摘要:

Population levels ofAdelges cooleyi(Gillette) were evaluated for 2 yr on 7-yr-old Douglas-fir trees after fertilization with 3 forms of nitrogen. Aphid fecundity on trees individually treated with equivalents of 50 and 200 Ib N/acre (56 and 224 kg N/ha) was 11–42% higher than on untreated trees in the first year of study and dropped to normal in the 2nd year. Winter survival of the aphid was 10–20% higher than normal on fertilized trees in both years. In the same period, aphid establishment appeared to be reduced on fertilized trees. Two years after fertilization, the population levels were essentially the same on treated and untreated trees.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.501

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Laboratory experiments indicated that last-day pupae of the braconid parasiteTrichogramma pretiosumRiley can be stored at 16.7°C from 4–10 days without detrimental effects on emergence, and up to 12 days if temperature is decreased to 15°C on the 6th day of storage. After such storage, an average of 93% of the adults emerged within 4 h at 26.7°C under a variety of light intensities.A sampling study showed that the number ofT. pretiosumadults produced on individual rearing cards could be estimated within 6% of the actual mean by selective sampling of 0.65% of the material.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.505

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Traps baited with synthetic sex pheromones were used in one unsprayed orchard and 6 sprayed orchards in 1971–3 to monitor the seasonal flight of the codling moth,Laspeyresia pomonella(L.), redbanded leafroller,Argyrotaenia velutinana(Walker), and the oriental fruit moth,Grapholitha molesta(Busch) in North Carolina. Seasonal flight of the apple maggot,Rhagoletis pomonella(Walsh), was monitored using visually attractant traps baited with olfactory attractants. There were 3 moth-catch peaks for the 3 moths studied and one flight period for the apple maggot. Of the total insects captured, 99% of the apple maggot, 71% of the codling moth, 30% of the oriental fruit moth, and 13% of the redbanded leafroller were captured at trap sites in the unsprayed orchard. The sprayed orchards received only 3 early season insecticide sprays for control of the 4 insects studied. In the sprayed orchards, the average weekly codling moth, oriental fruit moth, and apple maggot capture per trap site was less than one. The average weekly redbanded leafroller capture per trap site exceeded 2 only 3 times during the 3-year study.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.508

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The biology ofColladonus mendicus(Ball) was studied in central California from 1970–1973. Sticky-trap collections of adults showed main periods of flight activity during May, July and November. Populations were usually low in late summer due to the scarcity of the primary host plant,Urtica holosericea, a nettle. Comparisons of nymphal development and adult longevity were made on excised vs intact host leaves. Average developmental times on excised leaves at 24°C, 40±10% RH, and 14 h light were: eggs, 11.4 days; nymphs 23.2 days (males) and 25.9 days (females). Adults which were transferred daily to new host leaves lived an average of 74.3 days (males) and 50.3 days (females). Adults of both sexes lived more than 90 days when transferred to new leaves every 5th day. Nymphs ofC. mendicuswere parasitized in the field by a pipunculid fly,Pipunculus affinisCresson.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.511

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Adult female horse flies (Tabanusspp. L.) were collected hourly in modified Malaise traps. Regression analyses of numbers of flies collected and the values of various meteorological factors in the ranges observed indicated which factors influenced activity. From greater to lesser influence, these factors were: barometric pressure, temperature, evaporation and evaporation change per hour, total sky radiation change per hour, total sky radiation and wind velocity change per hour, and relative humidity and temperature change per hour. The influence of these factors upon activity of the 6 most abundant species was also determined. Prediction equations are presented and the traps described.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.515

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

In field tests, as little as 0.05 mg of (E,E)-8,10-dodecadien-1-ol acetate inhibited 95–100% of the attraction of male codling moths,Laspeyresia pomonella(L.), to either 0.2 mg of the synthetic sex pheromone ((E,E)-8,10-dodecadien-1-ol) or to 10 virgin female moths. In laboratory tests of a group of normal alcohols, CnH2n+1OH (n= 8,9,10…18), only undecanol showed significant inhibition. Undecanol also inhibited attraction in field tests, but required about 20 mg/trap.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.522

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

A strain of bollworm,Heliothis zea(Boddie), was selected that possessed a low incidence of diapause under normal diapause-inducing conditions. This strain was developed through the use of artificial mass selection under conditions of 10:14 L:D photoperiod and a temperature of 20±2°C. Fourteen cycles of selection reduced the incidence of diapause from 64.2% to 5.6%.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.525

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Five laboratory tests were performed using 3 Iowa surface soils (Clarion, Harps, and Webster) to determine the influence of AC 92,100 (Counter®),O,O-diethylS-[(tert-butylthio) methyl] phosphorodithioate, on microbial activities. The insecticide was applied to 10-g soil samples as rates of 0, 1, 10, 50, and 100 ppm. The 1 ppm rate is equivalent to a field application rate of 1 lb/acre. Soil samples were incubated at 22±1°C for as long as 6 weeks and samples were removed for analyses at weekly intervals. Microbial activities in the 3 soils were measured by ammonium production, nitrification, carbon dioxide evolution, sulfur oxidation, and cellulose decomposition. There were 276 analytical mean values for soil samples receiving insecticide treatment. Of these, 48 values were significantly (P=0.05) higher than control values (0 insecticide treatment), 14 values were significantly lower than control values, and 214 values were not significantly different from control values. From the data presented it was concluded that AC 92,100 has no inhibitory influence on soil microbial activities.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.528

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

A P-generation of femaleTetranychus urticaeKoch kept on residues of a 200 ppm spray of carbaryl, 100 ppm DDT, and 25 ppm dioxacarb showed significantly (carbaryl and DDT) higher egg-totals than their untreated controls. With dioxacarb the increase of egg production was marginal in the statistical analysis. The ratio females/males in the F1was shifted in favor of the females in the broods reared on carbaryl and DDT residues, but not in the case of dioxacarb. This increase in the female proportion is highly significant for carbaryl with the strongest shift and DDT with a lesser one. Adult females of the F1, too, had a significantly higher egg production on carbaryl and DDT than their untreated counterparts. Hormoligosis—stimulation by small quantities of a stressor—is assumed responsible for observed effects, not an improved nutritional basis via an altered physiology of the host plant.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.534

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

A preliminary deterministic simulation model of growth and ingestion inManduca sexta(L.) is presented. This system consists of 5 first order differential equations and 1 discontinuous function, describing the following biological processes: ingestion, assimilation, respiration, excretion, molting, and growth. Both ingestion and growth are predicted with a high degree of accuracy. This model is evaluated in terms of (1) mimicking real biological phenomena and (2) its applicability to the field situation.

ISSN:1754-5692    

DOI:10.1093/ee/3.3.541

出版商:Oxford University Press    

年代:1974

数据来源: OUP