摘要:

Oviposition of the corn earworm,Heliothis zea(Boddie), on corn in Idaho was observed to decrease from July 1–15 and then to increase again. A simple model based on heat units above 55°F predicted when the mid-July oviposition would begin. A thermodynamic model (WATBUG) was used to simulate seasonal development of the population, produce life tables, and evaluate the effect of control treatments.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.68

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Douglas-fir tussock moth (Orgyia pseudotsugata (McDunnough)) larvae were fed foliage obtained from the top and bottom of the crowns of Douglas-fir, grand fir, and subalpine fir under controlled laboratory conditions. High density field populations were simulated by forcing larvae to feed upon old-growth foliage creating a stress factor that was detrimental to the population. The host plant and crown position had a significant effect on frass production, head-capsule size, and pupal weight. The number of eggs produced was significantly greater from foliage obtained from the top of the crown. The most significant factor was whether larvae were forced to feed upon old-growth foliage. This “stress” resulted in increased development time, frass production, number of instars and decreased head capsule size, and egg production.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.73

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Male and female house flies,Musca domesticaL., bearing a heterozygous translocation that reduced fertility to ca. 32.5% in outcrosses and ca. 15% in intracrosses were released at a poultry farm. Fertility of the mixed population at the release site (determined weekly) ranged from 9.1 to 32.0% during the first 9 wk of the test; fertility at the control sites ranged from 63.4–95.7%. Average density (from weekly grid counts) ranged from>1 to>4 at the release site (an avg 1400 flies were released/day), 0 to>2 at control site 1, and 0–20 at control site 2. A high ratio of translocation-bearing to native flies could not subsequently be maintained at the test site during the final 14 wk of the test even though a larvicide was applied there. However, as long as the released translocation-bearing flies were at a high ratio to the native flies, fertility was low, and laboratory-reared semi-sterile flies did participate in the reproductive cycle.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.78

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Three laboratory strains of boll weevils,Anthonomus grandisBoheman, produced more pheromone than the standard laboratory strain. Soxhlet extraction of the frass provided a rapid method of analyzing for the pheromone.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.81

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

In a study of the microflora associated with the walnut husk fly,Rhagaletis campletaCresson, I obtained a total of 15 morphologically different isolates. Isolations were made from all life stages, as well as from rotted walnut pulp, under aerobic conditions. Out of the 15 isolates only 2, identified asPseudomonassp. andXanthomonassp., were associated with all life stages; a 3rd isolate,Serratiasp. was found to be associated with all but the pupal stage. None of the remaining isolates was associated with more than 2 life stages of the fly. The isolatedXanthomonassp. was very similar to the walnut blight bacterium but unable to cause either necrosis, when infiltrated into young walnut leaves, or the hypersensitive reaction within tobacco leaves. Both sexes of adultR. completabear an unpaired oesophageal diverticulum just anterior to the brain, housing bacteria.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.83

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Two alternative biological models are presented. They can be used as aids in determining sterile ♂ release strategies that maximize well-defined utility functions subject to the dynamics of the population and ecosystem. One model is a traditional deterministic population model, while the 2nd is a stochastic model in the sense that it accounts for the probabilistic outcome of a release of sterile ♂ into a wild population. The stochastic model is obviously more realistic and accurate, but it is much more costly to solve. Consequently, researchers must decide whether the added realism justifies the increased computational cost.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.87

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The influence of temperature and photoperiod on reproduction of the predatorHemerobius pacificusBanks was studied in the laboratory. Short photoperiods (8–12 h) and a relatively low temperature (18.3°C) were found to be favorable for mating, fecundity, fertility and longevity. A life table is presented for these conditions. The adults lived a mean of 72 days (maximum 147 days). They deposited a mean of 715 eggs/♀ (maximum 2554 eggs); fertility was 92.0% until a week before death. The mean generation time was 6.1 weeks.Reproduction occurred at temperatures as low as 4.4°C. Mating and fecundity decreased at a constant temperature of 23.9°C, even under a short photoperiod. Estival diapause, which would protect this predator from hot summer climates could not be induced. It is concluded thatH. pacificusis adapted to areas of California which have mild winter climates.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.96

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Overwintered ♂ boll weevils,Anthonomus grandisBoheman, were found to produce only very small quantities of pheromone. Also, the ratio of the 4 components in the pheromone of these weevils differed from that in the standard formulation of grandlure and was less attractive. Consequently, even sterilized laboratory weevils should be more attractive than overwintered males.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.101

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Border-harvesting in which narrow (3.1 m) strips of uncut alfalfa were left at 30–50 m intervals within the field at each harvest, was effective in reducing the emigration of natural enemy species from the field at cutting when compared with the conventional solid-harvesting technique. Of a total of 25,175 individuals collected in the 2 fields, 18,004 (71.7%) were captured in the border-cut field, 2.5 times the number collected in the solid-cut field. Population levels of all natural enemy species studied remained higher in the border-cut than in the solid-cut field throughout the season. The use of border cutting aided in retainingLygusbugs in alfalfa and reduced their emigration to surrounding crops.Neither grade nor quality of hay was affected by the harvesting technique.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.103

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The effectiveness of dermestid sex pheromone-baited traps as tools for the survey and detection of insect populations, was evaluated at 3 locations in Milwaukee, WI. Traps were constructed of single-backed corrugated paper and were treated with malathion. The pheromones used were megatomoic acid, the sex pheromone of the black carpet beetle,Attagenus megatoma(F.), and theZ-alcohol component of theTrogoderma inclusumLeConte pheromone. Traps treated with the pheromones caught significantly more target insects when compared to control traps.

ISSN:1754-5692    

DOI:10.1093/ee/5.1.111

出版商:Oxford University Press    

年代:1976

数据来源: OUP