Daily flight activity of the western flower thrips (Thysan., Thripidae) in nectarine orchards in British Columbia, Canada

Abstract

Hourly flight patterns of western flower thrips, Frankliniella occidentalis (Pergande) (Thysan., Thripidae) were assessed over a 24 h period in two nectarine orchards located in the Similkameen Valley, British Columbia, on 13 separate occasions between March and October 1994. The numbers of western flower thrips (male or female, dark or pale morphs) trapped per hour at between four to eight heights (0.25–2.00 m) were compared with temperature, wind speed, time of year and location of trap placement. Traps were placed within orchards, at the border of orchards and adjacent wild land, and within wildlands. Temperature and wind speed thresholds are defined, although the effect of wind speed varied with height of flight. Height of flight was affected by both the height of prevalent vegetation and temperature, with mean height of flight increasing linearly with temperature. Numbers of thrips in flight decreased with height of sticky trap from the ground. The pale morph was generally more common than the dark morph of western flower thrips. Males were not present until after emergence of the first generation in May, and were found at an approximate ratio of 4 : 1 (F : M) for the rest of the year. There were no differences between sexes or morphs of western flower thrips for location, height or daily patterns of flight.

Diurnal Flight Behavior of Ichneumonoidea (Insecta: Hymenoptera) Related to Environmental Factors in a Tropical Dry Forest

“…This result differs from other studies where temperature is the most important environmental factor that explains insect ßight activity (Williams and Osman 1960, Pearsall 2002, Briers et al 2003, Hodges et al 2003, Volynchik et al 2008, Mazó n et al 2009, Hennekeler et al 2010). This could be explained because in the tropics, temperature is relatively stable along the day (in our study 22 to 35ЊC), while the The values of Pare given in parenthesis.…”

“…On the other side, correlation coefÞcients of wind speed were signiÞcant for the ichneumonid, as reported in previous works (Taylor 1963, Pearsall 2002, Briers et al 2003, Peixoto and Benson 2009, there is an apparent paradox as preference curve models showed that this group preferred to ßy when the wind speeds were the lowest.…”

“…The optimum temperature range reported for insect diurnal ßight varies considerably. Some studies report range between 15ЊC and 32.5ЊC (Williams and Osman 1960, Pearsall 2002, Hodges et al 2003, Bonsignore and Bellamy 2007, with different values depending on the order and geographical region. Particularly in Ichneumonidae, Idris and GraÞus (1998) found an optimum temperature of Ϸ25ЊC.…”

“…Diurnal variations of temperature and wind speed, mainly, may have important effects on when an insect should be active (Taylor 1963, Pearsall 2002, Briers et al 2003, Peixoto and Benson 2009. However, studies about parasitoids, in particular about Ichneumonoidea, are scarce.…”

Seasonal and Daily Movement of <I>Scaphoideus titanus</I> Ball (Homoptera: Cicadellidae)

“…Some information on spatial distribution (Bosco et al 1997), population dynamics (Bernard and Du Fretay 1988), and seasonal adult occurrence (Lessio et al 2003) is available, but other aspects of its behavior such as daily ßight activity and inßuence of temperature and relative humidity on movement behavior were never investigated. Studies of daily movement are known for other vectors such as Frankliniella occidentalis (Pergande) (Pearsall 2002), Circulifer hematoceps (Mulsant et Rey) (Kersting and Baspinar 1995), Paraphlesius irroratus (Say) (Larsen and Whalon 1987), Bemisia tabaci (Gennadius) (Blackmer and Byrne 1993), and aphids (Wiktelius 1981). The inßu-ence of temperature on movement behavior and the occurrence of temperature thresholds for the initiation of ßight have been studied for some leafhoppers such as Graphocephala atropunctata (Signoret), a vector of grapevine PierceÕs disease (Feil et al 2000).…”