Host‐size‐dependent feeding behaviour and progeny sex ratio of Anisopteromalus calandrae (Hym., Pteromalidae)

Abstract

Host-size related feeding and oviposition behaviour, and allocation of progeny sex by Anisopteromalus calandrae (Howard) were tested on Sitophilus oryzae L. The parasitoid showed a host-size-dependent partition of feeding and oviposition behaviour, preferring small hosts for feeding, but large hosts for oviposition. Neither the mutual interference nor the host density showed any eect on the behaviour of the parasitoid. Allocation of progeny sex by the female parasitoid appeared to be based more likely on absolute than on relative host size encountered. A model for the progeny sex ratio was constructed based on: (1) ovipositional preference of the parasitoid on large hosts;(2) feeding preferentially on small hosts; and (3) host-size-related regulation of progeny sex ratio. The progeny sex ratio of the parasitoid predicted by the model was in close agreement with the observed value.

Tetrastichus howardi(Hymenoptera: Eulophidae) in Different Densities and Periods of Parasitism onDiatraea saccharalis(Lepidoptera: Crambidae) Caterpillars

“…The parasitoid density and length of exposure to the host may affect the successful of parasitism (Sagarra et al 2000, da Silva-Torres et al 2010, progeny production (Chong and Oetting 2006), offspring sex ratio (Choi et al 2001), life cycle length (egg to adult; Barbosa et al 2008Barbosa et al , 2010, and adult longevity in T. howardi. Thus, adequate parasitoid densities per host and exposure times can enhance the quality and number of individuals produced.…”

The density of females of Palmistichus elaeisis Delvare and LaSalle (Hymenoptera: Eulophidae) affects their reproductive performance on pupae of Bombyx mori L. (Lepidoptera: Bombycidae)

“…The density of parasitoids per host affects the parasitoid offspring (Thomazini andBerti Filho 2000, Matos Neto et al 2004), the sex ratio (Choi et al 2001), the parasitism capacity (Sampaio et al 2001), the duration of the life cycle, the size of the body, and the longevity of the imagines (Silva-Torres and Matthews 2003). To minimize the cost and labor and to maximize the production of parasitoids in mass rearing programs, it is, therefore, necessary to study the density of the parasitoids in relation to the host (Sagarra et al 2000a).…”

Egg-lying behavior of Anisopteromalus calandrae (Howard), an Ectoparasitoid of Lasioderma serricorne (Fabricius)

“…The highest number of eggs was laid on the larvae with tunnel diameter of 1.6 mm and the lowest was seen in pupae and small larvae. Choi et al (2001) also reported that A. calandrae preferred to lay eggs on relatively large S. oryzae larvae.…”

“…Visarathanonth et al (2010) investigated the egg laying duration of A. calandrae parasitizing S. zeamais fed with milled rice. Several authors determined the ovipositional preference of the parasitoid on different sizes of hosts (Choi et al, 2001;Smith, 1993).…”