Effects of temperature, photoperiod, and rainfall on morphometric variation of Diaphorina citri (Hemiptera: Liviidae)

Authors: PARIS, THOMSON - University Of Florida; Allan, Sandra - Sandy; Hall, David; Hentz, Matthew; CROXTON, SCOTT - University Of Florida; AINPUDI, NIHARIKA - University Of Florida; STANSLY, PHILIP - University Of Florida

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/10/2016
Publication Date: 12/27/2016
Citation: Paris, T.M., Allan, S.A., Hall, D.G., Hentz, M.G., Croxton, S.D., Ainpudi, N., Stansly, P.A. 2016. Effects of temperature, photoperiod, and rainfall on morphometric variation of Diaphorina citri (Hemiptera: Liviidae). Environmental Entomology. 46(1):143-158. https://doi.org/10.1093/ee/nvw161.
DOI: https://doi.org/10.1093/ee/nvw161

Interpretive Summary: The Asian citrus psyllids is one of the most serious citrus pests worldwide due to its ability to serve as a vector of pathogen causing citrus greening disease or huanglongbing. Key to protection of new citrus plantings against the disease is protection from dispersing infected psyllids, however, factors that cause dispersal and characteristics of dispersing psyllids are poorly understood. Often wing characteristics are associated with dispersing populations of insects. In this study ARS scientists from CMAVE (Gainesville, FL) and USHRL (Ft. Pierce), examined wing size and shape variation of Asian citrus psyllids reared in the laboratory under different temperatures and photoperiods, as well as those field-collected throughout the year. Rearing temperature clearly affected both size and shape of wings based on laboratory studies and field collections. In the field, photoperiod, rainfall and host plant species affected wing parameters as well. A better understanding of the factors causing these morphological differences provide insight into factors driving dispersal of psyllids and can ultimately lead to optimization of control strategies to mitigate dispersion of the Asian citrus psyllid and associated disease.

Technical Abstract: Phenotypic plasticity provides a mechanism by which an organism can adapt to new or changing environments. Earlier studies have demonstrated the variability of Diaphorina citri Kuwayama (Asian citrus psyllid) population dynamics, but no analysis of morphological changes induced by seasonal or artificial laboratory induced conditions has yet been documented. Such morphometric variation has been found to correspond in dispersal capabilities in several insect taxa. In this study, the effects of temperature and photoperiod on morphometric variation of D. citri were examined through laboratory rearing of psyllids under controlled temperatures (20oC, 28oC and 30oC) and under short (10.5 L: 13.5 D) and long (16 L: 8 D) day length photoperiods. Field-collected D. citri were collected monthly from three citrus groves in Fort Pierce, Gainesville and Immokalee, FL to evaluate potential field-associated environmental effects. Both traditional and geometric morphometric data were used to analyze the correlation between environmental and morphometric variation. A strong correlation was found between temperature and shape change, with larger and broader wings at colder temperatures in the laboratory. Short day length resulted in shorter and narrower wings as well. From the field, temperature, rainfall, and photoperiod were moderately associated with shape parameters. Adult D. citri with blue/green abdomens collected in the laboratory and field studies were larger in size and shape than those with brown/gray abdomens.