Paul B. Baker, PhD and Javier Miguelena University of Arizona Department of Entomology UC Riverside Urban Conference March 21th 2012 Overview- Ecology, Biology and Control (management)  Phx Ant Survey  Biology and ID  Location  Rearing  Research  Satellite nests  Supercolonies  Multiple queens  Management decisions  Conclusions

Total samples 44 Biology-Description/ID- scientific name: Brachymyrmex patagonicus Mayr (Insecta: Hymenoptera: Formicidae: Formicinae)

 Small, dark brown  1-node ants  Antennae 9 segmented.  Very small: 0.8 to 1

mm antweb.org  Nuisance pest: no structural damage or sting. Biology Description/ID-Continued  Colonies may grow to have thousand of individuals.  Somewhat erratic foraging pattern.  Very attracted to sugary liquids.  Can tend aphids or feed on plant nectar.

Alates (adults)

(c)A Bockoven

 Queens are larger (about 5mm in length) compared to minute males.  Attracted to light sources.  In southern AZ, mating flights may occur from February to October, although they peak during the monsoon. Worker Queen Location: Invasiveness and pest status

Map of distribution compiled by Alex Wild in 2008. Many locations have not been sampled yet.

 First recorded in Louisiana in 1976. Native to South America  No current map of distribution, but they are likely present most of the Southern US and Hawaii.  Dispersal is likely dependant on human transport.

Javier’s Research  Ants in Tucson Parks  Pitfall traps in 3 areas (6,500 ants collected) Figure : Diagram showing the distribution patterns of the species found. Underlined species where found only in one site and can be considered rare. Endemic species that are not rare (e.g. Formica sp.1 in parks) might be indicators of specific habitat conditions. U of A Laboratory colony rearing

 We started rearing colonies of rover ants in May of 2009.  Some of these still survive now and have come to the point of producing virgin queens and males.

Rearing

Research: survival of satellite nests  We separated queenless fragments of ant colonies with and without larvae.  Although populations were clearly decreasing, workers remained alive up to 8 months after.  Workers laid eggs which developed into males.  Implications for management? Research: supercolonies?  Supercolony: group of colonies of the same species that exchange food and workers freely without aggression.  Common trait of successful invasive ants: red imported fire ant, argentine ant, pharaoh ant, etc.  We tested for aggression between individuals from different colonies by putting pairs of ants from 7 different field colonies in vials and recording whether they fought each other or not. Research: supercolonies? NO!

No aggression was ever observed between individuals from the same colony. Ants from different colonies attacked each other approximately 60% of the time.

Research: Satellite nests and migration We observed the establishment of satellite nests in laboratory conditions.

Rover ants rapidly spread to new available habitats (less than 24h) and establish permanent satellite nests that may include eggs and larvae.

So what? Research: Multiple queens per nest  Rover ants were considered to have only 1 queen per nest.  However, reports of long term colony survival and rapid growth might suggest otherwise.  We started lab colonies with 1 or 2 queens.  Aggression was never observed between queens. One clump of eggs was produced by each pair. Queens only Research: Multiple queens per nest

•Colonies with 2 queens had twice as many workers for the first generation. •We have observed groups of 3, 4 and up to over 20 queens start laying eggs together. •Cooperative founding likely happens in the wild due to the aggregation of large numbers of ant queens near artificial lights. Laboratory Tests Laboratory tests-Objective evaluate products for rover ant control

 Two baits: Intice and Terro  Laboratory colonies-place in clear plastic boxes with no food but with water  Twenty fours later introduced bait and made observations  Seven and 14 days after bait placement counted the dead and alive

Control -Honey water only Figure: Intice® and Terro Ant Baits® (plus Control) vs Brachymyrmex patagonicus. Lab assay January 2012-1 week post application of the bait

General observations-management implications  They recruitment others through pheromones.  Need for continuous moisture source.  Interactions with other pest ants are undocumented, but they live side by side with argentine ants in Reid Park.  Also frequently observed living next to native ants. Conflict likely avoided by differences in size.

More implications/keys for management

 Use of non-repellent insecticides and sugar based baits.  Over use of spraying of insecticides might encourage migration to other part of the structure.  Major Key: Eliminating sources of moisture/water inside and outside buildings.

Summary  Biology/ecology in integral in understand the implications for management.  Queenless fragment can survive for upward of 8 months  Rover ants will expand their territories based on water  Control of water sources in the key to management. In support of a graduate student at the University of Arizona working in the urban community Questions??????