甜菜根蛆

There are four stages in the sugar beet root maggot lifecycle: egg, larva (maggot), pupa and adult.

甜菜根蛆的卵是白色的, 略弯曲，长约1/25英寸(1毫米)(图1).

幼虫(蛆)没有腿，没有明显的头或眼睛(图2)。. 幼虫经历三个不同的阶段(生长阶段). 当幼虫在第一龄时，它们很小，大约1/32到1/16英寸(0.75 ~ 2mm)长，透明白色. 这种小尺寸和白色的颜色使它们看起来像根毛. 随着幼虫的生长, they gradually become a more opaque white color and eventually reach lengths of up to 1/2 inch (1.2 cm).

Pupae have a hard, brown casing and are slightly smaller than the largest larval stage (Figure 3).

成虫体型很小, 闪亮的, 黑色的苍蝇，翅膀大多是透明的, 但是用不透明的, 在每只翅膀的外边缘有烟熏棕色斑块, 大约在机翼的1/3处(图4). 甜菜根蛆蝇和家蝇差不多大, 长度为1/4英寸(6mm), 虽然明显少了“毛”，多了光泽.

成年雌虫在出现后3 - 10天开始产卵, 每只雌性可以在甜菜植物附近的土壤中产下大约120颗卵. 卵在一到三天内孵化，蛆虫立即开始以甜菜根为食. By early to mid-July larvae may reach full size and will stop feeding to enter the overwintering state (diapause). There is some evidence that a small portion of the population may pupate in the late summer and emerge as adult flies in August.

损害

甜菜根蛆以植物的根为食. 在幼苗, their feeding can sever the thin taproot and cause significant wilting or death of the young plant (Figures 6-7). Feeding on the tip of the root in young plants can also lead to forking in the mature taproot. 在更成熟的植物中, 蛆以根的表面为食, 离开浅, 渗出, 黑色病灶(图8). These lesions range in size from tiny (about the size of a pinhead) to 3/4 inch (2 cm) long and may cover the entire root surface when infestations are severe. 根蛆进食造成的损伤可被根腐病病原体侵入, 哪些会导致严重的林分损失, 特别是在有根腐病史的田地里.

The following key features can be used to distinguish sugar beet root maggot flies from other commonly captured flies (e.g., anthomyiid family flies including beet leafminer, onion maggot and seedcorn maggot flies):

• 尺寸:1/4英寸(6毫米)长，粗壮的身体(有点像家蝇)
• 颜色:有光泽，体黑色，无刚毛或条纹
• 翅膀:透明, 一个是不透明的, 沿前缘的烟斑, 大约1/3的距离从翅膀附着到身体(图4)
• 腿:黑色，除了黄白色的“膝盖”和“脚踝”

用这个方案在甜菜地里寻找甜菜根蛆蝇:

1. Place three or more traps per field along fencerows or ditches adjacent to sugar beet fields. 空间间隔几百码. 确保橘子, 捕集器的粘性面朝向北方或东方, 它在土壤表面1英尺以上. 清除堵塞陷阱的杂草.
2. Check traps at least twice (ideally three times) weekly beginning by April 15 in western Idaho and by May 1 elsewhere. 每次你检查陷阱, 记录每个诱蝇器上的蝇数和每个农田中每个诱蝇器的平均蝇数. Divide the trap average by the number of days since the last trap check to get the daily average. 记录你在整个季节发现的陷阱平均值. 关于保存一个季节记录的示例，请查看 甜菜根蛆:鉴定、生物学和管理.
3. 要重新设置陷阱，要么更换橙色粘性表面，要么刮掉粘合剂并重新涂抹.
4. 继续检查陷阱，直到你看到苍蝇捕获的一个明确的高峰, 通常在五月底至六月初, 尽管这可能会受到异常天气的影响.
5. 一旦每日平均苍蝇捕获量达到峰值，就可以做出控制决策.*使用表1或 这个计算器 来决定你的经济门槛.
6. 您还可以使用a来预测旺季航班的日期 温度单位模型 (点击“快速开始”)，但这不应该取代粘性陷阱监控.

*Mini-Cassia and American Falls areas may experience heavy fly pressure over extended periods, necessitating split applications of granular insecticides into at-plant and post-emergence treatments. 视图 甜菜根蛆:鉴定、生物学和管理 欲知详情.

管理

主要管理策略

Sugar beet root maggots are primarily managed with granular insecticides targeting the larval stage and applied based on scouting and action thresholds. 提早播种可以使植株长得更大, 较不敏感的生长阶段，在蛆虫出现之前.

文化

• Early planting can avoid plants being in vulnerable seedling stage when flies reach their seasonal peak
• 秋季深耕的目标是越冬的幼虫, 让它们暴露在寒冷的温度和捕食者面前
• 频繁的灌溉会迫使幼虫游向土壤表面, where their feeding causes less severe damage and where they are more susceptible to insecticides. 然而，请记住，过度浇水会助长土壤传播的病原体.

行为

• Pheromone lures have been developed that improve monitoring traps and may be used in mass trapping, 但是，针对这些方法的具体建议仍有待提出.

生物

• 避免使用广谱杀虫剂可以保护天敌

化学

• 在土壤中施用颗粒杀虫剂，以幼虫为目标，是最有效的
• Post-emergence applications of granular insecticide are more cost-effective than at-plant applications in most parts of Idaho
• 申请应在航班高峰后10日内提出, though Mini-Cassia and American Falls areas with heavy fly pressure may need to split applications into at-plant and post-emergence treatments (at or near peak flight)
• 如果压力较低或适中，种子处理可能有效
• Foliar insecticides targeting adults should be used with caution since they require frequent reapplication and can trigger outbreaks of other pests like aphids and caterpillars
• Recommendations for pesticides to use in the management of sugar beet root maggot can be found on the 新界西北有害生物管理手册 网站

农药的警告

总是 阅读并遵循农药标签上的说明. The pesticide recommendations in this University of Idaho webpage do not substitute for instructions on the label. Pesticide laws and labels change frequently and may have changed since this publication was written. 一些农药可能已被撤回或某些用途已被禁止. 小心使用农药. 不要使用农药，除非特定的植物, 动物或其他应用地点在标签上特别列出. 将农药保存在原来的容器中，并放在儿童接触不到的地方, 宠物和牲畜.

贸易名称 -为了简化信息，使用了商品名称. No endorsement of named products is intended nor is criticism implied of similar products not mentioned.

地下水 -保护地下水, 当有杀虫剂的选择时, 涂抹者应该使用最不容易浸出的产品.

拿破仑情史Wickwar，昆虫学家，IPM项目经理
埃里克J. Wenninger，昆虫学教授，IPM协调员
2023