By Larry Hodgson
Question: What’s causing the yellow or white spots on our tomatoes? Underneath, the flesh is white, spongy and inedible and we have to remove almost half of the tomato to eliminate it. Is there a cure?
Luce Hamel
Answer: Your tomatoes are suffering from cloud spot. This sounds like a disease, but is actually the result of injuries due to piercing insects, usually stink bugs or leaf-footed bugs. There are several species that visit our gardens and cause this kind of damage.
Stink bugs are a foul-smelling, shield-shaped insects that can be, depending on the species and its degree of maturity, brown, green, red or other colors. Leaf-footed bugs, mostly seen in fairly mild climates, are similar, but more elongated with leaflike structures on their legs.
The adult (and in many species, also the nymph) pierces the fruit with its rostrum and injects it with enzymes which liquefy the tomato flesh so it can then suck it out, leaving a wound that turns white or yellow on the outside over time.
Inside the fruit, just under the skin, harder white masses form. They’re not very appetizing and need to be cut out with a knife when preparing the tomato. That wastes a lot of tomato flesh … and time.
You can often control this insect by rinsing the fruits with water daily shortly after they start to form or by hand-picking the bugs and dropping them in a bucket of soapy water where they’ll drown. To make picking them easier, place a cloth under the plant and give it a shake. That usually causes the bugs to drop off and then you can just pick up the cloth and shake it over soapy water.
Some people find they get good results by harvesting the bugs with a hand vacuum cleaner.