Temperature-dependent development, diapause and cold tolerance of Gratiana graminea, a potential biological control agent of Solanum viarum in Florida, USA

Abstract

The objectives of this study were to examine temperature-dependent development, diapause and cold tolerance of Gratiana graminea Klug (Chrysomelidae), a candidate biological control agent of tropical soda apple, Solanum viarum Dunal (Solanaceae). Immature development was examined at six constant temperatures ranging from 15°C to 30°C. Diapause induction was determined by exposing adults to either long or short photoperiods at 20°C and cold tolerance was assessed by exposing adults to 0°C. G. graminea completed development at temperatures ranging from 20°C to 30°C. Linear regression estimated a lower temperature threshold of 11.7°C and 312 degree-days were required to complete development. Diapause was induced when adults were exposed to short photoperiods (10:14 L:D h) at 20°C. The lethal times for diapausing adults of G. graminea at 0°C (LT 50 = 19 days, LT 90 = 41 days) were two times higher compared to Gratiana boliviana Spaeth, a biological control agent already established in south and central Florida, USA. The presence of diapause and the greater cold tolerance suggest that G. graminea may establish and perform better than G. boliviana in northern Florida.

Effects of Temperature on the Development and Survival of Cricket Species; Acheta domesticus and Gryllus bimaculatus (Orthoptera: Gryllidae)

“…According to Colin and Spurgeon (2019), extreme heat could result in either temporary or permanent infertility or the inactivation of sperm stored in the spermatheca, reducing fertility. High temperatures are known to frequently hasten pre-imaginal development in insects that overwinter as adults, ensuring the timely development of the diapausing stage before the start of winter (Manrique et al, 2012). Nonetheless, the maturation of different species is restricted naturally and consequently, miniature and diaphanous adults are usually produced with accelerated development (Lamb et al, 2009).…”

“…Insects respond either through a change in behaviour to avoid stress by migration or through changed activity patterns (Hagstrum & Miliken, 1988). These insects can continuously adapt to stress conditions through selection or by plastic responses, by changes in morphology, life history, or physiology (Manrique et al, 2012;Lopatina et al, 2007).…”

Effects of Temperature and Photoperiod on the Immature Development in Cassida rubiginosa Müll. and C. stigmatica Sffr. (Coleoptera: Chrysomelidae)

“…rubiginosa 11 , Chelymorpha cribraria 12 , Gratiana boliviana 13 , G . graminea 14 and Metriona elatior 15 . Unfortunately, reported developmental rates for C .…”