While the growing season seems to be winding down, there are still some crops that we can carry late into the fall that still need to be tended to and managed, especially for a few pesky late season pests. Let’s talk about a duo of major insect pests to keep a watchful eye for.
One of the primary late season pests that I have already encountered while scouting fall vine crops and late season cole crops are aphids. There are several species of aphids that may be found in several colors such as black, gray, green, yellow, or pink. Aphids are a small, soft bodied insect that have a mouth part that allows them to suck the sap out of the leaves. Their feeding damage can often result in leaf distortion and stunting of the plant. Not only is their feeding directly impacting plant health, but they are also a vector of numerous viruses in many plant families. Another impact felt by aphid feeding comes as a result of their excrement, known as honeydew. This honeydew is high in sugar concentration and can mold resulting in sooty mold fungi forming wherever honeydew has been accumulating. If the honeydew is on the harvestable fruit or vegetable, sooty mold development can make the fruit or vegetable less desirable and at times, unmarketable. Often times, biological control from natural enemies, such as lady beetles and lace wings, is sufficient for control. If infestations become overwhelming, spot treating with insecticidal soaps, oils, or appropriately labeled insecticides may be warranted. Sometimes, a heavy shower with the hose can wash them off and deter them enough to lower presence and pressure.
Check for this on pumpkins, squash, and cucurbits
A pest specific to pumpkins, squash and cucurbits that you may find are the squash bugs. Squash bugs, which are in the stink bug family, are large brown true bugs that can give off an off-putting smell if disturbed or crushed. They have a piercing mouthpart that they can use like a straw to suck sap out of the plant. Their feeding can be problematic and can cause plant decline, fruit quality issues and they also vector a bacterial disease called yellow vine decline. Squash bug eggs are copper colored and are laid in clusters on the leaves and stems. Eggs hatch about 10 days after being laid. The nymphs have several colorations as they mature, first starting as light green with reddish heads, then green and black, and then light gray and then maturing to brown. In smaller plantings, squash bugs can be hand picked off the plants and dropped into a bucket of soapy water. Another method for control in smaller areas is to lay out sets of shingles or boards, using rocks or sticks to form a small gap between them. This draws in the squash bugs as a desirable shelter and allows for quick eradication of adults and nymphs by crushing the boards or shingles together. If cucurbits are under major pressure from squash bugs, a chemical treatment may be warranted. Follow all labeled instructions if using a pesticide, the label is the law.
As you deal with pests like aphids and squash bugs, keep in mind that they can over winter in plant residue or on secondary hosts. Sanitation and residue management is a very important step to reduce the number of overwintering insects in the immediate area of your production area. This also includes weed control and keeping potential secondary host sites to a minimum. As for overall residue management, working in the plant residue or getting soil worked up onto the residue will help to encourage more rapid breakdown and hopefully discourage the pests from finding harborage there over the winter.
Frank Becker is the Agriculture and Natural Resources Extension Educator with Ohio State University Extension – Wayne County, and a Certified Crop Adviser, and may be reached at 330-264-8722 or becker.587@osu.edu
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This article was previously published in The Daily Record.