March 2004. An interesting questions from St Lucia concerning the treatment of tamarind pods to prevent the introduction of associated insects. A sample taken from an illegally imported consignment revealed seed and pod borers (Lepidoptera), not yet identified. They were found dead. The importer furnished information that the pods were subjected to steam treatment at 110⁰ Celsius for 12 minutes. Is this treatment sufficient to stop pod and seed borers in tamarind pods?

Another member reported that a shipment of Sweet Tamarind (in shell) from Thailand arrived in Trinidad in January 2004 without a permit. It was shipped at 2⁰ Celcius. The shipment was infested with a pod borer (Coleoptera) and is still being held at the port of entry. The photos above are from this import. Possibilities are: the tamarind beetle, Pachymerus (Coryoborus) gonogra, or tamarind seed borer, Calandra (Sitophilus) lineari.

Later, an expert from Thailand wrote: “It is definitely a seed bruchid. It was also revealed after my further digging that the bruchid is currently known as Caryedon serratus (Olivier) (Coleoptera: Bruchidae). It was previously known as Bruchus gonagra, Caryoborus gonagra, Caryoborus serratus, Pachymeron gonagra, and Caryedon gonagra. It is also reported from Bangladesh, Pakistan and India; New Zealand in the Pacific; Cameroon, Gambia, Madagascar, Mali, Nigeria and Uganda in Africa; as well as Colombia, Guyana and Mexico in the New World.”

It was suggested that the importer was asked to provide information on this treatment, including data on its efficacy; plant quarantine treatment manuals had failed to find the treatment.

To obtain a temperature with steam at 110⁰C the treatment would have to be done under pressure, and some pressure treatments are done with 10lbs per inch² which gives 239.4⁰F = 115⁰C. Normally sterilisation of microorganisms is done at 121⁰C for 15 minutes, so this (the importer’s) treatment is sub-sterilisation in both time and temperature parameters.

Hot forced air treatments are at far lower temperatures for internal pests such as fruit fly larvae, but seed and pod borers might well be more robust and require the temperatures and time as notified by the importer.

There is need to know what the treatment will do to the pests detected before accepting it as a quarantine pest management option for pests that would be in the pathway, and capable of infesting local host plants if not killed.

PestNet was also reminded by FAO that any matter which relates to the interpretation and implementation (treatments, etc.) of the International Standards for Phytosanitary Measures (ISPMs) is the responsibility of each NPPO. Contact information for NPPOs is available from the website of the International Plant Protection Convention (IPPC: www.ippc.int) under the tab ‘NPPO’ and then selecting the country for the contact person.