|Vitullo, Justin - Virginia Polytechnic Institution & State University|
|Mannion, Catharine - University Of Florida|
|Bergh, J. Christopher - Virginia Polytechnic Institution & State University|
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2013
Publication Date: N/A
Interpretive Summary: The pink hibiscus mealybug (PHM) is a serious pest of fruits, vegetables, ornamentals, and landscape plants. This exotic pest invaded south Florida in 2002, and subsequently spread to Louisiana, Texas, and Georgia. The spread of PHM is also a threat to numerous other southern states with climates considered suitable for its establishment. However, a problem of major concern was that it was not known how this pest was able to spread geographically. We studied this problem and found that newly hatched small forms of the insect called crawlers were being carried by prevailing winds during the afternoon. Maximum wind speed, relative humidity, temperature, solar radiation, and rainfall had minimal effect on the spreading rate. This information will be used by scientists and growers to predict where new PHM infestations are likely to develop by knowing prevailing winds from one region to another and where pest management interventions should be timely applied to retard further spreading of the pest.
Technical Abstract: Aerially dispersing pink hibiscus mealybug, Maconellicoccus hirsutus (Green) in south Florida were captured in traps and were predominantly (97%) first instar crawlers. Dispersal showed a dial periodicity that peaked between 14:00 and 18:00 h and was significantly influenced by mean wind speed. Maximum wind speed, relative humidity, temperature, solar radiation, and rain fall had minimal effect. Dispersing crawlers were carried passively on air currents, indicated by the correspondence between the directionality of captures and the prevailing wind direction. Population density had no significant effect on the number of dispersing individuals captured from plants initially infested with 5, 10, or 20 adult females. The number of crawlers captured at distances of 5, 10, 25, or 50 m from infested plants were not significantly different. Male captures in pheromone traps during a two week survey in May were reasonably accurate predictors of future captures in 2006 (r2 = 0. 712) and 2007 (r2 = 0.216). The number of potted sentinel hibiscus plants that became infested by mealybugs and the latency to their expression of feeding symptoms did not differ among residential sites ranked according to the relative number of males captured (low, moderate, or high) during the 2 wk survey. The on-going development of guidelines for pheromone based monitoring of pink hibiscus mealybug is discussed in relation to mitigating the risk from the spread of populations to commercial nursery operations.