Storage of Lacewing Eggs: Post-storage Hatching and Quality of Subsequent Larvae and Adults

Abstract

Abstract To facilitate short-term storage for the production, distribution, and release of subtropical or tropical lacewings, we evaluated the life-history consequences of exposing eggs to moderately low temperatures. We tested three Neotropical species: Ceraeochrysa cubana (Hagen), C. smithi (Navas), and Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae). For each species we subjected eggs of four different age groups to five temperatures between 4.5 and 15.6°C for 3 weeks, and we recorded the timing and incidence of hatching, post-storage larval molts, cocoon spinning, pupal molts, the preoviposition period, imaginal survival for 30 days after emergence, the number of eggs laid during the first 15 days of oviposition, and egg fertility. The results show that the temperature range for successfully storing eggs of the two Ceraeochrysa spp. is narrow and relatively high (∼14 days at ∼15.6°C), whereas that for Chrysoperla externa is considerably broader (∼14 to 21 days at 10 to 15.6°C, respectively). For all three species, immatures (larvae and pupae) from stored eggs developed slightly but significantly slower (by 0.4–1.6 days) than those from unstored eggs, and for Chrysoperla externa stored at 10 and 12.8°C, survival of late instars was reduced by 30–40%. Storage of the two Ceraeochrysa spp. did not affect any of the measures of post-storage reproductive success. In contrast, C. externa showed a lengthening of the preoviposition period in adults reared from eggs stored at 10°C. The results indicate that newly laid eggs of the three species can be held without hatching for approximately 2 weeks at 15.6°C and that storage of C. externa eggs can be extended to 3 weeks at 12.8°C. These regimens offer short-term storage capability and relatively good post-storage quality.