# Presentation: 473877

## Fatal Attraction:

- Blister beetle larvae cooperate to practice mass deception in the
- Mojave Desert
- Leslie Saul-Gershenz
- Center For Ecosystem Survival
- J. Millar, U. C. Riverside

## Mass Deception:

- A hitchhiker’s guide to the Mojave Desert
- Leslie Saul-Gershenz
- Center For Ecosystem Survival
- J. Millar
- University of California, Riverside

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## Meloid Larva Morphology

- Meloe

- Hornia

- Cysteodemus

- Meloe larvaclimb onto vegetation

- Larvae disperse
- & seek food

- Eggs laid in or
- near bee burrows

## Meloe franciscanus & Habropoda pallida distribution

**Habropoda pallida**

**Meloe franciscanus**

*Meloe franciscanus* & *Habropoda pallida* distribution

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## Bee-witched and bee-lievable

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## Host finding behavior

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## Questions

- How do triungulin aggregations attract bees?
- Illicit signaling:
- 1. Visual mimicry: size, color, location, plant
- 2. Olfactory mimicry
- 3. Auditory mimicry

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## Visits to models, masses &dead bees

## Visits & Hits

**aggregations ****	****98 ****	****	****5 obser. ****	****2/<1**
**	**
**dead female****	****	****24 ****	****	****12****	****	****5/2=7**
**Live female****	****	****7****	****	****4 ****	****	****7/4=11**
**live female ****(caged)****	****125 ****	****	****0****	****	****19/1 hr****	**
**Model of aggreg.****	****0****	****	****0****	****	****0**
**Dead male****	****	****0****	****	****0****	****	****0**

**	****	****	****visits****	****	****hits****	****	****mean(V/H)****	**

## Visual mimicry

**	****	****	****Bee****	****	****Triungulins**
**Size* ****	****	****	****8.5 mm****	****8.38 mm****	****P=.2448****	****	**
**Color****	****	****	****gray-black****	****red-brown**
**Height ****	****	****44.63 cm****	****28.13 cm****	****22-55**
**on plant****	****	****22-69 cm****	****10-55 cm****	****overlap**
**Plant perches****	****overlap of  species used**
**	****	****	**

- *not sign.different (Mann-Whitney U test, U=157, Z=-1.163, P=.2448, n=20). Kolmogorov-Smirnov (goodness of fit) -distribution of aggregation lengths was significantly different than the distribution of female bee abdomen lengths. (n =20), DF=2, chi square =8.1, P<.05).

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## How to hitch a ride in the Mojave Desert

- Blister beetle larvae practice mass deception

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## Cooperative Aggressive Mimicry

**Mass stayed aggregated****	****	****	****27 events**
**Mass moving up or down on plant stem****	****14 events**
**Mass moved to different stem together****	****3 events****	**
**Mass reformed after knocked down****	****4 events**

**Behavior****	****	****	****	****	****# observ.**

## Chemical profiles of female bees and triungulinsTo bee or not to bee

- Femalebee Triungulins

## Host location system

- Blister beetle larvae practice mass deception
- 1. Triungulins emerge and aggregate.
- 2. Triungulins cooperate to mimic female *H. pallida.*
- 3. Triungulins attract *H. pallida* male to pseudocopulate and then attach en masse during contact.
- 4. Triungulins travel by phoresy on male bee and transfer to female bee via “venereal transmission.”
- 5. Triungulins reach bee nest via phoresy on female *H. pallida**.*
- 6. Triungulins mimic female bees both visually and chemically.

## Factors affecting the evolution of host location behavior in parasitoids

- Abundance and density of the host from the point of view of the parasitoid:
- 	Bees are a patchy, mobile resource.
- 	Annual abundance and distribution varies from year to year.
- 	Nectar source location is unpredictable because of dune habitat
- 		patchiness and heterogeneity.
- 	Human activities can disturb host plants (fire, grazing & soil compaction).
- Selection pressures on parasitoid and its searching behavior:
- 	Sand substrate temperatures reach 50 ̊ C.
- 	Larva have a greater risk of desiccation as an individual.
- 	Eggs at plant base are at risk of exposure from wind and shifting 		sand.
- Synchrony of intersection
- 	Host location window is affected by annual patterns of precipitation, 			temperature and wind.
- 	Bee nesting varies with *Larrea* bloom onset.

