Managing orchard pests.

This chapter provides information on the various economically important insect and arthropod pests causing damage to cherry production, such as Rhagoletis indifferens, Drosophila suzukii, Choristoneura rosaceana, Tetranychus urticae and Caliroa cerasi, among others. Notes on their life cycle, damage and management methods are also presented.

Spatial distribution of spotted-wing drosophila (Diptera: Drosophilidae) and other insects in fruit of a sweet cherry (Rosaceae) orchard

Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is an invasive pest of many small and soft fruits. We present the first results concerning its oviposition in the canopy of a sweet cherry (Prunus avium Linnaeus; Rosaceae) orchard. We examined the distribution of arthropods emerging from fruits of five cultivars ripening successively over seven weeks, in interior and border rows, within four regions of the tree canopy (top/bottom height × north/south aspect), and measured the associated fruit ripeness (ºBrix). Single fruits were reared for more than two weeks: 1328 arthropods emerged from 887 cherries in June, and 10 426 emerged from 1071 cherries in July. When populations were low, significantly more D. suzukii were present in the northernmost row and northern canopy aspect. Later, its distribution with respect to cherry row, height, and aspect was homogenous. Drosophila suzukii density per sweet cherry was highest in the latest ripening cultivar, when its distribution was not homogeneous; significantly more D. suzukii were in the centre than the southernmost row, in the lower canopy, and the southern aspect, than elsewhere. In the early season, single egg clutches were found without aggregation. As population density increased, so did intraspecific aggregation, but D. suzukii did not co-exist with other Drosophila Fallén species, nor with Rhagoletis indifferens Curran (Diptera: Tephritidae) when present.

Low Temperature Duration and Adult Rearing Regimes Affect Eclosion of Rhagoletis indifferens (Tephritidae: Diptera)

Western cherry fruit fly, Rhagoletis indifferens Curran, is a quarantine pest of sweet cherries in the Pacific Northwest of the United States that overwinters as diapausing pupae. Eclosion responses of R. indifferens puparia to different low temperature durations and postdiapause conditions affect the pest status of the fly. Here, we determined the effects of holding R. indifferens puparia at 3°C for 0, 1, 2, 5, 10, 15, and 20 wk on adult eclosion times and rates at two simulated temperate and two simulated tropical climate treatments over 40 wk. When puparia were chilled 0, 1, or 2 wk, adult eclosion across the four climate treatments displayed a bimodal distribution with low eclosion at 3 wk and high eclosion at 23–35 wk. When puparia were chilled ≤ 10 wk, there was a weaker bimodal distribution. However, when puparia were chilled 15–30 wk, eclosion was more synchronous and occurred at 5–7 wk across the four postchill climate treatments. Eclosion was greater at a postdiapause temperature of 26°C than 23°C. Timing to 50% eclosion was faster at longer photoperiod (16:8 L:D) than shorter (12:12 L:D). The bimodality of eclosion in respect to the duration of low temperature exposure may be indicative of univoltine insect species with obligate diapause that may span over two seasons.

Evaluation of Cyantraniliprole, Spinetoram, and Chromobacterium subtsugae Extract in Bait for Killing and Reducing Oviposition of Rhagoletis indifferens (Diptera: Tephritidae)

Insecticides mixed in sugar-protein baits or insecticides alone have been used to control tephritid fruit flies for many years. Here, effects of cyantraniliprole, spinetoram, and the biopesticide Chromobacterium subtsugae extract in sucrose-yeast extract bait or alone on kill and oviposition of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), were evaluated in the laboratory. Flies were exposed to dry insecticide bait or insecticide alone in the presence or absence of a nontoxic food strip. Spinetoram alone caused greater mortality than cyantraniliprole alone, while cyantraniliprole in bait caused mortality as high as spinetoram bait and greater mortality than cyantraniliprole alone. Chromobacterium subtsugae extract alone but not in bait caused significant mortality compared with controls, but was much less effective than cyantraniliprole and spinetoram. Spinetoram alone reduced oviposition more than cyantraniliprole alone. However, cyantraniliprole bait reduced oviposition as much or more than spinetoram alone or spinetoram bait. Cyantraniliprole and spinetoram baits caused greater mortality when a nontoxic food strip was absent than present, but there was no corresponding reduction in oviposition. Chromobacterium subtsugae extract did not significantly reduce oviposition compared with controls. Potential benefits of using cyantraniliprole baits as an additional or alternative method to using more toxic spinosyn insecticides for controlling R. indifferens warrant study.

Three-Dimensional Versus Rectangular Sticky Yellow Traps for Western Cherry Fruit Fly (Diptera: Tephritidae)

The most effective traps tested against western cherry fruit fly, Rhagoletis indifferens Curran, have been the Yellow Sticky Strip (YSS) rectangle made of styrene and the three-dimensional yellow Rebell cross made of polypropylene. However, three-dimensional YSS styrene traps have never been tested against this or any other fruit fly. The main objectives of this study were to determine the efficacies of 1) YSS cross, Rebell cross, YSS cylinder, and YSS rectangle traps, 2) Rebell cross versus Rebell rectangle traps, and 3) YSS tent versus YSS rectangle traps for R. indifferens. For 1), the YSS cross caught more flies than the Rebell cross of equivalent surface area and more than a smaller YSS cylinder, but not any more than a YSS rectangle of similar surface area as the YSS cross. For 2), a Rebell cross caught more flies than a rectangle of equivalent surface area made of Rebell panels. For 3), YSS tent and YSS rectangle traps of equivalent surface area did not differ in fly captures. Results suggest that the YSS cross was more effective than the Rebell cross due to its color and that when trap color is highly attractive, three-dimensional shape may be unimportant, whereas it could be when trap color is less attractive. A new trap modeled after the YSS cross, compact but with high trap surface area to increase fly captures, could be an effective option or addition to rectangles for monitoring R. indifferens.