bluuebunny/crossref_metadata_2025 huggingface dataset:
Host Age Effects on Ovipositional and Developmental Biology of Baryscapus chrysopae (Hymenoptera: Eulophidae), a Parasitoid of Chrysopid Larvae
Authors: Ruberson John R. , Kring Timothy J.
Published: September 2017

The parasitoid, Baryscapus (=Tetrastichus) chrysopae (Crawford), is a widely-distributed gregarious parasitoid of chrysopid larvae. The ovipositional and developmental biology of this parasitoid in relation to the stage of its host, Chrysoperla rufilabris (Burmeister), was examined. Female B. chrysopae attacked all larval stages of the host tested (instars 1 to 3), and paralyzed all hosts soon after mounting and stinging. During the host's paralysis, females oviposited in and fed on hosts. The time females spent on hosts was directly related to host stage. All hosts recovered from paralysis. Parasitoid developmental time was inversely related to host stage and ranged from 27.5 d in 1-d-old hosts to 20.5 d in 10-d-old hosts. Most development of parasitoid larvae appears to occur after the host has spun its pupal cocoon. The number of parasitoids produced per host was unrelated to host stage, ranging from 10.5 (in 1-d-old hosts) to 14.2 (in 7-d-old hosts) parasitoids per host. The sex ratio was skewed toward females (81.6% pooled across host stages) and was unrelated to host stage. The developmental biology of B. chrysopae appears to be well synchronized with that of its host.
Feeding Preference by Stink Bugs (Heteroptera: Pentatomidae) for Seeds Within Soybean Pods
Authors: Panizzi Antônio R. , Niva Cintia C. , Hirose Edson
Published: September 2017

Studies were conducted in the laboratory and in growth chambers to determine if the location of particular seeds within soybean pods were preferred by adult Nezara viridula (L.), Euschistus heros (F.), and Piezodorus guildinii (Westwood) (Heteroptera: Pentatomidae). Results demonstrated that feeding frequency, as indicated by the number of punctures (i.e., stylet sheaths), was significantly greater (P < 0.05) on the proximal seed, than on other seeds, both for detached pods and pods on plants. In general, the number of punctures on the proximal seed was 2–3X greater than punctures observed in the medial or distal region. Of the three species studied, N. viridula showed the greatest feeding activity and P. guildinii the least. No significant differences in feeding activity between sexes were observed. N. viridula fed more frequently at 22 than at 29°C, while no significant temperature effect was observed for E. heros.
Degradation and Efficacy of Deltamethrin + Chlorpyrifosmethyl and Cyfluthrin + Chlorpyrifos-methyl as Protectants of Wheat Stored in Southeast Georgia1
Authors: Arthur Frank H.
Published: September 2017

Soft red winter wheat (27.27 kg replicates) treated with combinations of deltamethrin + chlorpyrifos-methyl, with and without piperonyl butoxide, and cyfluthrin, applied alone or with either chlorpyrifos-methyl or piperonyl butoxide, was stored from 15 May 1992 to 9 February 1993 (6 chemical treatments and an untreated control). Each replicate was artificially infested with 50 adult lesser grain borers, Rhyzopertha dominica (Fab.), and 50 adult rice weevils, Sitophilus oryzae (L.), upon initial storage, sampled with probe traps at monthly intervals, and subsequently reinfested. Trap catch of lesser grain borer was always 0, except for two traps at month 4 that contained one adult in each trap. Maximum population levels of rice weevil and a natural infestation of the red flour beetle, Tribolium castaneum (Herbst), occurred at month 5. Trap catch of these two species in the chemical treatments averaged 2.2 to 34.0 and 0.0 to 19.5 live adults per trap, respectively. From months 4 to 9, the percentage of insect-damaged kernels averaged 4.0 to 5.5% in wheat treated with 0.25 ppm deltamethrin + 6.0 ppm chlorpyrifos-methyl + 4.0 ppm piperonyl butoxide. Maximum kernel damage in the other chemical treatments was 3.2%.
Nuclear Polyhedrosis Virus of the Gypsy Moth (Lepidoptera: Lymantriidae): Potency and Effects of Selected Adjuvants on Insect Feeding Behavior2
Authors: Farrar Robert R. , Ridgway Richard L. , Cook Stephen P. , Thorpe Kevin W. , Webb Ralph E.
Published: September 2017

The potency of two formulations of the nuclear polyhedrosis virus of the gypsy moth (LdMNPV) was evaluated in the laboratory. Both formulations were prepared with the same batch of LdMNPV produced in live insects by the USDA Forest Service. A Forest Service-recommended tank-mix preparation (LdMNPV, molasses, ultraviolet light screen, and sticker in water) was found to be about 20 times more potent than an experimental wettable powder preparation. The wettable powder also deterred feeding; the 20-fold difference in potency, though, is based on actual doses consumed. The addition of a stilbenedisulfonic acid derivative, Blankophor BBH, to the tank-mix and wettable powder preparations at a concentration of 1% (wt./vol.) reduced the LD50s by 42- and 214-fold, respectively. Blankophor BBH was also a moderate feeding deterrent to gypsy moth, Lymantria dispar (L.), larvae which could limit its efficacy as an enhancer of the virus. However, the addition of molasses to Blankophor BBH at least partially overcame the feeding deterrence. Other adjuvants were also tested for effects on larval feeding behavior, including Bond (sticker), Lignosite AN (ultraviolet light screen), and Carrier 244 (spray carrier). Of the materials tested, molasses was the strongest feeding stimulant, followed by Carrier 244. Bond and Lignosite AN had no detectable effect on feeding behavior in these tests. These data demonstrate the importance of monitoring potency during any formulation process, the possibility of enhancing the virus with adjuvants, and of understanding the effects of adjuvants on feeding behavior.
Relative Abundance of Stink bugs (Hemiptera: Pentatomidae) in Southwestern Colombia Rice Fields
Authors: Pantoja Alberto , Daza Eugenia , Garcia César , Mejía Olga I. , Rider Dave A.
Published: September 2017

