Factors affecting the presence of Typhlodromusspp. (Acarina: Phytoseiidae) in the calyx cavities of apple fruits and implications for integrated pest management
Predatory mites of the family Phytoseiidae include several species of importance as biological control agents of phytophagous mites in various crops including apples. We report on the post-harvest presence of the motiles of two species, Typhlodromus occidentalis and Typhlodromus pyri, in the calyx cavities of apple fruits of three cultivars. The mean numbers of motiles per fruit were as high as 6.10. The phytoseiid densities were lowest in cv. Bonza and tended to be greater in samples taken in late autumn, particularly in cv. Red Delicious. No significant effect (p > 0.05) was observed for different insecticide treatments. Phytoseiids remained present within fruits of cv. Granny Smith left on the orchard floor in winter. Together with an observed reduction in the numbers of T. occidentalis in the early spring, this suggests that fruits constitute an overwintering refuge. The findings are discussed in relation to the implications for biological control, in particular the minimization of the removal of natural enemies from orchards.
Seasonal history ofTyphlodromus pyri (Acari: Mesostigmata: Phytoseiidae) in a commercial apple orchard in Czechoslovakia
The seasonal history and phenology of an indigenous field population ofTyphlodromus pyri Scheuten inhabiting a commercial apple orchard in South Bohemia are described. Data on population dynamics, number of generations, feeding, mating and reproductive habits as well as seasonal distribution within the apple tree canopy are discussed. Recommendations for mass retrieval ofT. pyri from apple orchards, their transfer to, and release in other orchards, are given. The conclusions and recommendations can be used for improving integrated pest management strategies in commercial apple orchards.
Phytophagous mites and their predators in an apple orchard at Bathurst (N.S.W., Australia)
Populations of three native mites (Acarina: Phytoseiidae) and Stethorus spp. (Coleoptera: Coccinellidae) were studied on Granny Smith apple trees in an experimental orchard at Bathurst, New South Wales, Australia, during the 1973–1974 growing season. Typhlodromus helenae Schicha and Dosse was the dominant predator of Tetranychus urticae (Koch) (Tetranychidae). Smaller numbers of Phytoseius fotheringhamiae Denmark and Schicha, Amblyseius lentiginosus Denmark and Schicha, and Stethorus spp. developed late in the season. A spray programme of ryania, captan and benomyl allowed native phytoseiid mites to survive and led to better control of T. urticae than that obtained during the two previous growing seasons when a ryania-captan-dinocap spray schedule was used (Schicha 1975b, 1975c). The influence of these pesticides on the microfauna of the apple trees is discussed. 
 
 
 
Zusammenfassung 
 
Phytophage Milben und ihre Pradatoren in einer Apfelanlage bei Bathurst (N.S.W., Australien). II. Wirkungen von Bekampfungsmaβnahmen mit Ryania-Captan-Benomyl-Sprays auf die Populationen 
 
 
 
Es wurden die Populationen der phytophagen Milbe Tetranychus urticae (Koch) und ihrer wichtigsten Pradatoren in einer Granny-Smith-Apfelanlage bei Bathurst wahrend der Vegetationsperiode 1973–1974 untersucht, als die Anlage einer kombinierten Sprayaktion mit Ryania, Captan und Benomyl unterworfen wurde. Bei Abwesenheit breitenwirksamer Insektizide und Acarizide wurde T. urticae hauptsachlich von rauberischen Milben der Familie Phytoseiidae, und nur zu geringem Mase von Marienkafern (Stethorus spp.), reguliert. Als haufigste Raubmilbe trat Typhlodromus helenae auf. 
 
 
 
Das Sparprogramm dieser Saison erlaubte es, das rauberische Milben besser uberlebten als wahrend vorjahriger okologischer Untersuchungen, und das Programm kann nun als Grundlage fur gezielte Experimente uber die Wirkung von Pestiziden auf einheimische rauberische Milben dienen.