摘要:

Upper temperature limits were established for beet armyworm moths,Spodoptera exigua(Hübner) (Noctuidae), under controlled humidity–air flow conditions. Preliminary tests determined that a one-hour exposure to 45°C resulted in an approximately 50% reduction in the number of moths capable of flight following a 24-h recovery period. Subsequent tests using 45°C as the stress temperature indicated a rapid decline in thermal resistance of moths with increasing age. Moths maintained at each of 3 temperature regimes (22, 27, or 32°C) for 72 h post-emergence were inconsistent in their flight capabilities following exposure to the stress temperature. Developmentally acclimated moths whose pre-adult stages were reared at these 3 temperatures showed decreased heat resistance at the lower temperature, but inconsistent responses at the higher temperature. Flight capability of irradiated moths in the absence of heat stress was unaffected; however, flight capability following exposure to 45°C significantly decreased as dosage (20, 40, 80 krads) increased

ISSN:0046-225X    

DOI:10.1093/ee/3.2.290

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The color preferences of 3 thrips populations were determined by placing 7.5×12.7-cm painted cards coated with Stickem® on 1.3 m stakes in a rye field.Sericothrips variabilisBeach was most attracted to yellow,Anaphothrips obscurusMuller andFrankliniella fusca(Hinds) to yellow and white, andF. tritici(Fitch) to yellow and low ultraviolet remitting white surfaces. In the greenhouse, the thripsTaeniothrips simplex(Morison) was most attracted to orange. OnlyF. tritici, a general flower inhabitant, clearly distinguished between low and high UV remitting white surfaces. Dilutions of paints with zinc white (a low UV remitter) revealed a consistent linear relationship between the catch ofF. triticiand the percentage zinc white in the mixtures within the upper and lower limits of response. In a black-zinc white dilution series, the catch ofF. triticiincreased at a near linear rate with the logarithm of the increase in the mean percent remission from 400 to 660 nm. Dilutions of red or black with lead white (a high UV remitter) produced no distinctive responses; however, certain dilutions of yellow with lead white caught moreF. triticithan the corresponding zinc white dilutions. Responses to color glass filters placed over various white or metallic surfaces indicated a high preference ofF. triticifor surfaces which remit only the near UV, the visible spectrum above 500 nm or which have a strong peak remission in the blue-violet region. It was also confirmed that elimination of the near UV remission by lead white and by aluminum foil increased their attractiveness to the level of zinc white.Lead white borders (28 cm2) greatly reduced the catch of all thrips species on 7 cm2yellow center cards, and a white paper border greatly reduced the catch ofF. triticion all 5 colors tested.

ISSN:0046-225X    

DOI:10.1093/ee/3.2.295

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

One year after treatment of pasture plots with 9 insecticides, there were no statistically significant differences (P=0.05) between numbers of earthworms in treated and untreated plots. Chemical analyses of earthworms obtained 3 weeks after application of the insecticides showed more than 125 ppm of total DDT residues, 22.52 ppm of the sulphone of Dasanit® (O,O-diethylO(p-(methyl sulfinyl) phenyl) phosphorothioate), 9.66 ppm of chlorpyrifos and 26.33 ppm of Bayer 37289 (O, ethylO-(2,4,5-trichloro-phenyl) ethyl phosphonothioate). Other residues were negligible. After one year, residues of only DDT and its metabolites were detected in appreciable amounts.

ISSN:0046-225X    

DOI:10.1093/ee/3.2.305

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

The sensitivity ofTrichoplusia ni(Hübner) eggs to gamma irradiation depended upon age and dose: no hatch occurred when 0- to 24-h-old eggs were exposed to 4 krad, 24- to 48-h-old eggs were exposed to 30 krad, or 48- to 72-h-old eggs were exposed to 70 krad. Also, when 24- to 48-h-old eggs were treated with 15 and 20 krad, none of the larvae pupated, but when they were treated with 10 krad, 6% pupated; even when these eggs were exposed to only 4–5 krad, the percentage that pupated, that emerged as normal adults, or that mated was lower than in the control. There were little differences in results between eggs irradiated when 24–48 hand 48–72 h old. Eggs 48–72 h old irradiated with 1.5–3.5 krad produced females that were more sterile than similarly exposed males, but the sterility was not sufficient to permit the use of the females in a sterile-insect release program. All Flprogeny of parents from treated eggs were fertile

ISSN:0046-225X    

DOI:10.1093/ee/3.2.309

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

A method is proposed for calculating the amount of interstitial space, or habitat space in the L or O1layer of the hardwood forest floor. Assessment of habitat space may be useful for comparing litter environments in studies of litter-dwelling arthropods and other invertebrates. The method, an extension of the standard litter measures of depth and volume, includes litter structure as a quantitative factor. Data indicate that habitat space in the litter layer varies with structural composition and moisture accumulation.