Relative abundance of stink bugs was determined from 01 May 1989 to 30 September 1992 in 80 commercial rice fields in Colombia and in 12 selected rice-producing countries of Latin America. Fifteen stink bug species from nine genera were found in Colombia. The species are Oebalus ornatus (Sailer), Mormidea maculata Dallas, Tribraca obscurata Bergroth, M. pictiventris Stål, O. pugnax torridus (Sailer), Proxys punctulatus (Palisot de Beauvois), O. insularis (Stål), T. limbativentris Stål, and O. ypsilongriseus (De Greer). In Valle del Cauca Department in southwestern Colombia, the most abundant species was O. ornatus representing 94.1% of the stink bugs collected. Seven species comprised the remaining 5.9%. Oebalus ornatus and O. ypsilongriseus were recovered from seven Latin America countries and had the widest geographical range of the stink bugs species collected during the study.
Effects of Dormancy and Photoperiod on Alfalfa Weevil (Coleoptera: Curculionidae) Reproductive Diapause
Authors: Elden T. C.
Published: September 2017

Alfalfa weevil, Hypera postica (Gyllenhal), adults reared as larvae in the laboratory under an 8-h photophase were subjected to three storage conditions and two photoperiods to determine their effects on female reproductive diapause and fecundity. Contrary to previous reports, weevils reared in the laboratory as larvae and adults under a short-day photoperiod remained in a partial reproductive diapause. Newly-emerged weevil adults subjected to a 5-wk dormant period followed by an 8-h photophase had a rate of oviposition nearly twice that of adults reared under an 8-h photophase without a dormant period. Adults reared under a 15-h photophase after the dormant period also remained in a partial reproductive diapause. Results demonstrate that alfalfa weevil reproductive diapause is influenced by dormancy (an inactive state) and photoperiod. This is the first report of an efficient method to break reproductive diapause in the alfalfa weevil which will enable continuous production of nondiapausing laboratory-reared weevils for research and mass production of predators and parasites for biological control.
Effectiveness of Spot Insecticide Treatments for Red Imported Fire Ant (Hymenoptera: Formicidae) Control2
Authors: Collins Homer L. , Callcott Anne-Marie A.
Published: September 2017

Spot treatments with Dursban 2EC, Optem PT-600, Bengal Fire Ant Killer, and Orthene 75S were evaluated for control of imported fire ant, Solenopsis invicta Buren, colonies. Because imported fire ant colonies frequently relocate their nest following insecticide applications, a field trial utilizing an experimental design which compensated for colony relocation was conducted. Results of this trial showed that, in addition to frequent colony relocation, large numbers of individual ants succumbed to several of the insecticides under trial. However, many ant colonies survived some treatments, and actual colony mortality ranged from 11.1% with Orthene 75S to 80.4% with Dursban 2EC 8 wks after treatment.
Overwintering and Cold Tolerance of Bemisia argentifolii (Homoptera: Aleyrodidae) in Coastal South Carolina
Authors: Simmons Alvin M. , Elsey Kent D.
Published: September 2017

Populations of Bemisia argentifolii Bellows and Perring in the Charleston, SC area declined sharply during December and remained low through March and April in a two-year study (1991–92). Populations of this whitefly increased slowly during spring with highest populations on collard (Brassica) and potato. Infestations of B. argentifolii were present in 13 of 14 greenhouses at 10 commercial nurseries that were monitored. Eggs were more cold-tolerant than adults and nymphs, respectively, at temperatures of −2°, − 6°, and −10°C.
Factors Affecting the Distribution of Bot Flies (Diptera: Oestridae) on Islands in Lake Barkley Kentucky and Tennessee
Authors: Kollars Thomas M.
Published: September 2017

The present study analyzes the effect of six abiotic and eight biotic variables on the presence of Cuterebra on islands in Lake Barkley in Kentucky and Tennessee. Abiotic factors were: area, length, distance to mainland, distance to nearest island, elevation, and last inundation. Biotic factors were: tree species diversity (sd), shrub sd, vine sd, and herbaceous sd, percent herbaceous cover, percent tree cover, mammal species, and small mammal sd. A Cuterebra, presumably C. fontinella fontinella (Clark), infested white-footed mice on two islands and house mice on one island. Six other small mammal species were not infested. There was no significant difference between prevalence and sex of host. No correlation between the presence of Cuterebra and biotic or abiotic factors was found (P > 0.05). The presence of house mice did not determine the presence of Cuterebra on islands. Factors associated with island biogeography did not appear to play a role in determining the presence of Cuterebra. Only the presence of white-footed mice was related functionally to the presence of Cuterebra on islands (R2 = 0.85; P < 0.05). Although other small mammals may be found on islands, the occurrence and prevalence of C. fontinella on islands was primarily limited by the presence of white-footed mice regardless of other abiotic or biotic factors.
Pyramidal Traps for Monitoring the Presence of Pecan Weevil (Coleoptera: Curculionidae)
Authors: Tedders W. L. , Wood B. W.
Published: September 2017

