Impact of UV metalized reflective mulch on Diaphorina citri and interaction with its natural enemies and biotic mortality in citrus

Diaphorina citri also known as Asian citrus psyllid is a serious pest of citrus and vector of huanglongbing (HLB) or citrus greening disease. ACP and HLB were identified from Florida in 1998 and 2005, respectively. It is vital to protect young trees from ACP to reduce the spread and severity of the disease to improve tree health and yield. More than 70% of citrus production has decreased since the discovery of HLB in Florida. Planting citrus on UV metalized reflective mulch could reduce psyllid infestations considering that these mulches reflect ultraviolet light and repel insects from colonizing the plants. The psyllid populations and interaction with natural enemies were studied in a replicated block of 450 young Valencia orange trees planted on mulch and bare ground at the University of Florida, Southwest Florida Research and Education Center, Immokalee, FL. Sampling was conducted using yellow sticky traps, tapping, visual observation, and suction samples. Psyllid colonization and infestation were significantly reduced in the trees planted on the mulch than on the bare ground. The predatory groups such as ladybeetles, lacewings, and spiders were common in both production systems. There was no effect on the biotic mortality in the eggs and nymphal colonies of psyllid developing on the mulch and bare ground. The common predators were ants, spiders (spiny orb-weaver), ladybeetles (Curinus coeruleus, Harmonia axyridis, Olla v-nigrum, Cycloneda sanguinea), and lacewing. Findings suggest UV metalized reflective mulch as a potential strategy to reduce vector populations and achieve associated benefits.