Influence of constant temperatures on life history of immature Lygus elisus (Hemiptera: Miridae)

Life history characteristics of Lygus elisus Van Duzee were studied at 10, 15,20, 25, 30, and 35degreesC in the laboratory. The egg incubation period, instar-specific nymphal development, survivorship, and longevity of L. elisus were influenced by temperature. Eggs did not hatch at 10degreesC. For the five remaining selected temperature treatments, the incubation period was longest at 15degreesC and decreased nonlinearly with an increase in temperature. Temperature influenced the developmental period differently for different instars, with the second stadium being the shortest at 10, 20, 25, and 30degreesC, whereas first and third stadia were the shot-test at 15 and 35degreesC, respectively. The final stadium was longest across all six temperatures. The relationships between temperature and total durations were described by the same equation for both males and females. Total nymphal duration was not significant with sexes. Sex ratio (proportion of males) of emerging adults of L. elisus did not deviate from 1:1. Both instar-specific and total nymphal survivorship varied significantly with temperature. Total nymphal survivorship was highest at 15degreesC and lowest at 10degreesC. Adult longevity ranged from 16 (35degreesC) to 122 d (15degreesC), with a curvilinear response to temperature. Females survived approximate to10 d longer than males at 20degreesC, but survivorship of males and females was similar at other temperatures. These life history data will be useful in developing a computer model simulating L. elisus population dynamics in the field.