摘要:

Survival of colonies of the red imported fire ant,Solenopsis invictaBuren, near its current northern range in the Georgia Piedmont during Oct.–Feb., 1975–76 was 96–100%. Workers moved brood underground when mound temperatures dropped to 10–12°C. Dead workers were removed from colonies following periods of −0°C. Workers, alate females, and males which were immobilized by −0° in the mounds were collected and held at room temperature, where recovery was 92.6%, 88.25% and 4%, respectively.S. invictashould be able to extend its present range based on lethal low temperatures as a limiting factor.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.50

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

The Banks grass mite,Oligonychus pratensis(Banks), was confined on the lower sides of corn leaves, using either clip-on cages or grid cages constructed from tree tanglefoot. Mites developed most rapidly when temperatures were high; the effects of relative humidity were significant but minimal. Significantly more mites survived and more eggs were laid on silking corn than on seedling corn. Significantly more eggs were laid on moisture-stressed plants than on corn plants receiving adequate moisture.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.53

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Apanteles porthetriaeMues. andApanteles liparidis(Bouche) are important regulating agents of the gypsy moth,Lymantria dispar(L.), throughout their native range. The failure of these parasites to become established in the U.S. has been attributed to their inability to find suitable alternate hosts. This study examined the status of native Lepidoptera as potential alternate hosts.A. porthetriaesuccessfully developed in 3 native species: the white-marked tussock moth,Orgyia leucostigma(J. E. Smith), the fall webworm,Hyphantria cunea(Drury), and the yellow woolly bear,Diacrisia virginica(F.).A. liparidisdid not develop in any native species.The possibility of the future establishment ofA. porthetriaeis discussed, emphasizing the importance ofO. leucostigmaas an alternate host.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.57

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Parasitism of the diprionid pine sawflies,Neodiprion excitansRohwer,N. merkeliRoss, andN. lecontei(Fitch) was studied in northern and western Florida, principally by rearing sawfly and parasite adults from cocoons collected from soil and litter under loblolly pine, sand pine, slash pine, and longleaf pine. The ichneumonid,Endasys subclavatusSay, was an important cocoon parasite ofN. excitans;the tachinid,Spathimeigenia spinigeraTownsend, was an important parasite of large, feeding larvae ofN. merkeli;ichneumonids such asE. subclavatuswere important asN. merkelicocoon parasites; and tachinids such asSpathimeigeniaspp. andDiplostichus lophyri(Townsend) [=Phorocera hamataAldrich and Webber] were important larval parasites ofN. lecontei, especially when cocoons were deep in well-drained sandy soils.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.60

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Larval development, pupation and adult emergence of black cutworms were investigated using 16 possible larval food sources. Food sources included crop plants, weeds and field debris. Larval survival was highest on bluegrass, curled dock and wheat while no larval survival occurred on giant foxtail or debris. Larval development from egg to pupa varied from 24.6 days on wheat to 47.0 days on annual morning glory.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.63

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

A new mixture of the screwworm,Cochliomyia hominivorax(Coquerel), chemical attractant was prepared and evaluated under field conditions. This new mixture, “Swormlure-2,” proved to be more attractive to screwworms than the mixture presently being used and at least as attractive as decomposing liver. In general, more unmated female flies were attracted to Swormlure-2 than were attracted to liver. Also, Swormlure-2 appeared to be more attractive than liver to unmated females that were in early stages of egg development.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.66

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

A study of the alfalfa weevil,Hypera postica(Gyllenhal) andBathyplectes curculionis(Thomson) in Colorado demonstrates that the population dynamics of these insects can be predicted by measuring the height of alfalfa. The data shows that alfalfa growth is directly proportional to the number of accumulated degree-days (°F.). Population curves based on the accumulated degree-days for the 2 species of insects were approximately the same in 1973 and 1974.The theoretical temperature of development for diapausing cocoons ofB. curculioniswas 43°F. The adult parasites required 425.7 degree days (°F.) to emerge. Results of the study show promise for the development of a pest management program utilizingB. curculionisas a management tool.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.69

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Releases of 835 mated adult femaleCampoletis sonorensis(Cameron) at a rate of 50–100/day for 10 days against an introduced population of tobacco budworms,Heliothis virescens(F.), on cotton in a 0.4-acre field cage resulted in 85–95% parasitization of tobacco budworm larvae for ca. 2 months. As host pressure was maintained by daily releases of adult moths,C. sonorensiswas eventually replaced as the major regulator of the tobacco budworm population by parasitization of host eggs byTrichogrammasp. and predation of host eggs and small larvae byOrius insidiosus(Say). TheC. sonorensispopulation was also greatly affected by the hyperparasitesCatolaccus aeneoviridis(Girault) andCeratosmicra immaculata(Cresson); and the predatorCollops vittatus(Say) consumed up to 70% of the cocoons ofC. sonorensis. Nevertheless, the beneficial species markedly suppressed the tobacco budworm population throughout the experiment. Weekly average temperatures between 80 and 86°F did not appear to reduce the efficiency ofC. sonorensis. The sex ratio of parasites produced in a field cage was near 1:1 as compared to 1:4 in a culture maintained in the laboratory.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.72

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

An outbreak ofHydria prunivorata(Ferguson) in north-central New York resulted in severe defoliation of black cherry,Prunus serotinaEhrh. from 1969–1971. Black cherry mortality caused by a scolytid,Phloeotribus liminaris(Harris), following defoliation was concentrated in areas with similar stand and soil characteristics. Polar ordination of 10 forest stands based on pre-mortality tree species composition grouped areas with high mortality. Mortality was significantly correlated with the relative importance value of black cherry in the stand and with the hydrogen ion concentration of the soil. SoilpH was lowest on poorly drained sites.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.77

出版商:Oxford University Press    

年代:1977

数据来源: OUP

摘要:

Most of the feeding of 2-, 3-, and 4-day-old larvae of the tobacco budworm,Heliothis virescens(F.), occurred on the anthers of detached cotton flowerbuds after they penetrated into the interior of the bud through the petals at the apex of the calyx. Consumption of petals increased with increasing larval age. When the component parts of the flowerbud were incorporated into larval diet, only the petals inhibited growth. This inhibition was about equal to that caused by lyophilized flowerbuds. Since the inhibition occurred even with glandless cotton lines, it was not related to gossypol content of the cotton bud.

ISSN:1754-5692    

DOI:10.1093/ee/6.1.82

出版商:Oxford University Press    

年代:1977

数据来源: OUP