Tambay, A. | bioRxiv Science

bioRxiv2025

Parasitoids reduce growth rate in oak-feeding caterpillars

O_LIKoinobiont parasitoids have been shown to both reduce and increase the growth rate of caterpillars. However, no comprehensive study has been conducted on all caterpillar hosts of a given plant species. Moreover, most of the existing case studies are on large caterpillars attacking crop plants. This may not be representative of the effect of parasitoids on caterpillar growth on trees. C_LIO_LIWe measured the growth rate of parasitised and non-parasitised spring caterpillars collected from oak trees (Quercus robur & Q. petraea) in France and Poland. C_LIO_LIAcross six species of Lepidoptera, parasitoids reduced caterpillar growth rate on average. C_LIO_LIFurther studies should determine if the reduced growth rate is accompanied by lower consumption rates, so that the plant directly benefits from attracting parasitoids when they are attacked by caterpillars. C_LI

ecology↗

bioRxiv2025

Larger and polymorphic noctuid moths tend to show less inter-annual abundance variation in the canopy of a temperate forest

Inter-annual variation in insect abundance and seasonal phenology can be related to species traits such as body size, larval diet, overwintering stage, and colour variations. We sampled noctuid moths in the canopy of a forest in Western Poland using flight-interception traps during two vegetative seasons. We calculated inter-annual variation for 31 species, and date of peak abundance and length of the flight season for 18 species. We found that for the 23 species for which we had phylogenetic information, larger moths and those with adult colour variation showed less inter-annual abundance variation, which corroborates results of previous studies. We found no indication that phenological traits are associated with the tested species traits. However, species that can feed on the dominant broad-leaved tree in which the traps were placed (Quercus petraea) tended to have a later date of peak abundance than other species. To draw more robust conclusions, future research should encompass a longer time span and a broader range of species. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=143 SRC="FIGDIR/small/643003v2_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@1ed537eorg.highwire.dtl.DTLVardef@494f5org.highwire.dtl.DTLVardef@cf7559org.highwire.dtl.DTLVardef@21495a_HPS_FORMAT_FIGEXP M_FIG C_FIG

ecology↗