Development of an Optimum Diet for Mass Rearing of the Rice Moth, Corcyra cephalonica (Lepidoptera: Pyralidae), and Production of the Parasitoid, Habrobracon hebetor (Hymenoptera: Braconidae), for the Control of Pearl Millet Head Miner

Abstract

The rice moth, Corcyra cephalonica Stainton, an alternate host for the production of the parasitoid, Habrobracon hebetor Say, was reared on different diets, including pearl millet [ Pennisetum glaucum (L.) R. Br.] (Poales: Poaceae) flour only, and in combinations of flours of sorghum [ Sorghum bicolor (L.) Moench] (Poales: Poaceae), peanut ( Arachis hypogea L.) (Fabales: Fabaceae), and cowpea [ Vigna unguiculata (L.) Walp.] (Fabales: Fabaceae) to identify the optimal and economical proportion to be used under the conditions of Niger. The addition of cowpea or peanut to the pearl millet diet slightly increased C. cephalonica larval development time. Likewise, the addition of cowpea or peanut to cereal diets yielded a higher C. cephalonica larval survival. Female moths emerging from larvae fed on cereal and legume mixed diets produced higher eggs compared to the ones fed on sole and mixed cereals. Among legumes, cowpea addition is most interesting in terms of cost/production of C. cephalonica larvae. However, female moths emerging from larvae fed on different millet cowpea mix (5, 25, and 50%) laid significantly more eggs than those fed on sole pearl millet. Further, individual C. cephalonica larvae fed on 75% pearl millet + 25% cowpea produced significantly more H. hebetor . With an initial 25 C. cephalonica larvae kept for a 3-mo rearing period, the number of H. hebetor parasitoids produced will reach 2.68–10.07 million. In terms of cost/production ratio, the 75% pearl millet: 25% cowpea yielded better results.

Influence of host diet on the biological characteristics of Bracon hebetor Say (Hymenoptera: Braconidae)

“…Therefore, our study revealed that nutritional compatibility changes the growth rate of Ephestia larvae and that these changes affect the development of B. hebetor. This result is also supported by other studies (Barbosa, 1988;Van Emden, 1995;Teder and Tammaru, 2002;Mauricio et al, 2007;Faal-Mohammad-Ali and Shishehbor, 2013;Amadou et al, 2019). Additionally, nutrients that positively affect the larval development time of B. hebetor also appear to be advantageous in terms of the pupal development time and total development time.…”

“…The different host diets used to rear E. kuehniella significantly affected the biological properties of the gregarious ectolarval parasitoid B. hebetor, including its development, survival and fecundity. There are many studies showing an important relationship between the host insect nutrient content (artificial food or host plant) and host preference/efficiency of the parasitoid in nature or under laboratory conditions (Campadelli and Barlotti, 1986;Fox et al, 1990;Harvey et al, 1995;Mallampalli et al, 1996;Teder andTammaru, 2002;Coley et al, 2006;Mauricio et al, 2007;Faal-Mohammad-Ali and Shishehbor, 2013;Amadou et al, 2019).…”

Timing of releases of the parasitoid Habrobracon hebetor and numbers needed in augmentative biological control against the millet head miner Heliocheilus albipunctella

“…The dose of 800 parasitoids was as effective as the 1600 parasitoids. Given the prohibitive cost for producing the parasitoid (Amadou et al 2019) one could recommend the use of 800 parasitoids. As suggested by Baoua et al (2018) the release of 900-1000 parasitoids can disperse over a distance of 3 km from the release point within 2-3 weeks.…”

Trichogramma yousufi sp. nov. Employed for the Management of Spodoptera exigua and Spodoptera litura in Indonesia

“…Drops of honey were placed on the inner surface of the jars daily as food for the Trichogramma adults. Steps used to rear the larvae, pupae, and adults of C. cephalonica followed Amadou et al (2019) with slight modifications.…”