摘要:

In a southern California reservoir, benthic larval density of chironomid midges was assessed 10 times between Aug. 1974 and July 1975, at>1 m, 3–4 m, and 6–8 m water depths. Larvae belonging to 9 midge genera were taken.Tanytarsusspp.,Chironomusspp., andProcladiusspp. were predominant, forming more than 85% of the total chironomid larvae recovered on any sampling occasion from the entire basin. The monthly qualitative composition of midge fauna differed slightly between the 3 depth levels, but the quantitative composition changed markedly from one level to the next. Midge density was consistently higher in the>1 m deep areas than in the 3–4 m and the 6–8 m deep levels.Tanytarsusspp. were predominant at the>1 m depths.Chironomusspp. andProcladiusspp. were more prevalent in the other 2 deeper regions.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1071

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Species of the generaEretmocerusandEncarsia(Order: Hymenoptera, Family: Eulophidae) are parasites of the bandedwing whitefly,Trialeurodes abutilonea(Haldeman) in Louisiana cotton and soybean agroecosystems. In the order of their prevalence, they are:Eretmocerus haldemaniHoward,Encarsiaspecies (undescribed),Encarsia quaintanceiHoward, and EncarsiapergandiellaHoward.E. haldemaniis the predominant species both in cotton fields and in other host crop fields within cotton producing areas, accounting for ca. 70% of all parasites. Pupal parasitism was lower in cotton than other crop fields.Insect predators of the whitefly in Louisiana are as follows:Coleomegilla maculatalengiTimberlake,Coccinella novemnotataHerbst,Hippodamia convergensGuerin-Menaville,Olla abdominalis(Say),Delphastis pusillusLeConte;Geocoris punctipes(Say),Orius insidiosus(Say); species of Chrysopidae and Hemerobiidae; andNabisspecies. Mixtures of broad spectrum insecticides such as methyl parathion, toxaphene and DDT used in cotton fields for the control of boll weevil andHeliothisspecies were extremely harmful to both parasites and predators ofT. abutilonea.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1075

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The seasonal development of the European corn borer,Ostrinia nubilalis(Hübner) was studied in the Hudson Valley of New York from 1973 through 1975 in relation to the phenological events of selected woody and herbaceous perennial plants. Adult occurrence periods—the initiation of 1st brood flight, peak 1st brood flight, approach of inter-brood, initiation of inter-brood, initiation of 2nd brood flight and peak 2nd brood flight—were selectively correlated with various phenological events of 10 plant species. General relationships among phenological events of 14 plant species and 6 pupal occurrence periods were also found. Observance of the phenological events should forecast the occurrence of each European corn borer period in areas of the Northeast where the indicator plants and insect occur together.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1079

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

A model is derived for calculating the percent surface damage to Valencia oranges by populations ofPhyllocoptruta oleivora(Ashmead), taking account of a seasonally-varying damage rate. Accumulated area under mite population curves (mite-days) was linearly related to accumulated damage on fruit surfaces. Linear correlations for all times of the growing season were very high (0.927–0.996). The slope of the regression of mite-days on cumulative damage increased gradually over the season from 0.001%/mite/day in spring to 0.01%/mite/day in winter. Attempts to include temperature effects by putting mites on a degree-day time scale did not produce a more constant damage rate.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1083

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Sepedon fuscipennisLoew was reared in the laboratory under constant temperature regimes to determine the effect of temperature on several life history features. Developmental and oviposition rates are greatest at 30°C. Total survival of the immature stages is greatest at 33°C. The intrinsic rate of increase is positive over the 15–33°C range, and it peaks at 30°C where rm= 0.137 day−1. Adult longevity increases as temperature decreases. Total fecundity is highest at 21°C. In the laboratory, most adults live beyond the age at which they contribute significantly to the intrinsic rate of increase.S. fuscipennisis a typical polyvoltine species exhibiting imaginal facultative diapause. Diapause is characterized by cessation of ovarian development, cessation of spermatogenesis, and hypertrophy of fat bodies. Both temperature and photoperiod influence diapause induction in the sensitive and responsive adult stage.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1089

