摘要:

Three levels of visible feeding damage of alfalfa plant-tips byHypera brunneipennis(Boheman) larvae were analyzed for quantitative and qualitative differences. No significant differences in quantitative losses existed between the moderate damage (M) and no visible damage (N) categories, but were found between these and the severe damage (S) category. Differences in such nutritional components as modified crude fiber, protein, calcium, and phosphorus existed among various of the damage categories. From these findings, the visual-damage level insecticide-treatment indexes similar to in magnitude or less than our M category, which are commonly used at present for the closely-related speciesH. postica(Gyllenhall), are criticized in terms of potential pesticide abuse. Sampling problems associated with visual indexes are discussed, and it is recommended that research on development of economic thresholds forHyperafocus on quantitative evaluation of the larval population itself rather than on visual damage patterns.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.891

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The effect of a mirex bait treatment was studied on 14 common ants in Washington Parish, southeastern Louisiana. The most noticeable effect was the suppression for 1 year of the red imported fire ant,Solenopsis invictaBuren. Reductions of 98% in the number of live mounds and 99.5% in the foraging workers occurred within 1 month of the treatment. Populations of 3 other species of ants,S. xyloniMcCook,Pogonomyrmex badius(Latreille), andMonomorium minimum(Buckley), were also reduced. Three species of ants,Iridomyrmex pruinosus(Roger),I. humilus(Mayr), andConomyrma insana(Buckley), were not adversely affected and may have benefited from the elimination of competition with the red imported fire ant. Two other species,S. Molesta(Say) andPrenolepis imparis(Say), and several genera,Camponotusspp.,Nylanderiaspp.,Aphanogasterspp., andPheidolespp., apparently were not directly affected either way by the bait application.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.895

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Megachile pacifica(Panzer) generally became more susceptible to carbaryl as adults aged. LD50values for carbaryl toxicity were 240, 166.5, 109.2, and 51.3 μg/g for the 1, 2, 3, and 4-day-old adult male bees. For the female bees, these values were 245.5, 550.5, 289.4, and 262.4 μ/g. Lipid content andin vitroEPN detoxication decreased in both sexes as the bees aged.Synergist ratios were measured. They are the ratio of the LD50of carbaryl alone to the LD50of carbaryl applied after the synergist piperonyl butoxide. These ratios, which did not correlate with either decreasing LD50values or decreasing EPN detoxication in the males, were 12, 21, 42, and 53 for the 1, 2, 3, and 4-day-old bees. female bees the synergist ratios corresponded more closely. They were 23, 49, 11, and 15 as the females aged from 1 to 4 days. The bees were very susceptible to the organo-phosphates monocrotophos, dicrotophos, or Gardona® [2-chloro-1-(2,4,5-trichloro-phenyl) vinyl dimethyl phosphate], (LD50<2 μg/g), but they were quite tolerant the carbamate Landrin® (3,4,5-trimethylphenyl methylcarbamate; 2,3,5-trimethylphenyl methylcarbamate).The use of enzyme-inducing drugs to protect bees from carbaryl poisoning was studied. Among the 3 drugs used, only chlorcyclizine increased the LD50value (to ca. 2-fold) in the 4-day-old male. Aminopyrine increased the male's susceptibility carbaryl while phenobarbital had no effect at all. None of the drugs significantly changed the female's susceptibility to carbaryl except aminopyrine which lowered LD50from 262.4 to 75.3 μg/g. Studies with invitroEPN detoxication indicated that all 3 drugs caused increases in microsomal enzyme activity up to 4 or 5-fold and decreases in lipid content of ca. 20–30%.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.899

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

A new method was used for determining the active nuclear polyhedrosis virus content of untreated marketable cabbages. The activity of the virus was determined by inter-polating the dose-mortality data obtained from bioassays of homogenized wrapper leaves, heads, and whole cabbages. An average of 4.61 × 103active polyhedra/g of cabbage was obtained from untreated edible cabbage heads assayed in 1972.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.908

