Hello,

Do you see a small white larvae in the fruit of the raspberries? If so, this is spotted-wing drosophila. It's becoming a common insect and is a type of fruit fly. However, it tends to feed on ripening fruit. The best way to avoid this pest is by picking fruit frequently (once or twice per day) and not letting any spent fruit drop to the ground. Also, either consume or refrigerate fruit immediate after picking.

Here is some more information: http://extension.colostate.edu/docs/pubs/insect/05596.pdf

As for the yellowing leaves, they look a bit chlorotic. What are your cultural conditions like? How much are you watering? Does the entire plant look yellow or just a small portion? Is it the newest leaves or older leaves? Have you fertilized this year? 

Yes now I see the small white larvae on the fruit. At first I didn't see them move but now I do. I read the page and will see what I can do. I am tempted to toss all the fruit for a while would that help to get rid of them? I water with a drip line every other day for about 30 minutes and yes I did fertilize this year. It seems to be the older leaves and just portions of the plants are turning. Thanks, John

Hi John,

If it's the older leaves, the plants may be selectively dropping them because of the heat or the plant over-produced leaves this spring. Fertilizer is good. Is the soil moist below the plants? It's hard to guess how much water you're applying in 30 minutes unless you know the emitter size.

Another thing...it could be TOO MUCH water. Sometimes we see yellowing from overwatering, so check the soil moisture.

As long as there is fruit for the drosophila to feed on, they will continue to lay eggs. So you can pick and toss, but the insect populations will continue to increase until September. You can set out a trap to see how many adults you catch: https://extension.unh.edu/Spotted-Wing-Drosophila-SWD/Monitoring-Spotted-Wing-Drosophila-Traps

And this may gross you out, but if you knew how many insects you ate each day, a couple of larvae may not bother you as much :) Of course, that's easier said than done. But again, try to pick the fruit often and perhaps a little under-ripe.

Thanks for the information. Reading about the traps looks like they could impact my fall strawberries too. It kind of seems like quite a challenge to keep them off the fruit. Is there any way to keep them from coming back next year? Thanks again

The insect is here to stay, but you can try to prevent more damage by following the suggestions in the Fact Sheet I originally sent you: sanitation, crop management, covering with fine netting or using insecticides. There is an organic insecticide you can use called Spinosad. But it needs to be applied frequently, about every 7 days.

Here's the link to the Fact Sheet again: http://extension.colostate.edu/docs/pubs/insect/05596.pdf

The other option, of course, is to stop growing these fruits :)