Since the 1950s, antifungal drug discovery has identified three classes of natural products (griseofulvin, polyenes and echinocandins) and four classes of synthetic chemicals (allylamines, azoles, flucytosine and phenylmorpholines) with clinical value against fungal infections. For life threatening fungal disease, the polyene amphotericin B is still a common choice despite toxic side-effects. The azoles remain the most widely used group of anti fungals active against a wide range of mycoses, benefiting from creative chemistry to boost their effectiveness. More recently, the echinocandins show great promise, with caspofungin licensed for clinical use in 2002 and two other molecules close to registration. New advances in molecular genetics afford the promise of revealing new antifungal targets, together with new agents to inhibit those targets specifically.

Twenty-two cases of perforated tympanic membrane due to fungal otitis externa were observed over a five-year period.

The diagnosis of fungal otitis externa was made on clinical grounds due to the obvious presence of fungal bloom in the external ear canal. Some perforations were noted at the first treatment after the fungal debris had been removed from the external ear canal using a microscope. Other perforations were observed to develop over a few days. Initially, a discrete area of the tympanic membrane appeared white and opaque. As time progressed the white area disintegrated, forming a perforation. Once the otitis externa had resolved most perforations healed spontaneously. Two that were observed to develop during treatment required a myringoplasty. Another one closed significantly but a tiny persistent perforation required cauterization with trichloracetic acid to encourage it to close over completely. The only residual hearing loss was in a case with almost total disintegration of the tympanic membrane requiring a myringoplasty.

Treatment of fungal otitis externa for the patients in this series was aural toilet using suction under a microscope and insertion of a gauze wick saturated in a combination of hydrocortisone, clotrimazole, framycetin and gramicidin.

Various aspects of the morphology, life cycle and several natural enemies of Heteronygmia dissimilis, a lymantriid defoliator of African mahogany, Khaya nyasica, were studied in Morogoro, Tanzania. This insect is a multivoltine species with at least four overlapping generations a year, all stages of which can be found from March to October. November to February are apparently spent in pupal aestivation. The September/October generation completed its life cycle from egg to adult in an average of 41 and 45 days for males (five moults) and females (six moults), respectively. On the average females produced 200 eggs. Larvae occurred in two colour variations. They are generally nocturnal feeders, skeletonizing leaflets while in the early instars and resting on foliage or bark during the day. Adults exhibit sexual dimorphism in terms of size, colour and shape. The sex factor was close to 0.5. Four species of hymenopterous parasites belonging to four families (Chalcidae, Encyrtidae, Eurytomidae and Ichneu-monidae), as well as two species of dipterous parasites (Tachinidae) were obtained from eggs, prepupae and pupae of H. dissimilis. During the rainy season, the entomopathogenic fungus Paecilomyces farinosus was epidemic among pupae.