摘要:

Second-instar gypsy moth,Lymantria dispar(L.), larvae parasitized byApanteles melanoscelus(Ratzeburg) are substantially more susceptible to carbaryl than unparasitized larvae. The 3-day LD95values for parasitized and unparasitized larvae were 0.143 and 0.469 μg carbaryl, respectively. During the next 12 days, the carbaryl-treated parasitized group showed higher mortality than treated unparasitized larvae, probably because of an interaction between the effects of parasitism and the sublethal effects of carbaryl. The time from the egg stage to cocoon formation by the parasite varied from 11.2 days in untreated gypsy moth larvae to 14.1 in insecticide-treated specimens, with the increase in time being proportional to the carbaryl dosage. The mortality due to parasite action alone occurred over a 24-day period, beginning on the 15th day after carbaryl treatment; there was no indication of insecticide-parasite lethal interaction during this period. Other effects of the treatments on gypsy moth were alteration of the sex ratio and an increased incidence of supernumerary molting.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1183

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Laboratory bioassay demonstrated that the pheromone (Z)-6-heneicosen-11-one, its (E)-stereoisomer, and an epoxide (Z)-6,7-epoxyheneicosan-11-one are all attractive to the male Douglas-fir tussock moth,Orgyia pseudotsugata(McDunnough). The pheromone was approximately 27 times more attractive than the (E)-isomer and 300 times more attractive than the epoxide. An alcohol, (Z)-6-heneicosen-11-ol, was found to have a weak inhibitory effect on pheromone response.In the field, dosages of synthetic pheromone as low as 10-ng captured males and 50-ng baits were still attractive after 7 days' exposure. A controlled-release formulation, emitting pheromone at an estimated rate of 4 ng/min at 25°C, approached but did not equal the attractiveness of a live female. It is likely that an additional compound is present in the natural pheromone that is required to optimize response to the synthetic preparation.(Z)-6-heneicosen-11-one is also an effective attractant for the western tussock moth,O. canaEdwards, the rusty tussock mothO. antiqua(Linn.),Dasychira vagans grisea(Barnes and McDunnough) andD. grisefacta ellaBryk.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1187

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Flight behavior and response to blacklight of black cutworm (BC),Agrotis ipsilon(Hufnagel) and European corn borer (ECB),Ostrinia nubilalis(Hübner) adults were determined in laboratory tests at temperatures ranging from 0–55°C. ECB was tested at 2 air moisture conditions, less than 30% RH and 30–60% RH, while BC was only tested at one condition, between 30–60% RH. BC moths were active at lower temperatures (3°C) than were ECB (15°C). Both species were above 90% active from the lower temperature limits up to 45°C. Male BC moths were slightly less responsive than females to blacklight. Male and female ECB moths responded similarly except at low temperatures. The peak for ECB flight response occurred at higher temperatures in conditions of low relative humidity than in conditions of moderate humidity.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1191

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Influence of cultivars and pesticides on population trends and interrelationships of pea aphid,Acyrthosiphon pisum(Harris), spotted alfalfa aphid,Therioaphis maculata(Buckton), and associated arthropod taxa were studied over 3 growing seasons at Rose-mount, Minn. Greatest cultivar differences in resistance were for pea aphid and spotted alfalfa aphid. Cultivar differences were less for other pest species, but significant some sampling periods. Pesticides increased forage yields, the benefit varying with severity of pest pressure and cultivar. Fungicidal sprays resulted in greater yield increases than did insecticidal sprays; combinations were additive in effect. Populations of both aphid species and of associated entomophagous taxa were consistently higher in subplots treated with fungicides. Fungicidal sprays enhanced aphid populations by suppressing entomogenous fungi.Weekly correlations between populations of aphids and associated arthropod taxa revealed consistent patterns of significant positive correlation. Taxa tending to strong association with pea aphid included: tarnished plant bug,Lygus lineolaris(Palisot de Beauvois); alfalfa plant bug,Adelphocoris lineolatus(Goeze); the coccinellids,Hippodamia convergensGuérin-Méneville,H. tredecimpunctata tibialis(Say), andColeomegilla maculata lengiTimberlake;Orius insidiosus(Say);Chrysopaspp.; hemerobiids; syrphids; spiders; nabids; and parasitic wasps. Taxa tending to strong association with spotted alfalfa aphid included potato leafhopper,Empoasca fabae(Harris); hemerobiids; nabids;Orius insidiosus; spiders; and parasitic wasps. Strong positive correlations between either aphid species and any entomophagous taxon were interpreted as evidence of a density-dependent relationship.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1195

