Mating Dynamics of Asian Citrus Psyllids in High Density Populations on Host Plants

Undergraduate #12
Discipline: Biological Sciences
Subcategory: Ecology

Juliana Cantillo - University of Florida
Co-Author(s): Richard Mankin, Everett Foreman, and Betty Weaver, USDA-ARS-CMAVE, Gainesville, FL Barukh Rohde and Sylvia Lujo, University of Florida, Gainesville, FL

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The Asian Citrus Psyllid (ACP), Diaphorina citri Kuwayama, is a known carrier of the bacterium Candidatus Liberibacter asiaticus, which causes citrus greening disease. With the aim of stopping or at least reducing the spread of this economically disastrous pathogen, recent investigations into methods of ACP detection have focused on the substrate-borne vibrations used for communication between ACP of the opposite sex. Obser-vations made during population density studies revealed that ACP at high population densities tend to call less frequently than at low densities. In addition, ACP at high densities tend to form aggregations on their host plant, mainly on the fleshy leaves and branches. A possible explanation for the reduction in calling rate may be that the occurrence of aggregations reduces the need to call in order to find a mate. In this case, it would be expected that both males and females are present together within the aggregations. To determine the ratio of males to females present in observed aggregations, clusters of four or more psyllids were identified and collected from host plants in USDA-CMAVE Gainesville colonies, and each individual was sexed. The averaged results of this inquiry so far seem to show that the clusters are split approximately fifty-fifty. The occurrence of mixed-sex aggregations supports a hypothesis that males call primarily when they cannot find a female in their immediate surroundings. Further research should be conducted to determine whether this phenomena is observed in natural settings, such as orange groves.

Funder Acknowledgement(s): USDA-ARS-CMAVE; NSF Graduate Research Fellowship.

Faculty Advisor: Richard Mankin,