摘要:

Data on the colonization and extinction of arthropods onSpartina alternifloraand soybeans are used to investigate the value of applying equilibrium biogeographic theory to the pests of cultivated crops. Care must be taken in the design, definition of terms, and evaluation of results of such attempts at practical applications of the equilibrium model because many potentially troublesome results are not obvious a priori. Equilibrium biogeographic theory is an extension, but not a substitute for, careful study of the natural history of the system in question.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.577

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Apple arthropod pest systems may be approaching a turning point relative to chemical controls tactics. Organophosphate resistance has not been reported for any major key pest; it has been widespread among mites, aphids and leafhoppers, and it is known for several important natural enemy species. The potential for developed resistance to O-P compounds and newly developed synthetic pyrethroid insecticides in key pest species is discussed. Management of O-P resistance among pest and beneficial arthropods by manipulation of operational factors affecting resistance development may be a feasible approach to chemical management of apple arthropods.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.583

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

The female navel orangeworm,Amyelois transitella(Walker), produces a sex pheromone that elicits both sexual excitation and upwind flight of males in laboratory bioassays. Quantitative bioassays were developed that employed either orientation (upwind movement) or activation (locomotion, wing-fluttering, clasper extension) as response criteria.Pheromone was released by females only during the last ⅓ of a 10-h scotophase, a time that coincided with maximal male pheromone responsiveness and mating. There were no significant differences between 1-, 2-, 3-, or 4-day-old unmated females in either the percentage of females calling or in the quantity of pheromone present in the superficial rinses of of excised abdominal tips during the 8th–10th h of the scotophase. Similarly, no significant differences were observed in pheromone responsiveness in 2- to 3-, or 4-day-old unmated males. Mating resulted in>90% reduction in female calling and at least a 10-fold decrease in the quantity of extractable pheromone.The activation and orientation responses of laboratory males did not differ significantly when pheromone extracts were prepared from either laboratory-reared or feral (collected as last-instar larvae) females.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.587

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Phyllophaga crinita(Burmeister) adult flights were closely related to rainfall patterns. In the laboratory, adults did not oviposit in very wet or very dry soil. Eggs and larvae survived in a relatively wide range of soil moisture conditions, but survival for eggs and early-instar larvae was poor in very wet or dry soil. When given a choice of soil moisture conditions for oviposition, adults either did not oviposit in wet soil, or eggs that were deposited did not survive. The relationship of human watering patterns in urban environments to immature survival is discussed.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.591

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Prior to parasitoid establishment, citrus blackfly (CBF),Aleurocanthus woglumiAshby, averaged 40–60 live nymphs/infested leaf. Parasitoid-induced mortality reduced the infestation 98% to a level of one infested leaf during an 8-mo period. The current density of immature CBF averages 8±5/infested leaf and has been maintained at that level or lower for 18 mo. Life tables show that parasitoid-induced mortality is the critical factor responsible for the decline in CBF numbers and for the continued regulation of the CBF population at its present level.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.595

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Since green peach aphid,Myzus persicae(Sulzer), on sugarbeets displayed a negative binomial distribution, a sampling plan was devised in which the dispersion parameter k was used to estimate the number of aphids per plant based on the percentage of leaves infested. Sampling data of the 3rd year was used to validate the sampling model based on the 1st 2 years' data. A convenient and practical plan of sampling was developed using the percentage of large leaves infested to estimate the number of aphids per plant.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.598

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

The effects of varietal characteristics, leaf-feeding damage, plant age and plant size on oviposition by the imported cabbageworm,Pieris rapae(L.) on cabbage were investigated during a 3-yr period in Chesterfield Co., VA. Varietal characteristics as manifest in cultivars of savoy, smooth green and red cabbage significantly affected egg-laying (P<0.05). However, cultivar preference was not definitive and temporal variation occurred as the season progressed (P<0.05). Plant size and age significantly affected oviposition (P0.05). These findings are discussed in relation toP. rapae's oviposition behavior.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.606

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Fluorophenols have been evaluated as chemical attractants for males of the grass grub beetleCostelytra zealandica(White). Both 2-fluorophenol and 4-fluorophenol were attractive, whereas 3-fluorophenol was an inhibitor.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.610

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

A procedure for estimating the threshold temperature for egg development of the meadow spittlebug (Philaenus spumariusL.) is discussed. Utilizing both laboratory and field data, heat unit accumulations (HU) based on this threshold were used to calculate the length of the egg hatching period in order to predict egg hatch in the field. It was found that an accumulation of 120 HU (°C) above a threshold of 6.5°C resulted in initial egg hatch, but the egg hatching period was not completed until 330 HU were accumulated.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.612

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Adult bean leaf beetle diurnal cycle of distribution on soybean plants was studied by sweepnet and whole plant sampling. Catches of beetles were lowest between 1100 and 1300 h and highest after 1500 h with some changes as the season progressed. The diurnal population sampling fluctuations could not be related to any distinct change in the vertical distribution of either sex of teneral or mature beetles on the plant. The effect of bean leaf beetle diurnal population fluctuations on sampling is also discussed.

ISSN:1754-5692    

DOI:10.1093/ee/8.4.615

出版商:Oxford University Press    

年代:1979

数据来源: OUP