Myllocerus undecimpustulatus undatus

Marshall

Sri Lankan weevil

Myllocerus undecimpustulatus undatus, the Sri Lankan , is a pest to Sri Lanka that has spread to India, Pakistan, and the United States. It was first identified in Florida in 2000 on Citrus and has since established in the state. The species exhibits with females typically larger than males. Research has documented its limitations, mating involving female abdominal rocking and prolonged copulatory guarding, and susceptibility to certain .

Pronunciation

How to pronounce Myllocerus undecimpustulatus undatus: //mɪlˈloʊsɛrəs ˌʌn.də.sɪm.pʌs.tjʊˈleɪ.təs ʌnˈdeɪ.təs//

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Habitat

Well-drained sandy soils of peninsular Florida; western Gulf Coast predicted unsuitable due to greater rainfall and aquic or udic soils

Distribution

to Sri Lanka; established in India, Pakistan, and United States (first recorded in Pompano Beach, Broward County, Florida in 2000). Models predict potential spread to southeastern and western United States with northern distribution limit near 33°N isothermal ; western Gulf Coast predicted unsuitable.

Diet

; documented feeding on leaves including cocoplum and peach foliage; associated with more than 20 in South Asia; first U.S. on Citrus sp.

Host Associations

Citrus sp. - First U.S. in Florida
Ficus - Collected from fig trees for mating study
Cinnamomum tamala - Indian bay leaf; first reported for this
Prunus persica - Peach; used in field cage studies
Chrysobalanus icaco - Cocoplum; used in laboratory

Behavior

Females exhibit vigorous to-and-fro abdominal rocking when approached by males, functioning as a mate-strength test that dislodges weaker males while persistent males maintain grip. Male-male competition occurs with non-mounting males attempting to displace mounted rivals. Copulation lasts several hours and is followed by extended copulatory guarding; effective sperm transfer completed approximately 2.5 hours after copulation onset. Forced separation during late guarding stages frequently results in male injury or death.

Ecological Role

agricultural pest with potential for significant damage; established in Florida with risk of further spread

Human Relevance

Agricultural pest of economic concern; subject of efficacy research including (BotaniGard, PFR-97, Met52) and biochemical (Entrust, PyGanic, AzaMax); Entrust and BotaniGard showed highest mortality rates in laboratory studies. Management complicated by prolonged mating making pairs difficult to separate without injury.

More Details

Taxonomic History

identification underwent revision by Dr. Charles W. O'Brien from Myllocerus undecimpustulatus to Myllocerus undatus, finally to Myllocerus undecimpustulatus undatus Marshall to clarify its status as a .

Cold Tolerance

after 2 days at 0°C and −5°C averaged 60% and 18% respectively; after 4 days, survivorship dropped to 11% at 0°C and 4% at −5°C. Summer-collected survived 3 times longer under repeated cold exposure (2 h cycles) than sustained cold (10 h). Winter-collected weevils showed 2–4 times greater leaf consumption after cold exposure than summer-collected weevils.

Sexual Dimorphism

Females are typically larger than males; both sexes exhibit distinctive morphological differences documented in studies.