摘要:

Research on flight activity of the western corn rootworm,Diabrotica virgifera virgiferaLeConte, is presented. Field-captured, mated females, aged 2–15 days posteclosion, were flown on flight mills linked to a microcomputer data-recording system. Flight duration ranged from 1 to 17 min for trivial flights; sustained flights lasted up to 4 h. Sustained flights were not made after females were 9 days old. Maximum distances of 24 km for one flight and 39.6 km for all flights during a 24-h period were recorded. Average speed of flight was 16 m/min for trivial fliers and 49 m/min for sustained fliers. Periodicity was observed for both types of flight; greatest flight activity occurred from 1800 to 2400 hours.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.620

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Rate of development and the survival of pupae ofDiabrotica virgifera virgiferaLeConte andD. undecimpunctata howardiBarber were studied under numerous constant temperature and humidity regimes. Temperature range for maximum survival, as measured by eclosion, was 18–30°C forD. v. virgiferaand 15–30°C forD. v. howardi.Time of development within these temperature ranges was similar for both species (5–10 days). At all temperatures studied, a saturated atmosphere (100% RH) was optimal for pupal survival and development.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.626

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Experiments conducted on the European corn borer (ECB),Ostrinia nubilalis(Hübner), in 1981 and 1982 showed that caged moths did not discriminate between corn,Zea maysL., in the fresh silking stage and sunflower,Helianthus annusL., in the pollen shedding stage for egg laying. ECB larvae which hatched from eggs that were laid on sunflower, however, were largely unable to establish themselves and/or survive on that crop. Once the stalk tissues had been penetrated, however, the amount of activity was essentially identical between the sunflower- and corn-reared larvae. Development of ECB larvae was slower on sunflower than on corn. ECB moths exhibited an oviposition preference for the underside of the sunflower leaves, but an occasional egg mass could be found on the head. ECB larvae almost always penetrated the sunflower stalk at the base of the petiole, but an occasional larva was found to have entered the plant through the soft head tissues.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.631

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Phyllonorycter elmaellaDoganlar&Mutuura was sampled in 1983 from Utah apple orchards that had different spray programs andP. elmaellapopulation histories.P. elmaellais multivoltine in Utah. Percent parasitism increased from the first to the third generations of fourth and fifth larval instars, then dropped in the overwintering (OW) generation. Dominant parasitoids wereSympiesis marylandensisGirault inP. elmaellagenerations one and three, andPnigalio flavipes(Ashmead) in the second and OW generations. The parasitoid complex in Utah included six species, and all were ectoparasitic. All parasitoid species were found in the OW generation ofP. elmaella.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.635

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Cowpea pest cadavers withBeauveria bassiana(Balsamo) mycoses were stored outdoors both under exposure to sunlight and rainfall and under protected conditions, and in the laboratory at 4 and 27°C over prolonged intervals. Conidia on cowpea curculio adults stored outdoors under protected conditions remained stable (i.e., without loss of viability) for at least 16 weeks and with only a slight decline in germinative ability for up to 24 weeks. Under the same outdoor conditions, conidia on chrysomelid beetle cadavers also survived well. In contrast, infected cowpea pest cadavers stored outdoors under direct exposure to rainfall and sunlight lost most of the conidia from their cuticles within 2 weeks; however, among the conidia that remained on the cadavers no decline in viability could be detected. The virulence ofB. bassianastrains to their host insects was not correlated with the stability of conidia on host cadavers stored outdoors.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.642

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Of 36 wild rices screened, 19 accessions were resistant or moderately resistant to three biotypes of the brown planthopper,Nilaparvata lugens(Stål), and 9 were resistant or moderately resistant to at least one biotype. Resistant accessions were nonpreferred andN. lugenscaged on resistant accessions had low food ingestion rates, slow nymphal development, reduced longevity, low fecundity, and consequently low populations. Two wild rice species decreased the percent hatchability ofN. lugenseggs. Some moderately resistant accessions have tolerance toN. lugens, as indicated by low plant damage ratings and plant loss and high percentageN. lugenssurvival and weight gain. Wild rices are possible sources of new genes forN. lugensresistance.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.648

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

The maize weevil,Sitophilus zeamaisMotschulsky, exhibited two types of feeding behavior on com seeds. Adults sometimes penetrated the pericarp over an irregularly sized area and fed lightly on the surface of the endosperm (shallow feeding). On other occasions they chewed through the pericarp in a localized area and fed to a much greater extent on the endosperm (deep feeding). Both sexes fed in these ways. Initially there was more shallow feeding followed by an increase in deep feeding in a susceptible line, Pa762. Deep feeding was the predominant activity throughout the test on Va26, a resistant line. The amount of deep feeding was more highly correlated with oviposition than was shallow feeding.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.654

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Overwintering byTrichogramma exiguumwas studied in an outdoor insectary using the eggs of captured moths as hosts.T. exiguumappears to overwinter by slowed temperature-dependent development in host eggs and by prolonged adult longevity. No diapause was detected. AdultT. exiguumemerged and oviposited during the winter at temperatures as low as 9°C.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.659

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Mortality of pupae ofApanteles fumiferanaeViereck andA. morrisi(Mason) that parasitize the jack pine budworm(Choristoneura pinusFreeman) was studied in the field for three years. Estimated mortality inflicted by hyperparasites, predators, and unknown sources was 63.9 and 58.2% in two successive years at one site. Hyperparasitism by various species varied both temporally and spatially in various microhabitats in jack pine stands. Mortality caused by one hyperparasite,Pteromalus phycidisAshmead, was dependent on local variation in density ofApantelesspp. pupae. The intensity of the density-dependent response was most evident when data were grouped by crown levels, and was reduced for larger or smaller habitat units.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.662

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Diapause induction in female face flies,Musca autumnalisDeGeer, was studied in the laboratory. A visual scale for fat body quantity was developed and tested to estimate crude lipid content. Dissected female flies were defined as being in apparent diapause if they possessed previtellogenic ovaries and hypertrophied fat body at the time they were removed from a diapause-inducing environment. In contrast, flies were defined as committed to diapause only if they still possessed the same symptoms after 8 additional days in a warm, long-day environment. Availability of blood did not significantly affect apparent diapause induction. An experiment using 15 combinations of temperatures and photoperiods revealed that temperature had a strong effect on rates of ovarian growth, fat body growth, development of apparent diapause, and development of commitment to diapause. The latter three were fastest at ca. 23°C, well below the temperature of fastest ovarian growth. Short photoperiods had no effect on ovarian growth but did accelerate development into diapause. A conceptual model is presented that describes induction and development into diapause in female face flies as a competitive rate process between reproductive development and commitment to diapause.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.669

出版商:Oxford University Press    

年代:1986

数据来源: OUP