Biology of the mealy bug, Rhizoecus amorphophalli infesting tubers of major aroids

Abstract

The present study was carried out to trace the life cycle of mealy bug, Rhizoecus amorphophalli on three different hosts including elephant foot yam, taro and tannia tubers. Investigation revealed that the mealy bug reproduces sexually and the adult female secretes an egg sac of white waxy substance in which eggs were laid. Female nymph moult normally, but male instar produces a cottony puparium around its body and form a pupal stage from which adult males emerge. On tubers of elephant foot yam, average fecundity and incubation period were 68.30±6.22 and 7.80±0.88 days respectively. But, it was significantly lesser for those on the taro and tannia tubers. Nevertheless irrespective of hosts, the percentage of hatching maintained uniformity. The total life cycle of bug which includes three instars and a pupal stage took 27.10 days for females and 22.40 days for males on tubers of elephant foot yam. The larval stages of mealy bug did not show prominent morphometric changes among the hosts used for life cycle study.

New Report of Oriental Mealybug Rhizoecus Amorphophalli Betrem (Hemiptera: Pseudococcidae) in Amorphophallus Muelleri Tubers in Indonesia

“…Rhizoecus genera is important economically as an agent of post-harvest storage. Rhizoecus species have been known infested elephant foot yam (Amorphophallus paeoniifolius) is R. amorphophalli Betrem [20,21]. Hardiyanti et al [6] reported R. amorphophalli attack the porang tuber in India.…”

“…Hardiyanti et al [6] reported R. amorphophalli attack the porang tuber in India. They suck cell sap from the elephant foot yam tubers, and the severely infested deformed tubers find no place in market, nor are accepted for cooking [9,17,20].…”

“…Porang (Amorphophallus muelleri Blume), a native aroid grows wild in Indonesian tropical forests, particularly in East Java and East Nusa Tenggara [1,20]. Since 2019, porang have become prima donna crop in Indonesia.…”

“…they were white, produced cotton-like masses. Inside the white masses found a population of crawlers, males, females and eggs of attacking insect pest [7,15,17,20,21]. Mealybugs (Hemiptera: Pseudococcidae) declared as economically important insect pests worldwide [12,20,22].…”

“…Inside the white masses found a population of crawlers, males, females and eggs of attacking insect pest [7,15,17,20,21]. Mealybugs (Hemiptera: Pseudococcidae) declared as economically important insect pests worldwide [12,20,22]. These pests are polyphagous, may attack many crops that cause the host growth and the tuber storage problems [5,8,14].…”