摘要:

LD5, 10, 25,and50values of the insecticides methyl parathion, decamethrin, and Perthane were estimated for the 5th instar nymphs ofN. lugens. LD values were lowest for decamethrin, followed by Perthane and methyl parathion. Topical applications of sub-lethal doses of methyl parathion and decamethrin on 5th instar nymphs caused increases in reproduction in the resulting adults. Highest reproductive stimulation occurred at the LD dosage for methyl parathion and at LD50for decamethrin. Perthane did not cause reproductive stimulation at any of the four dosages tested.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.778

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

The euplophid parasite,Euplectrus putlleriGordh, introduced from Colombia (S.A.) was released in southern (Dade Co.) Florida in 1976 and has become established onAnticarsia gemmatalis(Hübner). Small (<1 cm) and medium (1–2 cm) larvae were found parasitized and produced an average of 4.4 parasite adults per larva. The mean parasitism rates of small and medium size larvae at one site were 5.0 and 8.9%, respectively. The parasite has survived 3.5 years and spread at least 9.1 km.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.781

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Traps have been found useful in monitoring and reducing populations ofSapyga pumilaCresson an important parasite of the alfalfa leafcutting bee,Megachile rotundataFabricius. Traps painted white, light blue or green were more effective than brown or red. Traps painted white, shades of light blue or coated with transparent plastic were equal in trapping efficiency to the natural unpainted traps.S. pumilawas more responsive to the contrast between hole in the trap than to trap color. Largest numbers ofS. pumilawere caught in traps placed on the front of leafcutting bee domiciles.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.783

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Xanthene dye treatment caused mortality in every developmental stage of the house fly,Musca domestica. Treated adults exhibited decreased fecundity and reduced egg viability. Treated eggs allowed to develop in untreated media and untreated eggs allowed to develop in treated media resulted in greater than 90% mortality prior to adult emergence. Early fourth instar larvae placed in dye treated media at 2.0 g/kg exhibited reductions of up to 81% in adult emergence.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.785

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Plots of transplanted cauliflower were assessed over a 3-year period to determine the effects of insecticide on the cabbage maggot,Hylemya brassicae(Weidemann); the small carabid beetle,Bembidion lamprosHerbst and the staphylinid parasite,Aleochara bilineataGyllenhal.B. lamproswas the main species taken in pit-traps, and its numbers were unaffected by applications of granular chlorfenvinphos. Untreated plants averaged 7.7, 12.2 and 12.6 puparia in 1976, 1977 and 1978 respectively, of which 30.8, 42.6 and 62.2 percent were parasitized byA. billineata. Treated plants had fewer puparia with lesser percentage parasitism. Bioassays with granular insecticides in soil showed thatB. lamproswas quite tolerant to chlorfenvinphos, somewhat susceptible to carbofuran and isofenphos and very susceptible to terbufos.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.789

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

In field tests, traps baited with 1000 μg of(Z)-11-hexadecenal (the known pheromone component) and 25–50 μg of(Z)-9-hexadecenal captured 6 times as many maleChrysoteuchia topiariaas did traps baited only with 1000 μg of(Z)-11-hexadecenal.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.795

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Development and mortality of the potato leafhopper [Empoasca fabae(Harris)] were studied in the laboratory under constant temperature regimes. Lower thresholds for egg and nymphal development were 7.6 and 8.8°C, respectively, and the upper threshold for development was ca. 29°C. Nymphal mortality was high at 13°C, decreased at 18°C, and gradually increased to 81% at 35°C. Most mortality occurred in the first and fifth instars. Adult measurements indicated differences in size of head capsule width and body length due to sex, differences in whole length due to sex and temperature, and differences in wing length due to temperature. Centigrade degree day (CDD) accumulation for egg development was related to field monitoring of alfalfa for leafhopper eggs, nymphs, and adults during the spring of 1976 and 1977 in Montgomery Co., VA. Calculated CDD from first females collected to nymphal hatch and from first observed eggs to nymphal hatch was 199 ± 20.4 and 136±39.7 respectively. This system could be used in an alfalfa scouting program to indicate when nymphal samples should be collected based on accumulated temperatures after arrival of female potato leafhoppers in the spring.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.798

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Adults of the wood cricketNemobius sylvestris(Bose) make a daily migration across the ecotone between woodland and field. The rhythm of locomotor activity is bimodal with a morning peak characterized by movements from the field towards the wood and an afternoon peak when the net displacement is towards the field. The time-space patterns of these daily migrations are related to internal determinants (feeding activity) and to environmental factors (light intensity).

ISSN:0046-225X    

DOI:10.1093/ee/9.6.801

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

At Charleston, S. C. in 1978 and 1979 and at Blackville, S. C. in 1979, immature stages of the pickleworm(Diaphania nitidalis(Stoll) were collected on cucumber and densities were estimated. Populations were higher at Charleston than at Blackville. Egg parasitism byTrichogramma exiguumPinto and Platner ranged from 0 to 69% at Charleston and appeared to be density dependent and limited to late in the season but was unrecorded at Blackville. Larval parasitism (Apantalessp.) was low, ranging from 0 to 10%. Fire ants (Solanopsisspp.) were an important predator of pupae.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.806

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

A logistic model of population growth is presented which describes the effects of introducing sterile individuals into a wild population regulated by density-dependent factors. It is shown that for certain levels of sterile releases two steady states exist, of which the upper state is stable and the lower state is unstable. Once a population is driven to below the lower threshold, continued releases will cause (local) extinction. The 2 steady states exist for a wide variety of density-dependent growth functions. The release of sterile males alone is less effective than the release of sterile males and sterile females but not importantly so; however, the release of sterile females alone is not a satisfactory strategy for eradication.

ISSN:0046-225X    

DOI:10.1093/ee/9.6.810

出版商:Oxford University Press    

年代:1980

数据来源: OUP