Soybean Flour and Wheat Germ Proportions in Artificial Diet and Their Effect on the Growth Rates of the Tobacco Budworm,Heliothis virescens

Abstract

Soybean flour and wheat germ are the two most important protein components of wheat germ-based insect artificial diets. The effect of modifying the proportion of these two ingredients in a Noctuidae-specific diet was investigated utilizing the tobacco budworm Heliothis virescens (F.) (Lepidoptera: Noctuidae), with the goal of developing a suboptimal diet that, without drastically affecting this insect's growth and reproductive rates, could manifest subtle negative effects in this insect. The original diet formula contained 2.51% protein. When the proportions of soybean flour and wheat germ were changed to 2.15% protein the net reproductive rate of the first generation was significantly lower. In the second generation, the net reproductive rate, development time, percent female survivorship, fertility, intrinsic rate of increase, finite rate of increase and female longevity were significantly lower in both the 2.15% and 2.26% protein diets. The survival rate of immatures to the adult stage was 1% in the 2.05% protein diet in the first generation. Interestingly, females exposed to these suboptimal diets produced a significantly higher number of eggs but the survival of their larvae was significantly reduced. It is evident from these results that modifications to the protein content and the nutrient composition profile of the original wheat germ-based insect artificial formula can be used to produce subtle negative effects on the growth of tobacco budworm.

Paternity Allocation in a Mutant Heliothis virescens1Colony

“…1). All insects were reared on a wheat germ-based diet (Blanco et al 2008) and controlled environmental conditions of 27 ± 2ºC, 75 ± 10% relative humidity, and photoperiod of 14:10 L:D hours. Zweigar ® , Piscataway, NJ) and fed 10% sucrose solution for 2 days.…”

Activity of oil-formulated conidia of the fungal entomopathogens Nomuraea rileyi and Isaria tenuipes against lepidopterous larvae

“…Subsequently we used PDAY for culture of both fungi, where production of infective conidia was stable and sufficient. For inoculation, 3rd instar larvae from a S. frugiperda colony obtained from corn in Saltillo were used; this colony was maintained in the laboratory for six generations on wheat-germ based diet (Blanco et al, 2009). …”

<I>Bacillus thuringiensis</I> Cry1Ac Resistance Frequency in Tobacco Budworm (Lepidoptera: Noctuidae)

“…Containers were placed in front of a window facing north with natural photoperiod, kept at 28 Ϯ 2ЊC and 70 Ϯ 12% RH. Sixty Þrst-generation (F 1 ) neonates per single-pair family were placed on insect artiÞcial diet (Blanco et al 2008a) under the environmental conditions described above, except that they were not placed in front of a window. F 1 moths belonging to a single-pair family were sibmated with six (Ϯ1) pairs as described in Blanco et al (2008b).…”