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One of the main obstacles for a wider use of the Sterile Insect Technique (SIT) against the Mediterranean fruit fly (medfly) is the damage commercial fruit suffers due to sterile female stings. To overcome this obstacle, the Joint FAOlIAEA Division of Nuclear Techniques in Food and Agriculture has played a leading role in sponsoring and carrying out research to develop medfly genetic sexing strains that allow male-only SIT releases.Recently, as a result of this continued FAOjlAE.4 effort, genetic sexing strains based on a temperature sensitive lethal (/sl) mutation have been developed at the IAEA Laboratories at Seibersdorf. Unlike previous pupal color sexing strains, these 'second generation' sexing strains allow female killing at an early (embryonal) stage. In addition, they are essentially stable under mass rearing conditions. This represents an important breakthrough because both of these attributes were considered indispensable for genetic sexing strains with any potential to replace conventional strains with both sexes in large scale sterile medfly production facilities. Besides the considerable savings in the costs of release and field monitoring, genetic sexing strains in field tests have shown severalfold increases in the effectiveness of the SIT as compared with the standard strains involving males and females. When releasing both males and females, sterile males are apparently not used effectively, because they use their limited sperm mostly to mate with sterile females and because they do not disperse widely in the presence of these females. When males only are released, however, they disperse much further in search of wild females and compete more intensely with wild males for wild females.As a result of the availability of usable male-only strains, and the demonstration of their increased effectiveness, the applicability of the SIT against medfly has increased in two different ways. Highly developed commercial fruit growing regions, that previously had excluded application of SIT because of the fruit damage due to sterile female stings, are now reconsidering such free area/exclusion programs. More-importantly, sterile male releases can now also be used for routine control purposes, rather than only for eradication programs, partially or fully replacing chemical bait-sprays during the fruiting seasons.

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BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

No abstract

The larval parasitoid, Psyttalia cf. concolor (Szépligeti), reared on Mediterranean fruit fly, Ceratitis capitata (Weidemann), by the USDA-APHIS-PPQ, Guatemala City, Guatemala, was imported into California for biological control of olive fruit fly, Bactrocera oleae (Gmelin), in olives, Olea europaea L. Mean percentage parasitism of olive fruit fly third instars infesting fruit in field cages ranged from 7.0 in Grapevine to 59.7 in Santa Barbara and in free releases ranged from 0 in Grapevine to 10.6 in Santa Barbara after 4- to 6-d exposures. In the laboratory, more parasitoids developed to adults in olive fruit fly larvae that were 11-13 d old than in larvae 8-10 d old. Adult parasitoids lived significantly longer when provided with water than adults without water in environmental chambers at 5 degrees C, 85% RH; 15 degrees C, 65% RH; 25 degrees C, 25% RH; and 35 degrees C, 25% RH. Adult parasitoids lived for 48 d with honey for food and water and 32 d with food and sugar solution at 15 degrees C and 65% RH. Survival of adult parasitoids without food and water in greenhouse tests was approximately 4 d in a simulated coastal climate and 1 d in a simulated inland valley climate and was significantly increased by providing food and water. The parasitoid did not develop in the beneficial seedhead fly, Chaetorellia succinea (Costa), in yellow star thistle. The rate of parasitism of walnut husk fly, Rhagoletis completa Cresson, larvae in green walnut husks was 28.4% in laboratory no-choice tests. In choice tests, the rate of parasitism of walnut husk fly versus olive fruit fly larvae in olives was 11.5 and 24.2%, respectively.

No abstract

Caterpillars of key moth pests can cause significant losses in cropping systems worldwide, and globalization is spreading such pests. Failure to control some species can jeopardise the economics of food production. A Global Eradication and Response Database (http://b3.net.nz/gerda) was reviewed on known government-level incursion response programs specific to invasive Lepidoptera. Geographic range expansion of Lepidoptera was evident from 144 incursion response programs targeting 28 species in 10 families. The countries involved in responses to Lepidoptera were USA (104), Australia (8), Canada (7), New Zealand (6), Italy (3), Mexico (2), with the remainder with one programme each (Brazil, Czech Republic, France, Hungary, and Spain). Most programs have been undertaken since the 1990’s. Control options exist for the long-term management of Lepidoptera, but most have issues of cost, efficacy or non-target impacts that reduce their acceptance. Pheromone-based technologies are increasingly available and are generally highly compatible with other tactics. The development of tactics for new targets is a major undertaking, although previous programs can be invaluable. New and improved socially-acceptable technologies are needed to counteract range expansion in Lepidoptera, and usually need to be used in combinations to achieve eradication. The sterile insect technique, which involves mass-rearing and release of sterile insects to reduce wild populations of the pest, has been used successfully against a number of lepidopteran species. Several sterile moth programs are under development. New technologies must have a social license to operate in urban areas, where new incursions are frequently detected. This factor is likely to reduce tactical flexibility and increase the complexity of insect eradication.