Pyramidal traps constructed of masonite and painted to reflect light levels ranging from 1 to 84% reflectance (black, shades of gray and white) were evaluated for attractiveness to adult pecan weevils, Curculio caryae (Horn). Black (1% reflectance) and dark gray (5% reflectance) were found to be more attractive to weevils than traps having greater reflectance (lighter grays and white). Dark gray traps captured almost 9 fold more weevils than did standard cone emergence traps. Dark gray traps also captured weevils in orchards after the emergence period as indicated by screen cone traps. Trap distances of 1.9 and 4.6 m from tree trunks did not influence trap effectiveness. Trap density of 4/tree did not provide an economic level of weevil control as measured by number of infested nuts per tree. Traps positioned on the eastern side of trees caught more weevils (α ≤ 0.05) than traps on the northern side, but captures were not significantly different from those positioned at the southern and western sides of trees.
Extended Development in Thanasimus dubius (F.) (Coleoptera: Cleridae), a Predator of the Southern Pine Beetle
Authors: Reeve John D. , Simpson John A. , Fryar Jonny S.
Published: September 2017

Thanasimus dubius (F.) is an important predator of the southern pine beetle, Dendroctonus frontalis Zimmermann, a major pest of pine forests in the southern United States. We examined the development of T. dubius in the field using emergence traps, and by sampling the bark of trees previously attacked by D. frontalis. Over a 2-year period, several distinct episodes of T. dubius emergence occurred in trees enclosed by emergence traps, and bark sampling of other trees uncovered many T. dubius immatures almost 2 years after attack by D. frontalis. These results indicate that T. dubius development may be significantly longer and more variable under natural conditions than previously thought, and suggest that some individuals may undergo a diapause.
Symbiotic Fungus and Enzymatic Digestion in the Gut of the Termite, Macrotermes barneyi (Light) (Isoptera: Termitidae)
Authors: Crosland M. W. J. , Chan L. K. , Buswell J. A.
Published: September 2017

Gut polysaccharidase activity was examined in the fungus-growing termite, Macrotermes barneyi (Light). Rates of enzymatic digestion of 7 polysaccharides and 5 synthetic heterosides were compared among major and minor worker midguts and hindguts and mycotêtes of the Termitomyces fungus. Major workers showed substantially more hindgut polysaccharidase activity than minor workers, though for both worker types midgut activity was substantially higher than in the hindgut. For 10 out of the 12 enzymes tested (including cellulases), activities were significantly higher in the midguts of major workers than in the fungus mycotêtes. Acquired polysaccharidases from the mycotêtes have been suggested to play a role in digestion in the termite midgut in some other Macrotermes species. However, in M. barneyi, our results indicate that for 11 of the 12 enzymes we tested acquired fungal polysaccharidases are probably of relatively little importance.
Observations on the Life History of Onthophagous depressus (Coleoptera: Scarabaeidae)
Authors: Hunter J. S. , Fincher G. T. , Sheppard D. C.
Published: September 2017

Adult Onthophagus depressus Harold constructed brood cells of cattle dung 15 to 30 cm below the soil surface. These brood cells averaged 23.1 mm long and 16.1 mm wide. Adult females deposited a single egg in the egg chamber of each brood cell. Eggs were 2.3 to 2.5 mm long and 1.1 to 1.4 mm wide. Embryonic development required 2.5 to 4.3 d; larval development (three instars) 27 d, and pupal development about 12 d. Development from egg to adult averaged 46.3 d at 25–27°C. Adult beetles were captured in all months except February with peak flight activity between 2000 and 2100 h (EST). Overwintering occurred in the adult and/or pupal stage in southern Georgia.
Effect of Amitraz on Colorado Potato Beetle (Coleoptera: Chrysomelidae) Feeding, Development and Survival
Authors: Longtine Craig A. , Zehnder Geoff W. , Radcliffe Edward B.
Published: September 2017

Effects of amitraz, a formamidine insecticide, were studied in Colorado potato beetle, Leptinotarsa decemlineata (Say), populations from Minnesota, North Dakota and Virginia. Contact exposure or ingestion of leaves dipped in 4000 ppm amitraz was not lethal to adults. However, adult feeding was reduced 50% upon exposure to 90 ppm amitraz, a rate <1/8 that recommended by the manufacturer for testing as a foliar insecticide. Ingestion of foliage treated with 945 ppm amitraz by early instar larvae had long-term effects on Colorado potato beetle development and survival, delaying adult emergence 4.7 days and causing 87% mortality. In 72 h bioassays, LC50s by contact exposure or ingestion were > 3.2× the suggested field rate. LC50s determined by exposure of larvae to treated foliage were greater than LC50s determined by immersing larvae. Egg hatch was not reduced by application of ≤ 1840 ppm amitraz. In field trials, amitraz reduced defoliation as effectively as esfenvalerate, the insecticide of choice when these trials were conducted. Amitraz-treated plots had yields intermediate between esfenvalerate and control treatments.
Oral Toxicity of a Boric Acid - Sucrose Water Bait to Florida Carpenter Ants (Hymenoptera: Formicidae)
Authors: Klotz John H. , Moss James I.
Published: September 2017

The oral toxicity of boric acid to the Florida carpenter ant, Camponotus abdominalis floridanus (Buckley), was evaluated in laboratory tests. The ants were provided a sucrose water-based bait containing various concentrations of boric acid. Over the dosage range from 0.02 M (0.13% w/v) to 0.50 M (3.13% w/v) boric acid, median lethal times (LT50s) (95% CL) ranged from 9.7 (8.1–13.3) days to 1.5 (1.2–1.7) days. Over the same dosage range (0.02 M to 0.50 M), LT90s (95% CL) ranged from 27.1 (18.0–59.5) days to 4.2 (3.6–5.1) days. Some of the advantages of using boric acid as a bait toxicant for ants include its delayed activity and its solubility in water.
Comparison of Ceralure and Trimedlure Attractants for the Male Mediterranean Fruit Fly (Diptera: Tephritidae)2
Authors: Leonhardt B. A. , Cunningham R. T. , Avery J. W. , DeMilo A. B. , Warthen J. D.
Published: September 2017

