Ricciardi Renato, Lucchi Andrea, Benelli Giovanni, Suckling David Maxwell
Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
The New Zealand Institute for Plant & Food Research Limited, PB 4704, Christchurch 8140, New Zealand.
Insects. 2019 Sep 5;10(9):285. doi: 10.3390/insects10090285.
The citrophilous mealybug (Maskell) (Hemiptera, Pseudococcidae) is a primary pest of various crops, including grapevines. The use of insecticides against this species is difficult in most cases because its life cycle includes an extended duration of eggs, juveniles, and adults under the bark and on the roots. Pheromone-based control strategies can present new eco-friendly opportunities to manage this species, as in the case of (Signoret) and (Risso). With this aim it is critical to understand behavioral aspects that may influence pheromone-based control strategies. Herein, the capability of males to fertilize multiple females was investigated, trying to understand whether this behavior could negatively impact the efficacy of mass trapping, mating disruption, or the lure and kill technique. Results showed that a male can successfully mate and fertilize up to 13 females. The copulation time in subsequent mating events and the time between copulations did not change over time but the number of matings per day significantly decreased. In a further experiment, we investigated the mate location strategy of males, testing the attractiveness of different loadings of sex pheromone on males in a flight tunnel. Males constantly exposed to 16 rubber septa loaded with the sex pheromone showed a significant decrease in female detection at 1 and 30 μg loadings (0.18 and 0.74 visits per female for each visit per septum, respectively), whereas in the control about 9.2-fold more of the released males successfully detected the female in the center of the array of 16 septa without pheromone. Male location of females in the control (45%) was significantly higher than in the arrays with surrounding pheromone (5% and 20% at 1 and 30 μg loadings, respectively). Mating only occurred in the control arrays (45%). This study represents a useful first step to developing pheromone-based strategies for the control of citrophilous mealybugs.
嗜果小粉蚧（马斯克尔）（半翅目，粉蚧科）是包括葡萄树在内的多种作物的主要害虫。在大多数情况下，使用杀虫剂防治该物种很困难，因为其生命周期包括在树皮和根部下卵、若虫和成虫的较长时期。基于信息素的控制策略可以为管理该物种提供新的生态友好型机会，就像在葡萄根瘤蚜（西尼奥雷）和葡萄粉蚧（里索）的情况一样。出于这个目的，了解可能影响基于信息素的控制策略的行为方面至关重要。在此，研究了雄性使多只雌性交配的能力，试图了解这种行为是否会对大量诱捕、交配干扰或诱捕杀灭技术的效果产生负面影响。结果表明，一只雄性可以成功与多达13只雌性交配并使其受精。后续交配事件中的交配时间和交配之间的时间间隔不会随时间变化，但每天的交配次数显著减少。在进一步的实验中，我们研究了嗜果小粉蚧雄性的配偶定位策略，在飞行隧道中测试了不同剂量性信息素对雄性的吸引力。持续暴露于装有性信息素的16个橡胶隔片的雄性，在1微克和30微克剂量下对雌性的探测显著减少（每个隔片每次访问时，每只雌性分别为0.18次和0.74次访问），而在对照中，释放的雄性成功探测到无信息素的16个隔片阵列中心雌性的数量约为前者的9.2倍。对照中雄性对雌性的定位（45%）显著高于周围有信息素的阵列（1微克和30微克剂量下分别为5%和20%）。交配仅发生在对照阵列中（45%）。这项研究是开发基于信息素的嗜果小粉蚧防治策略的有用的第一步。
