Dear reader, you are among the privileged few to see the first record of the Lesser Coconut Weevil (Diocalandra frumenti) south of Byron Bay. It is about 6mm long. The beetle flew onto the head of a colleague at the edge of Sydney’s Domain. Perhaps it mistook their head for a coconut? (I’m not passing judgement on anybody.) Landing on entomologists is a dangerous occupation for young weevils and this one is now safely ensconced in the museum collection, after being posted on iNaturalist.
The Lesser Coconut Weevil is widespread in the Old World tropics, from East Africa to Tahiti in the Pacific – previous records in Australia were from the north and north-eastern coast, as far south as Byron Bay. So, probably another example of the influence of climate change on insect distributions. Of course, we can’t eliminate humans moving palms around, but the important thing is that it’s a tropical weevil surviving in Sydney.
The weevil does not confine its feeding to coconut, and is often regarded as a pest species, but Elwood Zimmerman, the former weevil expert at CSIRO, wrote that it attacks dead or damaged palm fronds rather than healthy plant material. As anyone who keeps palms will know, they shed a lot of dead material. So while it may turn up in the Illawarra soon, and may already be here, it is unlikely to cause problems.
A Lesser Coconut Weevil suggests there must be a Greater, and there is, a dark red monster up to 4cm long (Rhynchophorus ferrugineus). The Greater kills palms due to damage by the big fat tunnelling larvae – but fortunately it doesn’t occur in Australia (yet).
I knew Elwood Zimmerman (‘Zimmie’) well, as he was one of a cluster of octo- and nona-genarian retired entomologists hanging around CSIRO while I worked there in the 80s and 90s. (Entomology must be a healthy occupation.) His first published research papers were in 1936!
Zimmie was supposed to be completing a revision of the 8000 species of weevil thought to be present in Australia and he published five large books covering just a small portion of them. One volume includes the Lesser and Greater Palm Weevils and their relatives, enabling me to identify our species easily. The ambition was too much for Zimmie, of course, but he generously bequeathed enough money to employ researchers to continue that work, and they continue to this day.
You can read about Zimmie here.
