FOREIGN EXPLORATION FOR NATURAL ENEMIES OF ASIAN CITRUS PSYLLID, DIAPHORINA CITRI (HEMIPTERA: PSYLLIDAE), IN THE PUNJAB OF PAKISTAN FOR USE IN A CLASSICAL BIOLOGICAL CONTROL PROGRAM IN CALIFORNIA USA

Asian citrus psyllid, diaphornia citri, is a global pest of citrus and also the vector of a bacterium that causes huanglonbing (hlb), a lethal and incurable malady of citrus. this pest established populations in southern california usa in 2008. in 2012, hlb was discovered in california. as part of a much larger program targeting the control of d. citri, a classical biological control program was initiated with the intent of finding, importing and establishing in california host specific parasitoids that attack d. citri nymphs. foreign exploration efforts were focused in the punjab of pakistan, part of the presumed natural range of this pest and also an area which has a strong climatic match to the major citrus production areas of southern california. five foreign exploration trips were completed over the period september 2010 to june 2012. almost 2,000 parasitoids of d. citri were collected and returned to quarantine at the university of california riverside (ucr). the parasitoid guild was dominated by two primary parasitoids, tamarixia radiata and diaphorencyrtus aligarhensis. at least one hyperparasitoid, marietta leopardina, was found attacking immature t. radiata and d. aligarhensis. by june 2012, almost 5,000 t. radiata had been released in southern california and initial field surveys tentatively suggest establishment is likely at about 20% of release sites. molecular analyses are underway to confirm that collected t. radiata are of pakistani origin. the classical biological control program is now entering a more aggressive mass production phase for t. radiata and host specificity testing of d. aligarhensis is underway in quarantine at ucr.