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Although the European corn borer,Ostrinia nubilalis(Hübner), began flight shortly after dusk, capture of feral males in traps baited with virgin females or feral males and females captured in light traps and studies of released insects in cultivated and uncultivated corn showed that this early evening activity is not oriented toward mating. Sexual activity peaked between 2400 and 0100 h, and most of it took place in tall (57.5–117.5 cm), dense foxtailgrass (Setaria faberiiHerrn. andS. viridis(L.) Beaur.), where large numbers of both sexes aggregated. Aggregation and sexual activity occurred as much as 100 m from the nearest cornfield. The grass habitat is of major importance in the aggregating phenomenon though pheromone emission by females may also have a part. Techniques employed to disrupt pheromone communication between the sexes in cornfields might be futile because mating could occur in dense vegetation outside the cornfield.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1099

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Overwintering mortality of cagedRhinocyllus conicusFroelich, a weevil successfully introduced from France for the biological control ofCarduusthistles in Virginia, was studied over 4 consecutive winters. Mean mortality was 52.0±6.3%. Males suffered slightly lower mortality than females, but the difference was not significant. Prolonged caging as well as excessive moisture in cages caused significantly (P>0.01) increased mortality. Preferred overwintering sites were the thistle plant and its vicinity, cage corners, and excised thistle heads.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1105

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Static air and air-flow olfactometer results failed to substantiate earlier published reports of a volatile female sex pheromone in the mosquitoCuliseta inornata(Williston). Further investigations revealed that after male-female contact, stimuli on female legs are of prime importance in releasing male copulatory behavior. These leg-associated stimuli are rather species-specific, and they disappear slowly after the death of a female.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1109

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Methyl parathion was applied to Clear Lake at a rate of 3.3 ppb for control ofChaoborus astictopusDyar&Shannon. Three treatments at 20-day intervals had no lasting impact on zooplankton. Recovery to near or above pretreatment numbers was rapid for the organisms examined, including copepod nauplii,Diaptomus franciscanusLilljeborg,Cyclopssp.,Mesocyclopsspp.,Daphniaspp.,Bosmina longirostris(O. F. Muller),Diaphanosoma brachyurum(Lieven) andCeriodaphnia reticulata(Jurine).No residues were detected in lake sediments. Highest residues in water were found 8 and 24 h after the treatments, varying from 0.5–5.4 ppb, and generally declining after each treatment. However, generally larger residues were found with each successive treatment. Residues in bluegill sunfish,Lepomis macrochirusRafinesque, exposed to the treatments in live cars, varied from 11–110 ppb. A significant correlation was found between the methyl parathion levels in fish and water collected simultaneously.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1116

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Only 2 parasites of the larch sawfly,Pristiphora erichsonii(Hartig), were found in all 16 study plots in northern Minnesota from 1970–72: the tachina flyBessa harveyi(Townsend) averaged 30% parasitism over all plots; and the ichneumonMesoleius tenthredinisMorley seldom exceeded 10% parasitism. Approximately 26% of theB. harveyiadults emerged in late-summer rather than the more beneficial spring emergence.Olesicampe benefactorHinz, an ichneumon introduced into Minnesota in 1971 and 1972, was recovered from all 8 release plots. Parasitism reached 48% in one release plot, but was ca. 2% in other release plots by 1972. Dispersal into Minnesota, from releases in 1961 in Manitoba, was conspicuous by 1972 whenO. benefactorwas recovered from 5 of 8 check plots.Mesochorus dimidiatusHolmgren, an ichneumon hyperparasite ofO. benefactor, was found in Minnesota for the 1st time.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1121

出版商:Oxford University Press    

年代:1976

数据来源: OUP