Entomologist Mark Hoddle discussed his efforts to thwart psyllid movement from urban areas into commercial groves through biological control.

Over the last several years, Hoddle and his wife Christina, also a UCR entomologist, jetted back and forth to the Punjab region on the Pakistan-India border to find parasitic wasps which could biologically fight the psyllid, a native to the Punjab area of Pakistan.

After extensive work, the Hoddle’s gained permission from the USDA to bring back several species of parasitic wasps from Punjab to Southern California for further study and possible rearing, including 2,500 Tamarixia radiata wasps to attack the psyllid.

The female wasp, about half the size of a chocolate sprinkle, lays its eggs inside the psyllid nymph. The wasp larva eats the nymph from the inside out killing it.

Hoddle detailed his journey travelling halfway around the world with several thousand wasps in tow. Security checkpoints at international airports were a huge challenge which delayed the entomologists.

Yet with the required paperwork in hand, the Hoddle’s, and the wasps, finally landed on California soil.

After 18 months of mandatory safety studies conducted on the wasps in quarantine at UCR, the husband-wife entomology team received the green light to release the wasps in the L.A. area. Mark says Tamarixia radiata is a good fit for Southern California since the climate is very similar to the Punjab region.

To date, about 170,000 wasps have been released at about 600 release sites in the L.A. area and areas to the East, plus in Imperial, Orange, Riverside, San Bernardino, and San Diego counties. Hoddle is pleased that about 15 percent of the sites now have established wasp populations.

Parasitism, in this case dead psyllids, is found 5-8 miles from the release sites. DNA collected in the field confirms the parasites are those bred from Punjab wasps.

A second psyllid parasitoid, Diaphorencyrtus aligarhensis, is in quarantine at UCR. The safety testing has been completed and the USDA is reviewing the environment assessment report. It is anticipated that this second natural enemy from Pakistan will be cleared for release in California in early 2014.

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