Samaporn Saengyot and Intawat Burikam

pp. 1 - 7

Abstract

We investigated the life history, growth ratio and feeding potential of the hemipterophagous butterfly or the apefly,
Spalgis epius (Westwood) (Lepidoptera: Lycaenidae: Miletinae), a promising augmentative biological control agent of the
papaya mealybug, Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococcidae), which is an invasive
alien species detected in 2008 in Thailand. The investigation was carried out under laboratory conditions at 25-30ºC and 40-
60% RH using papaya mealybug reared on Thai pumpkin as its prey. The mean duration of the egg, larval and pupal stages
were 3.54±0.50, 12.01±2.40, and 10.32±0.88 days, respectively, and the mean duration from egg to adult emergence was 25.87
±3.78 days. The geometric growth ratio of successive larval instars using the head capsule width as a parameter was 1.65 and
conformed to Dyar’s Law. As for the predatory potential of S. epius, the total number of papaya mealybug consumed during
the larval stage were 4,115.75±553.28 eggs, 281.25±45.08 nymphs and 77.50±16.52 female adults. The instar-specific prey
consumption from the first to fifth larval instars in the order of eggs, nymphs and female adults were 170.00±26.32, 4.25±1.71
and 2.00±0.82; 654.00±67.97, 35.35±12.48 and 10.25±4.29; 1,376.75±130.95, 93.25±11.70 and 23.50±3.94; 1,426.50±252.93,
110.75±15.60 and 31.00±5.25; and 31.00±5.25, 37.75±3.59 and 10.75±2.22, respectively. These findings warrant further
investigation into the amenability and suitability of the entomophagous apefly, S. epius, for as an integrated pest management strategy for the augmentative biological control of the papaya mealybug in Thailand.