摘要:

Pest management, as a philosophy of pest control, has to displace the pesticide approach to pest problem solving in most agricultural production systems. Progress, to date, has been slow. The existence and maintenance of pesticide addiction has inhibited the acceptance of pest management philosophy by corn producers. Pesticide addiction has been supported by the agricultural establishment in various ways, including use of worst-case data, unjustifiable extrapolation of small plot data, unrealistic loss summation for various pests, and selective data use. Pest managers must understand the forces that directly or indirectly oppose establishment of the pest management philosophy to be able to promote its use.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.567

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

An equation based on enzyme kinetics was used to describe the effects of temperature on poikilothermic activity rates. This equation successfully described change in activity rates for both a variety of poikilotherms and rates including: photosynthetic, O2consumption, glucose oxidation, handling, search, and generation rates. All of the data sets tested had r2values greater than 0.92. This equation was the major component of a model predicting the interaction of temperature and a limiting nutrient on an activity rate. The model was developed from the case, where Kmis considered to be the product of two temperature dependent rates and allowed Kmis to be a simple or complex function of temperature. The model successfully described the interaction of temperature and limiting nutrient on rates from two data sets.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.573

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Behavior of adult alfalfa weevils,Hypera postica(Gyllenhal), was observed in free-choice arenas containing 1)Medicago sativaL. and glandular-hairedM. rugosaDesr. and 2) 4 glandular-haired annualMedicagospecies:M. blancheanaBoiss.,M. disciformisDC.,M. rugosa, andM. scutellata(L.) Mill.The weevils made significantly fewer contacts withM. rugosathan withM. sativain the first 30 minutes of the test. Also, the mean duration of the visits onM. rugosawas significantly shorter than that onM. sativa. Both pre-contact cues (olfactory or visual) and contact cues (chemotactic or mechanical) appeared to be used by the adults in rejectingM. rugosain favor ofM. sativa.The number of initial weevil contacts with each species did not differ significantly in a free-choice test with 4 glandular-haired species. However, significantly more weevils stayed onM. disciformisthan onM. blancheanaandM. rugosa. Differences betweenM. disciformisandM. scutellatawere nonsignificant. Contact cues (unlike pre-contact cues) appeared important to the weevils since these four nonpreferred species differed in the mean number of weevils visiting plants.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.580

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Measurements of the supercooling points of eggs of the gypsy moth,Lymantria disparL. (Lepidoptera: Lymantriidae), collected in two sites in Quebec, at various levels above the ground, indicate that the species is well able to withstand the Quebec winter. A high percentage of egg masses were laid above snow cover level, but winter mortality was never higher than 39.7%. Winter mortality was, however, positively correlated with the length of exposure to low winter temperatures and to the degree of cold experienced, and these two factors were affected by a protective snow cover.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.586

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

The deer flies,Chrysops atlanticus, are important pests of humans which move from the salt marsh and concentrate in wooded areas, especially along field edges. Studies at four sites showed that<2% of the deer flies attracted to a human host occur 50 and 100 m into the field whereas 64% were encountered at the field margin and the rest in the ecotone and on the salt marsh. No concentration of flies occurred where no vegetative barrier was present between the marsh and fields. More flies were taken in the morning than at noon and in the late afternoon during June and July near Cedarville, N.J.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.590

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

The ecology of the dry-season populations ofAedes Stegomyiamosquitoes was studied in Use, Uyo, Cross River State, Nigeria, between November 1977 and May 1978.The adult insects were sampled by two collection methods: (1) crepuscular human bait and (2) sweep-netting from forest and village (outdoor and indoor) locations. Oviposition and breeding habits of the insects were assessed from CDC ovitrap collections and from a survey of larval presence in domestic and peri-domestic containers. In each case, insects were sampled in the months of November, January, March, and May, corresponding with the early, mid, and late dry season, and the early rainy season, respectively.Fourteen species ofAedesmosquitoes, including fourAedes(Stegomyia) species, were found. Numbers and distribution of the species varied with the months and sampling methods. AdultAedes(Stegomyia) were most numerous in indoor and outdoor crepuscular human bait collections and least in forest sweep-net collections.Aedes aegyptiandA. africanuswere the most collected species. Unlike most otherAedesspp., they were consistently well represented in all the dry-season samples. Larval indices showed predominant breeding ofAedes(Stegomyia) species in peridomestic locations throughout the dry season, as well as the ecological adjustment to a container breeding habit by some otherwise well-known tree hole and pool breeding forms.Factors involved in the dry-season survival of the variousAedesspp. are discussed with reference to the possible implications of the insects' domesticity and year-round breeding activity.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.592

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Honey bee colonies under a 765-kV power line (electric field [E-field[ 7 kV/m) showed effects, with hive height and weather-influenced hive current distribution the controlling factors. Hive current was a mean of 59 μA(= 1 m hive height) or 85 μA (1.5 m). Shielded controls under the line had E-fields and hive currents 150- to 300- fold and 100-fold lower, respectively, than exposed hives. Groups were exposed or shielded 8 or 16 weeks, with treatment reversal for some at week 8. A 16-week exposure did not affect percent honey moisture or teneral adult weight. When first exposed, colonies exhibited pronounced but transient elevations in temperature. Capped brood was normal in exposed 1-m hives but declined (P<0.01) in 1.5-m hives by week 4, associated with higher incidence of queen loss and queen cells and colony failure. Weight gain was depressed in all exposed hives after 2 weeks, being severe in 1.5-m hives (P<0.001 at week 5) and intermediate in 1-m hives (P = 0.05 at week 8). Effects were more pronounced the first 8 weeks than the last 8. Painted hive interiors reduced bio-effects, presumably by reducing internal current flow. Only exposed colonies propolized hive entrances, but amount and time of onset were not dose related. Treatment reversal at midseason resulted in reversal of colony behavior, manifested more with hive weight than brood. Overwinter survival of exposed groups was ≤29% compared with ≥71% among shielded ones.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.600

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

AdultPissodes strobiactivity and brood production were compared at spruce plantations with high and low weevil infestation levels. During 2 years of observation, weevil activity started ca. 30 days earlier at the heavily infested plantation. Caging adults on terminals at both sites showed that the subsequent brood mortality was significantly higher at the plantation with low weevil damage. Poor brood survival was attributed mainly to resinosis.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.611

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

A 12-sided carrion bait trap permits omnidirectional sampling of arthropods. A system of eight immigrant and four emigrant funnels allows simultaneous sampling of immigrating and emigrating populations. Morrill's solution is the preferred general killing and preserving agent.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.615

出版商:Oxford University Press    

年代:1981

数据来源: OUP

摘要:

Rates of development were compared between lines ofTribolium castaneumselected for high and low responsiveness of egg production to conditioned medium. The selection lines were established from four strains which were each derived from another wild population in Israel. Each high-response line was compared with the low-response line of the same strain. All experiments were carried out in fresh medium. In three of the four comparisons, the high-response line proved to have a higher rate of development than the corresponding low-response line. It is suggested that the variability for responsiveness in natural populations is maintained by a balance between the selective advantage of the high responders in optimal environments and their selective disadvantage in suboptimal environments.

ISSN:0046-225X    

DOI:10.1093/ee/10.5.618

出版商:Oxford University Press    

年代:1981

数据来源: OUP