摘要:

(Z)-9-tetradecenyl formate (Z-9-TDF) had no disruptive effect inSpodoptera littoraliswhen released at high rates from 4 evaporators located at 3.5 m radius from the attractant. At this distance, (Z)-9-tetradecenyl acetate (Z-9-TDA) was an effective disruptant, somewhat less effective at 7 m radius and totally ineffective at 32 m. At 32 m, (Z,E)-9,12-tetradecadienyl acetate (Z,E-9,12-TDDA) was also ineffective. However, (Z,E)-9,11-tetradecadienyl acetate (Z,E-9,11-TDDA), the synthetic sex pheromone ofS. littoralis, was an effective disruptant even when released 44.5 m away from the attractant: 80–90% disruption was achieved at release rates of 2 to 4 mg/h/ha.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.973

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Large numbers of the red imported fire ant,Solenopsis invictaBuren, were unable to pauperize the predator arthropod fauna of a cotton field in east Texas. None of the 47 taxa sampled was significantly reduced as a result ofS. invictapredation. Because of its predatory habits on boll weevils,Anthonomus grandis grandisBoheman andHeliothisspp., and its failure to simplify the predator fauna,S. invictamust be considered an important predator in cotton agroecosystems where it is abundant. The evidence suggests thatS. invictais a fairly specialized predator though probably a polyphagous scavenger.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.976

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Intensive sampling of commercial Concord grape vineyards in North East, Erie Co., PA, during 1971–73 revealed the presence of 45 species of Hemiptera-Heteroptera. Eleven families were represented with the largest number of species occurring in the Miridae (14), Lygaeidae (12), Pentatomidae (5), and Nabidae (4). Abundant species collected were, in descending order of abundance,Orius insidiosus(Say),Geocoris bullatus(Say),Lygus lineolaris(P. de B.),Nabisspp.,Trigonotylussp.,Nysiusspp., andLigyrocoris diffusus(Uhler). The majority of the species collected were considered merely transients; those species that may feed on grapes or are predators of insects and mites are discussed in more detail and population trends presented. Sprays of carbaryl at recommended rates appeared to have little effect on populations ofNabis, Orius, andGeocoris. Species diversity was greater in the abandoned vineyard than in the commercial vineyards.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.982

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Mean progeny onHeliothis virescens(F.) produced by femaleBrachymeria ovata(Say) was 227.2±98.3 at 30° C in the laboratory, and more female progeny were produced at this temperature than at other temperatures. Males developing at 35° C were generally sterile, while those developing at lower temperatures became sterile after a few days of exposure to 35° C. Mean male longevity ranged from 34.4 days at 35° C to 162.9 days at 20° C; females lived somewhat shorter periods, but one female held at 15° C lived 326 days. The study was conducted to gain knowledge of reproductive potential of this parasite for use as a biological agent of the range caterpillar,Hemileuca oliviaeCockerell.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.987

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

When the surface area of sticky traps or cylindrical electric grid traps was increased, the number of male fall armyworm moths,Spodoptera frugiperda(J.E. Smith), captured showed a proportional increase. Wind direction affected the area on the surface of sticky traps where moths landed; significantly more moths were captured on the side of the trap downwind from the pheromone source.The location of pheromone-baited sticky traps placed in or along the edge of corn fields made no difference in captures ofS. frugiperdamoths when plant height ≤ trap height. In peanut fields, traps 1.2 m above ground level captured significantly more moths than those at heights of 0.7 and 0.5 m; also traps 25 m inside the fields captured significantly moreS. frugiperdamales than traps at field-edge or 50 m into fields.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.989

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

A study of the influences of stand factors on larval spruce budworm,Choristoneura fumiferana(Clem.), survival was conducted in north central and eastern Maine. Multiple regression andt-test analyses indicated that crown closure and non-host species had significant impact on survival rates of spring dispersing budworm. As crown closure increased, survival of dispersing larvae increased. The presence of hardwood species decreased survival.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.993

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Intra-tree dispersion of citrus blackfly (Aleurocanthus woglumiAshby) was measured by counting leaves infested with insect products (index) and live insects. Adults (16,000) were also released to measure within tree movement. Leaves infested with insect products (index) were found more concentrated in the lower and interior part of a tree. However leaves infested with live citrus blackfly were found more concentrated in the lower, but not interior part of a tree. Reasons for this discrepancy are discussed. Differences in directional quadrats were minor using both sampling techniques. No conclusions could be drawn from the experiment releasing adults because of the low recovery (<1%) 24 h later.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.997

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

The importance of the insect microclimate to insect pest management is discussed. The important microclimatic factors to measure are microhabitat temperature, humidity, wind speed, and radiation. Data presented shows how the microclimate of mites can vary considerably from standard meterological measurements.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.1000

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

An area sampler for quickly estimating absolute abundance of floodwater mosquito larvae (Diptera: Culicidae) was developed and evaluated. The instrument is useful in pools as shallow as 2 cm depth and requires 2 min/sample. Performance of the sampler was tested in an artificial pool employingAedes infirmatusDyar and Knab larvae at several water depths, temperatures, larval ages, and densities. Only water depth was found to significantly affect sampler efficiency, and a table of factors to correct for this bias is presented.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.1004

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

A new index of species abundance (ISA) is described that is calculated for individual species and encompasses numerical abundance and spatial distribution. Data for calculating theISAis arranged in a two-way table with species composing the rows and columns representing collection sites. The data of the index are ranks and the species in each column are ranked by numerical abundance, with average ranks used for tied scores. A value a is obtained by multiplying the number of zero cells in all columns for each row, byc. One is added to the single largest assigned rank in the columns to obtainc. The sum of ranks,Rjis the summation of assigned ranks in all columns for each row. TheISAis calculated with the formula,$\tt\ ISA = \frac{\text{a}+R_j}{\text{K}}$A formula is presented for astandardized ISA, giving indices between 0 and 1. An estimator of standard error for theISAis described along with an analysis of the components of theISAand a discussion of practical applications.

ISSN:1754-5692    

DOI:10.1093/ee/8.6.1007

出版商:Oxford University Press    

年代:1979

数据来源: OUP