摘要:

In field and laboratory studies, emergence of laboratory-reared pink bollworm,Pectinophora gossypiella(Saunders), was higher in moist soil than in dry soil. In the field, peak emergence occurred 16 to 20 days after larvae exited naturally from the release carton to the soil; however, some moths emerged as long as 46 days after larvae exited. In the laboratory, high soil temperature (32.2° C) and low soil moisture (2%) delayed moth emergence.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.147

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Pupal mass is significantly correlated with the fecundity of femaleAedes aegypti(Diptera: Culicidae); larger females mature more eggs than smaller females. Large pupal mass ameliorates the effects of starvation on adults of both sexes. Mass has no effect on the probability of being inseminated (for adult females) or inseminating (for adult males). Thus, larval growth directly affects the fecundity survival of individuals as adults. Also, it is likely that females will maximize their mass at pupation, whereas males will minimize age at pupation and maximize mass secondarily.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.150

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Overwintering larvae ofCylindrocopturus adspersus(LeConte) in roots and lower stalks of cultivated sunflower began pupating from early to mid-March in 1978 to 1980 at Bushland, Tex. Eclosion to adults occurred from late March to early April. Adult emergence from sunflower began in mid-March in 1978, and early April in 1979 and 1980. Mass emergence of adults occurred in early May each year and was completed by mid-June. Overwintering populations ofC. adspersusaveraged 38.1 and 19.7 larvae per plant during winters 1975–1979 and 1979–1980, respectively. Overwintering mortality from unknown causes ranged from 6 to 15%, and that from parasitism ranged from 2.8 to 5.3%, during winters 1975–1979 and 1979–1980.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.154

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Parasites predators had an insignificant effect on a population of the introduced weevil,Rhinocyllus conicusFroelich, during the 1975 through 1977 growing seasons in Montana. Predation upon adult weevils was unsuccessfully attempted by several spider, four ant, and one tiger beetle species. One species of bird was an incidental predator of adult weevils. No parasitism was observed among eggs, pupae, or adults. Two native species of Hymenoptera caused low levels of parasitism<1%) among larvae.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.157

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

A granulosis virus ofHeliothis armiger(Hübner) from South Africa was shown to be pathogenic toHeliothis zea(Boddie),Spodoptera frugiperda(J. E. Smith),S. exigua(Hübner), andTrichoplusia ni(Hübner), all Lepidoptera: Noctuidae.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.159

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Strains of the predatory mite,Amblyseius fallacisGarman, which were variably resistant to a synthetic pyrethroid permethrin, showed multiple-resistances to DDT and to azinphosmethyl. In a resistant strain selected with permethrin, cross-resistances to a variety of pyrethroid types, including natural crude pyrethrins and several synthetic pyrethroid compounds, were demonstrated. Mechanisms of resistance relative to field insecticide use patterns and possible uses of these mites in future integrated pest management programs are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.161

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Three rice varieties, IR29, IR40, and IR42, which are, respectively, susceptible, moderately resistant, and resistant, toNilaparvata lugensStål in the Philippines, were treated in the field with decamethrin, an insecticide known to cause resurgence.N. lugenspopulations increased to a significantly higher level in the treated plots than in untreated checks, but the degree of resurgence varied among varieties. the maximum population increases in the treated plots compared with the checks were ca. 74-, 50-, and 5-fold, respectively, for IR29, IR40, and IR42. Decamethrin was toxic to predators, and this reduction of natural enemies ofN. lugensmay have contributed to the pest resurgence. However, the differences between populations ofN. lugensin treated and nontreated plots within varieties were larger than differences in predator numbers, suggesting that other factors were also involved.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.165

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

In the spring of 1979, wheat and barley fields in Maryland were monitored to determine the spatial distribution of the armyworm,Pseudaletia unipuncta(Haw). The discrete frequency data for this insect were found to statistically fit the negative binomial distribution. By using a method which compared the sample sizes in terms of time and reliability, an appropriate sample unit size was determined to be 0.9 m of row. The parameters from the mean crowding (m*) and mean density (m) regression were used to develop a sequential sampling plan for the armyworm. In 1980, fixed samples were taken from 23 wheat and barley fields in Maryland. Simulations of the sequential sampling plan were practiced on the larval counts correctly predicting a treat or not-treat decision for 88% of the cases. Overall, an average of 12 sample units were required to reach a decision. This represented a 40% saving of time when compared with the fixed-sample number currently used for small-grain pest management.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.169

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Foliage from greenhouse-grown soybeans fumigated with 524 εgm−3of SO2or from control plants held under the same conditions without fumigation was fed to Mexican bean beetle larvae and adults. The larvae developed faster and grew larger when fed on the fumigated leaves; larval mortality was consistently low and showed no apparent relationship to the type of leaves used as the food source. Adult females showed a significant feeding preference for discs cut from fumigated leaves and were more fecund when fed on the treated foliage than when fed on control leaves. A greater percentage of the females laid eggs, and the viability of the eggs was higher when the females were fed on fumigated leaves. These females produced more eggs per individual, with significant increases in both the number of eggs per mass and the number of masses per female. The longevity of egg-laying females did not differ significantly between the treatments.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.173

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Barnacle scale,Ceroplastes cirripediformisComstock (Homoptera: Coccidae), reached damaging levels in several groves In the Lower Rio Grande Valley of Texas during 1975.Metaphycus eruptorHoward was the most numerous primary parasite, althoughCoccophagus ochraceusHoward,Ammonoencyrtus californicus(Compere), and an unknown encyrtid were also recovered. Effectiveness of the primary parasites was apparently reduced by the hyperparasitesMarietta pulchella(Howard),Tetrasticus minutus(Howard), andCheiloneurus inimicusCompere. Parasitism by primaries varied from 4 to 31%, and that by hyperparasites 0.0 to 56%. Individuals per host varied from 1 to 22 for primaries and 1 to 9 for hyperparasites. A single incident was found in research plots of a possible association between increase in barnacle scale and use of dicofol. Because of the effective biological control, barnacle scale was scarce on Texas citrus during 1977.

ISSN:1754-5692    

DOI:10.1093/ee/11.1.177

出版商:Oxford University Press    

年代:1982

数据来源: OUP