|Parajulee, Megha - TEXAS A&M|
|Nordheim, Erik - UNIVERSITY OF WISCONSIN|
Submitted to: Population Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 2, 1995
Publication Date: N/A
Interpretive Summary: The larger pirate bug (Lyctocoris campestris), a predator of moth and beetle pests of stored products, shows potential for use in biological control. Little is known concerning effects of temperature and relative humidity on development of the predator. This information is essential in developing mass rearing procedures. This article reports results of experiments in which immature stages of the bug were raised in the laboratory at four different temperatures and three different relative humidities. Egg hatch, development time and survival were noted. Relative humidity had no significant effect on development time or mortality of any life stage. Temperature had significant effects on development times of eggs and all nymphal stages, but did not significantly influence mortality rates. Development was shorter at higher temperatures. Mathematical formulas were generated and will be combined with additional information to construct a computer-based simulation model of pirate bug population growth. This study contributes to improved rearing of this predator for greater efficiency in biological control programs.
Technical Abstract: Life history of immature Lyctocoris campestris (F.), a predator of stored product insects, was investigated at 17, 21, 25, and 29C and 43, 58, and 75% RH in the laboratory. Most life history traits of L. campestris were influenced by temperature, but none of the traits was influenced by relative humidity. The egg incubation period was 7 d at 25-29C, but increased sharply at temperatures <25C. An equation was developed to predict egg incubation period over a range of temperatures. Egg hatch rate did not vary with temperatures nor with the relative humidities. The mean hatch rate ranged from 78 to 86%. The instar-specific nymphal development also varied with temperature. The 2nd stadium was the shortest followed by the 3rd, 1st, and the 4th, and the 5th stadium was the longest across all 4 temperatures. The relationships between temperature and instar-specific nymphal durations and total nymphal durations were described by the same equation for both females and males; total nymphal durations did not vary with sex. Nymphal survival rates ranged from 0.60 to 1.00 and did not vary significantly with temperature or relative humidity. Sex ratio (proportion of males) of emerging adults ranged from 0.40 to 0.70, but did not differ from 1:1. These life history data are reported in a manner useful for developing a computer model for simulating L. campestris population dynamics.