摘要:

Virgin females (VF),Heliothis virescens(F.), attracted 68 to 75% fewer males to grid traps when exposed to 7-W BLB or incandescent lamp radiation. Exposure of VF in sticky-type traps to a 15-W blacklight located 3.0, 9.1, 18.3, 36.6, and 73.2 m away reduced the male catch by 84, 85, 57, 6, and 0%, respectively. Sexual response of males appeared unaffected by the radiation. The time of sexual activity for either sex was shifted by exposing adults to darkness before or after ambient darkness.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1032

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

The effects of spring treatments of an insecticide, carbofuran, on the soil animal decomposer community of an Ontario cornfield were assessed by measuring fluctuations in soil animal populations and by measuring changes in rates of leaf litter decomposition from bags of different mesh sizes. For several weeks after treatment, reductions in soil microfauna and reductions in the rate of corn leaf decomposition could be observed, but by autumn, the total number of soil micro-arthropods and litter decomposition rates were similar to those in untreated control plots. Earthworm populations seemed unaffected by inrow treatments of carbofuran, but broadcast treatments reduced worm populations significantly.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1036

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

The Mediterranean flour moth,Anagasta (Ephestia) kuhniella(Zeller), was reared on whole wheat flour diets with and without a yeast supplement. Six mycotoxins produced by grain storage fungi were added to the diets in 10-fold concentrations. Larval growth was inhibited by orchratoxin A, citrinin, rubratoxin B, and patulin. Ten ppm of ochratoxin A and 100 ppm of citrinin and rubratoxin B caused significant mortality. No moths survived at 100-ppm ochratoxin A and 1,000-ppm citrinin. Rubratoxin B decreased fecundity and fertility, especially in diets without yeast. Penicillic acid and oxalic acid had no effect. Mycotoxin activity in the measured parameters of growth, development, reproduction, and mortality was mitigated by yeast supplementation of the diet.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1043

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Laboratory and field studies were conducted to investigate the relationship betweenOrius tristicolor(White) and the green peach aphid,Myzus persicae(Sulzer), in potato fields.O. tristicolorprovided with 1,5, and 10 aphids per day killed 11.4 ± 1.2, 37.2 ± 1.1, and 53.7 ± 1.2 aphids, respectively, during development. Adults killed an average of 0.9 ± 0.6, 1.9 ± 0.5, and 2.7 ± 0.6 aphids per day when supplied with 1,5, and 10 aphids per day, respectively. Development time was not affected by prey density; the mean time required for development (at 24.4°C)was 14.6 days. At low aphid densities, predation rates among nymphal instars were not significantly different. WhenO. tristicolorwere supplied with 10 aphids per day, 3rd instars killed more aphids than either the 5th instars or adults.O. tristicolorpopulations did not appear to be a significant cause of decline of green peach aphid populations in potatoes. Where the thrips,Frankliniella tritici. occurred, its occurrence was strongly correlated withO. tristicolor.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1046

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Tarnished plant bugs (TPB),Lygus lineolarisPalisot de Beauvois, are serious pests of cotton in some years in the Mississippi Delta. They hibernate during the winter in dead weeds and surface woods trash and feed on a variety of early-emerging plants in the spring. Fleabane,Erigeron annuus(L.) Pers.. is the most important spring host. TPB migrate to cotton during its most susceptible stage of growth from mid-May through June and may cause some fruit loss throughout the summer. The sequential occurrence of the various wild weed hosts supports TPB populations until the hosts are killed by frost.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1049

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Parasitism of European corn borer,Ostrinia nubilalis(Hübner), larvae byLixophaga diatraeae(Townsend) in the early 3rd, 4th, and 5th instars resulted in a significant reduction in the amount of food consumed, frass weight, weight gained, and length of feeding period. The approximate digestibility was significantly greater for parasitized larvae of all three instars fed an artificial diet. Efficiency of conversion of ingested food to body substance was higher in unparasitized than parasitized larvae of the 4th and 5th instars. Efficiency of conversion of digested food to body substance was higher in unparasitized larvae of all three instars. The effects ofL. diatraeaeonO. nubilalis, an unnatural host, are very similar to the effects of this parasite on its natural host,Diatraea saccharalis.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1053

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Reduced rates of Dipel 4L, Dylox 1.5 Oil, and Dimilin W-25 were applied to an outbreak infestation ofLymantria dispar(L.) in 1980. Treatment effects were investigated on larvae, pupae, adult males, and egg masses as well as on parasitism and defoliation in 1980 and partially in 1981. Treatment effects for Dimilin were not reported because of improper aerial application. Dipel and Dylox provided excellent foliage protection in 1980 and reduced populations of stages I to III by 87 and 38%, respectively. Enhancement of parasitism byApanteles melanoscelus(Ratzeburg) (Hymenoptera: Braconidae) was most apparent in blocks treated with Dipel. Other positive and negative effects on parasitism were detected by both insecticides. Cost was reduced over standard application.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1058

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Pollination activity of the alfalfa leafcutting bee,Megachile rotundata, in response to atmospheric humidity is considered. Although pollination activity shows a strong relationship with relative humidity, it is shown that this relationship falsely represents response to humidity. When the influence of temperature is incorporated, the effect of atmospheric vapor pressure on pollination activity is minimal. This suggests that care must be employed in assessing the effects of atmospheric humidity on biological activity.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1063

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Rectangular cardboard sticky traps placed at a height of 0.5 m on apple trees captured adults ofLygus lineolaris,Lygocoris communis,Lygidea mendax, andHeterocordylus malinusas they appeared in the orchard, but were set too low to catch adults ofCampylomma verbascipresent in the orchard. The mean numbers ofL. communiscaptured on traps set at 0.5, 1.5, and 2.5 m above the ground were not significantly different. These traps are useful for detecting the presence ofL. lineolarisearly in the spring and for monitoring incoming adults of the other species in a sprayed orchard.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1067

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Analyses of pupal mortality factors were made in six subpopulations of forest tent caterpillar (FTC),Malacosoma disstriaHübner (Lepidoptera: Lasiocampidae), in Baldwin and Mobile counties in southwestern Alabama in 1977, 1978, and 1979. Infestations were confined to a cypress-tupelo deltoid swamp with water tupelo,Nyssa aquaticaL., as the predominant host species. Major identifiable mortality factors included predation, disease, and parasitism. Pupal predation was attributable predominantly to birds and ants, whereas the entomogenous fungusBeauveria bassiana(Balsamo) Vuillemin caused all observed mortality attributable to disease. Fifteen parasitic insects were reared from FTC pupae; nine were considered primary parasites, and six were hyperparasites. Rate of pupal parasitization was less than 60% in 17 of 18 temporally or spatially distinct samples during the 3 year study. Although parasitism was the most important cause of pupal mortality, it did not appear to be a dominant regulatory factor for FTC in this ecosystem. Neither host population quality nor density was highly correlated with degree of parasitism. The aquatic habitat places severe restrictions on the species of parasites which can effectively utilize FTC as a host, which in turn limits total parasite impact.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1071

出版商:Oxford University Press    

年代:1982

数据来源: OUP