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is a major pest of fruits and vegetables in the world but, through an extensive trapping program, the continental United States has remained free of established populations. These traps are baited with 2 g of trimedlure which is highly attractive to the male flies. This study contrasts the effectiveness of trimedlure and a new attractant, ceralure, which is an iodo-analog of trimedlure. Field tests in Hawaii using released sterile flies showed that the most attractive B1 isomer of ceralure caught 2 to 3 times as many male flies per mg as did the most attractive C isomer of trimedlure.
Consumption of Eggplant Foliage by Colorado Potato Beetle (Coleoptera: Chrysomelidae)
Authors: Arpaia Salvatore , Lashomb James , Hamilton George C. , Vail Karen
Published: September 2017

Feeding of second- to fourth-instar Colorado potato beetle, Leptinotarsa decemlineata Say, on eggplant was monitored at constant temperatures of 20, 26, 29, 32 and 35° C, and at 16, 20, 27, 29, and 33° C for adults to determine the effects of temperature on consumption. For comparison, consumption by each stage relative to fourth instars was standardized to feeding equivalants. A significant non-linear relationship was found between temperature and consumption for each life stage tested. Placement of each life stage on an equivalent feeding basis showed second instars consume on average 21.5% as much foliage as fourth instars, third instars 51.2% the amount of fourth instars, and adults 39.0% the level of fourth instars. These feeding equivalents can be used to develop field sampling plans and toxicant bioassays.
Impacts of Red Imported Fire Ants (Hymenoptera: Formicidae) on Striped Pine Scale (Homoptera: Coccidae) Populations
Authors: Clarke Stephen R. , DeBarr Gary L.
Published: September 2017

Loblolly pines, Pinus taeda L., were banded in three seed orchards in Georgia to prevent the red imported fire ant, Solenopsis invicta (Buren), from tending infestations of striped pine scales, Toumeyella pini (King). Ant activity had no effect on female scale insect survival as numbers per shoot were never significantly different between check and banded trees in any of the orchards. Parasitism of females rarely differed between treatments, with higher rates twice in one orchard on unbanded trees and once in another orchard on banded trees. There also appeared to be no treatment effects on predator numbers. Coincident populations of the mealybug Oracella acuta (Lobdell) and the woolly pine scale, Pseudophilippia quaintancii Cockerell, on the shoots also were unaffected by the presence of fire ants.
Evaluation of an Entomopathogenic Nematode and Chemical Insecticides for Control of Metamasius hemipterus sericeus (Coleoptera: Curculionidae)2
Authors: Giblin-Davis R. M. , Peña J. E. , Duncan R. E.
Published: September 2017

Several chemical insecticides and the entomopathogenic nematode, Steinernema carpocapsae (Weiser) (All strain), were evaluated for efficacy against the West Indian sugarcane weevil, Metamasius hemipterus sericeus (Olivier), in laboratory and field tests. Three different bioassays and a field study with sugarcane demonstrated that S. carpocapsae were efficacious against larvae but not adults of the weevil. These bioassays also demonstrated that adults of M. h. sericeus were killed by labelled rates of commercial formulations of acephate 75WP, carbofuran 2F, chlorpyrifos 4 EC, cyfluthrin 2 EC, disulfoton 15G, imidacloprid 2F, isofenphos 2I, lindane 25WP, and Vydate L. In a field test with weevil-infested Canary Island date palms, Phoenix canariensis Hortorum ex Chabaud, lindane (25 WP, 1.5 g AI/palm), and imidacloprid (75 WP, 1.2 g AI/palm) had the greatest effect on the percentage mortality of total weevils present per palm (> 60%) followed by S. carpocapsae (8 × 106 infective juveniles [IJs]/palm) (51%) and acephate (2.9 g AI/palm) (39%) which were statistically equal to the controls (14%). Control palms harbored over 200 M. h. sericeus per tree in the petioles and stem periphery. Because of the potential for high weevil production per palm and the cryptic habitat of the boring stages of this weevil, chemical insecticides and/or entomopathogenic nematodes will need to be applied frequently and over a long period of time for effective management.
Topical Toxicity of Imidacloprid, Fipronil, and Seven Conventional Insecticides to the Adult Convergent Lady Beetle (Coleoptera: Coccinellidae)
Authors: Kaakeh Nawal , Kaakeh Walid , Bennett Gary W.
Published: September 2017

The relative toxicities (comparing LD50 and LT50s) of two synthetic pyrethroids (cypermethrin and fenvalerate), two organophosphorus insecticides (chlorpyrifos, diazinon), three carbamates (propoxur, carbaryl, bendiocarb), a phenylpyrazole representative (fipronil), and a heterocyclic nitromethylene representative (imidacloprid or NTN 33893) were assessed with topical bioassays in the laboratory against the convergent lady beetle, Hippodamia convergens Guérin Méneville. LD50 values decreased (i.e., toxicity increased) with an increased time after application of a specific insecticide. The differences between the LD50 values caused by various insecticides were significant. Among tested insecticides, cypermethrin and bendiocarb were the most toxic; fipronil was the least toxic. H. convergens responded differently to different insecticides within the same class. Beetles exhibited similar responses to both organophosphorothionates chlorpyrifos and diazinon 24 to 72 h after application. Of the carbamates, propoxur was 2.4 and 3.5 times less toxic than carbaryl and bendiocarb, respectively. Of the pyrethroids tested, cypermethrin was significantly more toxic than fenvalerate. At 800 ppm, cypermethrin and bendiocarb were the fastest in killing H. convergens among the tested insecticides. The ranking of insecticides in decreasing order of LT50 values was as follows: fipronil > diazinon > chlorpyrifos > propoxur > carbaryl > fenvalerate and imidacloprid.
Sugar Esters from Nicotiana Species as Potential Insecticides Against the Sweetpotato Whitefly (Homoptera: Aleyrodidae)
Authors: Nottingham Stephen F. , Chortyk Orestes T. , Stephenson Michael G.
Published: September 2017

