摘要:

Persistence of 5,6-dichloro-2-trifluoromethylbenzimidazole (NC-2983), a major degradation product of the new acaricide, fenazaflor, in Hagerstown silt loam soil was studied by applying commercial formulations (Lovozal®) at different rates in single and repeat applications to field plots in the fall and in summer. Soil samples from different depths were analyzed at various intervals for residues of NC-2983 by gas chromatography. No significant disappearance of NC-2983 occurred from field soils during the autumn, winter, and early spring. The amount of NC-2983 in the soil, however, declined rapidly during the summer. Approximately 80% of the amount applied in the summer of 1971 disappeared in 135 days after application, whereas about one year was required for a comparable amount to disappear when similar amounts were applied in the autumn. Residues of NC-2983 were not found beyond the 6-inch depth in field plots. NC-2983 was not found in the peel-free portions of potatoes, and only trace amounts were found in the peel-free parts of carrots. Significant amounts of NC-2983 were found in the peel of both crops, especially at the highest rate of application.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.730

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

Effects of gamma radiation dosages between 5 and 100 krad on all stages of the sawtoothed grain beetle,Oryzaephilus surinamensis(L.), and the merchant grain beetle,O. mercator(Fauvel), were studied. Results with the 2 species were similar, although the merchant grain beetle appeared the more sensitive. Adult development from treated eggs and larvae was prevented by 10 krad. Some adults emerged from pupae at all treatment levels, but no reproduction occurred at 10 krad or above. Adult sawtoothed grain beetle females were more sensitive to the sterilizing effects of gamma radiation than were males, but sterility of both species was complete at dosages of 20 krad and above. Control of these 2 species appears feasible with radiation levels currently approved for treatment of stored-grain insects.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.735

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

Total DDT-TDE residues in tobacco of cigarettes purchased in 1970, 1971, and 1972 were 36, 44, and 27 ppm, respectively. Ratios of individual DDT-TOE isomers were essentially the same as reported for cigarettes purchased in 1964, 1966, and 1967 by other workers. In all cases,p, p'-TDE constituted ca. 53% of the total DDT-TOE residues. Within any given year, there was no significant difference (P=<0.05) in the quantity of residues in the different brands tested or in the filtered and non filtered forms of the same brand. Endosulfan residues were nondetectable (<0.01 ppm) in the 1970 and 1971 cigarette tobacco, but in 1972 they averaged 0.4 ppm with 0.3 ppm as the sulfate form, 0.1 ppm as endosulfan II, and only trace amounts of endosulfan 1. Dieldrin and endrin were not present at detectable levels (<0.05 ppm) in any of the cigarette tobacco.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.739

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

Populations of springtails and 3 groups of mites—the predominant soil arthropods—were periodically surveyed during summer 1971 by extracting soil samples. These samples were obtained from a plot adjacent to a power substation and from 4 diverse habitats along the Sanguine antenna. The antenna is situated in northern Wisconsin and consists of a north-south and an east-west leg designed to test the environmental impact of operations in the extremely low frequency (ELF) range (45 or 75 Hertz). The “Sanguine effect” is defined to include ground current flow, electromagnetic fields, and ELF radiations produced by the antenna. Control samples were obtained from similar habitats situated 7 to 12 miles from either leg of the antenna. Fourteen of a total of 16 tests showed no significant differences in arthropod abundance at test and control sites. This includes the Main Test which was the most sensitively designed and involved analyses of subplot variations within test and control sites. Differences in the other 2 tests were marginal or of doubtful significance; in both cases, only 1 of 4 arthropod groups was involved. Additional evidence for the absence of a Sanguine effect is the occurrence of a midsummer peak in all 3 mite populations in both test and control plots of a woodland habitat. Ratios between the most numerous groups were compared for 1969 (just before antenna turn-on), 1970, and 1971, and were found to be similar, irrespective of site and date—further evidence that these populations are stabilized and functioning independently of a Sanguine effect after 2 years of antenna operation. Arthropod abundance in the proximity of a power substation was likewise found to he unaffected.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.743

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

Fluorescent powders used as markers for adultLaspeyresia pomonella(L.) bad significant effects on the fecundity or longevity of marked moths in the laboratory: Day-Glo® Blaze Orange and Rocket Red reduced the number of eggs per female, and Day-Glo Arc Yellow, Fire Orange, and Neon Red reduced egg hatch. In the greenhouse and in the orchard, Helecon® 2200 and Rocket Red produced a reduced response of marked males to females. Eosin-Y, included as a standard, bad no apparent effects on adult moths, but was harder to apply and more difficult to detect than were fluorescent powders.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.750

