摘要:

Simulium penobscotensisSnoddy and Bauer preferentially colonized vegetation of the generaPotamogetonandSparganumat water velocities ≥ 0.30 m/sec. ThePotamogetonandSparganumvegetation was primarily in water<1.25 m in depth, and in beds with 50–100% vegetation cover. There was an 80% increase in potential habitat of this description when Penobscot River water levels increased by 40 cm.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.412

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

The effect of trap heights above soil surface was determined when traps of different heights were competing to attract released boll weevils,Anthonomus grandisBoheman, and where the heights were separate and not competing for capture of the same weevils. Other factors compared in the same way were trap color, trap design, grandlure concentration, and ratio of the 4 grandlure components. These tests were conducted to determine the degree of bias that may result when trap factors compete for a natural field population of boll weevils. The importance of trap height, color, design and grandlure concentration was less in noncompetitive tests; however, 30:40:30 and 50:33:17 ratios of grandlure compounds I:II:III&IV were equally effective in both comparisons.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.416

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

The life history and seasonal population growth of the southern red mite,Oligonychus ilicis(McGregor), infestingIlex crenata‘Convexa’ are reported. Mean developmental times (in days) at 24°C are: egg incubation, 6.5; active larva, 1.4; quiescent larva, 1.0; active protonymph, 0.9; quiescent protonymph, 0.9; active deutonymph, 0.9; and quiescent deutonymph, 1.1. Females deposit 2.4 eggs/day, totaling 36 eggs/lifetime. Adults live for 16.5 days at 24°C.Field population growth ofO. iliciswas compared in random counts of mites infesting carbaryl-treated and untreated Japanese hollies during the 1977 season. Treated groups showed a 6-fold increase in the number of immature mites and a 13-fold increase in the number of adult females and eggs compared to populations on untreated hosts. Populations peaked in November at 387 females/100 carbaryl-treated leaves and 25 females/100 untreated leaves. Treated populations produced 50.9 diapausing eggs/leaf and resulted in severe injury to host fOliage as compared to only 3.8 overwintering eggs/leaf and no leaf damage on untreated hollies. Neither the treated nor untreated populations followed the seasonal population growth pattern previously described. Data suggest these differences are attributable to the adverse effects of carbaryl on indigenous predatory populations.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.420

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

A list of mites (Acarina) on leaves, twigs, and trunk from 10 sprayed and 13 nonsprayed apple orchards in North Carolina during the period 1968–70 was prepared. This list was compared with similar but less extensive study conducted in 1954. The phytoseiid,Neoseiulus fallacis(Garman) was the dominant phytoseiid in sprayed orchards in 1968–70 but was not collected in 1954. Eighty-one species of mites (26 gamasids, 39 actinedids, 4 acarids, and 12 oribatids) have been recorded from apple trees in North Carolina.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.425

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Foraging honey bees (Apis melliferaL.), exposed to birdsfoot trefoil (Lotus corniculatusL.) bloom treated with microencapsulated methyl parathion, continued to display pollen and midgut microcapsule contamination up to 9 days postspray. Nearly 10% of all pollen storage cells examined in combs taken from honey bee colonies exposed to the treated area were found to contain microcapsules.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.430

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Five populations of the red milkweed beetle,Tetraopes tetraopthalmus(Forster) (Coleoptera: Cerambycidae), in central Vermont and New Hampshire were sampled throughout the season and individual beetles were flight tested. The vagility of the populations (mean flight duration per sample) varied significantly during the season, with peak vagility coinciding with the flowering peak of its host plant during the 1st 3 wks of July. The findings show that it is possible to predict seasonal variation in vagility using basic life history information — lifespan, emergence times, and age-related patterns of vagility. Implications for pest management are suggested.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.432

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

A field trial on apples in southeastern England showed that pre-bloom “pink bud” sprays of 4 synthetic pyrethroids—permethrin, cypermethrin, fenvalerate, and decamethrin, were all highly toxic to the predatory miteTyphlodromus pyri, but had no appreciable toxicity to the dominant spider mite species,Panonychus ulmi. The virtual elimination of the predatory mite at this growth stage of apples led to a marked population increase ofP. ulmilater in the same season. The use of these pyrethroids for insect control is incompatible with integrated mite management on apples usingT. pyri. Laboratory data supported the field results.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.436

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

The relative diurnal and weekly abundance of the most common natural enemies of the green peach aphid,Myzus persicae(Sulzer, was determined in a potato field in 1977. Two sampling methods were also compared for use in sampling the natural enemies. Groundcloth samples were taken 4 times a day, twice weekly, for 7 wk during the growing season. A natural enemy sampling scheme was developed from the informatlon collected.Coleomegilla maculata(DeGeed adults (Coleoptera: Coccinellidae) and coccinellid larvae were the most abundant green peach aphid natural enemies collected. Linear models significantly explained the relationship between counts forC. maculataadults and degree days, and between counts for coccinellid larvae and degree days. The 0900–1115 period was the least variable sampling period tested for samplingC. maculataadults according to the results of a chi-square analysis on the ranks of the diurnal means. The groundcloth sampling technique was chosen for use in future studies because it is an absolute and non-destructive sampling method, and because it more accurately estimated the size of the larval coccinellid population peak than the other method tested. The between samples variance was the largest component of the variation in the experiment according to a variance component analysis.Coccinellid larvae were aggregated on a stem on 3 of 4 sample dates near the larval population peak according to a chi-square analysis on the variance:mean ratios.C. maculataadults were aggregated on a stem on only the last sample date, when many mating pairs were observed.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.440

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Diel and seasonal patterns of flight activity ofCulicoides variipennis(Coquillett),C. crepuscularisMalloch,C. hieroglyphicusMalloch, andC. palmeraeJames (Diptera: Ceratopogonidae) were studied in northeastern Colorado.Culicoides variipenniswas active Mar.–Nov., flying in the late afternoon in Mar., Apr., and Nov., throughout the diel pehod in May, June, Sept., and Oct., and during scotophase in July and Aug. Diel activity was greatest near sunset but sometimes increased near sunrise. Flight activity also increased during periods of moonlight. Flight was not observed at temp35°C.Culicoides crepusculariswas active May–Nov. Diel flight activity was greatest immediately after sunset, diminished during late scotophase, but increased occasionally near sunrise or during early photophase. Numbers ofC. crepuscularismales in flight increased during periods of moonlight.Culicoides hieroglyphicusandC. palmeraewere active Apr.–Oct. and May–June, respectively. Patterns of flight activity of both species were apparently a modal, but the greatest numbers were collected in the afternoon in June.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.446

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

A low-frequency, sodar (sound detecting and ranging) set was designed, constructed, and tested in cotton fields to detect flying tobacco budworm moths attracted at night to sex attractant dispensed from the sonic transmitter site. Counts made by the sodar set were compared with numbers of male budworms caught in traps baited with either synthetic pheromone or live female moths. Peak sonic transmission power was<25 W/2 ms at a 1.2% transmit-receive duty cycle. With sensitivity set at an effective range of 1 meter, the majority of moths counted by the battery-powered sodar set were tobacco budworms when their synthetic sex attractant was used as bait.

ISSN:1754-5692    

DOI:10.1093/ee/9.4.452

出版商:Oxford University Press    

年代:1980

数据来源: OUP