IMPORTANT POINTS 3rd or 4th most species-rich order. “Membrane-wing”; well developed ovipositor; most live in constructed “nests”. Includes: sawflies, parasitoids, “wasps”, ants, & bees. “Wasp” = general, paraphyletic term; may describe almost any hymenopteran. Many “beneficial” species but also many pests. In many habitats may be most numerous insects in numbers of individuals because of social species with large colonies, especially ants, which may be “keystone” species. Bees are the primary pollinators of zoophilous vascular plants; they are linked to survival of the earth’s modern vegetation. HYMENOPTERA

Taxonomy & Diversity Suborder SYMPHYTA sawflies <10% of species Suborder APOCRITA Division Parasitica, parasitoids, >70% of species Division Aculeata, stinging wasps, ants, & bees ~20% spp.

Phylogenetic hypothesis for the evolution of the Hymenoptera

IMPORTANCE Natural World “The little things that run the world.” --E. O. Wilson Special ecosystem functions: Resource cycling, especially ants Population control, parasitoids, predators Pollination (plant reproduction), bees, others

Anthropophilic World Beneficials Bioloical Control: horticultural & agricultural Pollinators: honey bees, bumble bees, solitary bees Hive Products: honey, wax, misc. Pests Agriculture: phytophagous sawflies Structural damage: carpenter bees & ants Nuisance: stinging wasps, ants Medical: stings to allergic individuals, trauma IMPORTANCE

Typical Features of HYMENOPTERA Sawflies vs. Apocrita Larvae Wings Mouthparts

Larvae Sawflies: caterpillar-like, one pair stemmata, > 6 pair prolegs; free-living. Apocrita: grub-like maggots, relatively featureless; live in protected nest cells.

SYMPHYTA, sawflies from Borror, Triplehorn & Johnson, 1980from Peterson 1962 lepidopterous caterpillar single stemma multiply-segmented antennae > 6 prolegs

sawfly larvae

Larvae of APOCRITA live in protected spaces fed by adults soft, grub-like, reduced features from Peterson 1962

Wings Sawflies: always 2 pair, veination heavy, basic Apocrita: 2 pair or one sex apterous, venation often reduced, mambrane may be patterned, fore- & hindwings attached with hammuli. representative sawfly wings

Wings of Apocrita Chalcidoid (parasitoid) wings, Most very small, reduced veins Wings of aculeate wasps & bees, normal size, rel. full veination

Wing coupling hamuli velcro-like

Adult Mouthparts Sawflies: chewing or nonfunctional Apocrita: may be highly modified with manipulative, chewing mandibles, maxillae & labium formed into a liquid-sucking device. In some very long for feeding from deep-corolla flowers.

Mouthparts tongue of a Euglossine bee honey bee mouthparts from Snodgrass

Other Features of APOCRITA Abdomen propodeum gaster petiole mesosoma metasoma

Propodeum & gaster configurations in APOCRITA

Sting Modified abdominal tergites/sternites Double stylet with levering valves at base Venom glands in some spp. Evolution: Ovipositor  Host-paralysing  Defensive Sting parasitoid, egg-laying aculeate bee or wasp, offensive, defensive specialized, barbed honey bee sting

Genetics Haplodiploidy is the rule: Female 2N, Male 1N Sociality Symphyta & Parasitica, solitary Aculeata, most solitary but many social Multiple origins of sociality, even within families, e.g. sweat bees

Parasitoids: Natural & Agricultural Biocontrol parasitoid & host aphid mummies chalcidoids

Braconid wasp ovipositing into lepidopterous pupae. Pupae of a parasitoid formed on host’s exterior as larvae exit.

Cynipidae, gall-wasps and parasitoids some cynipid galls A parasitoid cynipid ovipositing into a gall made by a gall-making cynipid.

velvet ant (Mutilidae) cuckoo wasp (Chrysididae) Charismatic aculeates. “Acule” = “spear”.

Important features of non-parasitic Aculeata Nests + Larval protection - Requires defense - Energetically expensive - Resource dependent “Central-place” foragers: Complex behavior, homing ability

Vespidae: yellow jackets, paper wasps: pests & beneficials

Nest-building Provisioning (hunting) Egg-Laying Larval Development larva

An important clade within the Hymenoptera Specialized wasps Food: nectar & pollen (not predators, as their close relatives) Coevolved with vascular plants Pollinaton Natural World Anthropophilic world (agriculture) More on BEES later…

Red Imported Fire Ant Solenopsis invicta Native to the Pantonal, a semi- tropical region in SW Brazil Introduced early 1900’s in Alabama Exotic pest with no natural enemies  explosive population growth Expansion to many warm regions Native counterparts in genus Solenopsis

RIFA range in USA (slightly outdated) Original introduction, 1920’s ~2008

Typical mode of infestation showing early mound development.

RIFA caste polymorphism Closely-related colonies may form “super colonies” covering many square miles. queen

typical RIFA welts & pustules day 1~ 1 week

dense population of RIFA in pasture

A generalist, RIFA attacks many species of wildlife

Integrated Pest Management of Red Imported Fire Ant RIFA is essentially impossible to eradicate in the open and difficult to manage. Toxic pesticides were initially sprayed over wide areas yielding no significant overall effect but causing massive contamination and side effects. Current use of pesticides is generally limited to local “mound drench”. Mounds can be knocked down but are quickly rebuilt. Biological control methods offer some promise of future management.

RIFA is climate limited but climate warming may expand its potential distribution northward. RIFA was detected in WA in 1999 in a greenhouse; it was eradicated.

~ fin ~