摘要:

Alfalfa,Medicago salimL., cultivars ‘Lahontan,’ ‘Hayden,’ ‘UC Cargo,’ and ‘Caliverde 65’ were screened and evaluated for resistance to biotypes Band H of the spotted alfalfa aphid (SAA),Therioaphis maculata(Buckton) (Homoptera: Aphididae). Surviving plants screened by biotype B or H were evaluated simultaneously for resistance to both biotypes, then were rated by their response to each biotype. There was a significant differential resistance to biotype B among cultivars screened by biotype B. Some of these plants in each cultivar were resistant to biotype H, thus showing combined resistance to both biotypes. These results suggested there was a number of selected plants from each cultivar that expressed genes for horizontal resistance. There was no differential resistance to biotype H among cultivars that had been screened by biotype H, but all surviving plants resistant to biotype H also were resistant to biotype B. Screening by biotype H detected significantly more ‘Lahontan’ plants having combined resistance than did screening by biotype B. Vertical resistance to SAA was demonstrated in the cultivars ‘Moapa,’ ‘Moapa 69,’ ‘Sonora,’ ‘Sonora 70,’ ‘Mesa-Sirsa,’ and experimental-line MSTT. Horizontal resistance to five SAA biotypes was demonstrated in three parent clones and in ca. 17% of the progeny of ‘Lahontan.’ We found an indication of horizontal resistance in ‘Mesa-Sirsa’ and MSTT.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.989

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Air temperature establişhes an environmental threshold for the initiation of pollination activity by the alfalfa leafcutting bee,Megachile rotundata. Once this threshold is surpassed, activity is dependent on solar irradiance.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.997

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Sulfur, the acaricide cyhexatin (Plictran 50W), and the fungicides benomyl (Benlate 50W) and fentin hydroxide (Duter 50W) were field tested against the pecan leaf scorch mite (PLSM),Eotetranychus hicoriae(McGregor), and other mites found on pecan foliage. All materials were toxic to the tydeid, tenuipalpid, phytoseiid, and eriophyoid mites present. Sulfur and cyhexatin acted rapidly and were the most toxic. Depending on species, benomyl and fentin hydroxide caused 40 to 90% reduction within 14 days. Pesticide effects on PLSM were inconclusive because of large variance associated with the populations. Benomyl and fentin hydroxide treatments resulted in change of relative abundance of phytoseiid species.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1001

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

A new plastic (polyvinyl chloridc [PVC]) capsule was introduced as a substrate for use as a dispenser of tobacco budworm (TBW) sex pheromone components. Infield bioassays, where the numbers and frequency in TBW trap catchcs were compared, showed that the capsule was more effective as a bait loaded with 10-mg doses of V-2 rather than for the same dosage of V-7. V-2 was (Z)-11-hexadecenal and (Z)-9-tetradecenal in a 16:1 ratio. V-7 was a mixture (with proponions) as follows: (Z)-11-hexadecenal (16); (Z)-9-tetradecenal (1); (Z)-11-hexadecen-1-ol (1.3); (Z)-9-hexadecenal (0.65); (Z)-7-hexadecenal (0.38); hexadecanal (1.6); and tetradecanal (0.33). A laminated PVC (Hereon) dispenser also was more effective as trap bait with 20-mg doses of V-2 when compared with the same dosage of V-7. When loaded with 10 mg of V-2, performance of both the new capsular and the laminated PVC dispensers as bait in traps was nearly equal for 2-week test periods.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1005

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Studies were conducted at two environments during 1978 and 1979 so that we could determine early-season insect damage on selected glabrous and nectariless coltons,Gossypium hirsutumL. To have different insect populations, we applied two granular insecticides (aldicarb and slow-release acephate) as sidedress applications. Insecticide treatments did not significantly affect plant bugs,Lygus lineolaris(Palisot de Beauvois) (Hemiptera: Miridae), but did significantly affect leafhoppers (primarilyEmpoasca), total lint yield, and lint yield at first picking. Significant varietal differences were shown with plant bug populations, leafhopper populations, total lint yield, and lint at first picking. Glabrous cottons had the highest insect populations and the lowest yields. Significant or highly significant negative correlations were shown between leafhoppers and yield (total and first picking) at two environments and for the mean of all four environments.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1011

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Dispersal behavior of the southern pine beetle,Dendroctonus frontalisZimmermann (Coleoptera: Scolytidae), in response to synthetic aggregating pheromone (frontalin) indicates an exponential decrease in response with distance from the site of emergence. Differential response during dispersal among genotypes at a polymorphic esterase locus was found by using starch gel electrophoresis. These differences produced allelic distributions that predict increased genetic diversity concurrent with increasing dispersal distance from the source population.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1014

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Larval populations of the black cutworm,Agrotis ipsilon(Hufnagel) (Lepidoptera: Noctuidae), and the dingy cutworm,Feltia ducensWalker (Lepidoptera: Noctuidae), were sampled in field crops in Missouri during the spring of 1978 and 1979. Dingy cutworms were captured in March, April, and May, whereas black cutworms were present only in May and June. Aggregation indices indicated that both dingy and black cutworms were random (Poisson) in distribution. No significant correlations between the abundance of black cutworms and the density and cover of several weeds species were detected.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1019

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

The linden aphid,Eucallipterus tiliaeL. (Homoptera: Callaphididae), is a pest on linden trees,Tiliaspp., which are common as urban shade trees throughout North America. The aphidiidTrioxys curvicaudusMackauer (Hymenoptera: Aphidiidae), which is monophagous onE. tilia, was imported from Europe and released in Berkeley, Calif., where it became established. Subsequent observations showed that the parasite had effectively reduced linden aphid populations below an aesthetic injury level.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1023

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

The ovipositional response of the parasitoidMeteorus leviventris(Wesmael) was examined over five host densities. Fecundity was the same for all host densities tested. Daily oviposition peaked ca. 48 h after emergence, then decreased as parasitoids aged. Both the total number of eggs deposited and the number of hosts parasitized per 12 h were significantly higher during the dark phase of the LD 12:12 cycle. The maximum number of hosts parasitized during a l2-h period for any parasitoid was 8, with an average of 3.5 hosts for parasitoids exposed to 12 hosts per 12 h. With increasing host density, more total hosts were parasitized, resulting in lower numbers of eggs per host and fewer incidences of superparasitism.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1026

出版商:Oxford University Press    

年代:1982

数据来源: OUP

摘要:

Adult boll weevils,Anthonomus grandisBoheman were held in two ambient air temperatures (31.1 and 28.9°C) at four different relative humidities (RHs) (35, 45, 55, and 65%) during the oviposition period to determine the influence of these environmental parameters on egg production and hatch in mass rearing size groups and cages. At 31. 1°C the egg production decreased with each increase in RH, but at 28.9°C egg production decreased only above the 45% RH level. Egg hatch decreased above the 45% RH level at 31.1°C and above the 55% level at 28.9°C. Egg production or hatch were not different at 31.1°C and 45% RH and at 28.9°C and 45% RH. Hatched egg production decreased only above 45% RH at both 31.1°C and 28.9°C.

ISSN:1754-5692    

DOI:10.1093/ee/11.5.1029

出版商:Oxford University Press    

年代:1982

数据来源: OUP