Eight Nicotiana species and three species accessions were grown and their sugar esters were isolated. Nicotiana trigonophylla, N. palmeri, and N. glutinosa gave the highest sugar ester yields. Sugar ester isolates were bioassayed at concentrations from 1.0 to 0.05 mg/ml against nymphs of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae). The highest mortalities were observed with isolates from N. gossei and N. langsdorffii. As the sugar ester isolate from N. gossei contained both sucrose esters and glucose esters, these were bioassayed separately and both caused high mortality. The isolates of three N. glutinosa accessions varied in sucrose ester and labdane terpenoid content; labdane fractions were less toxic than sucrose ester fractions. Nicotiana glutinosa 24, N. langsdorffii, and N. trigonophylla, in addition to N. gossei, showed good potential as sources of biorational insecticide against whitefly.
Field Evaluation of Transgenic Corn Containing a Bacillus thuringiensis Berliner Insecticidal Protein Gene Against Helicoverpa zea (Lepidoptera: Noctuidae)
Authors: Sims Steven R. , Pershing Jay C. , Reich Barbara J.
Published: September 2017

Twelve independently transformed lines of transgenic corn (Zea mays L.) expressing the CryIA(b) insecticidal protein from Bacillus thuringiensis var. kurstaki were field tested to evaluate their resistance to the corn earworm, Helicoverpa zea (Boddie). Silks of the primary (=top) ears of transgenic [CryIA(b) positive] and isoline control plants [no CryIA(b) protein] were artificially infested with first-instar H. zea larvae and the length of ear penetration was measured after 19 d. Eight of the 12 lines had significantly less ear damage than their respective isoline controls; 3 transgenic lines reduced H. zea feeding damage by > 75% and stunted surviving H. zea larvae. Concentration of the CryIA(b) protein (μg/g fresh weight) in silks of the transgenic lines, determined using ELISA, ranged from 0.0 to 1.28 μg/g. Within transgenic lines, there was a weak (P < 0.06) negative relationship between the concentration of CryIA(b) protein in fresh silks and the length of H. zea ear penetration.
Interrelationship of Bacillus thuringiensis Berliner to the Diamondback Moth (Lepidoptera: Noctuidae) and its Primary Parasitoid, Diadegma insulare (Hymenoptera: Ichneumonidae)
Authors: Ulpah S. , Kok L. T.
Published: September 2017

The interrelationship of Bacillus thuringiensis Berliner var. kurstaki to the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), and its primary parasitoid, Diadegma insulare Cress. (Hymenoptera: Ichneumonidae), was investigated using laboratory colonies of the insects. The differential response of third-instar diamondback moth, parasitized and unparasitized, to B. thuringiensis (Bt), and the ability of D. insulare to oviposit in Bt-stressed hosts were determined. No significant difference (P > 0.05) was found between the mean mortality of parasitized and unparasitized larvae at each of three concentrations (154, 334, and 2,237 IU/ml) of Bt endotoxin. The three concentrations were equivalent to the LC30, LC50, and LC90 of Bt potency based on preliminary tests. Parallel line assay analysis, however, revealed that the linear dose-response regressions of parasitized and unparasitized larvae were highly significant (P = 0.0001). The LC50s of parasitized versus unparasitized larvae were 373 and 175 IU/ml Bt endotoxin, respectively, indicating that parasitized larvae were less susceptible to Bt. Female D. insulare oviposited in Bt-stressed hosts. The percentage of D. insulare females emerging from Bt-treated larvae (41.4%) was not significantly different from that of untreated larvae (32.0%).
Horizontal Transmission of the Entomopathogenic Fungus Metarhizium anisopliae (Imperfect Fungi: Hyphomycetes) and Hydramethylnon Among German Cockroaches (Dictyoptera: Blattellidae)
Authors: Kaakeh Walid , Reid Byron L. , Bennett Gary W.
Published: September 2017

Horizontal transmission of the entomopathogenic fungus, Metarhizium anisopliae (Metchnikoff) Sorokin, and hydramethylnon toxicant among individuals of the German cockroach, Blattella germanica (L.), was evaluated in this study. Transmission of hydramethylnon occurred through the feces. Contaminated feces were toxic to other cockroaches when mixed with standard laboratory diet at different ratios. Lethal time (LT50) of the nymphs increased as the proportion of contaminated feces in the healthy laboratory diet was decreased. When cockroaches were fed a diet consisting of hydramethylnon-contaminated feces and a laboratory diet at ratios of 1:0, 1:1, and 1:5, the mortality reached 100% at days 9, 12, and 17, respectively. The mortality was reduced to approximately 80% at a ratio of 1:10. Fifth-stage nymphs exposed to the conidia of M. anisopliae or hydramethylnon toxicant for 6, 12, 24, or 48 h transferred the fungal conidia or the toxicant to healthy nymphs. Rate of mortality increased significantly by increasing the ratio of infected to unexposed cockroaches (i.e., 1:1 ratio >1:10 ratio), and by increasing the exposure time for the infected cockroaches (48 h versus 6 h) to both M. anisopliae and hydramethylnon. Cockroaches killed by M. anisopliae or hydramethylnon before being presented to healthy cockroaches were less effective in spreading the fungus or toxicant than were live infected cockroaches. When live infected nymphs were mixed with healthy cockroaches, M. anisopliae initially killed cockroaches slightly faster (LT50[95% CL] = 10.1 [9.2–11.0] d) than hydramethylnon (LT50[95% CL] = 12.5 [11.4 - 13.7] d). However, cumulative mortality reached 100% at day 26 for both M. anisopliae and hydramethylnon treatments. After mixing healthy nymphs with dead infected cockroaches, the rate of mortality was slower for M. anisopliae (LT50 = 20 [19.1 - 20.9] d) and hydramethylnon (LT50 = 14 [13.4 - 14.7] d) than those recorded in the previous test (that is, mixing live-infected nymphs with healthy cockroaches). However, the cumulative mortality 28 d after exposure to M. anisopliae and hydramethylnon reached 77 and 67%, respectively. Fungal growth was observed on all body parts of dead infected nymphs within 14 to 16 d of exposure to M. anisopliae. Dead infected nymphs were not cannibalized suggesting avoidance behavior by healthy nymphs. Consequently, the fungal conidia were not spread as effectively by dead nymphs as with live infected nymphs. Factors affecting performance in light of horizontal transmission of M. anisopliae are discussed.
Susceptibility of Phthorimaea operculella (Zeller) to Insecticides
Authors: Llanderal-Cázares Celina , Lagunes-Tejeda Angel , Carrillo-Sánchez José Luis , Sosa-Moss Carlos , Vera-Graziano Jorge , Bravo-Mojica Hiram
Published: September 2017

