Interpopulation variation in Chrysoperla carnea reproduction: implicationsfor mass-rearing and storage

To determine whether diverse populations and biotypes of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) can be mass-produced and stored under uniform conditions, we assessed reproduction in five North American popula tions, four from the carnea biotype and one from the mohave biotype. Non-di apause adults from the carnea biotype varied significantly in only one aspe ct of reproduction, viz., the preoviposition period, whereas the duration a nd rate of oviposition, as well as fecundity, did not vary significantly. R elative to the carnea populations, the mohave population typically had dela yed oviposition and a lower rate of oviposition; however, its oviposition p eriod was long, and thus its fecundity differed only from that of the most productive carnea populations. The shelf-life (= survival during storage, and subsequent survival and repr oduction after storage) was evaluated for four populations of the carnea bi otype. Survival of diapausing adults during the first 18 weeks of storage w as high among all four populations; adults from three populations also show ed high survival after 35 weeks of storage. A high incidence of females fro m all four populations laid some fertile eggs after being stored for up to 31 weeks or longer. After six or more weeks of storage, average fecundity w as high and ranged from similar to 400-900 eggs/female. Duration of storage (up to 39 weeks) was a significant determinant of fecundity in two of the four populations. In practice, diverse populations of C. carnea can be efficiently mass-produ ced (with or without storage) under uniform conditions in the insectary. Th us, the choice of which populations to mass-produce and use in augmentation can be based primarily on the characteristics (e.g., climate, habitat, cro p) of the intended area of release, rather than on considerations concernin g mass-rearing.