摘要:

Soybeans and cotton occupy vast acreages of the alluvial soils of eastern Arkansas. In this greatly simplified agro-ecosystem, soybeans are usually grown without sustaining economic damage from insects. Serious outbreaks do occur, however, and on the average 15% of the acreage is treated annually. Much of the cotton in northeastern Arkansas is not treated. Outbreaks of bollworm and boll weevil regularly require insecticide usage in central and southern Arkansas.Insect pest surveys and individual field scouting are used as the basis for determining the need for insecticides on both crops. This insect pest management system has been 50 years in the making in Arkansas.Current research in various areas, including innovative practices, should lead to improvement in the system. In-depth studies of all aspects of the several agro-ecosystems are essential for long-term progress in insect pest management. Given professional dedication by entomologists, with support from the agricultural community, industry, federal and state governments, and the public, progress should accelerate rapidly.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.1

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Field experiments were conducted during 1972 and 1973 to ascertain and quantify certain insect-pest migrations from alfalfa to soybeans after alfalfa cutting. Twelve soybean-alfalfa complexes were established and sampled before and after cutting. During 1972 theEmpoasca fabae(Harris) migration into soybeans, following alfalfa cutting, was detected only in the border rows of the cut complexes, but was observed throughout the plots in 1973. Inadequate numbers ofLygus lineolaris(Palisot de Beauvois) andAldelphocoris lineolatus(Goeze) were collected during 1972 to evaluate treatment effects. During 1973L. lineolaris(nymphs and adults) migration was restricted to the soybean border rows, andA. lineolatus(adults) migration occurred throughout the soybean plot.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.8

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

One week after stored soybeans were treated with 20 ppm dichlorvos in a water emulsion, all milling and processing fractions contained residues though less than 1 ppm was present on the whole beans. Steaming did not remove residues from the dehulled meats, crude oil, or meal. Residues from the flakes passed into the miscella (extracted oil in hexane) and extracted marc (flakes with oil removed by extraction) and were subsequently detected in the crude oil and crude meal and in the hexane from both of these fractions. The residues could be removed from the hulls and crude meal by toasting and from the crude oil by refining.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.11

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Nymphs of the mayflyHexagenia limbata(Serville) were subjected to hydrogen sulfide in test chambers with a mud substrate into which they could burrow. Acute and chronic tests were in flow-through apparatus. At 17.8–18.3°C and O2of 4.5–6.6, 96-h LC50was 0.165 mg/liter H2S and LC50at 12 days was 0.060 mg/liter H2S. In chronic tests running 138 days with 0.029 mg/liter H2S, 37% mortality occurred, and at 0.0762 mg/liter H2S, none survived. No subimagos emerged at concentrations of 0.0348 mg/liter H2S but below this level 30–70% emerged.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.15

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Principal plant hosts ofAnthonomus grandisBoheman are in 4 closely related genera of the Malvaceae:Gossypium, Cienfuegosia, Thespesia, andHampea. AfterGossypium, the most important host in the United States isCienfuegosia drummondii(Gray) Lewt. in Southern Texas. However, the complexity of hosts increases in tropical areas. Plant species first reported herein as hosts of the boll weevil are:Gossypium harknessiiBrandg.,G. lobatumGentry,G. laxumPhill.,Cienfuegosia roseiFryx.,Hampea rovirosaeStandl., andPseudabutilon lozani(Rose) R. E. Fries.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.19

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

A blend of 4 components, 2 alcohols and 2 lactone esters, was isolated from 114,000 male Caribbean fruit flies,Anastrepha suspensa(Loew). Pheromone was also purified from water washes of the holding cages. The alcohols contain 9 carbons and 1 and 2 double bonds, respectively. The lactone esters have a molecular weight of 196. A male contains 0.012 and 0.016 μg, respectively, of the 2 alcohols, and 0.12 and 0.41 μg, respectively, of the lactone esters. Each compound is attractive to female flies, and combinations of all 4 are significantly more attractive than combinations of 2 or 3.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.27

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

We found the first (spring) generation ofPsilopa leucostoma(Meigen), a leafminer, develops onAtriplex patulavar.hastata(L.) Gray growing in sheltered and fairly humid locations, frequently in irrigation canals. At this time, the dry soil under unirrigated sugarbeets and the lack of a protective foliage canopy in young plants make sugarbeets a poor host until 6–8 wk after adults are present in warmer and more humid areas.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.31

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Pupae and adults ofApanteles melanoscelus(Ratzeburg) (Hymenoptera: Braconidae) were released in 5 plots in 3 sites in Connecticut during the summers of 1973 and 1974. Gypsy moth numbers varied from low to high in the different sites. Weekly collections of caterpillars showed consistently greater percent parasitism byA. melanoscelusin the release plots than in the check plots at all 3 sites for at least the first 2–3 wk after release. In later collections no differences occurred in the 2 sites where gypsy moth numbers were low. In the site with high host numbers, percentage parasitism in the release plots were higher than in the checks even at the 7th weekly collection after release.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.33

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

Growth of 3 laboratory populations ofBlattella germanica(L.) was followed by monthly censuses. Two of them, Populations A and B, originated from 5 wild type ♀, 3 wild type ♂ and 6 ♂ heterozygous for T(9;11). The 3rd was a control started with 5 pairs of wild type. T(9;11) male nymphs were released repeatedly into Pop. B so as to maintain about 2–3 T/+ ♂:1 +/+ ♂. Releases were timed to match oncoming groups of female nymphs in age.The single introduction of T(9;11) into Pop. A held the F1and an oncoming F2group to ca. ½ the size of comparable groups in the control. This experiment was terminated after 4 months. Repeated introductions markedly retarded, but did not prevent, the growth of Pop. B throughout a 6-month period. Analyses of oothecae for mating types indicated good competitiveness of T(9;11) males. About 4% of the matings in Pop. B were +/+ × +/+. The others were either T/+ × +/+ (semisterile) or T/+ × T/+ (sterile). The translocation was successfully incorporated into the population by careful timing of male releases.An analysis is presented as to the origin and growth of nymphal groups present at successive censuses. Population size replacement, mortality, carrying capacity of the breeder jar and other data useful to future population studies are discussed.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.37

出版商:Oxford University Press    

年代:1975

数据来源: OUP

摘要:

The insect growth regulators methoprene, Thompson-Hayward TH 6040 (N-(4-chlorophenyl)-N'-(2,6-difluorobenzoyl)urea), and Hoffmann-La Roche Ro 20-3600 ((E)-4-[(6,7-epoxy-3,7-dimethyl-2-nonenyl)oxy]-1,2( methylenedioxy) benzene), were fed to Holstein cows in amounts sufficient to control larvaeMusca autumnalisDe Geer in their feces. Methoprene was not active against nontarget insects, Ro 20-3600 was active against Hydrophilidae and Scarabaeidae, and TH 6040 was active against all the major nontarget insects except Scarabaeidae.

ISSN:0046-225X    

DOI:10.1093/ee/4.1.46

出版商:Oxford University Press    

年代:1975

数据来源: OUP