Microlarinus lareynii is a seed weevil that deposits its eggs in the young burr or flower bud. The larvae feed on and destroy the seeds before they pupate, emerge, disperse, and start the cycle over again. Its life cycle time is 19 to 24 days. Microlarinus lypriformis is a stem weevil that has a similar life cycle, excepting the location of the eggs, which includes the undersides of stems, branches, and the root crown. The larvae tunnel in the pith where they feed and pupate. Adults of both species overwinter in plant debris. Although the stem weevil is slightly more effective than the seed weevil when each is used alone, the weevils are most effective if used together and the T. terrestris plant is moisture-stressed.
Treatment: If a pancreatic or liver tumor is identified and able to be surgically excised, the skin lesions may normalize for an extended period of time, but because these tumors metastasize (spread to other areas of the body) quickly, surgery is not curative. In cases of end stage liver disease, surgery is not possible, and the goal of therapy is to increase quality of life and decrease uncomfortable skin lesions with supportive care and addressing the nutritional abnormalities. Supportive care includes supplementing protein and necessary minerals and enzymes through the diet and oral supplements or by weekly intravenous amino acid infusions that are performed in the hospital on an outpatient basis until improvement in the skin is noted. Unfortunately, despite the supportive care, the disease will progress.