The dreaded cowpea curculio
Living in the Southeastern US as I do, it is only natural that I grow cowpeas. Cowpeas, also know as field peas, are a legume orginally from Africa and likely introduced to the American South via the slave trade. There are likely several hundred named varieties but outside of the South, the only that US folks likely have encountered are blackeyed peas which are a type of cowpea. Those in the South are more likely to be acquainted with with the pleasures of fresh shelled versions of other varieties which are culinary ecstasy though likely decreasing true as the handshelling is very labor intensive.
A serious pest afflicting cowpeas is the Cowpea Curculio. Curculios are a subset of insects know as weevils and are distinguished by a long specialized snout for piercing the pods of legumes. I actually have never seen an adult Cowpea Curculio but have seen and also likely consumed 1000's of their larval form which develop within the peas. While I have no objection to consuming the larvae, the act of piercing the pod to lay the eggs often promotes other forms of spoilage rendering the peas unusable at least by my standards.
I have been gardening in my current location since 2005. The Cowpea Curculio problem became increasingly severe up to 2012 when the crop was a total loss, not worth the effort to pick and shell. Online research revealed that the curculios propagate through several generations each year and a portion of the adults manage to overwinter from the last generation to afflict the following year. Research also indicates that there isn't much effective that can be done at least for commercial growers. Once the problem becomes too severe they abandon cowpeas as a viable crop and move on to something else. Despite what I had learned via online research I went by to visit my county extention agent to discuss the issue. As expected, he didn't know much as I am in the North end of the State and the commercial productions [what is left of it] is in the South. He did commit to research it and get back to me which he did and basically confirmed what I had already learned. OK, I'm on my own at this point. I do have options unavailable to commercial growers as my labor is free. While cowpeas are very much a hot weather crop, they only need about 90 days of hot weather to produce a decent yield. Going forward I decided to deprive the overwintering adults of a suitable host plant by not planting until early to mid July. Furthermore, when fresh shelling I would save and dry the hulls. Once dry I would pick all visibly spoiled pods and burn in a fire using the dried hulls as fuel. I can now report that after following this regimen for 5 years I achieved a yield that equalled my previous best ever year. Some garden problems take lots of time to solve.