摘要:

Two applications of the plant growth regulator daminozide at 2000 ppm, timed approximately 30 and 50 days following full bloom of Bartlett pears, resulted in reduced terminal shoot growth and subsequently in lowered pear psylla (Psylla pyricolaFoerster) nymphal densities, and in reduced honeydew fruit damage. Over a 3-yr. peroid shoot growth was reduced an average of 33%, psylla nymph density and damaged fruit were reduced 35 and 57% respectively, compared to the untreated check.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.275

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

By capillary gas chromatography, mass spectrometry, electroantennogram measurements, and male behavioral response tests, (Z)-5,(E)-7-dodecadienal was identified as the principal component of the sex pheromone of the forest tent caterpillar,Malacosoma disstria(Hubner). (Z)-5,(E)-7-Dodecadien-l-ol was indicated as a secondary component. In field trapping males were attracted to lures containing each component separately but best trapping occurred with aldehyde:alcohol ratios between 1:10 and 1:3.n-Dodecanal was also found in female tip extracts.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.278

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Studies conducted from May through Nov., 1979 determined that the distribution and abundance ofScaphytopius acutus acutus(Say) (Homoptera: Cicadellidae), a vector of peach (Prunus persicaBatsch) X-disease, in a Connecticut peach orchard were related to the distance from wild host species at the orchard edge and to the relative abundance of wild host plants in the orchard ground cover. Greatest numbers of adultS. acutusfor spring and summer generations were captured on yellow sticky traps located among wild host plants at the orchard edge while fewest were caught on traps in peach trees furthest from the edge. Density of nymphs and adults on peach trees and in ground cover in 32 plots along a transect through the orchard increased with the relative abundance of wild host plants in the ground cover and decreased with distance from the orchard edge.Host preference experiments conducted in the laboratory revealed that both generations ofS. acutuswere most highly attracted to red clover,Trifolium pratenseL. (Leguminosae), for feeding and oviposition. However, this plant comprised less than 1% of the orchard ground cover. Peach was preferred as a food host by both generations over 8 wild host species, which comprised 94% of the ground cover. Oviposition preference experiments indicated that peach was among the least preferred hosts for both generations while several rosaceous species, in particular strawberry,Fragaria virginianaDuchesne and blackberry,Rubus allegheniensisPorter, comprising 65% of the ground cover, were most highly preferred for oviposition. The differential utilization of peach and wild rosaceous hosts byS. acutusfor feeding and oviposition would encourage frequent movement of adults between peach and the ground cover.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.283

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Dispersal ofNezara viridula(L.) andPiezodorus guildinii(Westwood) nymphs, the 2 most abundant stink bugs in soybeans in Brazil, was studied. Results showed that they moved more along than across rows. Maximum distance recorded for both species along rows was 12 m, while across rows was 7.2 m forN. viridulaand 4.8 m forP. guildinii.The total number of nymphs recaptured was higher forP. guildiniithanN. viridula, and the recovery rate decreased with increase in distance from the release point. Nymphs in the 2nd and 3rd stages showed strong gregarism and dispersal was more pronounced for 4th and 5th stages, which were the principal ages involved in colonization of the field. Dispersal patterns of the nymphs best fitted the equationY=a+bLogx+c/x, where Y= density,x= distance from the release point,a= intercept,b= slope, andc= a proportionality constant.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.293

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Fecundity and development of the predatory mitesGalendromus longipilis(Nesbitt),Neoseiulus fallacis(Garman),Phytoseiulus macropilis(Banks),Proprioseiopsis temperellus(Muma and Denmark) (Acarina: Phytoseiidae) and the prey,Tetranychus urticaeKoch (Tetranychidae) was studied at 13.3° and 26.4°C. All predators developed faster thenT. urticae.N. fallacishad the shortest development time and one of the highest oviposition rates of the predators at both temperatures, followed byG. longipilis.P. temperellusrequired the most prey, consuming 48.2T. urticaeeggs/day at 26.4°C.On restricted universes,G. longipilisandN. fallaciscontrolled highT. urticaepopulations within 11 days after introduction.T. urticaewas not controlled byP. temperelluson the universe and appeared to be unsuitable as prey for this species.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.298

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Two applications of the fungicides Benlate®, Du Ter®, and Bravo®, and Benlate in combination with carbaryl were made to soybean. Infection of lepidopterous larvae by the entomogenous fungusNomuraea rileyi(Farlow) Samson was inhibited to some degree by application of Benlate ®, Du Ter®, and Bravo®. Bravo caused the most inhibition followed by Bentlate and Du Ter respectively. In one instance the combination of Benlate + carbaryl was more disruptive toN. rileyithan either chemical alone. Inhibition was greatest when pesticide application coincided with the early stages ofN. rileyiepizootics.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.304

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Boll weevils,Anthonomus grandisBoheman, remained paralyzed for 1–60 h following 5-min exposures to temperatures between 46° and 51°C. Males were slightly more tolerant than females. The 28-day survival of males that had remained comatose for ca. one day after exposure to 50°C was no different than that of the controls. Females treated at this temperature remained paralyzed for 1–2 days, but then resumed normal feeding activity and laid almost as many viable eggs as the controls by the 7th day posttreatment.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.309

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Soil samples from a cherry orchard heavily infested with pupae of the western cherry fruit fly,Rhagoletis indifferensCurran, showed significantly fewer (40%) pupae on the west side of the tree than the other 3 sides. Yields of fruit fly pupae/929 cm2sample (0–3.04 m radii) ranged from an average low of 0.7 at 305 cm (10 ft) to a high of 8.4 at 152 cm from the trunk.Fruit fly populations in soil beyond the canopy of the tree (avg 1.3) were only 25% those under the canopy (avg 5.1). Tree size (large or medium) made only slight differences in the density patterns of cherry fruit fly pupae.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.311

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

Approximately 200 specimens of predators representing 16 species were evaluated in field cage tests to determine daily consumption levels of eggs and larvae of the soybean looper,Pseudoplusia includens(Walker). The highest predation rates were recorded for the nabidsReduviolus roseipennis(Reuter),Tropiconabis capsiformis(Germar), andHoplistoscelis deceptivus(Harris); the green lacewing,Chrysopa rufilabris(Burmeister); and the lygaeidsGeocoris punctipes(Say) andGeocoris uliginosus(Say). Consumption of small larvae was largest for the nabidsT. capsiformisandH. deceptivus, the lygaeidsG. punctipesandG. uliginosus, and the carabid beetleCalleida decora(F.). The pentatomidStiretrus anchorago(F.) and the reduviidArilus cristatus(L.) consumed the most medium-sized larvae.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.315

出版商:Oxford University Press    

年代:1980

数据来源: OUP

摘要:

First-instarTrichoplusia nilarvae feeding on cabbage deterred oviposition by adult moths in laboratory assays.The effect remained for at least 3 days after removal of larvae from plants.When cabbage plants were treated with a dispersion of larval frass in water, oviposition was also deterred. The results suggest that larval frass can serve as a signal of occupancy to gravid females searching for oviposition sites.

ISSN:0046-225X    

DOI:10.1093/ee/9.3.318

出版商:Oxford University Press    

年代:1980

数据来源: OUP