(E,Z)-3,13-octadecadien-1-ol acetate, and (Z,Z)-3,13-octadecadien-1-ol acetate, isolated from the female lesser peachtree borer, Synanthedon pictipes (Grote and Robinson), and the female peachtree borer, Sanninoidea exitiosa (Say), respectively, strongly attract the respective males of these species in field bioassays. These compounds are the largest pheromones isolated thus far from a lepidopterous species. Sanninoidea exitiosa males did not respond to the synthesized (E,Z)-isomer, and low concentrations of it in the synthesized (Z,Z)-isomer did not interfere with their response to the (Z,Z)-isomer. In contrast, even very low concentrations of the (Z,Z)-isomer (1 percent) in the (E,Z)-isomer significantly inhibited the response of Synanthedon pictipes males.
Euschistus servus (Say) and E. tristigmus (Say) were monitored near and in pecan orchards at ground level only and in pecan orchards from the ground to the upper canopy. Modified pyramidal traps, baited with Euschistus spp. aggregation pheromone, were placed on the ground along a hedgerow adjacent to a pecan orchard, at the orchard edge, and at the orchard center to monitor seasonal occurrence. Vertical distribution of E. servus and E. tristigmus was monitored by placing pheromone-baited traps at preselected heights. Traps on the ground along the hedgerow, orchard edge, and orchard center captured similar numbers of stink bugs each month from May through September, with an increase in October at all locations (combined data for both species). Single traps placed at different heights captured peak numbers of E. servus in early and late season; whereas, traps captured peak numbers of E. tristigmus during the late season. More E. servus were captured in traps on the ground than in traps in the canopy, but more E. tristigmus were captured in the canopy at 9 m. With two baited traps placed at different heights at the same tree, more E. servus were captured on the ground than in the lower or upper canopy, but most E. tristigmus were captured in the lower and upper canopy than on the ground. Placement of traps on the ground or at 9 m resulted in more captures of E. servus on the ground and more captures of E. tristigmus at 9 m. Although E. servus and E. tristigmus were captured both on the ground and in the pecan canopy, numbers of captured E. servus and E. tristigmus were affected by trap height. Thus, sampling Euschistus species in pecan, and possibly other arboreal habitats, should be done throughout the canopy.
Plum curculio, Conotrachelus nenuphar (Herbst), enroute from hibernating sites in the woods were first recovered from plum trees at 95% full bloom. First mating occurred as early as 95% full bloom and no later than 90% petal fall. Most matings occurred during April when the adult population was highest. Fruit injury (feeding and oviposition) was greater on plum than on peach or other Prunus species. Little feeding and/or oviposition was recorded on fruit of Prunus japonica Thunb. in field nursery plots. However, when P. japonica fruit was picked, brought into the laboratory, put in cups with laboratory-reared plum curculio, the weevils fed and oviposited as well as on other Prunus species fruit. First field brood emergence was detected when most collected adult females (16 of 18) were virgin during 26 May - 1 June 1991. The 7-day period was indicative of a new generation because newly-emerged females were sexually immature for approximately 7 days. Prior to and after that 7-day emergence period, most females were mated. Various monitoring methods were evaluated which included green sticky balls, pitfall traps, sticky trunk bands, boll weevil traps, and tree jarring. Tree jarring was the best method for monitoring plum curculio.
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