October 23, 2010
October 23 - Trombidium holosericeum
The animal in the photo is not a parasite - but its offspring are. Like Eutrombicula alfreduggesi, Trombidium holosericeum is a mite that has parasitic larvae and nymphs. The larvae, commonly known as chiggers, can cause real distress to their hosts - including humans - as they feed. They do not crawl under the skin, nor do they feed on blood - what they do is attach themselves to the skin, pierce it. and inject enzymes that can break down the tissue. A hollow tube known as a stylosome forms - the chiggers will continue to "spit" in these enzymes and then suck up the nutrients. After about 3 to 5 days, they will drop off the host and transform into nymphs. They find a new host, feed in a similar way, and then drop off to molt into adults. The adults are not parasitic, but rather feed on plant juices or are predatory to other small arthropods.