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Corn plant roots exposed to amine salt of 2,4-dichlorophenoxyacetic acid at dosages of 5, 20, 80, and 320 ppm applied to the soil surface in pots were infested with the corn leaf aphid,Rhopalosiphum maidis(Fitch), and injected with the common com smut pathogen,Ustilago maydis(DC.) Cda, in the laboratory. Aphids were about 45% more abundant on com plants treated with 5 and 20 ppm (20 ppm equivalent to about 1 liter of 2,4-D formulation/ha) than on the untreated corn plants. The weight of common corn smut galls on corn plants treated with 20 and 80 ppm was more than twice that of galls on untreated plants.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.911

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Females ofSinella curviseta(Collembola: Entomobryidae) were shown to produce 2 stimuli that increase the deposition of stalked spermatophores by males. One stimulus, the instar stimulus, is associated only with females in reproductive instars. The second, the position stimulus, increases spermatophore deposition in the brief interval preceding and coinciding with the female's receptive period within the reproductive instar. Further investigation determined that the position stimulus is a volatile pheromone.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.916

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

A study in east-central South Dakota during the summers of 1971 and 1972 evaluated insecticidal control of horn and face flies (Haematobia irritans(L.) andMusca autumnalisDe Geer, respectively) on cattle, as well as potential side effects to the insects of the bovine coprocoenosis. Three organophosphate compounds were aerially applied in ULV formulations: Ravap®, a 1:4 mixture of dichlorvos and Rabon® [2-chloro-1- (2,4,5-trichlorophenyl) vinyl dimethyl phosphate)], Rabon, and malathion. All 3 insecticides reduced the number of adult flies of both species for at least 1 day but for less than 1 wk. No residual control was noted. No significant effects to the dung biota could be attributed to Ravap or malathion. Rabon significantly (P=0.01) diminished only numbers ofPlatystethus americanusErichson,Falagria dissecta(Erichson),Aphodius fimetarius(L.), andCercyon pygmaeusIlliger, and, to a lesser degree (P=0.05), a miscellaneous group of unidentified dipterous larvae and larval hydrophilids. Most of the dung fauna, however, were unaffected by the insecticides.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.919

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Males ofSynanthedon pictipes(Grote and Robinson) were released at 4 distances downwind of female pheromone traps. The recovery was 67% at 100 m and decreased gradually to 40% at 800 m. Findings from diffusion and probit theory were combined to derive a linear relationship between log of distance and probit of percent recovery that described the data. Various effects of wind velocity and associated turbulence on insect pheromone communication are briefly discussed.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.923

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

A new type of bait dispenser for insect traps is a 3-layer plastic laminate in which pheromone is concentrated in the inner layer. When the dispenser was compared with currently used dispensers of pheromone of the cabbage looper,Trichoplusia ni(Hübner), and of the gypsy moth,Porthetria dispar(L.), the laminate dispenser generally caught greater numbers of insects. Also, in an aging test, the attraction of the laminate dispenser containing gypsy moth pheromone remained high for 120 days, and even the aged laminates outdrew freshly baited, standard bait-dispensers in all but one instance. Dispensers that emit lure at a constant rate are needed if traps are to be used for reliable estimates of insect populations.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.926

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Some factors which affect the population size ofThyridopteryx ephemeraeformis(Haworth) were studied by inspection of its cases collected from the field in witer. Average fecundity, frequency of reproductive females, percentage females, parasitism, and predation varied significantly among samples from different host plants and among samples from trees ofJuniperus virginianaL., all in the same grove. Percent mortality from unknown causes was significantly dependent on host species. Frequency of reproductive females was density dependent in bagworms feeding on J. virginiana. Groups of bagworms might escape parasites and other causes of mortality by colonizing new host individuals. Females which fed onAcer palmatum atropurpureumNichols did not reproduce. If a 1: 1 sex ratio can be assumed to occur in bagworms at birth, males, on the average, suffered higher mortality than females.

ISSN:1754-5692    

DOI:10.1093/ee/3.6.929

出版商:Oxford University Press    

年代:1974

数据来源: OUP