Identification tip: Brown to reddish green, discolored streaks on the rind called tearstaining are symptomatic of anthracnose (shown here). Septoria spot and occasionally other fungal diseases cause similar discoloring. Identification tip: Infection results in small black spots on the fruit. Also called Citrus blast or black pit on lemons, dead leaves and twigs are often present when the cause was infection by this bacterium. Rind disorder. Identification tip: Brown, water-soaked blotches or dark, sunken areas develop on the rind after rainy weather and as fruit matures and turns orange.