Metisa Plana

''Metisa plana'' (or "bagworm") is a moth of the family Psychidae (the bagworms) first described by Francis Walker in 1883. It is found in Sumatra, Malaysia and Sri Lanka. It is a major pest on '' Elaeis guineensis'', the African oil palm.

Description

The moth completes a mean life time of 90 days. After the female lays 200–300 yellowish eggs, a single egg mass can become about 140–210 neonates. The larva has a portable case which it carries around as it feeds. The first instar is about long. About an hour after emergence from the case, the larva starts to construct a small case around the posterior of their body using oil palm leaves. This constructed case is cone shaped. The case enlarges with each instar. At the fourth instar, the case is covered with loosely-attached large round or rectangular leaf pieces. At the sixth instar, the case surface is smooth and without loose leaf pieces. The larva turns whitish gray. It takes a mean of 71.5 days to reach the sixth instar.

Early instar stages are brownish. Dark patches are found all over the head and thorax. The body is completely covered by sensory setae. Convex shaped stemmata are well differentiated and cover the sides of the head laterally. Thorax is immediately behind the head and comprised three true leg pairs with hooks. Abdomen comprised five pairs of prolegs. Fully grown pupa is long. Male and female pupal cases are different in color. Male pupa has a big blackish head, whereas female with creamy yellowish head. Generally females pupate away from the host.

Adults show strong sexual dimorphism. The adult female is wingless and legless. Head dark brown. Body yellowish brown. Average size is . The male has a wingspan of . Wings smoky brown and body is hairy black. Head chubby. Antennae feathery bipectinate (comb like on both sides). During mating, the male cuts the distal end (lower end) of the case of the female. After laying a large clutch of eggs in her case, the female leaves the case and dies a few hours later. The adult male may live 3 to 4 days.

Timeline

* Average life span from egg to adult: 90 days
* 1st instar: 9–16 days
* 2nd instar: 16–17 days
* 3rd instar: 16–18 days
* 4th instar: 10–15 days
* 5th instar: 12–16 days
* Average life span from 1st instar to 5th instar: 71.5 days
* Pupation: 8–12 days

Ecology and control

It is an important pest of oil palms. Larval outbreaks have been observed from Malaysian oil palm plantations from late 1950s to early 1960s.

Applying chemical insecticides is the fastest and most effective method to control the pest, even though that causes environmental problems. A knapsack sprayer is used to spray insecticides from the ground. Chemicals such as trichlorfon and chlorpyrifos, cypermethrin and lambda- cyhalothrin can be applied as soil drenches. Chlorantraniliprole and indoxacarb are highly effective.

Biological predators such as '' Brachymeria carinata'', '' Buysmania oxymora'', '' Goryphus bunoh'', ''Eupelmus cotoxanthae'', ''Dolichogenidea metesae'', ''Pediobius anomalus'', '' Pediobius imbreus'' and ''Bacillus thuringiensis'' are known to be effective. Use of ''Apanteles metesae'', '' Cosmelestes picticeps'' are also effective measures. Entomopathogenic fungi such as ''Paecilomyces fumosoroseus'' and '' Metarhizium anisopliae'' show effective results under laboratory conditions, but field observations should be carried out.

''M. plana'' outbreaks in Malaysian plantations are highly correlated with relative humidity. Relative humidity estimates based on satellite remote sensing data were fed into both regression models and neural networks. The predictions of both were found to be closely correlated with actual ''M. plana'' appearance on plantations, with the NN producing the best results.

References

External links

Population Assessment and Appropriate Spraying Technique to Control the Bagworm (''Metisa plana'' Walker) in North Sumatra and LampungEvaluation of Infestation in Parasitoids On ''Metisa plana'' Walker (Lepidoptera: Psychidae) in Three Oil Palm Plantations in Peninsular MalaysiaDispersal by bagworm larvae, ''Metisa plana'': effects of population density, larval sex, and host plant attributesResponse of the male ''Metisa plana'' Walker (Lepidoptera: Psychidae) towards female bagworm pheromone lure in wind tunnel bioassaysHymenopterous parasitoids associated with the bagworms ''Metisa plana'' and ''Mahasena corbetti''The Effective Application Time to Spray ''Bacillus thuringiensis'' Subspecies ''kurstaki'' for Managing Bagworm, ''Metisa plana'' Walker on Oil PalmNatural enemies of the bagworm, ''Metisa plana'' Walker (Lepidoptera: Psychidae) and their impact on host population regulationTransgenic Oil Palm with Stably Integrated CpTI Gene Confers Resistance to Bagworm Larvae

{{Taxonbar, from=Q13482376

Moths of Asia
Moths described in 1883
Psychidae
Pests of oil palm