摘要:

An extensive baculovirus epizootic occurred during the autumn of 1976 in a larval population of the clover cutworm,Scatogramma trifolii(Rottenberg), breeding on Russian thistle,Salsola iberica(Sennen and Pau), in southern California. The primary causal agent of the epizootic was a granulosis virus although a nuclear polyhedrosis virus was involved at several locations. The epizootic extended over an area of ca. 1000 km2and included within its limits the suburban Los Angeles cities of Colton, Corona, Fontana, Ontario, Redlands, Riverside, San Bernardino, and portions of Pomona. The incidence of the granulosis disease was greater than 90% at all sites sampled regardless of larval density. This is the 1st report of a granulosis virus fromS. trifolii.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.423

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Six new synthetic pyrethroids, some of which possess exceptionally high mosquito larvicidal activity, were studied for their toxicity against 4 species of game and predatory fish. The various species showed different levels of susceptibility to the various compounds. As a whole most of the pyrethroids showed a good margin of safety (derived from the ratio of LC50–90fish to LC50–90mosquito larvae) to the test fish species. It is very likely that the pyrethroids with high margins of safety can be utilized in larvicidal programs without marked acute effects on fish fauna, while others possessing low margin of safety will pose a serious hazard to fish in aquatic habitats treated with these materials.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.428

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Representatives of different types of insecticides were tested for toxicity to larvae of a common green lacewing,Chrysopa carnea(Stephens). This insect is a predator of many phytophagous arthropods including the tobacco budworm,Heliothis virescens(F.). Most organophosphate insecticides and the carbamate, methomyl, were highly toxic to the predator. Another carbamate, carbaryl, a formamidine, chlordimeform, several pyrethroids and several organochlorines were much less toxic toC. carnea. In comparison with the tobacco budworm, phosphorothionate (P=S) insecticides were highly selective against the predator. In contrast, synthetic pyrethroids and endosulfan were highly selective against the tobacco budworm. Most other insecticides were of similar toxicity to both species or slightly more toxic to the predator. The relative usefulness of the different insecticide types in integrated control programs is discussed.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.431

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Three weekly applications of 5.0 kg of rubidium chloride (RbCl)/ha to corn plants beginning when the plants were at 1st tassel were superior to a single application of 10 kg/ha made when silks began to dry for labeling the corn earworm,Heliothis zea(Boddie), with Rb. The Rb contents of larvae and moths from the former treatment did not overlap with those of insects from untreated plots. Fall armyworms,Spodoptera frugiperda(J. E. Smith), on corn were also labeled using the RbCl sprays.In a study on dispersal of corn earworm moths from a corn field labeled with Rb, male moths were collected in traps baited with virgin females in 4 cotton fields 0.5–2.8 km from the treated corn.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.435

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Seasonal field increases in the number of boll weevils in Dickens and Kent Counties of Texas were found to fit logistic growth curves. Boll weevil numbers increased exponentially through July, Aug., and Sept. at rates up to ca. 2.70-fold/wk in an untreated field compared to 1.74-fold avg in insecticide treated fields. During Oct. the population growth rate slowed and finally reached zero.The relation between the mean number of squares available to each weevil and percentage of weevil damaged squares fit a curvilinear model. This model can be used to provide an estimate of the number of adult weevils per ha based on % damaged squares and an estimate of the number of squares per ha. Conversely, numbers of damaged squares can be estimated based on numbers of adult weevils.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.439

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

A gall-producing fly,Urophora affinisFrfld., was released at a site in western Montana in 1973 for the control of spotted knapweed (Centaurea maculosaLam.). A total of 279U. affiniswas field-released while 150 were released into a field cage. TheU. affinispopulation within the field cage increased significantly over a 2-yr period as evidenced by an increase of infested seed heads from 15.2–71.3%. Galls of field-releasedU. affiniswere found at a distance of 50 m from the initial release point after 2 yr; adults were found throughout the field in small numbers. The life-history of the fly was closely synchronized with the development of its host plant.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.445

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Cone-orifice traps were found more suitable than sticky traps for capture of 4 moth species with sex attractant lures. Single-cone wind-directional traps were as efficient overall as double-cone fixed traps of similar dimensions. The best orifice diam for capture and retention of 5 species equaled ca. 2× the thorax width of the males; radical departures from this optimum resulted in greatly decreased capture totals. Up to a limiting value trap catches were proportional to the cross-sectional air flow diam of the trap.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.449

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The summer activity (pupa development and adult emergence) ofVitacea polistiformis(Harris) in 3 north central Georgia Concord grape vineyards is presented as a set of regression models of pupal development and grape berry sugar accumulation as state variables forced by degree-day input. The significant correlation between these 2 phenological progressions is a useful pest management tool which can predict the pupal developmental state from the accumulated berry sugar content.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.456

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The distribution of the subterranean life stages of the grape root borer,Vitacea polistiformis(Harris), were estimated by sampling 2 habitat units; a unit of the soil surface for pupae and a unit of the grape root system for larvae. Pupae were distributed evenly around the trunk base with no significant angular orientation. Pupal density decreased exponentially from the trunk base to the periphery of the sample unit. The mean distance of the pupae from the trunk base ranged from 12.8–17.1 cm at 4 sites with no significant difference between male and female pupae. The sex ratio (♂/♀) ranged from 0.62–1.27 at these sites. The distribution of larvae in 3 size classes was modeled by multiple regression equations which related larval density to concomitant values of depth in the soil, distance from the trunk base and diam of the inhabited root. Small larvae were distributed evenly throughout the sample unit, whereas medium and large larvae had distributions skewed toward the larger roots and the trunk base of the vine.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.461

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The larval gypsy moth parasite,Parasetigena silvestris, deposits a greater number of eggs on larvae tethered to red oaks compared to those tethered to white pine. Parasite response to gypsy moth host plant is not based on the density of larvae on oaks. Factors associated with pine bark do not provide conditions which reduceP. silvestrisoviposition. Experiments on the role of other specific components of the host's habitat did not provide any evidence of the factors affecting host-habitat selection byP. silvestris.

ISSN:0046-225X    

DOI:10.1093/ee/7.3.466

出版商:Oxford University Press    

年代:1978

数据来源: OUP