Wednesday, December 13, 2006
D0451

Ovigeny in selected generalist predators

Jesusa Crisostomo Legaspi, jlegaspi@saa.ars.usda.gov, USDA-ARS-CMAVE-FAMU-CBC, 6383 Mahan Dr, Tallahassee, FL, Mark Jervis, Cardiff University, Cardiff School of Biosciences, Museum Ave, Cardiff, Cardiff, United Kingdom, and Benjamin Legaspi, Florida PSC, Shumard Oak Blvd, Tallahassee, FL.

Ovigeny refers to the process of egg production in adult insects. Pro-ovigenic adult insects emerge with a fixed complement of mature eggs; whereas, synovigenic species continuously produce and develop eggs throughout adulthood. Very little work has been done on ovigeny in insect predators. We studied 4 predators such as Podisus maculiventris (Heteroptera: Pentatomidae), Orius insidiosus (Heteroptera: Anthocoridae), Delphastus catalinae (Coleoptera: Coccinellidae), and Geocoris punctipes (Heteroptera: Lygaeidae). We examined egg load at regular time intervals (dependent on lifespan). Numbers of eggs laid were also recorded. In P. maculiventris, numbers of immature eggs increased with predator age whereas numbers of mature eggs declined providing clear indication of continuous egg production. Similar results were found in G. punctipes. In other predators, egg loads tended to increase with time, except in D. catalinae. However, numbers of eggs laid all increased with time. These findings suggest that egg production occurs during the adult stage in all these predators and that all predators studied were synovigenic to varying degrees.


Species 1: Hemiptera Pentatomidae Podisus maculiventris (spined soldier bug)
Species 2: Hemiptera Anthocoridae Orius insidiosus (minute pirate bug)
Species 3: Coleoptera Coccinellidae Delphastus catalinae