摘要:

Standard-size (10-frame Langstroth) field colonies of honey bees,Apis melliferaL., located in an area that forced the bees to accept offered food because of lack of natural bee forage, were fed long-term, controlled low doses of carbofuran in sucrose syrup throughout the summers of 1976 and 1977. The effect of poisoning on queens by feeding carbofuran at any level that killed colonies was indirect, because queen mortality was related to insufficient care through lack of attendants to feed, groom, and regulate temperatures vital to queen survival. Queens were fed mostly glandular secretions by attendants, rather than honey or pollen, and evidently the glandular food contained no poison. Feeding honey bee colonies sucrose syrup contaming 0.1- or 0.01-ppm carbofuran did little to impede survival of sealed brood or adult bees to maintain the population of colonies at functional levels. However, 1.0-ppm carbofuran was the threshold of serious damage; colonies fed this level of the insecticide sustained continual reduction of sealed brood and adult bees that led to eventual death of these colonies in the winter.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.53

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Heliothis virescens(Fabricius) eggs labeled with radioactive phosphorus were placed in an east Texas cotton field, and 777 radioactive arthropods were later captured. These captures consisted of 12 species and 3 arthropods identified only to family. Singularly placedH. virescenseggs exposed to predation after the onset of pinhead squaring averaged 77% predation in 24 h. When all nonflying predators were excluded from plants, egg predation averaged 46%, and on plants where nonflying predators and alate predators were unable to penetrate the 42-cm2mesh, egg predation averaged 34%. The seasonal cumulative percent predation onH. virescenseggs averaged 77.6 and 86.6 for 24 h and 48 h, respectively. D-Vac® sampling of predator numbers and whole-plant sampling of theHeliothisspp. egg numbers revealed a seasonal mean of 137:1 (predator-to-egg ratio). The equation Y = 71.449 (X)0.194, X>0 with an r value of 0.60 predicts the expected percentHeliothisspp. egg predation, using the log predator-to-egg ratio as the rredictor. Predator efficiency values were calculated for several species or groups of species and presented as number of eggs individually consumed per 24 h. Eggs consumed per individual per day ranged from 14.2 eggs forChiracanthium inclusum(Hentz) to 0.3 eggs consumed bySolenopsis invictaBuren.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.60

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

The effect of pesticides on development ofBeauveria bassiana(Balsamo) was examined both in liquid culture and in the field. The commonly recommended lateblight fungicides and insecticides inhibited growth ofB. bassiana. The experimental fungicide CGA48988 and the insecticide permethrin showed the least inhibition of the fungus. Field experiments with the Colorado potato beetle,Leptinotarsa decemlineata(Say), supported laboratory findings.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.67

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Flower heads and peduncles of musk thistle,Carduus thoermeriWeinmann, and flower heads of plumeless thistle,Carduus acanthoidesL., infested withRhinocyllus conicusFroelich were collected to study parasitism of the different developmental stages of the weevil in 1978 and 1979. No parasites of eggs or adults were found. Major larval-pupal parasites wereBracon mellitor(Say) (Braconidae),Nealiolus curculionis(previously known asAliolus curculionis) (Fitch) (Braconidae),Zatropissp. (Pteromalidae), andNeocatolaccussp. (Pteromalidae).B. mellitor,N. curculionis, andZatropissp. attackedR. conicusover a 4-week period; parasitism was greatest during the first 2 weeks of July. Rate of parasitization differed between locations on thistle plants, thistle species, sites with different periods of weevil establishment, years of collections, and sample date. Although high levels of parastization sometimes occurred, the overall rate was low.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.71

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Resurgence ofNilaparvata lugens(Stål) after insecticide application is a common phenomenon in rice in South and Southeast Asia. Among other insecticides inducing resurgence, carbofuran, decamethrin, and methyl parathion were selected for this study. Of the various methods of carbofuran application tested, foliar sprays were most active in inducing resurgence. Extent of resurgence was highly influenced by time of insecticide application. Sprays of methyl parathion and decamethrin applied 50 and 65 days after transplanting (DT) induced resurgence in the third generation ofN. lugensat ca. 90 DT, whereas earlier applications had little effect. The cause(s) for resurgence was not definitely established, but stimulation ofN. lugensreproduction appeared to be of more significance than destruction of natural enemies.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.78

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

The release of an insect pest-resistant variety and subsequent adaptation of the insect species to that variety through the process of biotype selection has occurred on many cultivated crops. The present study was designed to obtain detailed information on some of the processes involved in the selection of biotypes ofNilaparvata lugens(Stål) on two rice varieties with different major genes for resistance. TheN. Lugenspopulation selected for the study, which had originally been collected in the field and reared on a susceptible variety for 12 years (ca. 140 generations), initially had a low survival on the resistant rice varieties Mudgo (Bph 1 gene) and ASD7 (bph 2 gene) and high survival on the susceptible variety, Taichung Native 1 (TN1). Monitoring the survival and length of the developmental period for seven generations indicated a progressive increase in the survival and shortening of the nymphal period in each generation on the heretofore resistant varieties until they were similar to those on TN1. The shift in the population to a more virulent biotype was also confirmed by the seedling bulk test. The selected populations reared on Mudgo or ASD7 were not able to kill Mudgo or ASD7, respectively, in the fifth generation but by the eighth generation were able to do so. In addition, adult longevity and fecundity on the resistant varieties increased during the selection process.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.85

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Movement of all instars ofHippodamia convergensGuérin-Méneville was affected by the sticky exudates of leaf trichomes of tobacco cultivars. The younger the instar and the longer the larvae were on these leaves, the greater was the inhibition of movement. The alkaloid content of the plant had no effect on movement.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.91

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Honey bees were trained to fly 400 m from their colony to an indoor laboratory foraging arena exposed to 2.45 GHz continuous wave microwaves at 5 power densities (0, 5, 10, 20, and 40 mW/cm2). Foraging behavior did not differ from controls foraging within an unexposed sham arena in (1) number of round trips completed during a 3-h exposure session, (2) round trip time between the colony and the foraging arena, and (3) the length of time required to navigate the illuminated foraging arena. This study indicates that honey bees would not be adversely affected by foraging within a similar microwave field that would exist in future receivmg antennae for the proposed solar power satellite energy transmission system in which power levels are expected to range from 23 mW/cm2at the antenna center to 1 mW/cm2at the edge.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.95

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Braconid wasps,Apanteles euphydryidis, attended webs of their lepidopteran hosts,Euphydryas phaeton, for hours, with one-third of each hour spent searching for caterpillars. Encounters with larvae on the outside of webs were frequent and usually resulted in parasitoids turning away. Head-jerking exhibited by caterpillars was effective in knocking parasitoids away. Ichneumonid wasps,Benjaminia euphydryadis, traveled from web to web, spending less than 1 min per web. Overall, the defensive mechanisms exhibited by the caterpillars and their distribution on and in webs were effective in deterring parasitoids.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.100

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Predators removed a highly variable proportion of western spruce budworm pupae from several sites in north-central Washington, With standard methodology, these insects would have been classified as missing larvae. Subsequent analyses would necessarily have led to faulty and misleading conclusions.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.105

出版商:Oxford University Press    

年代:1982

数据来源: OUP