Technique for using microencapsulated terpenes in lepidopteran artificial diets.

We have developed and tested a technique to microencapsulate terpene compounds by forming gelatin-walled microcapsules around the terpene essential oils. Eight terpenes that are common constituents of Douglas fir (Pseudotsuga menziesii) oleoresin were encapsulated, including five monoterpenes (α-pinene,ß-pinene, camphene, myrcene, and limonene) and three oxygenated monoterpenes (bornyl acetate, linalool, andß-citronellol). The encapsulated terpenes were mixed into artificial diets to determine the effects they had on western spruce budworm (Choristoneura occidentalis) survival and reproduction, using a three-generation bioassay. We describe the technique and present data from preliminary bioassays with seven of the terpenes to demonstrate thatC. occidentalis larvae would consume diets fortified with microencapsulated terpenes. The technique is useful because it helps to reduce the rate at which terpenes volatilize from the diets and it "packages" the terpenes in a manner more closely resembling the way they are present in the resin canals of plant foliage. Many scientists investigating the biological importance of terpenes in mediating plant-herbivore interactions may find that microencapsulated terpenes are useful in both laboratory diet studies and field and greenhouse experiments with plant material.

The natural history of reflux and long-term effects of reflux on the kidney.

Spontaneous cessation of vesicoureteral reflux occurred in 42 per cent of 102 patients. It ceased in 65 per cent of the patients with unilateral reflux, in 50 per cent of those with bilateral reflux in normal caliber ureters and in 9 per cent of those with bilateral dilated ureters. Renal parenchymal changes were seen most frequently in patients with urinary infection after diagnosis. The likelihood of such infections lessened if reflux ceased. Proportionately more male than female subjects were free of infection. Renal damage may follow even 1 episode of infection. Lesions appeared with equal frequency during the entire followup period, whereas urinary infection was more common in the 5-year period after diagnosis. Renal damage was more likely to occur in kidneys that were already abnormal. Reflux should be controlled surgically if urinary infections occur after diagnosis and during long-term chemotherapy and careful observation. In the absence of infection indications for operation are infrequent. Non-surgical management may apply to normal caliber ureters and in infancy, while antireflux operation may be considered at diagnosis in dilated ureters, bilateral reflux or in the presence of renal lesions.