ISSN:0046-225X    

DOI:10.1093/ee/3.2.313

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

A multifactorial experiment was conducted to determine the relative influence of photoperiod, temperature, water content of the diet, and parental age on the induction of diapause in an Arizona strain ofPectinophora gossypiella(Saunders) reared on a wheat germ-casein diet. The highest level of diapause (100%) occurred when the following conditions were combined: (1) 11-h daily photoperiod; (2) 19°C; (3) low water content of the larval diet; and (4) larval progeny were derived from eggs laid by young (3-day-old) females. If larval progeny were derived from older (10-day-old) parents or the larvae were reared on diet containing a higher water content, there was a significant reduction in the incidence of diapause. Photoperiod and temperature were the predominant factors in the induction of diapause, but dryness of the larval diet and parental age significantly influenced the overall level of response.

ISSN:0046-225X    

DOI:10.1093/ee/3.2.316

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Laboratory and field cage studies were conducted to determine the degree of successful parasitization by selectedTrichogrammastocks for the eggs ofHeliothis zea(Boddie), the bollworm, andTrichoplusia ni(Hübner), the cabbage looper.The laboratory studies showed significant increases in female longevity, number of eggs successfully parasitized, and progeny production whenH. zeaeggs were used as hosts.Two types of field cage experiments were conducted in cotton fields. The 1st type, which had eitherH. zeaorT. niegg cards in a given field cage, indicated that twice as manyH. zeaegg cards were found. The 2nd type of experiment had both hosts in varying proportions in each cage, and showed that a higher proportion ofH. zeaeggs were successfully parasitized even whenT. nieggs were more abundant.

ISSN:0046-225X    

DOI:10.1093/ee/3.2.319

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Rhythms of flight and ambulatory activity ofPlecia nearcticaHardy were determined by field observation and remote monitoring to be bimodal-diurnal. Light was not essential for mating in these insects, but they required light and an ambient temperature of at least 20°C for sustained flight. “Hovering flights” occurred early and late in the day; dispersal and “searching flights” occurred mainly during the afternoon. Feeding was necessary to the survival of field-collected adults in the laboratory. These males and females lived ca. 3 and 5 days, respectively. Periodicity was similar for both sexes, but males were the most active fliers.

ISSN:0046-225X    

DOI:10.1093/ee/3.2.323

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

AdultPieris rapae(L.) collected from a collard field that had been treated with an aqueous solution of rubidium chloride were found to contain levels of Rb significantly above the levels of those collected near untreated vegetables. Ordinary rubidium can therefore be used as a tag for native phytophagous insects.

ISSN:0046-225X    

DOI:10.1093/ee/3.2.327

出版商:Oxford University Press    

年代:1974

数据来源: OUP

摘要:

Over 11,000 microlepidoptera pupae were randomly collected over a one week period in June 1972 from a mixed oak forest in central Pennsylvania. Of the adults emerging (58.87%), 98.67% wereArchips semiferanus(Walker). Males emerged earlier than females; a sex ratio of 1.22 ♂:1 ♀ was found.Six Hymenoptera pupal parasites were observed, withItoplectis conquisitor(Say) (3.52%) andPhaeogenes gilvilabrisAllen (2.62%) the most common.A. semiferanusis the 1st reported host forP. gilvilabris. The male parasites emerged earlier than the females with the following sex ratio:I. conquisitor, 2.10 ♂:1 ♀;P. gilvilabris, 3.70 ♂: 1 ♀. In general male Hymenoptera parasites emerged from maleA. semiferanuspupae, and female parasites from female hosts.

ISSN:0046-225X    

DOI:10.1093/ee/3.2.329

出版商:Oxford University Press    

年代:1974

数据来源: OUP