摘要:

Carpenterworm (Prionoxystus robiniaePeck) attractant dispensers, trap height, and trap color were evaluated for attractiveness to the male carpenterworm in Mississippi (MS) and North Dakota (ND). The effect of understory density on trap site was also checked. In the humid MS hardwood forest, a standard cotton wick dispenser baited with synthetic sex attractant (Z,E) -3,5 tetradecadien-1-ol acetate was more effective in attracting males than a sheath type dispenser, but in the drier ND environment, it was less effective than a sheath dispenser or any of four other dispensers.Trap catches in MS generally increased with trap height, but in ND, most moths were caught between the tree canopy and the undergrowth. In MS, the capture rate in 1.5 m high traps was not influenced by light or medium understory densities, but heavy understory reduced trap catches. Trap color had no effect on the rate of moths captured.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.322

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Larval development and oviposition behavior of the tree hole breeding mosquito,Aedes triseriatus(Say), in relation to the varying concentrations of 2 inorganic salts, NaC1 and Ca(NO3)2, were investigated. Calcium nitrate, at the concentrations used in this study, had no significant effect on the larval mortality. Although higher concentrations of NaC1 had significant effect on larval mortality, larvae were able to tolerate a wide range of salinity in water.Although adults laid significantly fewer eggs in containers of water with 5 g/liter of Ca(NO3)2neither distilled water nor water containing up to 2.5 g/liter of Ca(NO3)2were oviposition deterrents. The inorganic salt content of water may not be as important a factor in the selection of oviposition sites as has been previously speculated.A. triseriatusfemales will oviposit in relatively saline habitats if the other physical and chemical factors are favorable. The fact that the interaction of the salts did not significantly alter the oviposition behavior of this mosquito species suggests that there is some influential factor other than osmotic pressure involved in the discrimination between different concentrations of electrolytes by gravid females.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.326

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Female navel orangeworm,Amyelois transitella(Walker), laid the greatest number of eggs on mature or green almond fruits, stems or leaves of an almond tree, or filter paper substrates treated with a water extract of larval frass. Similar acetone and acetonitrile extracts of frass also stimulated oviposition on some tests on some substrates as did extracts of macerated larvae prepared with any of the 3 solvents, but to a lesser extent. Phenyl propionate inhibited oviposition on mature almonds.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.330

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

The effects of soybean planting date, row width and seeding rate on populations ofPlathypena scabra,Heliothis zea,Pseudoplusia includens, and their natural enemiesGeocoris punctipes,Orius insidiosus,Nabisspp., Araneida andNomuraea rileyiwere monitored in a 3-yr study in North Carolina. Of the cultural variables, seeding rate had the least effect and planting date generally had the greatest effect on all populations exceptO. insidiosus. Early-planted soybeans in narrow rows at a high seeding rate generally had larger numbers ofN. rileyi-killed larvae and a higher percentage of mortality of the total larval population due toN. rileyi.There is strong evidence to support the recommendation of planting soybeans early (before June 5) because yields were higher and parasitism (byN. rileyi) and predation on the key pests were higher than on late-planted soybeans. When soybeans are planted late as a 2nd crop following small grain, planting in narrow rows at a high seeding rate maximizes the effects ofN. rileyiand key predators.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.334

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Cocoon distribution ofPikonema alaskensis(Rohwer) was studied in 10- to 12-yr-old white spruce plantations in Minnesota. Adjacent soil cores were taken radially from the trunk, extending 88 cm beyond the crown. Adult emergence traps were placed under, at the edge, and outside of the crowns.There were twice as many sawflies outside of the crown area with males predominating. The north and west sides had more sawflies.Fully developed larvae released in flats with one half of the area shaded did not show a cocooning preference for either the sunny or shaded side. Observations relate cocooning preferences to grass and moisture. Therefore, we feel that the preference for cocooning outside of the crown-covered ground is a grass and moisture related, rather than a sun-related, preference.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.340

