Depths and type of substrate influence the ability of Nasonia vitripennis Walker (Hymenoptera: Pteromalidae) to encounter host

in Journal of Insect Science [=JIS] (in press)

The foraging behaviour of a parasitoid insect species includes the host’s habitat and subsequent location of the host. Habitats-substrate, substrate moisture and light levels can affect the host location ... [more ▼]

The foraging behaviour of a parasitoid insect species includes the host’s habitat and subsequent location of the host. Habitats-substrate, substrate moisture and light levels can affect the host location made by different species of parasitoids. However, the depth at which parasitoids concentrate their search effort is an another important ecological characteristic and play an important role on the host location. Here, we have investigated the ability of a pupal parasitoid, Nasonia vitripennis Walker, to penetrate and kill fly pupae located at different depth of the substrate. Three different types of substrate were tested: loam soil, compost and vermiculite substrate. In both loam soil and compost, all of the parasitism activity was restricted to pupae placed directly on the surface. Parasitism activity in vermiculite showed that the average number of pupae parasitized was decreased with depth. These results suggest that fly pupae situated deeper in the substrate are less subjected to parasitism by N. vitripennis. [less ▲]

Carrion beetles visiting pig carcasses during early spring in urban, forest and agricultural biotopes of Western Europe

in Journal of Insect Science [=JIS] (2011), 11

Carrion beetles are important in terrestrial ecosystems, consuming dead mammals and promoting the recycling of organic matter into ecosystems. Most forensic studies are focused on succession of Diptera ... [more ▼]

Carrion beetles are important in terrestrial ecosystems, consuming dead mammals and promoting the recycling of organic matter into ecosystems. Most forensic studies are focused on succession of Diptera while neglecting Coleoptera. So far, little information is available on carrion beetles postmortem colonization and decomposition process in temperate biogeoclimatic countries. These beetles are however part of the entomofaunal colonization of a dead body. Forensic entomologists need databases concerning the distribution, ecology and phenology of necrophagous insects, including silphids. Forensic entomology uses pig carcasses to surrogate human decomposition and to investigate entomofaunal succession. However, few studies have been conducted in Europe on large carcasses. The work reported here monitored the presence of the carrion beetles (Coleoptera: Silphidae) on decaying pig carcasses in three selected biotopes (forest, crop field, urban site) at the beginning of spring. Seven species of Silphidae were recorded: Nicrophorus humator (Gleditsch), Nicrophorus vespillo (L.), Nicrophorus vespilloides (Herbst), Necrodes littoralis L., Oiceoptoma thoracica L., Thanatophilus sinuatus (Fabricius), Thanatophilus rugosus (L.). All of these species were caught in the forest biotope, and all but O. thoracica were caught in the agricultural biotope. No silphids were caught in the urban site [less ▲]

Reproductive Strategies Of Tribolium Flour Beetles

in Journal of Insect Science [=JIS] (2005), 5(33),

Although, beetles of the genus Tribolium first evolved as saprophylic insects, they have adapted to the stored products environment for several thousand years. In this study reproductive strategies are ... [more ▼]

Although, beetles of the genus Tribolium first evolved as saprophylic insects, they have adapted to the stored products environment for several thousand years. In this study reproductive strategies are described for eight species of Tribolium that are known to occur in this environment. Experiments were conducted under the same conditions for every species, and several life history traits, including egg mass, adult mass, developmental time and fecundity were examined and compared among these species. Common reproductive strategies were not found among the different species and univariate analysis highlighted strong differences between the species for most of the traits investigated. Some species showed reproductive traits that are likely to give a fitness advantage in the environment of stored products. Multivariate statistical analysis allowed the detection of different sub-groups with respect to their reproductive strategy. Adult mass and egg-to-adult developmental time discriminated between groups. Intraspecific allometric relationships were further investigated but only a few correlations appeared to be significant. [less ▲]