My technician, Anna Chapman, and I spent the morning at the Piedmont Research Station in Salisbury visiting high tunnel biological control plots. We will release predators next Wednesday, and today, we collected pretreatment samples in our test and treated buffer plots. This is the second year of this trial, and in addition to assessing reductions in twospotted spider mite numbers, we will also be periodically testing the ability of our selected predator species to remain active in tunnels over the winter. Samples from last week and this week suggest that our releases from last year may have established populations of at least 2 of the predator species in these tunnels. This may complicate our experiments, but it's certainly an interesting development!
After collecting our samples, we visited Patterson Farms where Barclay Poling and Jeremy Pattison have a collaborative project with the growers, funded by the Golden LEAF Foundation, to study the dynamics of scaling up tunnel strawberry production.
The plants look great, but I found several interesting insects crawling around. Particularly, there were lots of Lepidopterans (caterpillars).
Cutworms, likely variegated, were scattered throughout the tunnels. Only one was observed feeding on flowers (top image), which is more problematic than their typical feeding behavior (small holes on leaves and cutting of leaves as larvae grow).
In addition to cutworms, which can be fairly common in fall strawberries, there were several fuzzy (Arctiidae) caterpillars, including wooly bears (not shown). These larvae are probably moving in from weedy vegetation in surrounded woody areas. These larvae will pupate soon and not develop into crop pests.
Several stick mimicking Geometridae were also present in the tunnels--they are responsible for the small holes in the leaves on the above plant.
Although there were many caterpillars present, I do not think the density or damage justified treatment. The larvae present now will pupate soon, and the plants are large enough that they are not threatened by the small amount of feeding damage.
Also roaming around the tunnel were several southern corn rootworms (above). These may feed lightly on leaves, but will soon overwinter as adults, perhaps around the base of the plants. We're learning more about what expect in tunnel berries where we go for full out growth right away. All sorts of interesting, probably incidental, insects are moving into the same space to overwinter or grab a quick bite to eat before winter sets in. It remains to be seen what, if any, of these insects will cause damage we need to worry about it, but we're keeping eyes open.