A Comparison of Longevity and Fecundity of Adult Trichogramma platneri (Hymenoptera: Trichogrammatidae) Reared from Eggs of the Cabbage Looper and the Angumouis Grain Moth, with and without Access to Honey

Abstract

The effects of Sitotroga cerealella (Olivier) and Trichoplusia ni (Hübner) eggs on the size, fecundity, and longevity, and of honey on the fecundity and longevity of Trichogramma platneri Nagarkatti were investigated. Variation in the average length of the hind tibiae (HTL), a measure of a wasp’s body size, accounted for 72% of the variance in the number of mature eggs present in the ovaries of a 24-h-old T. platneri. Females with longer HTLs produced significantly more eggs and lived longer than did those with shorter HTLs. Large females (HTL = 0.21 ± 0.009 mm, x ± SD) produced 2.3 times more offspring than medium-sized females (HTL =0.17 ± 0.009 mm) and 5.5 times more than small females (HTL = 0.15 ± 0.004 mm). Females reared from S. cerealella eggs were significantly smaller (HTL = 0.14 ± 0.006 mm) than those reared from T. ni eggs (HTL = 0.17 ± 0.020 mm) and produced fewer offspring (18.2 ± 13 eggs versus 42.6 ± 25 eggs, respectively); hence, S. cerealella eggs apparently produce low-quality T. platneri females. Furthermore, T. Platneri lived longer with than without honey whether or not host eggs were present. Thus, the absence of a carbohydrate source (e.g., honey or honeydew) at the time of field release may limit the effectiveness of T. platneri.