Seven technical grade insecticides were evaluated against a susceptible population and against two field populations of the potato tuberworm Phthorimaea operculella (Zeller) by topical application to third-instar larvae. Using a standard susceptible laboratory colony, we calculated median lethal doses (LD50) of 0.39, 0.059, 0.12, 0.00022, 0.18, 0.010 and 0.0007 μg/larvae for the insecticides DDT, methyl parathion, ethyl parathion, azinphosmethyl, malathion, carbaryl and permethrin, respectively. By comparison, we found that a wild population from Oyameles, Puebla was susceptible to the insecticides while a population from Leon, Guanajuato was susceptible to DDT, methyl parathion, ethyl parathion, malathion and permethrin, but was resistant to azinphosmethyl and carbaryl.
Reproductive Potential and Development of Rose Leafhopper, Edwardsiana rosae (L.) (Homoptera: Cicadellidae), at Constant Temperatures on Apple
Authors: Day M. L. , Hogmire H. W. , Brown M. W.
Published: September 2017

Reproductive potential and developmental rates for rose leafhopper, Edwardsiana rosae (L.), were determined in a constant-temperature study at 13, 17, 23, and 30°C. Developmental rate was faster at progressively higher temperatures, except at 30°C, where there was no egg hatch. Developmental rate was faster for males than for females at each temperature. Regression equations yielded an estimate of 7°C as the temperature threshold for development. The largest number of progeny was produced at the lowest temperature, and survival decreased with increasing temperature. Body length and head capsule width of the five nymphal instars and adult stages of rose leafhopper did not vary among temperatures or between male and female.
Seasonal Density and Impact of Mining of Lyonetia prunifoliella (Lepidoptera: Lyonetiidae) on Semidwarf Apple Trees in Connecticut
Authors: Maier Chris T.
Published: September 2017

Number of adults on unbaited yellow sticky traps and of new mines and pupae on semidwarf ‘Mcintosh’ or ‘Mutsu’ apple, Malus domestica Borkhausen, trees was recorded weekly at Southington, CT, to determine the seasonal density of Lyonetia prunifoliella (Hübner) in 1989 and 1990. Densities were highest between August and October when leaves of the second flush were developing. On sprayed ‘Mutsu’ trees, L. prunifoliella had at least six generations between May and November 1989, and four during these months in 1990. An application of permethrin in April probably eliminated the first generation in 1990. On ‘Mutsu’ apple trees, the loss of leaves of the second flush in 1990 was significantly greater on terminal shoots with mining than on those without it. Foliar mining also significantly reduced the length and basal diameter of terminal shoots. By reducing woody growth on young trees, the premature loss of leaves may delay the first harvest. Pruning in summer and fewer applications of fertilizer might slow the population growth of L. prunifoliella.
An Evaluation of the Parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae) and the Predator Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) for Biological Control of Aphis gossypii Glover (Homoptera: Aphididae) on Cucumber
Authors: Harizanova Vili , Ekbom Barbara
Published: September 2017

Developmental time and fecundity of Aphidius colemani Viereck and Aphidoletes aphidimyza Rondani were studied under laboratory conditions on cucumber plants infested with Aphis gossypii Glover at a constant temperature of 20° C, photoperiod of 18 hours and 70% R. H. Developmental time from egg to adult for A. colemani lasted 13.9 days and for A. aphidimyza, from egg to larva was 3 days, larva to pupa 5.8 days, from pupa to adult 11.9 days, and total developmental time was 20.6 days. The average lifetime fecundity was 57.7 for A. colemani and 55.07 for A. aphidimyza. The variation for both species was considerable. Percentage of females for A. colemani was 58% and for A. aphidimyza 66%. One larva of A. aphidimyza will, on average, kill 23.8 A. gossypii during its life. Predation of parasitized aphids by A. aphidimyza was observed. Production of parasitoids was lower when the predator was present. The use of the two natural enemies together in control programs against A. gossypii is discussed.
Behavioral and Electrophysiological Activity of the Racemate and Enantiomers of a Monofluorinated Analog of European Corn Borer (Lepidoptera: Pyralidae) Sex Pheromone
Authors: Klun Jerome A. , Oliver James E. , Khrimian Achot P. , Dickens Joseph C. , Potts William J. E.
Published: September 2017

