摘要:

A previous manuscript (Lockwood 1993) questioned the introduction of exotic natural enemies for control of grasshoppers that affect rangeland and agricultural crops. This article presents some opposite viewpoints on the use of classical biological control, grasshopper biology, economic impact, management tactics, the specific natural enemies either released or slated for release, environmental concerns, and the review of these programs before release. In many areas, full agreement is indicated with positions presented by Lockwood; however, major differences of opinion exist. We believe that there is no scientific basis for establishing the new terminology “neoclassical biological control,” so traditional terminology is retained. Data on the use of arthropods and pathogensin classical biological control (including use of exotic natural enemies for control of native pests) show that this approach to pest management has controlled important pest species, has been associated with few if any serious environmental problems, and is aviable technique that was endorsed by the National Academy of Sciences and others. Therefore, the notion that the introduction of exotic natural enemies is categorically inappropriate is not accepted, nor is the idea that increased federal regulation would necessarily improve natural enemy establishment, improve control success, or eliminate negative environmental side effects. Rather, it is felt that mandatory Environmental Assessments and Environmental Impact Statements would restrict implementation of classical biological control. The specific programs questioned by Lockwood (1993) were based on significant biological information, were reviewed thoroughly, and hold potential to provide long-term mitigation of a severe economic pest problem while reducing environmental risk linked with widespread pesticide application.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.885

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

The rebuttal of Lockwood (1993, Environ. Entomol. 22:503–518) by Carruthers&Onsager (1993, Environ. Entomol. 22:[in press]) focuses on the elements of cost-benefit analysis and regulatory policy. I present the case that “native” has ecological, evolutionary, ethical, and legal meaning (hence the term neoclassical biological control is justified). In comparing the costs and benefits of grasshoppers (using only conditional values), the argument that costs of widespread damage and control exceed the benefits interms of sustained ecological and economic productivity is not supported by available data, whether we consider the interests of the rancher or the public. Moreover, when unconditional values are included, neoclassical control of rangeland grasshoppers becomes indefensible. Contrary to selected evidence presented by Carruthers&Onsager (1993), existing data show that native biological control agents are as or more effective in population regulation than the exotic agents. Host ranges of the exotic organisms are essentially unknown given the quality and quantity of available data, so ecological safety assurances are unfounded. A careful review of the data used to demonstrate the probability of success by the proposed exotic agents clearly demonstrates that these organisms have a very lowlikelihood of economic or ecological benefit. The essential ecological differences between various forms of biological control must be addressed in terms of regulatory policies and procedures. Existing federal laws may be sufficient to protect the agricultural and environmental interests of western rangeland, but only if these laws are interpreted and enforced from a sound ecological basis.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.904

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

An electronic feeding monitor was used to examine the feeding behavior of the green peach aphid,Myzus persicae(Sulzer), on lettuce,Lactuca sativaL. ‘Empire’ sprayed with a number of behavior-modifying compounds. The number of probing events recorded per hour was significantly higher on plants treated with an insecticidal soap(M-Pede), azadirachtin (Margosan-O), and an acrylic copolymer (Forevergreen) than on controls. Ingestion events occurred significantly less often on plants treated with nicotine sulfate (Black Leaf 40), the acrylic copolymer, and the insecticidal soap than on control plants. Aphids spent significantly more time in preprobing activities on plants treated with the acrylic copolymer compared with the untreated control. Aphid feeding behavior on plants treated with sabadilla was not significantly different from that on plants treated with distilled water. The use of these results in an IPM context is discussed.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.915

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

A variety of chemicals that are identical or similar to known ant alarm pheromone components or ant-defensive allomones produced by organisms other than ants were evaluated for effectiveness in disrupting the foraging activities ofFormica aerata(Francoeur). The chemicals were applied as bands around the trunks of plum trees or around wooden stakes holding ant feeding stations at their tops. Some of the chemicals were highly effective in excluding ants from the trees or feeding stations. Long-duration(up to 53 d) disruption of foraging was obtained with farnesol when incorporated in Stickem as a slow-release substrate.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.920

