Apple and Sugar Feeding in Adult Codling Moths, Cydia pomonella: Effects on Longevity, Fecundity, and Egg Fertility

Attraction of adult codling moths, Cydia pomonella (L.) (Lepidoptera: Tortricidae), to sweet baits has been well documented. However, beneficial effects of sugar feeding on moth fitness have not been demonstrated. Longevity, fecundity, and egg fertility were examined for female/male pairs of moths maintained with the following food regimens: water, sucrose water, honey water, apple juice, apple flesh, or starved, i.e., no food or water provided. Longevity and total fecundity were enhanced in all treatments relative to the starved treatment moths. Sucrose water, honey water, and apple juice treatments yielded the highest longevity, but total fecundity was highest for moths maintained on honey water or apple juice. Total egg fertility did not differ among treatments. However, egg fertility declined more gradually over the female lifespan for the three aqueous solution diets of sucrose water, honey water, and apple juice. Similarly, fecundity per day declined more gradually over time for honey water and apple juice treatments. Performance of moths maintained with apple flesh was generally intermediate between that of moths with water and the three aqueous solution treatments. This suggests that moths benefit from feeding on ripe apple flesh, although apple may be more difficult to ingest or its nutrients less concentrated compared to aqueous solutions. The results presented here may explain attraction of adult moths to sweet baits as well as to odors from ripe fruit, which may be a natural source of food in the fall

Occurrence and Population Density of Aphids in Apple Orchards of South Bulgaria

In a 2006-2008 study, seven aphid species (Hemiptera: Aphididae) were detected on apple trees in South Bulgaria: Rhopalosiphum insertum Walk. (apple-grass aphid), Dysaphis plantaginea Pass (rosy apple aphid), Dysaphis devecta Walker (rosy leaf-curling aphid), Macrosiphum euphorbiae Thomas (potato aphid), Aphis pomi De Geer (green apple aphid), Aphis spiraecola Patch. (spiraea aphid/green citrus aphid) and Eriosoma lanigerum Nausm. (wooly apple aphid). The dominant species were D. plantaginea, found in 97.8% of the surveyed orchards. Two green aphid species from the genus Aphis were both found in 96.4% of the orchards. The rosy apple aphid was a more important pest of bearing orchards, where infestation in spring always exceeded the economic injury level (1-2% of infested shoots). The green aphids were more important in young orchards and nurseries, where they developed during the entire vegetation period and infestation sometimes exceed 50-80% of shoots. A. pomi was still more widespread, but A. spiraecola was found throughout all of South Bulgaria. As pests of apple, the other species were less common, causing lower infestations and minor economic importance

Successful application of the baculovirus product Madex for control of Cydia pomonella (L.) in Bulgaria

The codling moth (CM), Cydia pomonella (L.), causes heavy damage in Bulgarian apple orchards. Conventionally treated orchards, were monitored in this study. In spite of numerous chemical treatments, these orchards showed increasing flight densities of CM moths, growing populations of hibernating larvae and rising fruit damage rates. Thus, the control of CM by conventional spraying programmes became ineffective, apparently due to the development of resistance to insecticides. Products based on the Cydia pomonella granulosis virus (CpGV), such as Madex®, may provide alternative control tools that can be applied with other approaches, for a sustainable control strategy. The trials were carried out in Central-South and South-East Bulgaria, in 2006-2010. Four treatments of Madex® against the first generation, and six treatments against the second generation kept the fruit damage and population density of CM at a low level. Based on the obtained results, different control strategies have been suggested, depending on the initial CM pressure in a particular orchard. Madex® may be a promising alternative to traditional programmes of CM control. Its dose, however, should be adjusted to the initial CM population density. Also, at a high or moderate CM population density Madex® applications should be combined with MD to avoid resistance of CM to granulovirus. At the peak of CM hatching, additional chemical treatments may be sometimes necessary. Such treatments include using insecticides which are still effective against CM