Environmental Entomology (1999) 28, 518-522

Cesar R. Rodriguez-Saona and Jeffrey C. Miller (1999)
Temperature-dependent effects on development, mortality, and growth of Hippodamia convergens (Coleoptera : Coccinellidae)
Environmental Entomology 28 (3), 518-522
Abstract: Insect natural enemies selected for specific traits such as faster developmental times, higher survivorship, increased fecundity, and larger body size might be considered during production of biological control agents in certain situations. For instance, traits related to developmental rates may be selected for if genetically based variation exists within temperature-dependent responses. We compared preimaginal development, mortality, and size of Hippodamia convergens Guérin-Méneville at 4 constant temperatures (18, 22, 26, and 30°C). Total preimaginal development ranged from 51 d at 18°C to 14 d at 30°C. Developmental times were significantly different among isofemale lines of field-collected H. convergens from Oregon at all temperatures tested (18, 22, 26, and 30°C). Variation within female lines was significant only at 26°C. The lower developmental thresholds for egg, larval, and pupal stages were 9.9, 13.7, and 14.5°C, respectively. Degree-day (DD) requirements for development were 58.8, 166.7, and 52.6 for eggs, larvae, and pupae, respectively. Total preimaginal development required 231 DD above a temperature threshold of 13.6°C. Degree-day requirements for 14 field-collected female lines varied from 223 to 273, whereas the lower threshold for development ranged from 13.1 to 13.8°C. Mortality decreased with increasing temperatures. At the lower temperature (18°C), higher mortality occurred during the 4th instar and pupa. Pupal and adult weights differed across temperatures. Heavier pupae and adult beetles were reared at 22°C. Also, wings were larger among beetles reared at 22°C. The development, mortality, and size measurements provide data for establishing suitable rearing conditions for future studies on the ecology of H. convergens.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Cesar R. Rodriguez-Saona

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
population dynamics/epizootiology

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Hippodamia convergens (predator)			U.S.A. (NW)