Gulu la ng'ombe ndi mtundu wa mapanelo oweta ziweto m'mafamu.Amapangidwa kuchokera ku machubu achitsulo oval ndi machubu akulu.The chowulungika machubu ndi otentha choviikidwa kanasonkhezereka ndiyeno utoto mu pamwamba mankhwala.Kutalika kwake ndi 1.5-2 mm.