Archive | 11:00 am

Thrips and other possibly imaginary pains

5 Oct
Yellow thrips

Close up of a thrips.

While checking out the pecan gall phylloxera from the last post under the scope I observed this little guy exiting the opened gall.  Thrips inquilines have been reported in phylloxera galls, so this may indeed have been a houseguest of the phylloxera colony.

Thrips (awkwardly, this is both the plural and the singular of the word) are exceedingly tiny little insects that are often plant pests as many feed on the mesophyll and epidermal fluid of plants.  Their puncture-style feeding leaves very characteristic spot-like damage on the leaves of plants they feed on.  Because of their small size and ability to tuck themselves into crevices they are often resistant to pesticide applications, particularly those in the form of aerial sprays.  Some thrips may also opportunistically predate on other small arthropods, while some species are exclusive predators.  This also means that when they get into our aphid colony we have to kill everything, bleach the entire room, and start from scratch.  Not that I am bitter.

The order name, Thysanoptera, means “fringe wings” and refers to the unique feathered wings of the thrips.  Although thrips are not strong fliers they are so light that winds can carry them long distances.

Tiny Yellow Thrips on a Leaf

Close up of a thrips on a pecan leaf with the fringed wings visible.

Although these guys are quite tiny they also pack a pretty painful bite!  (It’s rather like getting jabbed with a needle.)  Because thrips are so tiny many people never connect them to  that sudden jab of pain apparently from nowhere.  I personally experienced this MANY TIMES in our cotton fields and while assisting my labmate with his thrips colony before anyone enlightened me on the subject.  If you would like to observe your possibly imaginary antagonists you can try this simple trick for collecting them:  In the spring, tap out a flower over a white piece of paper.  Look closely.  Some of the grains of pollen may appear to be moving.  Thrips!