摘要:

A population model of the codling moth,Laspeyresia pomonella(L.), is presented which simulates population behavior over several years. Derivation of the theoretical and biological structure of this model is discussed on a state by state basis. Each transition equation is developed around a central framework which separates density-dependent and -independent effects. These equations are then fitted to observed data.The transition equations are assembled into a computer program, CODMOTH. Output from this program shows acceptable agreement with observed data from field and laboratory, indicating that the model can adequately simulate population behavior for at least 5 yr.Model sensitivity to equation parameters and program constants is examined to determine the allowable error for these values. Model output varies by only 10% if a parameter is changed by an avg of 45%.The significance of the density-dependence component of each equation is examined. Feedback processes are found to be most important in the fecundity and 1st-instar survival equations. Sex ratio and voltinism are least affected while larval survival within the apple and survival to cocooning sites are intermediately affected.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.219

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The distribution and activities of honey bees (Apis melliferaL.) foraging on alfalfa (Medicago sativaL.), safflower (Carthamnus tinctoriusL.), and yellow star thistle (Centaurea solstitialisL.) were determined by magnetically recovering 74.9% of 3200 tags applied to bees foraging in the fields. Common Italian stock was compared with “Hy-Queen” stock selected for alfalfa preference and high pollen collection.A significantly shorter foraging distance was detected for Hy-Queen stock to yellow star thistle but not to alfalfa or safflower. Mean foraging distances to the combined floral sources were 404 m for common Italian and 357 m for Hy-Queen stocks. Other foraging activities, including pollen collection, were similar for both stocks. The foraging activity and distance of alfalfa foragers gradually increased each day after colony relocation until observations ceased 7 days later.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.228

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The distribution and foraging activities of honey bees (Apis melliferaL.) were compared for common Italian and Hy-Queen stocks, the latter selected for alfalfa (Medicago sativaL.) preference and high pollen collection from general sources. The experimental area contained 674 colonies in 27 apiaries. Foraging bees (4000) were collected throughout an alfalfa field (34.0 ha) and tagged with metal discs that were recovered (78.1%) magnetically at hives. Most (81.6%) alfalfa foragers originated from 263 colonies in 12 apiaries at the field. Territorial dominance was evident by bees from the nearest apiaries.Mean foraging distances were 338±56.7 m (common stock) and 237±13.9 m (Hy-queen). Pollen collection from all sources was greater for Hy-Queen (37.9%) than for common stock (30.9%). Stocks were very similar otherwise.Only 1.4% of the alfalfa foragers carried pollen loads, 84.2% of which were from other plant species in the area. Nectar loads of bees collected during foraging were small (mean range = 5.2–9.2μliters) and independent of pollen foraging activity.Weak apparent preference for alfalfa by Hy-Queen stock may be caused in part by a genetically reduced foraging distance.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.233

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

In an attempt to better understand the host-parasite relationship of the alfalfa weevil,Hypera postica(Gyllenhal) (Coleoptera:Curculionidae) andBathyplectes curculionis(Thomson) (Hymenoptera:Ichneumonidae), all life stages of the parasite were monitored throughout the spring. Sampling was conducted on a degree day basis from early March–late May in an alfalfa field in Mason County, Illinois.Dissections of host alfalfa weevil larvae revealed 2nd and 3rd host instars were preferred larvae for oviposition. Peak parasite densities were found to precede peak total host larval densities, but coincided with peak densities of the preferred 2nd and 3rd instars. Larger host instars were superparasitized at a higher rate than smaller instars.The standard procedure for determining percent parasitism in an alfalfa field by rearing large larvae was found to give an artificially high estimate, compared to dissection.Insecticide treatments in central Illinois coincide with peak spring emergence of the parasite. A method for predicting spring emergence is suggested that may enable insecticide applications to be adjusted around the parasite population.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.241

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

A factorial experiment utilizing bovine manure type, time of day, and distance from a barn as the independent variables, showed that the number of house fly and face fly pupae recovered from exposed samples varied in response to their preferred habitat. Analysis of variance showed distance from a barn and manure type to be significant factors influencing house fly pupal recovery while showing all 3 factors to be significant in influencing face fly pupal recovery. Curvilinear regression curves showed the greatest recovery of face fly pupae to be from grass manure and an equal mixture of grass and grain manure exposed at 100, 200, and 300 m from the barn between 9:00 a.m. and noon. House fly pupae were recovered almost exclusively from grain manure samples exposed at 0 m from the bam. Approximately equal quantities of house fly pupae were recovered from the samples exposed at 9:00 a.m., noon, and 3:00 p.m.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.246

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Five exotic parasite species of the European corn borer,Ostrinia nubilalis(Hbn.), were introduced into Nebraska in 1948–1950. Only 3 species became established: a tachinid,Lydella thompsoniHerting (=grissescensRobineau-Desvoidy of Authors); an ichneumonid,Eriborus terebrans(Gravenhorst) (=Horogenes punctorius(Roman)); and a eulophid,Sympiesis viridula(Thomson) (=Eulophus viridulus). Population trends forL. thompsoniandE. terebransare reported for 2 counties for the years 1957–1971. No evidence has been found ofL. thompsonisince 1965 butE. terebranswas widespread and present in low numbers in 1975 and 1976.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.249

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Recent literature described the potentiating effects of several herbicides on the contact toxicity of a large number of insecticides to certain Diptera. This effect appeared to be general and might pose a hazard to foraging honey bees. Bees were offered both herbicides and insecticides (carbamates and organophosphates). There appears to be no additional danger to honey bees through co-ingestion of these pesticides.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.254

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Coleophora klimeschiellaToll, whose larvae feed as case bearers on the foliage of Russian thistle,Salsola ibericaSennen and Pau, was introduced into quarantine in the U. S. in 1975. Detailed oviposition and larval feeding tests were conducted during 1975–76 on closely related plants and crop and ornamental species. Although eggs were laid on several non-host plant species, the insect was not able to complete larval development on any plant tested except Russian thistle.Coleophora klimeschiellahas been approved for field release by state and federal agencies.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.257

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Survival of colonies of the red imported fire ant,Solenopsis invictaBuren, during the record-breaking low winter temperatures of 1976–77 was low (4–42%) in the Piedmont Plateau in central Georgia. Most surviving colonies were near trees or ditches which were protective weather barriers. Occasionally, colonies survived in open unprotected fields. Provision of supplemental food did not increase survival. Mortality was low in the Coastal Plain in southern Georgia.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.262

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Preaestival cereal leaf beetles,Oulema melanopus(L.), that fed on the 1st blade of corn died significantly sooner than starved beetles. Approximately ⅔ of the preaestival beetles that fed on the 3rd blade of corn died with the remaining beetles aestivating. Postaestival beetles that fed on the 1st blade of corn died at the same rate as postaestival starved beetles, although they ate significantly more and lived longer than preaestival beetles. An anomaly exists between the feeding and survival of pre- and postaestival beetles in that preaestival beetles, although they ate less of the 1st blade of corn, died sooner than postaestival beetles that had eaten more. Although the 1st blade was apparently less toxic to postaestival beetles, postaestival survival on 1st-blade corn was very similar to the survival of starved beetles. Corn appears to be nutritionally unusable by postaestival beetles which may be the reason beetles avoid seedling corn in the spring. Newly emerged preaestival beetles can be distinguished from postaestival beetles because the tergites under the elytra of preaestival beetles are light yellow and remain so until several days after feeding is initiated; the tergites of postaestival beetles are dark.

ISSN:0046-225X    

DOI:10.1093/ee/7.2.265

出版商:Oxford University Press    

年代:1978

数据来源: OUP