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Sexually mature 9-day-old male Caribbean fruit flies,Anastrepha suspensa(Loew), attracted both female and male flies under field conditions. Male-baited sticky traps captured females and males in equal numbers while McPhail traps baited with an aqueous preparation of yeast hydrolysate attracted from 1.4–1.8 times as many females as males. The presence of released males did not reduce the recapture percentage of females, nor did the presence of females influence recapture of males. Males released in the absence of females Were as strongly attracted to males as when females were present.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1208

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

In October issue of Environmental Entomology (5: 943–7), article entitled Colonization and Establishment of the Red Pine Scale,Matsucoccus resinosae(Homoptera: Margarodidae) in a Connecticut Plantation by Mark S. McClure, change the numbers in Table 1 under Total individuals/North facing from 2900 for settled larvae to 2951 and from 132 for cast skins to 160.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1210

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Vertebrate predators killed about 70% of the gypsy moth,Lymantria dispar(L.), pupae in a series of sparse, numerically stable populations studied in New England between 1965 and 1968; and white-footed mice,Peromyscus leucopusRaf., were the most important predators. Pupae in the litter were more likely to be preyed upon than those in other locations, and female pupae were more likely than males to be killed by vertebrates. All other agents (primarily parasites) killed about 15% of the pupae. It is postulated that the growing insects exhibit behavior that enables them to evade natural enemies in Europe, by resting and pupating in the litter at the bases of their host trees. In North America, however, this behavioral trait often assures not only high gypsy moth mortality but also the destruction of many of the parasites that may have caused this trait to evolve. It is also postulated that a new behavioral adaptation may be evolving by this pest in response to new conditions in North America. Certain management implications from the above findings and postulates are described, and further research studies are recommended.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1211

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Sparse gypsy moth,Lymantria dispar(L.), populations studied in the vicinity of Glenville, N. Y., between 1958 and 1964 tended to increase rapidly to outbreak levels. Conversely, equally sparse populations studied in the vicinity of Eastford, CT between 1965 and 1971, tended to remain sparse. Major mechanisms determining numerical differences between the two areas acted primarily during three age-intervals. First, the survival rate among instars I–III was higher in Glenville than in Eastford, although this difference decreased as density increased. These results were interpreted as a consequence primarily of airborne dispersal processes that occur largely during instar I. Second, the survival rate among instars IV–VI was higher in Glenville than in Eastford, and this difference increased as density increased. Although predation processes were probably responsible for most of the instar IV–VI mortality among the sparse populations in both areas, these results suggest that predation during this stage was effective in maintaining sparse populations at innocuous levels only in Eastford. Third, pupae were more likely to survive in Glenville than in Eastford, and this difference was relatively constant across the entire density range that was common to the 2 areas. Since vertebrate predators, especiallyPeromyscus leucopus, were known to have killed most of the pupae in the Eastford populations, these results imply that these predators played a major role in maintaining the Eastford populations at innocuous levels.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1218

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

Sample data from 215 infested lodgepole pines from 11 separate locations in the United States and Canada were analyzed to determine the relative effect of the measured variables on mountain pine beetle emergence density (production). From this analysis a model was developed which expresses production as a function of attack density and basic habitat suitability. The measured variables having the most influence on basic habitat suitability were lodgepole pine phloem thickness, cortical resin canals, host resistance, and predation by woodpeckers. Host resistance was also found to influence the intensity of attack. A theoretical model was constructed to examine the relative effects of lodgepole pine phloem thickness, and resistance to attack, on the dynamics of the beetle population. Analysis indicated that mountain pine beetle outbreaks are triggered by rapid declines in stand resistance resulting from climatic disturbances, insect defoliation, etc.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1225

出版商:Oxford University Press    

年代:1976

数据来源: OUP

摘要:

The volatiles emitted by growing cotton,Gossypiumsp. in the open field were collected daily during June to September 1957 by pulling an air stream through a porous polymer and then desorption with pentane. From analysis by GLC and GLC-MS, a total of 70 compounds was identified, only 15 of which were also found in cotton bud essential oil. The amount of total volatiles collected reached a maximum in late July and early August when the cotton plant squaring and flowering was highest. Then production decreased, to some degree with continued fruit set and more rapidly with approaching senescence. Although the sex pheromone of the boll weevil is a more powerful attractant than the plant for this insect, the plant may play some role in its migration.

ISSN:1754-5692    

DOI:10.1093/ee/5.6.1234

出版商:Oxford University Press    

年代:1976

数据来源: OUP