Development and thermal requirements of the Nearctic predator Geocoris punctipes (Hemiptera: Geocoridae) reared at constant and alternating temperatures and fed on Anagasta kuehniella (Lepidoptera: Pyralidae) eggs

Abstract

Knowledge of the optimal temperatures for development and survival of biological control agents is essential for efficient mass-rearing and introduction of natural enemies in augmentative biological control programs. We studied the effect of constant and alternating temperatures on development and survival of immature stages and the sex ratio at emergence of adults of the Nearctic generalist predator Geocoris punctipes (Say). We also determined its thermal requirements. They were reared in climatic chambers at alternating (21/11°C, 24/18°C, 27/21°C and 30/26°C ± 1°C) and constant temperatures (16.8°C, 21.5°C, 24.5°C and 28.3°C ± 1°C), RH 70 ± 10% and a 14 h photophase. Survival and development of G. punctipes were the same when reared at constant and alternating temperatures. Five instars were recorded in all temperature regimes. The duration of the egg stage and each instar, as well as that of total larval development were longer, and larval survival lower when reared at 16.8°C, 21/11°C, 21.5°C and 24/18°C than at 24.5°C, 27/21°C, 28.3°C and 30/26°C. The optimal temperature range for development and survival of G. punctipes is 24.5°C to 30°C, its lower development threshold temperature is 13.5°C and its thermal constant 295.9 DD. Sex ratios were not significantly different from 1 : 1 male : female ratio in all temperature regimes. There is an excellent match between the temperature regimes at which the prey Tuta absoluta (Meyrick) and predator G. punctipes are active, which indicates that this predator will function well in crops where this pest is present.

Reproduction and population parameters of the Nearctic predator Geocoris punctipes at constant and varying temperature regimes

“…The mean number of eggs/female/day and the total number of eggs laid initially increased with increasing temperature, but decreased again at the highest temperatures (figs 1a,b; 2a,b; 3a,b; 4a,b Survival rates (l x ) decreased linearly with female age at most temperature regimes (figs 1c,d; 2c,d; 3c,d; 4c,d) and, as expected, survival is longer at lower than at higher temperatures. As can be seen in these figures, survival rates start around 0.5 at all temperature regimes because we earlier found immature mortalities of about 50% for G. punctipes nymphs (Calixto et al 2014). …”

“…The age (in days) at which the insects began adulthood, immature survival and sex ratio of offspring of the juveniles exposed to the same temperature regimes (Calixto et al 2014) were used in the calculation of the population growth parameters. The life table parameters and their standard errors were estimated according to the procedure described by Maia et al (2000Maia et al ( , 2014.…”

“…in several crops of economic importance (Garcia et al 2004;Brondani et al 2008;Torres 2008). We recently published the first data on developmental time, immature survival, sex ratio at constant and varying (day/night) temperature regimes (Calixto et al 2014), and adult lifespan, fecundity and egg and larval predation of G. punctipes with T. absoluta as prey on tomato (Bueno et al 2013).…”

“…The majority of studies performed at variable temperatures have focused on effects on insect developmental time (e.g., Jakobsen et al 2006;Calixto et al 2014;Vangansbeke et al 2015), and only a few on effects on reproduction and population growth (e.g. Siddiqui et al 1973).…”

Intraguild predation of Geocoris punctipes on Eretmocerus eremicus and its influence on the control of the whitefly Trialeurodes vaporariorum

“…In turn, the predator Geocoris punctipes (Hemiptera: Lygaeidae) is another common natural enemy of this pest in the Americas . This polyphagous predator has a nymphal development of 23–36 days and a subsequent adult stage than can last up to 108 days .…”