摘要:

Partial life tables were prepared for the red pine shoot moth,Dioryctria resinosellaMutuura, in three red-pine,Pinus resinosaAiton, plantations in central Wisconsin during a period of shoot-moth population decline. Survivorship in the early instars ranged from 72–78% in 1982 and from 22–75% in 1983. In the fifth instar, survivorship ranged from 0–4% in 1982 and 0–31% in 1983. Pupal numbers were very low both years and survivorship was variable; it ranged from 0–100%.Phrynofrontinasp.,Exeristes comstockii(Cresson),Bracon rhyacioniae(Muesebeck),Hyssopus rhyacioniae(Gahan), andElachertussp. were parasitoids present in high numbers.B. rhyacioniaecaused the greatest impact on shoot-moth populations, particularly in the fifth instar. Heavy fifth-instar mortality appeared related to shoot-moth population declines. However, mortality in other life stages not included in the partial life tables, such as dispersing early instar larvae, possibly were involved.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.545

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

Monoterpenes present in grand fir,Abies grandis(Douglas) Lindley, phloem were tested for their effects on fir engraver,Scolytus ventralisLeConte, adults and the symbiotic fungusTrichosporium symbioticumWright. All of the monoterpene vapors caused significant beetle mortality within 4 h. Toxicity was observed at doses normally found in the host tree, either in unattacked phloem or in reaction tissue induced by the pathogen. Incorporation of any monoterpenes into the growth medium, at doses normally found in the host tree, substantially reducedT. symbioticumgrowth. Limonene was the most inhibitory synthetic compound, but grand fir resin had a greater effect. This suggests that other factors are also involved in fungal inhibition.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.552

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

Susceptibility ofDelia antiqua(Meigen) to 11 isolates of entomopathogenic hyphomycetous fungi was studied in the laboratory. Newly formed pupae were sprayed directly with four concentrations of aqueous spore suspensions ofBeauveria bassiana(Balsamo) Vuillemin (three isolates),Metarhizium anisopliae(Metschnikoff) Sorokin (three isolates), and one isolate each ofMetarhizium flavovirideGams&Rozsypal,Nomuraea rileyi(Farlow) Samson,Paecilomyces farinosus(Dickson ex Fries) Brown&Smith,Paecilomyces fumosoroseus(Wize) Brown&Smith, andTolypocladium cylindrosporumGams. Pupae were generally not susceptible to mycoses but deferred mortality was observed in adults that emerged from puparia treated with nine of the fungal isolates.N. rileyi5 andM. anisopliae120 did not induce mycosis in adult flies. Mortality due to the other isolates ranged from<5% (T. cylindrosporumat 4 × 105blastospores ml−1) to 75% forP. farinosusandP. fumosoroseus(4 × 105conidia ml−1). The threeBeauveriawere moderately pathogenic at all four concentrations tested. Sporulation occurred on 56% of adults infected withM. anisopliae71 and on 17% of those infected withM. flavoviride(4 × 105conidia ml−1). Significant differences were thus found between isolates with regard to their ability to infect emerging adults, but dose-level differences for a given isolate were generally not significant. Overall, toxicity appeared to have been more evident than pathogenicity and resulted in reduction in numbers of viable and fertile adults that emerged from puparia treated with nine of the isolates.P. farinosus46 andP. fumosoroseus45 (LD50's in the range of 103conidia cm−2) are promising candidates for the control ofD. antiqua.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.557

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

The hatching ofNezara viridulawas found to be a function of a photoperiodically entrained rhythm. Periodicity of hatching found in a constant photoperiod was shifted by 12 h from that found in a 14:10 (L:D) photoperiod and the former was probably a reflection of periodicity of oviposition. Both the onset and distribution of the photoperiodic hatching rhythm were dependent on the temperature of incubation. Although emergence was temperature dependent, it was not thermoperiodically entrained. The synchronization of hatching within an egg mass was the result of the interaction of emerging nymphs stimulating hatching in adjacent eggs and was not due to independent timing of eclosion of each egg. Thus, in addition to timing eclosion at the onset of light, the photoperiodic rhythm may also have functioned to synchronize development so that all eggs in an egg mass were simultaneously capable of hatching when stimulated by the emergence of siblings.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.562

