predicted to be low to moderate (e.g., <1 adult per 5 stems), whereas two applications may be most effective in fields where densities are greater.
Bean Leaf Beetle (Coleoptera: Chrysomelidae) Abundance in Soybean Fields Protected and Unprotected by Shelterbelts
Authors: Danielson S. D. , Brandle J. R. , Hodges L. , Srinivas P.
Published: September 2017

The bean leaf beetle, Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), is a major insect pest of soybean in Nebraska and throughout much of the Midwest. This insect overwinters in the adult stage in litter in wooded areas such as shelterbelts. Historically, crop producers have been unsure of the merits of shelterbelts, especially if nearby crops are more likely to be infested by insect pests as a result. In this study, bean leaf beetle adults were sampled during the season by visually counting the number of beetles found on soybean plants early in the season and by sweep net sampling once plants were at the V4 stage (approximately 0.33 m tall). Sampling was done in 1997 and 1998 at the University of Nebraska Agricultural Research and Development Center in Saunders Co. in east-central Nebraska. Beetle counts were compared between shelterbelt-protected and -unprotected fields. In general, bean leaf beetles were more numerous in 1997 than in 1998, with abundance peaks occurring in late-July and early-September in both years. There were significant differences in bean leaf beetle counts from protected and unprotected fields on only three of the 11 and four of the 13 sampling dates in 1997 and 1998, respectively. On the sampling dates when significant differences were found, two of three in 1997 and three of four in 1998 had higher bean leaf beetle abundance in the protected soybean fields. The results of this study indicate a tendency for more bean leaf beetles in shelterbelt-protected soybean fields when differences are found, but beetle numbers were not significantly different between protected and unprotected fields on the majority of sample dates in the two years of this study. This study also reconfirms the presence of two generations of the bean leaf beetle in Nebraska.
Effect of Low Temperature Exposure on the Supercooling Point of Oriental Cockroach (Dictyoptera: Blattidae)
Authors: Park No-Joong , Kamble Shripat T.
Published: September 2017

A system constructed with thermocouples and a conventional refrigerating bath was used to measure the freezing and melting points of various developmental stages of oriental cockroach, Blatta orientalis L., after exposure to different pre-freezing temperature conditions. Low temperature exposure of the oriental cockroach was not consistently effective in enhancing the supercooling capacity at various stages. There were minimal differences among the various developmental stages, and freezing points ranged −6.85 to −11.18°C. A significant lowering of freezing point (P< 0.05) was observed only from the first and second nymphal stages; freezing points were below −11°C after exposure at 5°C after 2 wks at 10°C. The melting points were consistently around 0°C (range of −0.19 to 0.31 °C). The relatively limited supercooling capacity of oriental cockroaches suggest that freezing avoidance by microhabitat selection is a major mechanism for overwintering of this insect.
Host Plant Quality and Male Wheat Stem Sawfly (Hymenoptera: Cephidae) Fitness
Authors: Morrill Wendell L. , Weaver David K.
Published: September 2017

The size of male Cephus cinctus Norton (Hymenoptera: Cephidae) adults did not significantly increase with the size of host stems in which larvae developed. Larger adult male sawflies had higher longevity. There was no statistically significant relationship between wing length and the emergence date, mating success, or dispersal from overwintering sites. The relation of host plant quality and sawfly fitness was less apparent for male adults than that which we previously reported for females.
Population Cycles of the Larkspur Mirid (Heteroptera: Miridae)
Authors: Ralphs Michael H. , Jones Walker A.
Published: September 2017

The larkspur mirid, Hoplomachus affiguratus Uhler, has been proposed as a biological control agent to damage tall larkspur, Delphinium barbeyi (L.) Huth, to prevent cattle from grazing it and becoming poisoned. The objective of this study was to monitor mirid populations and feeding damage to larkspur over time and determine if its population cycles are related to specific weather patterns. Individual larkspur plants were marked and the extent of damage estimated at 5 locations on 3 National Forests in Utah and Colorado. In years when mirid populations were high, damage to larkspur leaves ranged from 50 to 100% and greater than 75% of flowering heads aborted. In years and locations when its population was down, damage was minimal. The amount of larkspur damage was negatively correlated with the previous year's total precipitation and the previous September precipitation (r = −0.68 to −83) and was positively correlated with July and August temperature the previous year (r = 0.61 to 0.75). When mirid populations are high, damage levels appear to be sufficient to deter cattle grazing, but low levels of damage at the bottom of the cycle will likely not deter grazing.
Comparison of Functional Response and Mutual Interference Between Two Aphelinid Parasitoids of Bemisia argentifolii (Homoptera: Aleyrodidae)
Authors: Greenberg Shoil M. , Legaspi Benjamin C. , Jones Walker A.
Published: September 2017

Functional responses and mutual interference were compared in an indigenous parasitoid, Encarsia pergandiella Howard (Hymenoptera: Aphelinidae), with that of an exotic parasitoid, Eretmocerus mundus Mercet (Aphelinidae) from Spain, attacking the silverleaf whitefly, Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae). Type II functional response curves were fitted to the data and were used to calculate handling time. Eretmocerus mundus attacked more whitefly nymphs than E. pergandiella. Handling times estimated from the functional responses were 72 min for E. pergandiella and 12 min for E. mundus, suggesting that lower attack rates for the former parasitoid may be attributed to longer handling times. The statistically estimated handling time for E. mundus was compared with an estimate derived from empirical observations of parasitoid behavior. Actual observations of handling time, defined as oviposition, host feeding and associated preening, yielded a mean handling time of <2 min, suggesting that functional response experiments may not produce reliable estimates of handling time. The mutual interference coefficient m of E. mundus was numerically higher than that for E. pergandiella (0.238 vs 0.184, respectively). Although there were no significant differences in m, the comparison raises the interesting question of whether parasitoids with higher attack rates may also have higher levels of mutual interference under conditions of high parasitoid density (e.g., mass rearing).
Insect Resistance in Vegetable and Tofu Soybeans1
Authors: Kraemer Mark E.
Published: September 2017

Ten tofu and 14 green-vegetable soybean, Glycine max (L.) Merrill, genotypes were evaluated over 3 yrs for resistance to defoliation by the corn earworm, Helicoverpa zea (Boddie), and seed damage by a hemipteran complex. Petri-dish assays were used to determine foliar antibiosis to corn earworm. Larvae were weighed after feeding for 10 d on excised soybean leaves. Hemipteran damage was determined at harvest by individually rating 300 randomly sampled seeds from each subplot for severity of damage and calculating a weighted damage index. The specialty soybeans most resistant to corn earworm defoliation were Tousan 122, Guanyun da hei dun, and Enrei; whereas, those with the least seed damage were Barc-8 and Houjaku. There was no significant (F = 1.193; df = 1,300; P < 0.276) correlation of larval weight with seed damage index. It is likely that different mechanisms are responsible for seed and foliage resistance. There was a small but significant correlation (F = 40; df = 1,300); P < 0.001, R2 = 0.12) of seed damage index with maturity group that may be related to the phenology of soybean seed development and insect populations.