BIOLOGICAL ASPECTS AND INSECTICIDE ACTION OF PLANT SPECIES ON EGGS AND NYMPHS OF CITRUS BLACK FLY (Aleurocanthus woglumi Ashby - Aleyrodidae)AT LABORATORY LEVEL

ABSTRACT Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) is an important pest of many plant species in particular citrus species. The aims of this study were: (1) to observe ;'in vitro'; biological aspects in three hosts and (2) to evaluate the bioactivity of plant species on immature A.woglum. Aqueous neem extract (Meliaceae), cassava wastewater, pepper sauce and gravy peduncle floral carnation guinea button and commercial neem were used in the experiment. Egg viability (%), nymphal period duration, nymphal mortality (%), puparium stage duration and pupae viability (%) were evaluated in 50 egg positions, with minimum of five eggs in "Pera" orange, mango and malay apple leaves obtained in the field. The insecticide effect (translaminar action and direct spray) at different concentrations on immature A.woglumi was evaluated. The first bioassay conducted to evaluate the bioactivity of species by translaminar action, each sample unit corresponded to three leaves, with minimum of 20 eggs and 20 1st instar nymphs, the variables were unviable eggs and nymph mortality (%); the experiment had a completely randomized design with four replications. In the second bioassay, fully infected branches were sprayed on upper and lower face of leaves with all treatments. Leaves with at least 40 eggs and 40 1st instar nymphs were marked, and mortality (%) and emergence (%) of adults were evaluated for seven days; each sample unit was represented by 40 eggs and 40 1st instar nymphs and the experiment had a completely randomized design with four replications. The average duration of the nymphal period ranged from 7.76 to 24.18 days in 'Pera'; orange, and from 8.86 to 25.20 days in mango. There was no significant difference between the viability of eggs and nymphs in ;'Pera'; orange and mango or pupae viability between ;'Pera'; orange and malay apple. Treatment efficiency was evaluated using the Abbott's formula [E(%) = T-I/T x 100], where E ( % ) = efficiency percentage, T = number of live insects in the control treatment and I = number of live insects in treatment with insecticide. Therefore, in the first bioassay conducted to evaluate the bioactivity of species by translaminar action, all treatments showed efficiency greater than 50%. In the second bioassay by direct spraying to cassava wastewater (100% and 50 %) and commercial neem oil (1%), treatment had nymphal mortality efficiency greater than 80%.

摘要 柑橘黑刺粉虱（Aleurocanthus woglumi Ashby，半翅目Hemiptera：粉虱科Aleyrodidae）是多种植物，尤其是柑橘类植物的重要害虫。本研究的目的为：(1) 观测三种寄主上的离体（in vitro）生物学特性；(2) 评价多种植物源物质对该粉虱未成熟期的生物活性。本实验选用了印楝水提物（楝科Meliaceae）、木薯废水、胡椒酱、几内亚纽扣康乃馨花茎汁以及商业印楝制剂。以田间采集的“佩拉”橙、芒果和马来苹果叶片为材料，每个卵位接种50粒卵（最少5粒），并检测卵孵化率（%）、若虫期时长、若虫死亡率（%）、蛹壳期时长以及蛹存活率（%）。本研究还评估了不同浓度药剂对柑橘黑刺粉虱未成熟期的杀虫效果，包括内吸传导作用（translaminar action）和直接喷雾两种施药方式。第一项生物测定以施药的内吸传导作用来评价植物源物质的生物活性，每个样本单元对应3片叶片，接种至少20粒卵和20头1龄若虫（1st instar nymphs），观测指标为非存活卵数与若虫死亡率（%）；实验采用完全随机设计（completely randomized design），设置4次重复。第二项生物测定中，将完全感染的枝条正反面喷施所有供试药剂，标记带有至少40粒卵和40头1龄若虫的叶片，连续7天观测若虫死亡率（%）与成虫羽化率（%）；每个样本单元对应40粒卵和40头1龄若虫，实验采用完全随机设计，设置4次重复。“佩拉”橙上若虫期平均时长为7.76~24.18天，芒果上为8.86~25.20天。“佩拉”橙与芒果的卵、若虫存活率，以及“佩拉”橙与马来苹果的蛹存活率均无显著差异。本研究采用阿博特公式（Abbott's formula）[E(%) = (T-I)/T × 100]评价防治效率，其中E(%)为防治效率百分比，T为对照处理活虫数，I为药剂处理组活虫数。因此，在内吸传导作用的第一项生物测定中，所有供试药剂的防治效率均高于50%。在直接喷雾的第二项生物测定中，木薯废水（100%与50%浓度）及1%商业印楝油的若虫死亡率防治效率均高于80%。