## Ecosystem Interactions 

**Habropoda**
**bee**

**Kelso Dunes**

**30 species **
**of bees**

- Nectar/ pollen

- predator

- predator

- predator

- Nectar/ pollen

- Nectar/ pollen

- Perching

**Petalonyx**

**Grasses**

- predator

- Dasymutilla

- Metepiera
- spider

- Crab spider

- Phiddipus spider

- Wilson’s
- warbler

- Fringe-toed,
- leopard, brush

- Sidewinder

**Larrea**

- shelter

- shelter

- Perching

- predator

- shelter

- Nectar/ pollen

- Herbivore

- Perching

- predator

- Eggs

- Eggs

## Science

- 1895 Harrington large # triungulins on bees

- 1928 Van Dyke describes adult *Meloe franciscanus* from S.F

- 1956 McSwain describes larvae as *Meloe* sp. A

- 1982 Pinto determines
*Meloe *sp. A as
*M. franciscanus*

- 1993-2000
- Saul-Gershenz
- triungulins
- mimic bees

- 33 years

- 28 years

- 26 years

- 18 years

- 1841 Siebold recognizes phoretic relationship

- 54 years

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## Meloid History

**1700**, Goedart was the first to associate the triungulin larvae of *Meloe* with adults
**1727** Frisch considered them to be _lice_ and this error was perpetuated.
**1767** Linnaeus in Systema Naturae gave the name *Pediculus apis. *
**1828** Dufour described the genus *Triungulinus* for larvae of *Meloe* attached to an *Andrena* bee.** ***Meloe* triungulin claws in the form of a trident inspired Dufour to name his ‘bee louse’ *Triungulinus*
**1841 **Seibold** **recognized the phoretic relationship between triungulin of *Meloe* & bees.
**1851** Newport definitely established that larvae of *Meloe* develop in the cells of bees
**1857** and **1859** Fabre observed the feeding behavior of the triungulin larvae in bee nests and applied the term hypermetamorphosis.
**1895** Harrington notes large numbers of triungulins on bees
**1928** Van Dyke describes *Meloe franciscanus* adult from SF
**1956 **McSwain** **describes larvae,*Meloe* sp. A
**1982** Pinto identifies *Meloe *sp. A larvae as *Meloe franciscanus*.

- Adapted from Pinto & Selander 1970

## Venereal transfer

Bee bee contact

- Bee bee contact

**Count**

**Aggregation height vs. perching bee height**

## Ecosystem Interactions 

**Habropoda**
**bee**

**Kelso Dunes**

**30 species **
**of bees**

- Nectar/ pollen

- Nectar/ pollen

- Nectar/ pollen

- Perching

**Petalonyx**

**Grasses**

**Larrea**

- Perching

- Nectar/ pollen

- Herbivore

- Perching

- predator

- Eggs

- Eggs

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## Science

- 1895 Harrington large # triungulins on bees

- 1928 Van Dyke describes adult *Meloe franciscanus* from S.F

- 1956 McSwain describes larvae as *Meloe* sp. A

- 1982 Pinto determines
*Meloe *sp. A as
*M. franciscanus*

- 1993-2000
- Saul-Gershenz
- triungulins
- mimic bees

- 33 years

- 28 years

- 26 years

- 18 years

- 1841 Siebold recognizes phoretic relationship

- 54 years

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## Adaptation for grasping

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## Why aggregate?

- 1 Defense against predation-Distastfulness precedes gregariousness
- 2. Reduction of water loss - small insects
- 3. Start out aggregated due to the oviposition behavior of female, the eggs laid in large groups
- 4. Patchy resources, patchy environment

## Pheromones or Allomones

- Intra-specific  bee-bee		sexual atttractant
- Intra-specific  triung-triung	aggregation
- Interspecific   triungulin-bee	aggressive mimicry
- proportion
- concentration
- context

## Hypermetamorphosis

- in Meloe

## How to get to your dream house -”patch leaving mechanisms”

- Hitchhiking is an iffy mode of transport if your time is limited
- However, if it’s a long way you might as well get a direct flight or at least one with just a few stops and bumps.
- And if your hitching  a little cheesecake goes a long way

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