The racemate and individual enantiomers of 2-fluoro-Z-11-tetradecenyl acetate (2F-Z-11), analogs of a European corn borer moth, Ostrinia nubilalis (Hübner), female sex pheromone were compared with the natural pheromone, Z-11-tetradecenyl acetate, in field trapping experiments, flight tunnel studies, mating disruption assays and electrophysiological experiments. While the racemate and R-2F-Z-11 mimicked the natural female sex pheromone, they were not more biologically potent than the pheromone. The S-2F-Z-11 was largely ineffective in all assays and was, therefore, incompatible with the pheromone receptor system.
Methods of Evaluating Pecan Cultivars for Tolerance to Feeding Damage Caused by the Black Pecan Aphid, Melanocallis caryaefoliae (Davis)
Authors: Hale T. C. , Estes P. M.
Published: September 2017

Two aphid rearing methods were evaluated for their suitability of making biological observations on the black pecan aphid, Melanocallis caryaefoliae (Davis), and as rapid assessments of pecan cultivars for tolerance to aphid feeding damage. There were no significant differences in the biological and feeding damage data between the two experiments. In comparison, the agar method produced less aphid mortality, was easier to maintain, utilized less space, and would allow fewer samples to provide accurate results. ‘Melrose’ was the most tolerant of the nine cultivars evaluated for tolerance to feeding damage by the black pecan aphid using water agar plates. ‘Jubilee’, ‘Suprize’, and ‘82-17-680’ (Wichita open-pollinated) exhibited intermediate tolerance to feeding damage while ‘Salado’, ‘82-17-1316’ (Wichita open-pollinated), ‘Schley’, ‘Oconee’, and seedlings expressed little tolerance to damage caused by feeding. It has yet to be seen if there is a correlation between tolerance to aphid feeding defined by this experiment and actual resistance to the black pecan aphid in the field.
Diamondback Moth (Lepidoptera: Plutellidae) in Cabbage: Influence of Initial Immigration Sites on Population Distribution, Density and Larval Parasitism
Authors: Hu G. Y. , Mitchell E. R. , Okine J. S.
Published: September 2017

Examinations of cabbage plants in five fields near Bunnell, Flagler Co., FL, in spring 1995 showed that larvae of the diamondback moth, Plutella xylostella (L.), were more abundant on the field ends (perpendicular to cabbage rows) adjacent to weed-filled drainage ditches than the fields ends abutting wooded swamp areas. There were no significant differences in the numbers of diamondback moth larvae on cabbage plants on the ends next to other cabbage fields or at sites located within the interior of the fields. Cabbage heads rated for damage due to diamondback moth larvae at harvest showed a distributional pattern similar to that observed for diamondback moth larvae. Parasitism of diamondback moth larvae was not significantly different between field ends and interior fields. Cabbage damage ratings on field sides (parallel to cabbage rows) showed that no edge effect was detected on the sides abutting other cabbage fields, that edge effect only occurred on the first one or few rows on the sides adjacent to other cabbage fields but separated by irrigation ditches, and that edge effect occurred continuously and decreased from the first to the 12th row on sides adjacent to earlier planted cabbage or an open weed-filled ditch area. These results suggest that diamondback moth first invaded cabbage fields from outside areas, and that more diamondback moth spread to the interior of the fields from adjacent open, weed-filled ditches than from bordering wooded and bushy areas.
Volatile Components of a Chicken Feather Hydrolysate that is Highly Attractive to the West Indian and Mexican Fruit Fly (Diptera: Tephritidae)2
Authors: DeMilo Albert B. , Lee Chang-Joo , Levi Victor A. , Moreno Daniel S.
Published: September 2017

A chicken feather hydrolysate prepared by heating feathers with 6N hydrochloric acid was highly attractive to the West Indian fruit fly, Anastrepha obliqua (Macquart), and the Mexican fruit fly, Anastrepha ludens (Loew). In cage-top laboratory tests to determine the influence of pH on attraction, chicken feather hydrolysate, adjusted to pH 8.0, elicited the greatest response from adult A. obliqua; the attraction response was more than twice that observed for a 10% NuLure® (Miller Chemical and Fertilizer Corp., Hanover, PA) standard. Neutral or slightly acidic preparations of chicken feather hydrolysate were less effective. While A. ludens was less attractive in the laboratory tests to a 25% chicken feather hydrolysate than a 10% NuLure standard, A. obliqua appeared slightly more attracted to the hydrolysate than NuLure, but not significantly. In a 5-day field test using sterile released A. ludens, 4.5% chicken feather hydrolysate, adjusted to pH 8.0, caught almost 2.5 times more flies than 10% NuLure. Twenty-three volatile compounds that emanated from chicken feather hydrolysate were identified by headspace analysis using GC-MS and GC retention index comparison techniques. Among the volatiles were 7 ketones, 6 alcohols, 2 aldehydes, 2 chlorocarbons and 2 furans. At pH 8.0, the five most abundant compounds in decreasing order were 4-methyl-2-pentanone (76.3%), 4-methyl-2-pentanol (16.5%), 1-hexanol (3.1%), 1-heptanol (0.81%) and 2-butoxyethanol (0.64%).
Seasonal Abundance and Mathematical Distribution of Wireworms and Wireworm Feeding Damage in Sweet Potato
Authors: Seal Dakshina R. , Chalfant Richard B. , McSorley R.
Published: September 2017

Seasonal abundance and spatial distribution of wireworm feeding damage were determined for sweet potato by examining storage roots. Spatial distribution of wireworms was determined by sampling corn-wheat seed baits. Wireworm feeding damage (deep, shallow and healed holes) increased as the season progressed. The distribution of wireworms in sweet potato fields was clumped as was feeding damage distribution. The spatial distribution of wireworm damage on sweet potato roots fits the negative binomial distribution. Values for the negative binomial parameter k for two fields indicated a clustered distribution of wireworm feeding damage. Greater k-values for healed feeding damage and total feeding damage than for deep and shallow feeding damage indicate that sample size could be adjusted, depending on seasons, to achieve optimal sampling efficiency. As feeding damage can predict wireworm populations, a sampling strategy based on early-season wireworm damage data is particularly timely, efficient and economical for evaluating wireworm damage data.
Aphid (Homoptera: Aphididae) Management in Alfalfa by Spring Grazing with Cattle
Authors: Buntin G. D. , Bouton J. H.
Published: September 2017