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

The role of living gastrointestinal bacteria in the growth and development of face fly (Musca autumnalisDeGeer) larvae in bovine feces was evaluated. Egg-to-pupa survival and mean pupal weight were lower for larvae grown in steam-sterilized feces than for larvae grown in unsterilized feces (4.6 versus 28.0% and 15.3 versus 26.1 mg, respectively). However, larval development was not retarded in sterilized feces that had been inoculated with bacteria collected from the bovine rumen or with a mixture of 11 bacterial isolates representing the major bacterial groups from the gastrointestinal tract. When tested individually, all of the isolates tended to improve larvae survival in sterilized feces, but no single isolate provided for survival rates equivalent to those observed with the mixed inoculum. Survival rates were greatest when sterilized feces were inoculated with strains ofEscherichia coliorLactobacillus plantarumwhich gave survival rates of 57.2 and 32.8% of the unsterilized control, respectively. These data suggest that the presence of living bacteria in bovine feces is essential to normal growth and development of face fly larvae.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.568

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

The entomogenous nematodesSteinernema feltiaeFilipjev (=Neoaplectana carpocapsaeWeiser) andHeterorhabditis heliothidis(Khan, Brooks&Hirschmann) were encapsulated in calcium alginate and fed to larvae ofSpodoptera exigua(Hübner) in petri dishes. While feeding on the capsules, the larvae released the nematodes. When moisture was present, larval mortality was nearly 100%, but little or no mortality occurred when free moisture was not present.S. feltiaein the capsules survived for 8 months with no detectable loss in survivability or infectivity when stored at 4°C. Capsules coated with a lipid membrane were completely desiccated at 50% RH with no nematode survivors, but at 72% RH, 71.2% of the nematodes were alive after 24 h. Potential use of the capsules containing these nematodes for insect control is discussed.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.572

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

Diamondback moth,Plutella xylostella(L.), oviposition was deterred by spraying the plant secondary compounds coumarin and rutin on cabbage plants in laboratory choice tests. Deterrent effects of the compounds were not reduced when females were exposed to treated plants for 48 h. Coumarin was a more potent deterrent in darkness (4.1-fold) than in light (2.3-fold), but rutin's effect was stronger in light (3.2-fold) than in darkness (1.9-fold). Results support the view that diamondback moth oviposition is mediated by several sensory modalities including vision, chemoreception, and mechanoreception.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.575

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

Sections of the upper or lower surfaces of leaves of cabbage plants were painted with the cabbage looper,Trichoplusia ni(Hübner), single-embedded nuclear polyhedrosis virus (100 PIB/mm2). Discs of leaves sampled between 0 and 28 days after treatment were fed to individually reared first-instarT. nifor 48 h. The larvae were subsequently fed semisynthetic diet and held to determine mortality. The insecticidal activity of the virus placed on the lower leaf surfaces was more persistent (50% mortality of test larvae after 3 weeks), compared with the activity of the virus on the upper leaf surfaces (13% mortality after 5 days). The importance of virus placement on the plants and of the feeding behavior of the target insect on virus effectiveness is discussed.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.579

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

When house fly,Musca domesticaL., populations were exposed to five insecticides (arsenite, dieldrin, malathion, methomyl, and fenvalerate) in different sequences and rotations, the development of resistance was slowed only slightly and cross-resistance was reduced compared with exposure to one insecticide. In only one population that evolved methomyl resistance was there evidence that it evolved significantly greater susceptibility to two insecticides (arsenite and fenvalerate). When a fly population was exposed to a combination of fenvalerate, a sticky trap, and a biocontrol agent (wasp parasite), it evolved resistance to fenvalerate, but not to the sticky trap or parasite. However, populations exposed to one control factor evolved resistance to the sticky trap, parasite, and fenvalerate.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.582

出版商:Oxford University Press    

年代:1985

数据来源: OUP

摘要:

Age-grouping techniques were applied to 15 face fly (Musca autumnalisDe Geer) populations, representing two locations in central Iowa, three locations in Minnesota, and one location in northern California. A total of 11,839 females was graded by age. Up to 13 gonotrophic (age) groups were recognized. Age distributions of all populations were compared. Bias due to sampling methods and sampling location was evaluated. Flies on sticky traps suggested younger population age structures than did flies obtained with sweep nets. Suitability of the data for achieving a synthetic, vertical life table was determined. Survival functions were fitted to the gonotrophic distributions. Average daily survival probabilities varied from 0.87 in Minnesota to 0.95 in Iowa when estimates were made from proportions parous. The survival distributions were remarkably uniform among years and locations. The proportions multiparous gave estimates of lesser survival rates, suggesting that this age group was not accurately classified or that risk of mortality increased with age.

ISSN:0046-225X    

DOI:10.1093/ee/14.5.590

出版商:Oxford University Press    

年代:1985

数据来源: OUP