摘要:

Feeding activity ofNilaparvata lugens(Stål) biotype 3 on five rice cultivars was monitored with an electronic recording device. Cultivars tested wereN. lugens-resistant‘IR56’ with theBph3 gene, field-resistant ‘IR36’, ‘IR42’, and ‘Utri Rajapan’, and susceptible ‘Taichung Native 1’, Distinct differences in waveforms for probing, salivation, A waveforms, and ingestion were recorded on resistant and susceptible cultivars.N. lugensprobed repeatedly, salivated for a long time, and ingested for a very short period on resistant ‘IR56’ when compared with the susceptible cultivar. Phloem ingestion decreased significantly with an increase in age of ‘IR36’, ‘IR42’, and ‘Utri Rajapan’.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.678

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

A field investigation was conducted near Kenansville, Duplin County, N.C., to determine the distribution of floodwater mosquito eggs and their association with selected edaphic parameters of a woodland depression. Soil samples were collected, analyzed chemically and densiometrically, and examined for mosquito eggs. Spatial distribution of eggs was found to fit the negative binomial model. Ninety-three percent of eggs were identified asPsorophora ferox(Humboldt). No significant correlations were found between individual edaphic parameters and number of eggs per sample. Values for edaphic parameters were converted into principal components and regressed against egg abundance data using standard linear regression techniques. Generally, principal components tested were not significant and models had low predictability (R2values). Therefore, within the range of variation detected, we found no association between the independent edaphic variables investigated and density of floodwater mosquito eggs.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.683

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Effect of background contrast on attraction of host-seekingTabanus nigrovittatusMacquart was examined using small test panels against large background panels. Attraction ofT. nigrovittatusto gray test panels was significantly greater when contrast against gray background panels was highest. Maximum numbers were attracted to high-intensity blue test panels against low-intensity gray backgrounds and low-intensity saturated blue panels against all-gray backgrounds regardless of intensity. The latter indicates the attractive effect of hue independent of intensity. Flies collected on test and background panels were clumped on the test panel (32.6%), along the boundary of the test panel and the background panel (59.9%), and from 15.2 to 38.0 cm above ground level (85%). Direct observation revealed that 60% of the flies approaching the panel landed and all did so below the height of initial approach. Only 20% landed immediately; the remainder flew past the panel first, then returned. The majority of flies (85.5%) approached panels at 30.4–53.2 cm above ground level.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.689

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

A survey of overwintering thrips and the potential forThrips tabaciLindeman to overwinter in upstate New York were investigated during the winters of 1982–83 and 1983–84. Six species—T. tabaci, Anaphothrips obscurus(Müller),Chirothrips manicatusHaliday,Limothrips denticornis(Haliday),Frankltniella tenuicornis(Uzel), andAptinothrips rufus(Gmelin)—were able to survive as adults in the vegetation sampled, but only Anaphothripini survived as larvae.T. tabaciadults overwinter within winter wheat, alfalfa, and weedy vegetation, and these overwintering females are capable of ovipositing on these plants during the spring. Winter wheat, oats, and alfalfa were the best oviposition and reproduction hosts we examined.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.695

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

‘Largo’ is an amphiploid betweenTrilicum turgidumL. andT. tauschii(Coss.) Schmal. This germ plasm line is highly resistant to greenbug,Schizaphis graminum(Rondani), biotypes C and E, which are currently the predominant biotypes of the Great Plains. Another biotype, designated as B, was prevalent on the Great Plains in the late 1950's and early 1960's, but is now difficult to find in the field. Since the possibility exists that B may again become predominant, this research was conducted to evaluate the reaction of ‘Largo’ to this biotype in comparison with a susceptible entry, ‘TAM W-101’, and OK 78047, which possesses a biotype C resistance gene derived from ‘Amigo’. Tests showed that the antibiosis and antixenosis of ‘Largo’ were considerably reduced compared with the ‘Amigo’ line, and it was also less tolerant of greenbug attack. Thus, lines with the ‘Largo’ gene would perform poorly in regions infested with biotype B.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.700

