The effect of a ‘cover crop–vegetable cash crop’ intercropping system on arthropod dynamics and biodiversity, was investigated in four different European countries (Italy, Denmark, Germany, and Slovenia), by means of two-seasonal experiments. The soil arthropod fauna was used to compare the ecosystem services of living mulched systems with sole crop ones. The living mulch (LM) technique did not affect the infestation of cabbage caterpillar Pieris spp., showing no detrimental effect of this technique on this key pest of cabbage. In Denmark, aphid populations were higher in the sole crop system than in the LM system. In Italy, a very high level of larval parasitization was detected and in 1 year the percentage of parasitization was higher in LM (88%) than in sole crop (63%). Overall, the LM positively affected the activity density of Carabid beetles, also increasing diversity and evenness of species (Italy and Slovenia) or activity density of some taxa (Slovenia and Denmark). Our results indicate a general positive influence of LM techniques on arthropods in plant/soil systems, as shown by a high level of soil biodiversity and a general lack of negative effects on the density of canopy pests.

The homopteran bug Cofanaspectra (Distant), also known as the white leafhopper, is abundant in rice-growing areas of India (West Bengal, Northeast and southern states) and considered as a minor pest of paddy. The proportion of Cofanaspectra and the endoparasitoid Halictophagus australensis Perkins varied between months and demonstrated peak abundance during March to May and October to December, which corresponded with the rice cropping periods boro (winter crop) and aman (monsoon crop), respectively. There was a negative correlation between the influence of environmental factors (air temperature, rainfall and relative humidity) and the abundance of normal and parasitized C. spectra. The proportion of parasitization by H. australensis varied with the relative abundance of C. spectra. The effect of stylopization on C.spectra by the Strepsiptera may be one of the factors attributable to the suppression of the population levels of the paddy pest.

The limpet Lepetodrilus fucensis McLean is very abundant at hydrothermal vents on the Juan de Fuca and Explorer Ridges in the northeast Pacific Ocean. This limpet is parasitized by an undescribed chitonophilid copepod throughout the limpet's range. The parasite copepodite enters the mantle cavity and attaches to the afferent branchial vein. The initial invasive stage is a vermiform endosome within the vein that develops an extensive rootlet system causing an enlargement of the afferent branchial vein. Subsequently, an ectosomal female body grows outside the vein to sizes up to 2 mm in width. Once a dwarf male attaches, egg clusters form and nauplii are released. In over 3000 limpets examined from 30 populations, prevalence averaged about 5% with localized infections in female limpets over 25%. After the establishment of limpet populations at new vents, copepod prevalence increased over the succeeding months to 3 years. Host effects were marked and included castration of both sexes and deterioration in gill condition which affected both food acquisition and the gill symbiont. There was a significantly greater parasite prevalence in larger females which likely modifies the reproductive and competitive success of local host populations.

Diamondback moth (DBM), Plutella xylostella, is known for causing damage to Brassica crops and developing resistance to chemical and biological pesticides; it has become one of the most difficult pests to manage in many regions around the world. The only way to reduce reliance on pesticides is to maximize the role of natural control agents for integrated pest management programs and be able to incorporate the mortality from control agents into pest control decision-making. More than 90 hymenopterous parasitoids are associated with DBM worldwide; among them, Diadegma semiclausum, is a major endoparasitoid of P. xylostella. To optimize parasitism of pests in pest control decision-making, it is necessary to develop rapid and simple methods for distinguishing parasitized from non-parasitized larvae in the field. Here we report on a number of diagnostic tools to identify parasitized larvae. One is based on differential melanization reactions in hemolymph due to immune suppression in parasitized larvae. The lack of coagulation reactions in hemolymph provides a simple initial test, where squashing a non-parasitized larva onto nitrocellulose membrane traps chlorophyll-containing gut content on the membrane leaving a green dot of clotted gut material. However, in immune-suppressed parasitized larvae, the gut content was washed away in absence of coagulation reactions and the membrane lacks a green dot. This tool alone or combined with others, allows quick detection of parasitized caterpillars in the field. We further showed that the antibody MAb 9A5 can be used to detect D. semiclausum parasitized larvae of DBM in Western blots.

Larva of fifth instar silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), parasitized by uji-fly, Exorista sorbillans (Weidemann) (Diptera: Tachinidae), consumed less food and egested less faecal matter than unparasitized one in the instar period. Uji-fly infested worm showed increased digestibility in the last 2 days while the unparasitized larva ingested excessive amounts of food than needed during these days. A reduction of 18.1% in the mean weight of parasitized worm at pupation was recorded. Further, parasitization resulted in 50.7% reduction in the mean cocoon weight and 51.12% reduction in the mean shell weight. Parasitized worms started spinning a day earlier than the healthy ones and the cocoon spun by the former was abnormal.

Infection of Diacrisia obliqua larva by Apanteles flavipes resulted in a significant decrease in the lipid and protein content of the host. In about 8 days the parasitoid larvae developing in the host not only utilized these components of the host but also depressed food consumption of the host. Consequently, at the time of emergence of the parasitoid larvae, the host tissue consisted of simply carcass. The parasitoid larvae utilized lipids at the rate of 0.9–10.0 μg/mg/day.