摘要:

(−)-Disparlure reduced: (1) the durations of anemotactic flights of male gypsy moths,Lymantria dispar(L.), in plumes of (+)-disparlure; (2) the rate of moth flight with respect to a moving floor pattern; and (3) the percentage of moths initiating anemotactic flights. The effects of (−)-disparlure were much more apparent on in-flight than pre-flight behavior.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.42

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Males of the day-flying mothLymantria disparL. (gypsy moth), while flying upwind toward a pheromone source, respond to high frequency (>15KHz) sounds by deviating sharply from the established flight course and flying away rapidly. Pheromone-stimulated males fanning their wings while walking on the substrate “freeze” momentarily in response to high-frequency sound. The puncturing of both tympana eliminates auditory behavior, whereas perforation of only one tympanum causes highly directional flight course deviations toward the perforated (silent) side. The retention of ultrasonic sensitivity in this essentially day-flying species may be explained by the selective advantage from bat predation gained by individuals active near dusk.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.45

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Larvae of 5 species of Lepidoptera known to attack soybeans were exposed on greenhouse-grown soybean plants to 5th-instar nymphs of the spined soldier bug,Podisus maculiventris(Say), to evaluate the influence of larval behavior on the ability of this predator to kill its potential prey. Species tested included the corn earworm,Heliothis zea(Boddie), the cabbage looper,Trichoplusia ni(Hübner), the soybean looper,Pseudoplusia includens(Walker), the velvetbean caterpillar,Anticarsia gemmatalisHübner, and the green cloverworm,Plathypena scabra(F.). Differences in larval behavior among the species had no significant effect on the ability of the predator to contact a larva with its proboscis, though the approach behavior and the time required to make contact varied. However, once contact was made, behavior of the prey larvae significantly affected the ability of the predator to subdue them.Anticarsia gemmatalisandPlathypena scabrareacted most vigorously to attack and suffered the least mortality (ca. 20–35%).Trichoplusia niandPseudoplusia includensoffered the least resistance and were killed most frequently (ca. 75–80%). Resistance byH. zeaand its mortality (ca. 60%) were intermediate. Pest management programs involving releases ofPodisus macuiventrisshould regard the species composition of a pest population as a critical variable.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.53

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Rubber septa used as substrates for gossyplure (1:1 ratio ofZ,Z-andZ,E-isomers of hexadecadienyl acetate), the sex pheromone of the pink bollworm,Pectinophora gossypiella(Saunders), produced 1st-order loss curves with a half-life of 159 days in the laboratory (release rate constant, k = 1.8×10−4h−1) and an avg half-life of 120 days in the field (k = 2.4×−4h−1; the rate of evaporation equals kM where M is the amount of pheromone on the septa at a given time). Male moths responded equally well to emission rates of 0.012–0.98μg/h in field tests conducted May and July and 0.084–8.8μg/h in Sept. Baits emitting in the range of ca. 0.2–2μg/h (3570μg/septum) would be attractive throughout a 6-mo season. Single virgin native female moths were as attractive as septa baits treated with 1000μg of gossyplure in trapping tests conducted in the field. Males showed the same diurnal rhythm in responding to female moths and to the baits.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.57

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

In population studies, sampling resources are often limited. To maximize the precision of the resulting estimates, it is essential to consider not only the usual statistical parameters of mean and variance, but also the specific research objectives and such distributional phenomena as stratification and spatial homogeneity.Formulae are derived for the optimal allocation of a limited number of emergence traps for estimating a regional population of overwintering cereal leaf beetles which is distributed among 5 different habitat types. With stratified sampling, a substantial increase in reliability per unit cost over simple random sampling can be obtained. Previously published estimates of the number of traps needed to obtain population estimates with a given precision are too large. It is further demonstrated that when estimates of the density of beetles in each separate habitat are wanted with equal precision, the allocation of samples among habitats is quite different from the optimal allocation for estimating the total regional population. The successful application of this last allocation is demonstrated with field results of trapping conducted for validation purposes.An analysis of variance showed that grouping traps into clusters within each habitat to reduce travel costs does not, for the case of cereal leaf beetle emergence data, result in a significant loss of information compared to a stratified random sample.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.62

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The vertical movement of stable fly larvae in response to temperature gradients in simulated sections of a manure mound was measured and described by a simple model. Temperature gradients in an actual manure mound were recorded and combined with the larval migration model to simulate the migration of overwintering larvae. The data and the simulation indicated that stable fly larvae easily avoid freezing by migrating downwards in manure mounds during the winter. The larvae dispersed so widely in the simulated mound sections that survival of a portion of overwintering larvae seems almost certain.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.67

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Treatment of gypsy moth,Lymantria dispar(L.), larvae with the parasiteApanteles melanoscelusRatzeburg and the microbial insecticideBacillus thuringiensisBerliner yielded a higher mortality than treatment withA. melanoscelusorB. thuringiensisalone. The mortality was, however, less than the sum of the mortalities for the separate treatments. The 7- and 14-day LC50values for parasitized (97.6 and 50.2 IU ofB. thuringiensisper ml of diet, respectively) and for unparasitized (95.3 and 43.4 IU ofB. thuringiensisper ml of diet, respectively) larvae showed no significant differences with respect toB. thuringiensistreatment. Mortality due toB. thuringiensistreatment continued up to the 28th day and was dependent on dosage. The majority of deaths due to parasitism alone occurred between the 15th and 28th days.B. thuringiensistreatment of host larvae caused an increase of ca. 3 days in the total development time ofA. melanoscelus.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.73

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Laboratory studies of interaction of the red flour beetle,Tribolium castaneum(Herbst), and the cigarette beetle,Lasioderma serricorne(F.), revealed that numbers of the latter were reduced, at all densities, by predation by the red flour beetle. Numbers of red flour beetles were increased when immatures of the cigarette beetle were supplied as prey. Adult and late-instar red flour beetles generally killed more immobile prey (eggs and pupae) than mobile prey (larvae). The number of prey killed per predator increased as prey density and duration of exposure to the predator increased.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.77

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

The life histories of the walnut husk maggot,Rhagoletis suavis, and the walnut husk fly,R. completa, were determined between 1973–75 for Missouri. Emphasis was placed on the use of various trapping techniques for adult flies. The Zoecon “Pherocon AM Insect Traps” were most successful. The peak emergence period for both species is mid- to late Sept. The larvae overwinter in the 2.54–5.08 cm layer of soil. Some overwinter for more than 1 year.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.81

出版商:Oxford University Press    

年代:1978

数据来源: OUP

摘要:

Shortgrass prairie carabids responded positively to ecosystem stress in the form of water and/or nitrogen by tending to concentrate within replicated plots receiving water treatment and within those which received both water and nitrogen. Statistical analyses were carried out on 3 of the most abundant species,Harpalus desertus, Selenophorus planipennis, andStenolophus rotundatus. Concentrations ofH. desertusoccurred in the nitrogen and water plus nitrogen plots, whereas those ofS. planipennisandS. rotundatuswere found primarily in the water plus nitrogen plots.

ISSN:1754-5692    

DOI:10.1093/ee/7.1.88

出版商:Oxford University Press    

年代:1978

数据来源: OUP