Life History of Altica aenea (Olivier, 1808) (Coleoptera: Chrysomelidae) on Ludwigia hyssopifolia (G. Don) Exell

The life histories of Altica cyanea and other Altica species have been reported in several Ludwigia species. However, no reports yet on the life history of Altica aenea (Olivier, 1808), particularly on L. hyssopifolia (G. Don) Exell under Philippine conditions. This research study was carried out to investigate and describe the life cycle, reproduction, growth, and survival rate of A. aenea on L. hyssopifolia (G. Don) Exell. Altica aenea completed seven growth stages on the weed: egg, first larval instar, second larval instar, third larval instar, pre-pupa, pupa, and adult. Female beetles lay eggs in clusters on the lower surface of leaves. The mean incubation period for the eggs is 5 d, whereas the first, second, and third larval instars developed in 3.0, 3.3, and 7.2 d, respectively. The pupa had a developmental period of 5–6 d. On average, the females were longer (6.2 mm) than the males (5.2 mm). The male-to-female sex ratio was 2.42:1, with a mortality rate of 31.18%. The courtship and copulation of males and females took 4–8 h. The females laid eggs 5–8 d after emergence from the pupa and 1–4 d after mating. During their lifetime, the females deposited a mean of 708.4 eggs (263–1004 eggs) at 26.3 eggs/d (17.7–35.9 eggs). When fed via L. hyssopifolia (G. Don) Exell, the developmental period of A. aenea from egg to adult was 22.7 d for the female and 21.1 d for the male. The mean adult females’ longevity was 60.9 d (34–81 d) and 45.5 d (24–76 d) for adult males. The lifespan of A. aenea on L. hyssopifolia (G. Don) Exell was 88 d for females and 72 d for males. The results of this study could provide insights into assessing its suitability as a biological control against the weed.