摘要:

Present-day boll weevil,Anthonomus grandisBoheman, problems in the northern Rolling Plains of Texas are linked to shelterbelt plantings made during the late 1930's. Available evidence suggests that boll weevil populations surviving the winter in 0.6 ha of shelterbelt litter may infest and reach damaging levels in 13.2 ha of cotton by mid-Aug. Where heavy sustained boll weevil infestations are not controlled, an estimated $1786 is lost due to yield reduction in the 13.2 ha. Several potential solutions to the boll weevil problem are presented. These soiutions include habitat destruction or management, and the use of insecticides, biotic agents, and fire. The use of these techniques is extended to the management of other habitat types such as rangeland shinnery oak,Quercus havardiiRybd. An impending move to renew shelterbelt plantings, particularly in the High Plains where boll weevils do not overwinter, is discussed. The lessons learned in the Rolling Plains regarding the interaction between boll weevils, shelterbelts, and colton should be taken as a serious guideline to the management of new shelterbelt plantings.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.1

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Male and femaleProctacanthella leucopogon(Williston) did not differ significantly in their attack rates toward orange and black models of a given size. Attack response for both sexes was inversely correlated with model size. Homoptera, Diptera, and Hymenoptera constituted 86% of the recorded prey items. Recorded prey lengths ranged from 1.6–13.0 mm with a mean of 4.04 mm. Diet composition and prey size characteristics are similar to those forP. leucopogonin Colorado and Mexico.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.7

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Eastern tent caterpillars,Malacosoma americanum(F.) (Lepidoptera: Lasiocampidae), and leaves of their host plant, black cherry,Prunus serotinaEhrh., were collected in May, 1978, at various distances from the Baltimore-Washington Parkway, Prince George's Co., MD, and were analyzed for lead by atomic absorption spectrophotometry. Caterpillars collected within 10 m of the parkway contained 7.1–7.4 ppm lead (dry weight). Caterpillars collected at greater distances from the parkway and from a control area had lead concentrations ca. half as high (2.6–5.3 ppm). Lead concentrations in caterpillars averaged 76% as high as those in leaves and were much lower than concentrations that have been reported in some roadside soil and litter invertebrates.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.10

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Field populations ofHaplaxius crudus(Van Duzee) were studied on St. Augustinegrass,Stenotaphrum secundatum(Walt.) Kunze; bahiagrass,Paspalum notatumFlugge; and bermudagrass,Cynodon dactylon(L.) Pers. andC. X magenissiiHurcombe, from July, 1974, to July, 1975, in Ft. Lauderdale, Florida.Haplaxius cruduscompleted development on all 3 species of grasses. Significantly higher numbers (P<0.01) of adults and nymphs were collected on St. Augustinegrass; however, populations fluctuated less throughout the year on bahiagrass.H. crudushad a sex ratio of 1.7♀:1♂ in this study. The sex ratio was biased toward males during the population peaks of adults.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.13

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Studies of 2 species of flour beetles,Tribolium confusum(du Val) andT. castaneum(Herbst), were conducted to determine the toxicity of ozone given at specific life cycle stages. Toxicity was measured in terms of adult survival one mo posteclosion. Results indicated that the younger larval and pupal stages ofT. castaneumwere more ozone sensitive than similar older stages; 28-d-old pupae were the most ozone resistant of the stages tested. For a given stage, the younger forms ofT. confusumwere more ozone sensitive than older ones. Ozone resistance ofT. confusumprogressively increased with age, except the resistance of 20-d-old larvae was comparable to that of adults: In general, all stages ofT. castaneumwere more ozone sensitive than those ofT. confusum; however, for both species the l5-d-old larvae were equally sensitive at each exposure, as were the 28 d pupal stages. The hours of ozone exposure for 100% lethality of 15-, 20-, 23-, 28-d-old forms and adults (T. confusum : T. castaneum) were 3½:3½; 6½:5½; 5½:3½; 6:6; and 6½:5, respectively.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.16

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

The toxicity of acridine toAcheta domesticus(L.) was determined to evaluate the potential for this pollutant from synthetic fuels production to affect insect populations. Acridine was highly toxic to cricket eggs but not toxic to nymphs or adults. An LD50for eggs = 7.4 εg/g was calculated from the LC50= 15.1±0.61 ppm. The 24-h LD10of acridine to nymphal crickets was>332 εg/g. Male and female crickets consumed up to 1.0% of their weight in acridine over an 18-day period with no significant effect on mortality, weight gain, digestibility of food, or fecundity. Percent hatch of eggs from treated crickets (81.0±6.7) was not significantly different from controls (77.2±5.1).

ISSN:1754-5692    

DOI:10.1093/ee/9.1.18

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

At least 120 species of Coleoptera were recovered from poultry manure in narrow, widespan, and high-rise types of caged-layer poultry houses in the Mountains, Piedmont, and Coastal Plain regions of North Carolina.Carcinops pumilio(Erichson) andAlphitobius diaperinus(Panzer) were consistently the most abundant species in all 3 regions, followed byGnathoncus nanus(Scriba) and the Aleocharinae (Staphylinidae). According to 5 indices of diversity, the Piedmont ranked 1st in overall diversity, species richness and equitability, followed by the Coastal Plain, and thirdly, by the Mountains.Narrow and high/rise house types were compared for adult and larvalC. pumilioandA. diaperinus. The larval population peak forA. diaperinusoccurred significantly earlier in the high-rise than in the narrow houses, however, the narrow houses had significantly higher beetle diversity.A qualitative examination of overwintering forms showed that most species overwintered primarily, but not exclusively, as adults.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.21

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Aqueous sprays of rubidium chloride (RbCl) were applied to host plants of the black-faced leafhopperGraminella nigrifrons(Forbes) for determining the feasibility of Rb tagging in monitoring the rate of maize chlorotic dwarf virus (MCDV) dispersal by its leafhopper vector. Concentrations up to 18,000 ppm RbCl had no effect on mortality or development of the vector species. The properties of plant uptake and translocation of Rb provide a new mechanism for MCDV dispersal studies since Rb can be acquired byG. nigrifronsin a manner similar to virus acquisition and detected in vectors during a time span corresponding to the inoculative period for MCDV. Detection of Rb levels in vectors was easily facilitated by X-ray fluorescence and atomic absorption spectroscopy.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.29

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

An actograph was used to determine diel locomotor periodicity and influence of constant and changing temperatures on adult western corn rootworm (Diabrotica virgiferaLeConte) locomotor activity in the laboratory. Diel periodic fluctuations in activity occurred with reduced activity from 9 a.m. to 5 p.m. and a high level of activity from 5 p.m. to 8 a.m. Maximum activity for males and females occurred at 23°–25° and 25°–27°C, respectively, with negligible activity for both sexes at 10° and 40°C. Males were generally more active than females, especially in the maximum activity temperature range. Female activity exceeded male activity at high temperature ranges. Decreasing temperature conditions increased activity levels over constant-temperature comparisons at low temperatures for both male and female beetles.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.32

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Lead contamination of insects near an interstate highway in Kansas averaged 50 ppm, but only 15 ppm in those collected far from heavily traveled roads. Lead in gizzard contents of meadowlarks (Sturnella neglectaandS. magna) collected near the interstate was 6 ppm, almost identical to that in gizzard contents of birds far from heavily traveled roads. Low levels of lead in meadowlark livers reflected little active exposure of meadowlarks to lead-contaminated insects.

ISSN:1754-5692    

DOI:10.1093/ee/9.1.35

出版商:Oxford University Press    

年代:1980

数据来源: OUP