Apiomerus

Hahn, 1831

Bee Assassins, Bee Assassin Bugs

Species Guides

9

Apiomerus is a of brightly colored, conspicuous assassin bugs in the Reduviidae, commonly known as bee assassins. The genus contains approximately 110 described and represents the largest clade within the monophyletic tribe Apiomerini. Members are characterized by their use of plant resin as 'sticky traps' to capture prey, a trait unique among assassin bugs. Females possess specialized tibial combs for resin collection and application onto masses, providing maternal care. The genus exhibits significant and extreme diversity in genital , hypothesized to result from driving speciation.

Apiomerus crassipes by no rights reserved, uploaded by kcthetc1. Used under a CC0 license.Apiomerus flaviventris by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.Apiomerus floridensis by (c) Judy Gallagher, some rights reserved (CC BY). Used under a CC-BY license.

Pronunciation

How to pronounce Apiomerus: /ˌæpiˈoʊmɛrəs/

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Identification

Resin-collecting and associated leg (tibial combs) are diagnostic for the . Females can be distinguished by the metatibial comb used for resin transfer to masses. -level identification requires examination of genital morphology, which is highly variable and considered the most reliable diagnostic character. The crassipes and pictipes species groups contain 12 species and can be distinguished by specific genitalic features. Some species exhibit discrete color morphs while others show continuous polychromatism.

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Habitat

Found in diverse across the New World, from southwestern United States through tropical America. Frequently associated with flowering plants where they ambush prey. Documented on flowers including coneflower (Echinacea), brittlebrush (Encelia farinosa, Asteraceae), and Andean blackberry (Rubus glaucus, Rosaceae). Also observed in agricultural settings such as soybean fields and sand scrub habitat.

Distribution

New World ranging from the United States through tropical America. Highest diversity in southwestern United States within North America. Nearctic–Neotropical boundary occurs along the Isthmus of Tehuantepec in southern Mexico. Specific distribution varies by : A. flavipennis known only from Argentina and southern Brazil; A. lanipes ranges from Panama to Argentina; A. spissipes broadly distributed across Great Plains; A. crassipes occurs in eastern North America.

Seasonality

activity documented from September through March in Missouri, with small nymphs found during November and December. Summer records also exist. Activity patterns vary geographically across the broad New World range.

Diet

ambush targeting prey at flowers. Documented prey includes bees (Hymenoptera), stink bugs (Pentatomidae, including Piezodorus guildinii), and other flower-visiting insects. Apiomerus crassipes attracted to cerambycid beetle , indicating on longhorn beetles. Prey capture aided by resin 'sticky traps' applied to forelegs.

Life Cycle

Females apply collected plant resin onto masses post-oviposition, providing protection from desiccation and egg such as ants. Resin serves as for emerging nymphs to form their first sticky traps. Early nymphal stages actively collect sap from the environment. females have been observed harvesting leftover resin from post-moulting.

Behavior

ambush that lurk on flowers and bramble for prey. Resin collection involves scraping plant surfaces with forelegs, transferring material through tibial combs. In females, resin moves from foretibiae to mesotibia to metatibial comb, then stored in setae until application. Some possess ventral glands that may prevent resin hardening. Maternal care unique within Apiomerini: females apply resin to clutches. Kleptoparasitic flies (Milichiidae, Chloropidae) attracted to feeding events, apparently cueing on defensive compounds from prey.

Ecological Role

of flower-visiting arthropods including and agricultural pests. Acts as natural agent for pest such as stink bugs in soybean agroecosystems. Resin-based maternal care provides protection for offspring and resource for nymphal development. Subject to kleptoparasitism by flies that exploit their events.

Human Relevance

Potential value as agents in agricultural systems, particularly for management of pests. Bright aposematic coloration and painful defensive bite may cause concern, but no significant medical or economic impacts documented. Subject of systematic research due to complex evolutionary patterns including polychromatism and .

Similar Taxa

  • ZelusAlso uses sticky traps for prey capture, but employs self-produced glandular secretions rather than collected plant resin; sundew setae on legs serve similar function but through different evolutionary origin.
  • PhymataAmbush bugs that lurk on flowers, but lack resin-collecting and possess forelegs modified for grasping rather than sticky trap .
  • Other HarpactorinaeMost lack specialized resin collection and maternal care ; Apiomerus distinguished by tibial comb and documented resin use across all life stages.

Misconceptions

'bee assassins' implies specialization on bees, but foraging habits are ; documented prey includes diverse arthropods beyond Hymenoptera. Some color morphs were historically described as separate , but many have been synonymized following genitalic examination.

More Details

Resin Collection Biology

The use of plant resin as sticky traps is a derived trait within Apiomerini, with the metatibial comb representing an ancestral feature for the . Resin is collected from diverse plant sources including Asteraceae and Rosaceae. The is prevalent in all life stages, with nymphs actively collecting sap and females demonstrating maternal application to .

Systematic Significance

Apiomerus exhibits the most extreme genitalic diversity in the Harpactorinae, with complex abdominal constructions in both sexes. This morphological diversity correlates with high and is hypothesized to result from as the primary driver of speciation. The crassipes and pictipes groups together contain 12 species and represent the majority of Nearctic diversity.

Taxonomic Challenges

Frequent color variation within has led to taxonomic confusion, with many color morphs historically described as distinct species. Recent phylogenetic and morphological analyses using genital characters have revealed numerous synonyms. A 1980 dissertation describing 19 new species including 'A. floridensis' remains unpublished and therefore nomenclaturally unavailable.

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