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

When blacklight traps were operated at a density of 3/mile2for 43 months on St. Croix, U. S. Virgin Islands, the collections of sphingid moths were found to be associated with the seasonal pattern of rainfall. The 12-month collection ofHyles lineata(F.) was 17.5% of the 1st 12 months collection after 43 months. The collcction ofCallionima ramsdeni(Clark) had dropped 50% after 33 months of trapping but increased to 64% of the 1st 12 months after 43 months. The collection ofAgrius cingulatus(F.) was 32% that of the 1st year after 36 months but increased to 81% after 43 months. The collection ofManduca rustica harterti(Rothschild) was 14% that of the base year after 39 months but increased to 21% after 43 months. The collection ofEumorpha vitis(L.) was 15% that of the base year after 39 months but increased to 19% after 43 months. The collection ofXylophanes pluto(F.) was 36% that of the initial year after 36 months but increased to 70% after 43 months. The collection ofXylophanes tersa(L.) was 59% that of the base year after 37 months but increased to 80% after 43 months. The increased collections the last year of trapping were attributed to the absence of a dry season that year. If the collection trends prior to that unusual rainfall pattern had continued, several species would have been eradicated by an additional year of trapping pressure.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.753

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

Parasitism ofMusca autumnalisDe Geer by the nematodeHeterotylenchus autumnalisNickle was investigated at 2 farms in central Missouri during 1970. Mean seasonal parasitism at the 2 farms averaged 33.5 and 26.2%, whereas face fly populations averaged 7.4 and 8.7/head of cattle, respectively.Five methods of sampling face flies to measure parasitism by the nematode were evaluated. Parasitism was significantly higher in flies collected from the surface of manure pats than those collected from either the sides of a truck or the faces of the cattle.Most unparasitized flies (94.2%) had undergone only 2 gonadotrophic cycles. Also, a majority of the unparasitized flies collectcd from the manure pats (61.3%) contained mature eggs, whereas only 17.1% of those collected from the truck and the faces of the cattle had mature eggs.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.759

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

The bioenergetics ofPogonomyrmex occidentalis(Cresson) was studied on the IBP grassland intensive study site in northeast Colorado. Energy flow values were determined by estimating the energy required per colony for production of ant tissue and for respiratory energy loss. Extrapolation of the energy values per colony to colony densities in the differentially grazed pastures resulted in seasonal estimates of population energy flow values for western harvester ant populations in ungrazed, lightly grazed, moderately grazed, and heavily grazed pastures.Excavation of 11 colonies resulted in estimates of 2032 worker ants and 315 winged reproductives produced per colony each year. This resulted in an estimate of 46.81 kcal per colony required for secondary production per year.Respiratory energy losses were estimated from measurements of CO2production in relation to field temperatures, as determined from measurements conducted on 2 colonies established in the laboratory. Annual energy requirements for respiration were estimated at 418.42 kcal per colony.Energy flow values (tissue production + heat production) ranged from 1.45 kcal per m3per year in the moderately grazed pasture to 0.14 kcal per m2per year under heavy grazing pressure. The energy flow values forP. occidentalisare much lower than those calculated forP. badius(Latreille). The major area of difference occurs in estimates made of energy required for respiration.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.763

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

Data were collected June through August 1970 onMusca autumnalisDe Geer on dairy cattle on 5 farms in Hunterdon County, New Jersey, and at the same time on environmental factors including exposure (sun or shade), cow posture (standing or lying), control by sprays, time of day, temperature, relative humidity, and wind speed. Fly activity, as evidenced by the number of flies on face and body, was analyzed by analysis of covariance. Covariates used were the day of the year and its square, air temperature, relative humidity, wind speed, and full quadratic polynomial in the latter 3 variables. The covariates in order of decreasing importance were wind speed, wind speed × temperature, relative humidity × wind speed, and relative humidity. Assuming changes in the seasonal component of fly activity to be small the use of Ciovap® (1% crotoxyphos + 0.25% dichlorvos) is shown to reduce fly activity.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.768

出版商:Oxford University Press    

年代:1972

数据来源: OUP

摘要:

A sequential decision plan based on the sequential probability ratio test has been derived for determining the infestation status ofHeliothis zea(Boddie) in cotton. In addition, a sequential counting or estimation plan has also been derived for fixing the coefficient of variation of the mean. Both of these plans are based on 3 years of data from 5 different untreated cotton fields in the San Joaquin Valley of California.Our general findings based on computer calculations and field trials follow: (1) Five adjacent cotton plants have been found to be a preferable sampling unit to 1- or 3-plant sample units in a sequential decision plan. Although a slight advantage exists in smaller sample units in terms of total plants required, the increased amount of walking between the larger number of small units more than offsets any advantage. (2) If 50 plants per 20 acres arc taken as a practical limit on sampling, up to 25% chance of error must he tolerated in a test of 8 vs. 15 worms/100 plants. Up to 20% chance of error must he tolerated in a test of 10 vs. 20 worms/100 plants. (3) The sequential decision plan agrees well with previous methods (12 5-plant samples) with only one disagreement out of 40 comparisons. In addition, good agreement between predicted and observed sampling requirements was found. (4) Sampling distributions for the cotton bollworm have the characteristic that the sample variance increases more rapidly than the mean. This suggests a clustered spatial pattern and is in wide agreement with the literature. (5) In a sequential counting plan which fixes C, the standard error to mean ratio, very high sampling requirements are indicated at low population means.

ISSN:1754-5692    

DOI:10.1093/ee/1.6.771

出版商:Oxford University Press    

年代:1972

数据来源: OUP