Viability of Nezara viridula (L.) eggs for parasitism by Trissolcus basalis (Woll.), under different storage techniques in liquid nitrogen

Abstract

Different egg conservation techniques were assessed under low temperature conditions to multiply the parasitoid of stink bug eggs Trissolcus basalis (Woll.) (Hymenoptera:Scelionidae). Masses of fresh Nezara viridula (L.) eggs were stored for 12 months in liquid nitrogen (-196ºC), wrapped in aluminum foil, in microcentrifuge tubes ("eppendorf") or in vacuum sealed double plastic bags (500 eggs/technique/month). Every 30 days, 10 egg masses from each of the different storage techniques, were taken out, thawed immediately and subjected to parasitism by T. basalis. Green stink bug eggs, stored at -196ºC presented conservation conditions and viability for T. basalis development, with high parasitism rates and emergence in the eggs stored under the three different techniques. Parasitism of eggs stored wrapped in aluminum foil (95.4%), in tubes (92.3%), and under vacuum (93.7%) were statistically equal to parasitism in fresh eggs (97.3%). Egg viability, expressed by the rate of emergence of adult parasitoids, indicates that the three techniques studied provided excellent T. basalis development and emergence conditions with no significant differences when compared with fresh eggs. Throughout the total storage period (12 months) there was no reduction in the number of females hatched, although there were fluctuations in the sexual ratio for some periods. These results make green stink bug egg conservation, and later multiplication of the parasitoid T. basalis possible for a period twice as long as that known and used today.

Use of Low Temperature Storage to Preserve Host and Parasitoid to Improve the Rearing of Telenomus podisi (Hymenoptera: Platygastridae) on Euschistus heros (Hemiptera: Pentatomidae) Eggs

“…Preservation of E. heros eggs in liquid nitrogen (− 196°C) or in a − 80°C ultrafreezer requires their protection from desiccation in aluminum foil (Corrêa-Ferreira & Oliveira 1998), often with a variable number of eggs stored per portion. When removing a recipient with stored eggs from liquid nitrogen (− 196°C) or an ultrafreezer (− 80°C), unused eggs are usually kept at 5°C for several days until later usage in parasitoid rearing.…”

Egg Parasitoids Commercialization in the New World

“…Sometimes long periods are required to go from a laboratory production of 20 g of Anagasta kuehniella eggs (720,000 eggs) in research, to a daily yield of 2-3 kg (72,000,000-108,000,000 eggs) in the company; • storage techniques for periods during which the produced insect is not used [diapause (Pizzol 1978), liquid nitrogen (Ma Huai-Yi 1988and Corrêa-Ferreira and Oliveira 1998, low temperatures (Drooz 1981), etc. ]; • government support for starting small companies;…”

Conservation of Ephestia kuehniella eggs as hosts for Trichogramma ostriniae

“…Liquid nitrogen offers various levels of success depending on the host and the technique. Parasitism of Nezara viridula Linnaeus (Hemiptera: Pentatomidae) eggs stored during 12 months in liquid nitrogen was not significantly different than parasitism of fresh eggs by the parasitoid Trissolcus basalis Wollaston (Hymenoptera: Scelionidae) (Corrêa‐Ferreira and de Oliveira ). Similarly, Ma () observed no differences in the parasitism and emergence rates of Trichogramma dendrolimi Matsumara and Trichogramma confusum Viggiani (Hymenoptera: Trichogrammatidae) when these exploited tussah moth, Antheraea pernyi Guerin‐Meneville (Lepidoptera: Saturniidae) eggs, whether fresh or stored in liquid nitrogen followed by thawing in water at 30°C.…”