摘要:

Seven chitin synthesis-inhibiting compounds were evaluated for activity against stored product insects in wheat. None of the compounds was acutely toxic to any species. N-[4-(4-nitrophenoxy)-3, 5-dichlorophenyl amino carbonyl]-2-chlorobenzamide with ID95values of 0.1, 0.1, 0.3, 0.7, 0.8, 0.3, and 0.5 ppm, was most effective as a suppressor of development of the confused flour beetle,Tribolium confusumJacquelin duVal, granary weevil,Sitophilus granarius(L.), lesser grain borer,Rhyzopertha dominica(F.), rice weevil,S. oryzae(L.), sawtoothed grain beetle,Oryzaephilus surinamensis(L.), almond mothEphestia cautella(Walker), and Indianmeal moth,Plodia interpunctella(Hübner), respectively. Other compounds were at least 10 times less effective.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.274

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Evidence is presented demonstrating that the regular distribution observed in larvae and eggs ofHylemyasp. (Diptera: Anthomyiidae) is due to an oviposition-deterring pheromone. The pheromone is secreted at the time of oviposition and is associated with the egg. Females actively search for this pheromone before deciding whether to oviposit.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.277

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

At a constant soil temperature of 18°C, ‘Abe’ wheat was resistant to Biotype B of the Hessian fly,Mayetiola destructor(Say). However, when Abe was exposed to 1-day-old Biotype B larvae at 27°C for one day and then transferred to 18°C, more than ½ of the plants were susceptible. Also, each additional day of exposure to 27°C caused susceptibility to increase until it reached 100% after 7 days. In the reciprocal test, with one day of exposure to 18°C, only 4% of the plants were resistant, but plants exposed for 4 days to 18°C were 100% resistant and not affected by ensuing exposure to 27°C.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.280

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

A discrete-time, population model describing biological control of the spider mite,Panonychus ulmi(Koch), by the phytoseiid mite,Amblyseius fallacis(Garman) on apple is described. Discussed are features of development, consumption, oviposition, mortality and dispersal for each species. Also included is a spatial component for within tree variation in population densities which is used to compute stochastic features of encounter and consumption. Validations of the model with field derived data are presented.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.282

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

A computer simulation model was constructed to organize existing data and explore possible results of actions taken to manage colonizing populations ofLymantria dispar(L.). The model consisted of a forest submodel, a gypsy moth population sub model and a tree mortality submodel. Various control policies were examined on poor, medium and good forest sites over an 80-yr period. Current eradication policies fail owing to low density survival of portions of the populations. Periodic management of moderate to high gypsy moth populations is effective and can be accomplished at lower cost due to fewer sprays being required over time. Trees growing on poor sites are most subject to mortality from defoliation due to less foliage surface area available for gypsy moth feeding.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.293

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Mean densities were determined forXyletinus peltatus(Harris) exit holes, parasite holes, and beetle larvae per 0.0929 m2(ft2) of joist surface in 19 naturally infested buildings built during World War II. Maximum densities for individual samples were 381 for beetles, 72 for parasites, and 65 for larvae. Only 4 buildings had mean beetle hole densities>26. After>30 yr of exposure, over 66% of the 1550 samples had<10 holes but 16% had 70 holes/0.0929 m2. Number of larvae within wood was not significantly correlated with number of adult exit holes. Braconid parasites probably reduced beetle populations, but did not control infestations. Factors influencing the activity and spread of an infestation are discussed.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.300

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Xyletinus peltatusdamaged wood from buildings>30 yr old was not significantly weaker than undamaged wood from the same buildings. At 70 beetle exit holes/0.0929 m2for all samples and at 27 holes for samples with<0.51 sp gr, the MOR was reduced 31–37% and the MOE 21–27%. Although such strength reductions may be of concern, load sharing of complete floor systems should adequately compensate for structural weakening beetles may cause.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.304

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

Five groups of 20 elm leaf beetle (ELB) larvae,Pyrrhalta luteola(Müller) and 20 prs (♂ and ♀) of ELB adults were reared on leaves from 4 elm species: one group each on American elm (Ulmus americanaL.), English elm (U. proceraSalisb.), Siberian elm (U. pumilaL.), and on new (currently growing) and old leaves of Chinese elm (U. parvifoliaJacq.). English elm leaves produced the highest larval survivorship (70%), but the shortest adult life expectancy; Siberian and American elm leaves produced low larval survivorship (25 and 15%, respectively), but caused the longest life expectancy of adults. ELB larvae failed to survive when fed old leaves of Chinese elm, while those fed new leaves exhibited low levels of larval and adult survivorship. Thus, the 4 species may be ranked from most to least susceptible as follows: English, Siberian, American, and Chinese elm. These results generally reflect those reported previously with the exception of Chinese elm. The most important host in southern California is Siberian elm because it is so widely planted. English elm, although more vulnerable, is an infrequently planted species in the area.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.307

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

In laboratory tests, only 8–13% survived of 1st-instar nymphs of the green peach aphid (GPA),Myzus persicae(Sulzer), placed on young lambsquarters,Chenopodium albumL., and redroot pigweed,Amaranthus retroflexusL., with 2–4 leaves initially and held to adult stage. GPA had 80% survival and shorter developmental time on radish,Raphanus sativusL., shepherdspurse,Capsella bursa-pastoris(L.) Medik, field bindweed,Convolvulus arvenisL., hoary cress,Cardaria draba(L.) Desv., yellowflower pepperweed,Lepidium perfoliatumL., and hairy nightshade,Solanum sarrachoidesSendt. When life table statistics were determined for the 7 weed plants and radish, hoary cress had the highest intrinsic rate of increase, r = 0.401; and that for radish was r = 0.357. In field cage experiments, with plants with 6 true leaves initially, the GPA multiplied faster on shepherdspurse, radish, and hairy nightshade than other weeds. In the orchard, the GPA population in late May on 6 common weed species ranged from 608/pigweed plant to 4659/yellowflower pepperweed plant. Winged migrants contributed from 3.8–26% of these populations and the estimated production of winged GPA was 70 million migrants/ha. Since about half of these orchard weed species are known hosts of beet western yellow virus (BWYV), many of the winged GPA from the orchard weeds are potential vectors of BWYV.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.314

出版商:Oxford University Press    

年代:1979

数据来源: OUP

摘要:

In an air permeation test in a pear orchard in 1975, 98% disruption of trap capture was achieved for 7 wk with the antipheromone of the codling moth,Laspeyresia pomonella(L.), (E,E,)-8,10-dodecadien-1-olacetate, permeating the test area at an initial rate of 127 mg h−1ha−1and decreasing to a final rate of 62 mg h−1ha−1. When the antipheromone and the sex pheromone, (E,E,)-8, 10-dodecadien-1-ol, were compared for disruption efficiency in an apple orchard in 1976, a minimum evaporation rate of 25 mg h−1ha−1of the antipheromone and 15 mg h−1ha−1of the sex pheromone were required to effect 98% disruption of trap capture.

ISSN:0046-225X    

DOI:10.1093/ee/8.2.318

出版商:Oxford University Press    

年代:1979

数据来源: OUP