COMPARATIVE MORTALITIES OF 6 TORTRICID (LEPIDOPTERA) SPECIES TO 2 HIGH-TEMPERATURE CONTROLLED ATMOSPHERES AND AIR

Mortality responses of 3-d-old eggs and 1st, 3rd, and 5th instars of 6 New Zealand tortricids to 2 controlled atmospheres (1.2% O-2 and 4.2% O-2 with 5% CO2 at 40 degrees C) and 40 degrees C air were determined . Endemic species, Ctenopseustis obliquana (Walker), Ctenopseustis her ana (Felder and Rogenhofer), Planotortrix excessana (Walker), Planotor trix octo Dugdale, and Cnephasia jactatana (Walker), all exhibited sim ilar mortality responses, with a common pattern of increasing time LT( 99) as the oxygen level increased (1.2% Or atmosphere less than or equ al to 4.2% O-2 atmosphere less than or equal to air). Typically, 3-d-o ld eggs were more susceptible to treatment than larval stages tested. However, this pattern lessened with increasing O-2 concentration of tr eatment in three species. All endemic leafroller species were sensitiv e to the high treatment temperature. Collectively (over all life stage s tested), the LT(99) never differed by > 3.9 h within a single treatm ent or by 4.6 h over all 3 treatments. Whereas Epiphyas postvittana di splayed a similar order of increasing tolerance to treatment (1.2% O-2 atmosphere < 4.2% O-2 atmosphere < air), response differences among t he treatments were greater than in endemic species. Mean LT(99) values for stages of E. postvittana decreased in the following order: 5th in stars greater than or equal to 3rd instars > 1st instars approximate t o 3-d-old eggs. Only LT(99)s of 3rd and 5th instar E. postvittana exce eded those of their endemic counterparts. Mean LT(99) values for 5th i nstar E. postvittana to the 1.2% O-2 atmosphere, 4.2% O-2 atmosphere a nd air treatments were 8.5, 15.5, and 21.1 h, respectively.