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

A 4-yr study determined the impact of methyl parathion, as commonly used against the alfalfa weevil, on the alfalfa weevil parasiteBathyplectes curculionisin Pennsylvania. The 1st generation ofB. curculioniseach spring coincided with the peak alfalfa weevil larval population and produced the greatest number of parasitized larvae. Each year the insecticide treatment significantly reduced the number of immature and adult parasites. The parasite-host ratio also declined relative to that in the unsprayed area. One week after spraying, each year, the numbers of immature parasites were reduced 93.2–100%. This reduction over the total period between spray and harvest ranged between 84.6 and 95.3%. In addition, the number of nonparasitized host weevil larvae also declined to near undetectable levels, consequently, reducing the oviposition potential for any adult parasites surviving in the sprayed area.The number of parasite larvae in the methyl parathion area declined significantly during the 3-yr spray program. During the 4th yr, when no spray was applied,B. curculionislarval populations increased in both the sprayed and unsprayed areas. However, the population in the sprayed area remained significantly lower than that in the unsprayed area indicating thatB. curculionispopulations did not fully recover following 3 yr of insecticide stress. The reduction in parasite numbers during this study was accompanied by a 9x increase in the weevil larval population. It is apparent that alfalfa weevil management schemes which do not judiciously integrate insecticide programs withB. curculionisbiology can greatly reduce this parasite's potential.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.344

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

The results of field releases of backcross (BC) males or females obtained by backcrossing hybrid females resulting from a cross betweenHetiothis subflexa(Guenee) females andH. virescens(F.) males toH. virescensmales, indicated that native males mated with BC females; but BC males were observed only rarely mating with native females. When both BC sexes were released in the same field, the BC male was competitive for BC females but not for native females. Generally the behavior of the BC culture was similar to that of the laboratory strain of tobacco budworms used in its production. Field observations indicated that peak emergence and mating occurred 8–9 days before peak captures in pheromone traps. Also, peak mating occurred 4 days before the full moon and peak trap capture occurred 4 days after the full moon.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.349

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Male and female mice were administered (gastric intubation) 24.8×108conidia/mouse, the equivalent of a 70-kg man receiving a 0.4-ha application of conidia. No deleterious effects were observed and greater than 99.9% of the infectivity of conidia was lost during passage through the alimentary tract. Also,>99% of the total infectivity that was recovered from feces was recovered one day after feeding conidia. No apparent clinical, pathological, or histological abnormalities were observed when white rats were exposed to 1.1 × 107viable conidia/liter of air for one h, the equivalent of a 70-kg man inhaling conidia applied to ca. 1/500 of a ha. Eyes and the abraded skin of rabbits treated with a dose of 1.2×108conidia/eye or 3×109conidia/cm2of skin, respectively, showed no apparent clinical, pathological, or histological abnormalities. These studies demonstrated thatN. rileyishould not pose a serious, acute hazard to mammals.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.354

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Trees in 3 southern pine beetle infestations were treated with one of 4 treatments of inhibitors of southern pine beetle aggregation behavior to determine their effects on beetle aggregation behavior. Brevicomin isomers and brevicomin isomers + verbenone reduced landing trap catch by 74 and 84%, respectively. These same compounds effected a 52 and 92% reduction in southern pine beetle galleries in treated trees. There was an increase in theIps avulsustrapped on the treated trees. Verbenone alone did not affect either southern pine beetle orI. avulsusactivity. None of the inhibitor treatments prevented the treated trees from succumbing to the southern pine beetle and/or possibleIpsattack. However, the reduction in both number and length of beetle galleries indicates that the brevicomin isomers and brevicomin isomers + verbenone could cause significant reduction in brood production. These results suggest the potential use of these compounds in reducing tree mortality by reducing brood production. The numbers and distribution of predaceous clerids,Thanasimus dubius(Say), on attacked trees were unaffected by the inhibitors.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.360

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Apanteles marginiventris(Cresson) is a major parasite of green cloverworm,Plathypena scabra(F.) on soybean in Arkansas.A. marginiventrisprefers 1st and 2nd stageP. scabralarvae as ovipositional hosts. Mean developmental time from oviposition to larval emergence from the host is ca. 8 days at 30°C and 11 days at 25°C. Pupal development ofA. marginiventrisranges from 3–5 days at 30°C and 4–7 days at 25°C. Mean adult longevity in the absence of hosts is ca. 5.6 and 9 days at 30° and 25°C respectively. Usually only one parasite develops within a single host. Parasitism byA. marginiventrisoccurs primarily during daylight hours. The mean number ofP. seabralarvae parasitized by a female during her life span is ca. 82.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.365

出版商:Oxford University Press    

年代:1979

数据来源: OUP