The invasive giant whitefly Aleurodicus dugesii Cockerell (Hemiptera: Aleyrodidae), a pest of many important crops and ornamentals, has established throughout southern California, USA. The parasitoids Encarsia noyesi Hayat (Hymenoptera: Aphelinidae), Idioporous affinis LaSalle and Polaszek (Hymenoptera: Pteromalidae), and Entedononecremnus krauteri Zolnerowich and Rose (Hymenoptera: Eulophidae) were introduced as part of a classical biological control program against giant whitefly. Populations of giant whitefly can still reach high numbers, however, despite biological control efforts. Seasonal variation in giant whitefly population densities and parasitoids' species-specific parasitism rates across three climates types in southern California were examined by repeated censuses during 2015–2016 in order to identify potential underlying factors influencing giant whitefly population dynamics. Giant whitefly population densities did not vary between southern California climate types, but varied seasonally, with the highest observed population densities in the spring. Parasitism rates of all three parasitoids also varied seasonally, with total parasitism reaching a peak in late summer and declining until the start of spring. Only I. affinis parasitism rates varied between climate types. Parasitism rates of I. affinis were the highest of the three parasitoid species observed, followed by E. noyesi and E. krauteri. Potential explanations for these findings and their impact on giant whitefly control are discussed.

中文翻译：

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气候和季节对美国加利福尼亚州南部带有寄生虫的巨大粉虱Aleurodicus dugesii（Hemiptera：Aleyrodidae）物候和生物学控制的影响

入侵性巨大的粉虱Aleurodicus dugesii Cockerell（半翅目：Aleyrodidae）是许多重要农作物和观赏植物的害虫，已在美国加利福尼亚州南部建立。寄生寄生虫（Encarsia noyesi Hayat）（膜翅目：Aphelinidae），特孔亲和性LaSalle和Polaszek（膜翅目：翼手龙科）和Entedononecremnus krauteri引入Zolnerowich和Rose（膜翅目：Eulophidae）作为针对大型粉虱的经典生物防治计划的一部分。尽管进行了生物防治，但巨大的粉虱种群仍然可以达到很高的数量。在2015-2016年期间，通过反复普查，对南加州三种气候类型中巨型粉虱种群密度的季节性变化和类寄生虫的特定物种寄生率进行了调查，以确定潜在的潜在影响大型粉虱种群动态的潜在因素。巨型粉虱的种群密度在南加州的气候类型之间没有变化，但随季节变化，春季观测到的种群密度最高。这三种寄生虫的寄生虫率也随季节变化，总体寄生率在夏末达到顶峰，然后下降到春季开始。只要I. affinis寄生率在不同气候类型之间有所不同。寄生率率一周，慈竹是最高的观察三个寄生物种，其次是E. noyesi和E. krauteri。讨论了这些发现的潜在解释及其对巨型粉虱防治的影响。