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Cucurbitacins, toxic to most organisms, are arrestants and phagostimulants for diabroticite chrysomelid beetles. Little is known about variation in the response of diabroticites to cucurbitacins. To quantify the effects of age, sex, reproductive status, and prior exposure to cucurbitacins on the sensitivity to cucurbitacin B of the southern corn rootworm,Diabrotica undecimpunctata howardiBarber, beetles were separated by sex and grouped for treatment with diets including or excluding cucurbitacins. Sensitivity to cucurbitacins was assayed over the first 43 d of adulthood by exposing beetles in groups of five for 24 h to filter paper strips spotted with serial methanol dilutions of cucurbitacin B ranging from 800 to 0.1 ng/ml. The areas consumed by the beetles at each dilution were then measured, and dose-response curves for each treatment were drawn. Treatments were compared in terms of the area under the mean dose response curve (AUC). Sex, age, reproductive activity, and prior exposure to cucurbitacins all significantly affected beetle sensitivity, though prior exposure was the most consistent in its effect. Exposure to cucurbitacins for as little as 6 d permanently reduced sensitivity, whereas beetles without prior exposure remained sensitive to our assay throughout the study. Reproductive activity depressed sensitivity in males but increased sensitivity in females. These results are discussed in terms of their relevance to semiochemical diabroticite baits and also to the proposed role of cucurbitacins in protecting these beetles from predators, parasites, or pathogens.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.925

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Velvetbean caterpillars,Anticarsia gemmatalisHübner, were reared at different larval densities on meridic diets containing different amounts of foliage. The degree of dark body color and yellow to orange head color was highest in larvae reared crowded and on meridic diets containing the most dried soybean foliage in artificial diet or consisting completely of fresh kudzu or soybean foliage. No body color change from green was observed in solitary larvae reared on the same diets as crowded larvae. Larvae developed most rapidly on meridic diets containing the lowest and highest amounts of foliage. On all meridic diets tested, solitary larvae developed to the pupal stage at least 1 d faster than crowded larvae. Larvae reared on fresh foliage developed into pupae and adults that weighed the least.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.933

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Pheromone production was quantified for males of the Caribbean fruit fly,Anastrepha suspensa(Loew), with access to protein, sugar, and water (fully fed), sugar and water (sugar only), or water (water only) overnight. Water-only males produced little pheromone the next day, and production was significantly less than pheromone production by sugar-only and fully fed males during peak periods. Food access significantly affected pheromone component blend. Late in the photophase, percentage epianastrephin was highest and percentage suspensolide was lowest in water-only males. Fully fed males exhibited a sharp increase in pheromone production late in photophase, whereas sugar-only males exhibited a fairly broad peak in production that started earlier in photophase. Pheromone production was less dependent on availability of food, however, if males had adequate access to food earlier in photophase. Female response to pheromone in a flight tunnel was directly related to amount of pheromone produced.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.942

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

We modified soil water supply to two groups of juvenile loblolly pines,Pinus taedaL., by sheltering or irrigating root systems in early summer or in late summer and measured oleoresin flow (primary defense), net photosynthesis, xylem water potential, and cambial growth throughout the growing season. When consistent significant differences in oleoresin flow and water potentials were detected between treatments, we induced attack by the southern pine beetle,Dendroctonus frontalisZimmermann. Compared with irrigated trees, sheltered trees had lower xylem water potentials, reduced cambial growth, reduced photosynthesis, and reduced resin flow. In terms of response to beetle attack, sheltered trees had fewer attacks and less total gallery constructed, but those beetles that did attack sheltered trees were more successful (50–100% more eggs per attacking pair). However, the success of attacking beetles was generally very low, even in sheltered trees (only three to eight eggs per attacking pair). This performance, along with water deficits that strongly affected tree physiology, growth, and development, indicates that juvenile loblolly pine can make internal adjustments that limit the success of southern pine beetle attack.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.948

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

Six different detoxification enzymes including general esterase, permethrin hydrolase, total cytochrome P-450, aldrin epoxidase, and glutathione transferase measured with two different substrates were recorded from a variety of terrestrial and aquatic insects. Aquatic insects generally exhibited a well-developed detoxification enzyme system and often displayed activities equal to or greater than those of the terrestrial species tested. Canonical discriminant analysis revealed significant differences in overall activity profiles between terrestrial and aquatic insects. Such differences may contribute to higher sensitivity of aquatic insects to insecticide poisoning but are insufficient to explain overall differences between terrestrial and aquatic insects with regard to insecticide susceptibility.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.958

出版商:Oxford University Press    

年代:1993

数据来源: OUP

摘要:

The attraction of adultRhyzopertha dominica(F.) to its aggregation pheromone and to volatiles of infested wheat was examined in relation to age, sex, and female mating status. Male and female beetles did not differ in their response to pheromone or wheat volatiles regardless of insect age. Virgin and mated females did not differ in their response to the pheromone or wheat volatiles.R. dominicawas more responsive to wheat that was infested than to clean wheat, and the response was proportional to the density of insects in the wheat. This suggests a strong attraction to the insect pheromone in infested grain. The implications of these findings for the attraction and migration ofR. dominicato stored wheat are discussed.

ISSN:1754-5692    

DOI:10.1093/ee/22.5.965

出版商:Oxford University Press    

年代:1993

数据来源: OUP