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Bacillus popilliaeDutky was the major pathogen found in grubs ofCyclocephala parallelaCasey andLigyrus subtropicusBlatchley in Florida sugarcane fields. The milky disease was widespread among fields in the sugarcane-producing region, and two differentB. popilliaevarieties infected the grubs. The type A milky disease, containing a parasporal crystal and spore in the sporangium, was the prevalent variety infectingC. parallela.The type B variety, possessing only a centrally located spore within the sporangium, infected mainlyL. subtropicusgrubs. The overall infection rate ofB. popilliaewas significantly greater inC. parallelathan inL. subtropicus.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.703

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Clear fiber glass panels have been extensively used for constructing traps for stable flies,Stomoxys calcitrans(L.). Numbers of stable flies trapped on clear Alsynite fiber glass panels, covered with plastic film and adhesive, during 1-h periods at cattle feedlots, were related to concurrent measurements of air temperature, solar radiation, relative humidity, and wind speed. Temperature appeared to have greater effect on the trap collections than other weather variables, with maximum responses occurring between 25 and 31°C. Increasing radiation and increasing relative humidity both increased trap collections. Wind speed had no detectable effect. The differing effect of radiation on trap collections and on feeding activity of stable flies may account for previously noted differences between trap counts and counts of feeding flies for estimating population size.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.706

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Relative attraction of the black turpentine beetle (BTB),Dendroctonus terebrans(Olivier), to the monoterpene constituents of gum turpentine, a synthetic mixture of monoterpenes approximating the composition of turpentine, and whole gum turpentine was determined in the field by comparing each of the test substances as baits in standard BTB traps. Both individual monoterpenes and the monoterpene mixture were less attractive to BTB adults than whole gum turpentine. The preferential attraction of BTB adults to slash pine,Pinus elliottiiEngelm. var.elliottii, trees stressed by application of the herbicide paraquat to a bark wound was investigated and changes in the monoterpene compositions of the stressed trees were compared with BTB attack and landing rates. Paraquat-treated trees attracted significantly more BTB and received significantly more attacks than wounded or nontreated trees. Paraquat treatments resulted in small but significant changes in the oleoresin percentages of α-pinene and β-pinene. These changes could not be correlated with increased attraction of BTB to paraquat-treated trees, however.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.710

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

Effects of sinusoidally fluctuating diurnal temperature regimes on longevity and daily oviposition rate of adult female lesser cornstalk borers (LCB),Elasmopalpus lignosellus(Zeller), were determined in controlled environment chambers. Mean daily oviposition rate decreased exponentially with an increase in adult age and changed with the temperature regime. Adults held in a cool day/hot night environment had a significantly lower daily oviposition rate than those held in a hot day/cool night or a very hot day/warm night regime. Total number of eggs laid per female LCB was less in the cool day/hot night regime than in the other two environments. Longevity of adult female LCB was greater in all three fluctuating temperature environments than in constant-temperature regimes reported in the literature.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.715

出版商:Oxford University Press    

年代:1986

数据来源: OUP

摘要:

The lupine aphid,Macrosiphum albifronsEssig, occurs throughout southwestern British Columbia onLupinus arcticusS. Wats. andL. polyphyllusLindl., and less frequently onL. sericeusPursch. It is parasitized by four species of Aphidiidae:Aphidius lupiniLiu,Ephedrus californicusBaker, and two unidentified species ofPraon.Percentage of parasitism varied seasonally and between collecting sites.A. lupiniwas the most common and widespread parasite; it killed an average of 5.2, 7.6, and 9.0% of secondo-, third- and fourth-instar aphids, respectively, over the season as a whole. A fungal pathogen,Entomophthorasp., caused ca. 60% mortality among third- and fourth-instar aphids during rainy periods in late spring and late summer.A. lupiniis considered as a potential agent for biological control of the lupine aphid in England.

ISSN:1754-5692    

DOI:10.1093/ee/15.3.719

出版商:Oxford University Press    

年代:1986

数据来源: OUP