North Carolina State University, Department of Entomology, 13 Campus Box 7613, Raleigh, NC 27695, USA.
J Econ Entomol. 2011 Dec;104(6):1960-8. doi: 10.1603/ec11124.
Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) are increasingly important pests of nursery-grown trees because of the arrival of several invasive species. Ambrosia beetles bore into young trees and inoculate them with ambrosia fungus, which interferes with vascular transport resulting in limb or tree death. In spring, when beetles are active, growers make frequent applications of pyrethroid insecticides to susceptible tree species to deter beetles from boring into trees. Applications often are made with airblast sprayers that forcefully release insecticide mist that billows through nursery beds. Our objective was to compare the environmental, nontarget, and economic effects of airblast sprayer applications to applications made with a new dual-nozzle spray wand that makes targeted applications only to tree trunks where beetles attack. Through replicated experiments at commercial nurseries, we found that 5 times more insecticide was released by airblast sprayers than the manual spray wand. The extra insecticide from airblast applications landed on tree canopies, between rows, and left the nursery beds as drift. As a consequence of not spraying tree canopies, 50% more natural enemies and 50% fewer spider mites were captured in nursery beds treated with the manual spray wand than beds treated with the airblast sprayer. Manual applications require 12 times more labor than airblast applications. However, increased need for expensive miticide applications may make manual applications an economically feasible strategy for integrated pest management (IPM) of ambrosia beetles in nurseries.
榆绿毛萤叶甲（鞘翅目：象甲科：小蠹科）由于几种入侵物种的到来，对苗圃中生长的树木的危害性越来越大。榆绿毛萤叶甲在幼树中钻孔，并将其与榆绿毛萤叶甲真菌一起接种，这会干扰血管运输，导致树枝或树木死亡。在春天，当甲虫活跃时，种植者会频繁地对易受侵害的树种使用拟除虫菊酯杀虫剂，以阻止甲虫钻入树木。这些应用通常使用空气喷雾器进行，空气喷雾器强制释放杀虫剂雾，在苗圃中弥漫。我们的目标是比较空气喷雾器应用和新的双喷嘴喷雾棒应用的环境、非目标和经济影响，这种喷雾棒只对甲虫攻击的树干进行有针对性的应用。通过在商业苗圃进行的重复实验，我们发现空气喷雾器释放的杀虫剂比手动喷雾棒多 5 倍。空气喷雾器应用的额外杀虫剂落在树冠上、行间，并作为漂移离开苗圃床。由于没有对树冠进行喷雾，使用手动喷雾棒处理的苗圃床中捕获的自然天敌数量比使用空气喷雾器处理的苗圃床多 50%，而蜘蛛螨数量则少 50%。手动应用比空气喷雾应用需要多 12 倍的劳动力。然而，由于需要昂贵的杀螨剂应用，手动应用可能成为苗圃中榆绿毛萤叶甲综合虫害管理（IPM）的一种经济可行的策略。
