Diaphorina citri, the Asian citrus psyllid, is a sap-sucking, hemipteran bug now in the taxonomic family Liviidae.

The Asian citrus psyllid originated in Asia but it is now also found in parts of the Middle East, South and Central America, Mexico, and the Caribbean.

In the United States, the psyllid was first detected in Florida in 1998 and is now also found in Louisiana, Georgia, Arizona, South Carolina, Texas, and since 2003 in California.

Profftella armatura, which provides nutrition, defense toxins, and carotenoids, lives inside the syncytial cytoplasm of the organ.

[7][8] Polyketide synthesis by the Profftella symbiont is increased when the insect is carrying the Huanglongbing pathogen Liberibacter.

[19][20][21][22][23][24][25] All these resources have enabled the development of broad strategic approaches to manage psyllid populations, like RNAi biopesticides.

The major breakthroughs on psyllid management that were developed include three types of antisense oligonucleotides (double-stranded RNA, single stranded antisense oligos (like FANA[26][27] and Morpholio's)[28][29][30] that can target the Asian citrus psyllid, and the bacterial pathogen,[31] without harming other beneficial insects, like pollinators and predators.

As they feed, they produce a toxin that causes the plant tips to die back or become contorted, preventing the leaves from expanding normally.

Affected trees bear small, asymmetrical fruit which are partially green and which are unsellable because of their poor size and quality.

[35] One of these wasps, Tamarixia radiata, has proved very effective at controlling the pest and has been successfully released and become established in a number of citrus growing areas including Florida.

[41] It appears that this tiny insect is attracted by color (yellow and UV wavelengths) and decides to stay and feed on a particular plant only after alighting on a leaf and tasting it by probing with its mouthparts (stylets).

Recent effort has illustrated that the spatial distribution of eggs and nymphs is a result of the movement patterns of gravid females in response to the oviposition sites.

Measurable tests showed that distributions of eggs and nymphs in naturally occurring psyllid populations were highly aggregated, following initially aggregated migrations of adults and a contagious dispersion of adults on the flushes within trees as population densities increased.