摘要:

Larvae ofPieris rapaeL., when parasitized by larvae ofApanteles glomeratusL., have a 57% greater dry biomass at the beginning of the 5th instar and accumulate energy and nitrogen into their biomass at significantly higher rates (34 and 32%, respectively) during this instar than normal larvae. This occurs because parasitized larvae convert 17% more of their assimilated energy (net growth efficiency) and of their ingested nitrogen (nitrogen utilization efficiency) into biomass; the difference in the efficiency of energy assimilation between parasitized and normal larvae is slight. Also, parasitized larvae consume energy and nitrogen at absolute rates which are 14% faster than normal larvae.In spite of a 14% lower relative food consumption rate (mg dry food ingested/mg dry larval biomass × day), parasitized larvae have a relative growth rate (mg dry biomass gained/mg dry larval biomass × day) similar to normal larvae. This occurs because parasitized larvae have a 21% lower relative metabolic rate (cal oxidized/mg dry larval biomass × day). This lower relative metabolic rate also contributes to the higher net growth efficiency of the parasitized larvae.Host compensation for a supposed energy and nutrient drain caused by the feeding of the parasites may be involved in these changes but passive effects due to the presence of the parasites in the host and active influence on host physiology by the parasites are probably foremost.Food utilization budgets for normal and parasitized 5th-instarP. rapaelarvae are presented. During their life within a host larva, a mean of 28A. glomeratuslarvae/host consume ca. 50–60% of the energy and 60–70% of the nitrogen assimilated by the host without reducing energy or nutrient intake rates or laboratory survival of the host.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.179

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

In Michigan, 27–70% of the prepupae ofHeterocampa manteo(Dbldy) remained in diapause longer than 1 yr and up to 31% diapaused for 2 yr. Diapause was facultative but the factors of development were not determined. Prolonged prepupal diapause ofH. manteois believed to contribute to cyclical outbreaks and provides a means of avoiding population collapse due to starvation and parasitism. Application of insecticides over extensive areas could, by depressing univoltine parasites ofH. manteo,reduce the parasitism rates of thoseH. manteoin prolonged diapause and emerging the year subsequent to insecticide applications.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.186

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Adult pink bollworms,Pectinophora gossypiella(Saunders), that emerged from hibernation before small squares were on the cotton plant (21 days before blooming) usually failed to produce any progeny in field cage tests. Thus all emergence up to this time may be considered suicidal. Rate of reproduction by overwintered moths ranged from<1- to 9.4-fold depending on temperature and stage of fruiting on the plants at the time of moth emergence. High temperatures (42°C or more) for the 4 days immediately after emergence greatly reduced reproduction. In the field cages, the rate of reproduction of laboratory-reared moths was ca. 1/10 that of native overwintered moths. Partially sterile moths (irradiated as newly emerged adults with 10 krad of∞Co gamma rays) did not produce any progeny in field cages.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.189

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Numbers of late-instar larvae, pupae, and adults ofHeliothis zea(Boddie) produced from ears of late-planted corn were estimated. Larval and pupal production ranged from 1.3–2.5/ear and from 0.6–0.8/ear, respectively. Survival of individuals from late–instar larvae to pupae ranged from 33.0–55.3%. Of those surviving, 21–84% were in diapause. Survival of diapausing pupae from fall to spring was 7.7–58.8% and of the fall pupal population to emerged adults, 1.9–27.9 %. Of the total larvae produced in the late-planted corn with the potential for developing to diapausing pupae, only 0.7–9.2% produced spring adults.Cannibalism was considered an important mortality factor limiting the production of late-instar larvae. Heavy mortality occurred from spring diapause termination to adult emergence.A technique found useful in monitoring pupal production from corn ears is described.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.193

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Orius tristicolorWhite was exposed to increasing numbers of the western flower thrips,Frankliniella occidentalis(Pergande), as prey. As the number of thrips increased from 0–735, the adult pirate bug mortality decreased and nymph production perO. tristicolorfemale increased. Similarly, the pirate bug nymphal survival was longer when more thrips were available as prey.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.197

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

A study was conducted in a Louisiana coastal marsh to determine the ecological impact of the insect growth regulator diflubenzuron on populations of non-target aquatic organisms.Six applications of diflubenzuron (28 mg AI/ha) over an 18-mo period caused statistically significant differences in the population density of aquatic organisms when treated and untreated populations were compared. Populations of 5 taxa (nymphs ofTrichocorixa louisianaeJaczewski andBuenoaspp., Coenagrionidae naiad spp.,Berosus infuscatusLeConte adults, andHyalella azteca(Saussure)) were significantly (P<0.01) reduced while populations of 15 taxa (Physasp.,Caenissp. andCallibaetissp. naiads, Noteridae larvae,Hydrovatus cuspidatusKunze adults,Hydrovatussp. larvae, Dytiscidae (tribe Bidessini) larvae,Mesovelia mulsantiJaczewski adults,Trichocorixa louisianaeadults, larvae of Chironomidae, Ephdridae, Dolichopodiae, and Tabanidae, and the fishesGambusia affinis(Baird and Girard) andJordanella fioridae(Goode and Bean) showed significant (P0.05) difference when the treated and untreated populations were compared.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.199

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

A series of 6 xanthene dyes—rose bengal, phloxin B, erythrosin B, eosin yellowish, fluorescein, and rhodamine B—caused a light-dependent toxicity in the house fly,Musca domestica, after oral ingestion. Relative toxicities were described by means of rate constants of photooxidation calculated for each dye which include both the LT50and the tissue dye level. These values were compared with similar values determined for reactions in the boll weevil,Anthonomus grandis, and with the phosphorescence quantum yields of the dyes, the number of halogen substituents, and the halogen content by weight. Lowered mortality at higher dietary concentrations was due to lowered consumption and was taken as preliminary evidence of feeding inhibition.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.205

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

A pyrethrin drench appeared to be as efficient as or more efficient than soil sifting as a method of detecting adult alfalfa weevils,Hypera postica(Gyllenhal), in the soil. Adult weevils fed on cut alfalfa treated with32P were labeled and could be detected in the field for at least 6 wk. The procedures were used to determine that most adult weevils left the study field during the month following 1st harvest for more sheltered locations, but they were not found congregated in any single location.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.209

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The oviposition of stable flies,Stomoxys calcitrans(L.), was determined for several temperature and humidity conditions in the laboratory. Oviposition was greater and began at younger ages at the higher temperatures. Ovarian development and oviposition rates appeared to respond to temperature in the same manner as development of immature stages in previous work. Humidity did not appear to affect oviposition. The flies produced more eggs at a particular air temperature if the temperatures for adults and immatures were similar. A simple procedure for predicting oviposition rates in variable temperature regimes was developed.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.213

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The half-life of conidia ofNomuraea rileyitreated in vitro with human gastric juice (pH 1.2) was ca. 23 min as measured by mortality of larvae ofTrichoplusia ni(Hübner). Ca. 20 and 90% of the infectivity was lost after 20 and 30 min, respectively. The half-life in infectivity of conidia exposed to HCI (pH 1.2) was ca. 30 min. No loss of infectivity was detected in conidia exposed to either neutralized human gastric juice or phosphate buffer. Conidia exposed to human gastric juice for more than 30 min would not grow when cultured on Sabouraud maltose agar plus yeast.

ISSN:1754-5692    

DOI:10.1093/ee/7.2.217

出版商:Oxford University Press    

年代:1978

数据来源: OUP