The effect of continuous, intensive grazing by cattle on aphid populations was examined in the first growth cycle of ‘Alfagraze’ and ‘Apollo’ alfalfa which are tolerant and not tolerant to grazing, respectively. Populations were almost entirely pea aphid, Acyrthosiphon pisum (Harris). The effect of grazing on aphid populations was examined in small plot exclusion studies in 1991 and 1992, and the effects of grazing and use of an early insecticide application with ≤7 day grazing restriction were examined in large plot exclusion trials in 1993 and 1994. Grazing reduced aphid populations by 66% to 90% when numbers exceeded ~1 aphid per stem. Populations were not significantly reduced by grazing when numbers did not exceed 1 per stem. Permethrin reduced aphid numbers for up to 7 wks and was more effective than carbofuran. Effects of grazing were similar regardless of insecticide usage. Coccinellid beetle populations in 1993 and 1994 were composed of Coccinella septempunctata L., Harmonia axyridis (Pallas), and Coleomegilla maculata DeGeer. Coccinellid numbers were much lower in grazed than ungrazed plots when aphid numbers were reduced by grazing in 1993, but were not greatly affected by grazing in 1994 when aphid numbers were low. Coccinellid numbers paralleled trends in aphid numbers. Continuous, intensive grazing or the early application of an insecticide at a low rate followed by grazing were effective approaches for suppressing pea aphid in alfalfa.
Labortory Bioassays for Evaluating Sweet Corn Antibiosis on European Corn Borer (Lepidoptera: Pyralidae) Larval Development
Authors: Warnock Daniel F. , Hutchison William D. , Kurtti Timothy J. , Davis David W.
Published: September 2017

European corn borer (Ostrinia nubilalis Hübner) can severely affect commercial sweet corn quality during years of heavy infestation. The isolation and identification of allelochemicals in sweet corn which detrimentally affect O. nubilalis may enhance breeder selection for greater ear feeding resistance, thus reducing the need for insecticide application. Field selection techniques for improving plant resistance to O. nubilalis cannot easily distinguish between plant tolerance or antibiosis. A laboratory bioassay incorporating ear tissues from field resistant and susceptible sweet corn genotypes into a nutritionally complete O. nubilalis larval diet was developed as an initial step to facilitate the isolation and identification of potential chemical resistance factors in sweet corn. Neonates reared for 7 d on a meridic diet with limited fungal and bacterial contaminant control agents weighed more than larvae grown on a comparable diet with high levels of contaminant control (5.96 and 2.46 mg, respectively). Silk tissue from several sweet corn genotypes significantly reduced larval weight and increased total larval development time compared with kernel tissue. Silk tissues incorporated on a weight basis had volumes about 3 × that of an equal weight of kernel tissues. However, tissues incorporated into a specific diet volume on a weight or volume basis usually did not alter larval weight or time to pupation within a genotype. Incorporation on a weight basis was most time efficient. Future bioassays screening for antibiotic effects of sweet corn tissue on O. nubilalis development should utilize a diet with limited contaminant control agents, incorporate tissue on a weight basis, and focus on silk tissue.
Alightment of Edovum puttleri Grissell (Hymenoptera: Eulophidae) in Response to Colors Mimicking Three Hosts of the Colorado Potato Beetle (Coleoptera: Chrysomelidae)
Authors: Vasquez Barbra , Lashomb James H. , Hamilton George
Published: September 2017

The effect of leaf color on alighting behavior of Edovum puttleri Grissell was examined in a laboratory sticky-board test. Paint models mimicking the leaf top colors of eggplant, potato, and tomato and a model mimicking average underside leaf color were tested in paired comparisons. The underside leaf color mimic was the most preferred; no significant differences in landing rates occurred among any of the three leaf top color mimics. The underside leaf color mimic also was tested against two gray shades sharing the same intensity of reflectance; no significant differences were detected. The parasitoid, therefore, preferentially alighted based on the intensity and not the hue of the models. For all assays, a significant departure from randomness was found because a higher percentage of females alighted on the paint models than that which was in the colony. This suggests that parasitoids were alighting in a search for host eggs.
Assessment of Pesticide Use by Commercial Landscape Maintenance and Lawn Care Firms in Georgia
Authors: Braman S. Kristine , Oetting Ronald D. , Florkowski Wojciech
Published: September 2017

Questionnaires on pesticide use and pest management practices were mailed to landscape maintenance/lawn care firms in the metro-Atlanta area; 25.4% or 350 firms responded. Of these firms, 159 provide pest management services for turfgrass or ornamentals or both. Responding professionals purchased 13,210 kg AI of insecticides, 93,447 kg AI herbicide, and 3,867 kg AI of fungicides during 1993. Total area serviced by these firms was 14,770 ha. The most commonly-purchased insecticides included products containing hydramethylnon, acephate, chlorpyrifos, carbaryl, and horticultural oil. Frequently-purchased herbicides included products that contain pendimethalin, 2,4-D, glyphosate, MCPP, dicamba, oryzalin, benefin, and oxadiazon. Fungicidal products purchased by the most respondents were chlorothalonil, thiophanate-methyl, oxazoladinadione, matalayl, and triadimefon.

Insecticides were most frequently applied to ornamentals (65%), while herbicides were the primary pesticide used on turf (93% preemergence, 79% postemergence). Fungicides were more evenly distributed. Prescheduled applications determined timing of application for 32% of respondents, while 46% report that monitoring of pest populations influences treatment decisions. Only 8% of respondents incorporate monitoring of beneficial arthropods into this decision-making process.