Background: Spodoptera frugiperda (JE Smith), or fall armyworm, is one of major migratory agricultural pests with a wide range of hosts. The effect of different hosts (maize and kidney bean) on the growth and reproduction of S. frugiperda were investigated using the age-stage, two-sex life table method. Results: The results showed that S. frugiperda could complete its entire life cycle on both hosts, albeit with significantly different development and reproduction. The durations of larval and pupal development were significantly prolonged whereas adult lifespan was shortened on kidney bean compared to maize. The differences of survival rates at each instar, prepupal and pupal stages between the two hosts were not statistically significant. The total pre-oviposition period was longer on kidney bean than that on maize (42.05 vs 39.04 days), but there was no difference in the oviposition rate (64.77 on kidney bean vs 62.48 on maize). The differences of net reproductive rate, intrinsic rate of increase and finite rate of increase were nonsignificant, while the mean generation time on kidney bean (42.05 days) was significantly longer than that on maize (40.92 days). Conclusions: The results indicate that S. frugiperda can grow and reproduce normally on both hosts, although maize is more suitable. Nonetheless, the data show that this pest is harmful when the population density is high or when the preferred host is scarce. Graphic

A new species of entomopathogenic fungi, Lecanicilliumcauligalbarum , was discovered from a survey of invertebrate-associated fungi in the Yao Ren National Forest Mountain Park in China. The synnemata of this species emerged from the corpse of a stemborer (Lepidoptera), which was hidden amongst pieces of wood on the forest floor. It differs from morphologically similar Lecanicillium species mainly in its short conidiogenous cells and ellipsoid to ovoid and aseptate conidia. Phylogenetic analysis of a combined data set comprising ITS, SSU , LSU , TEF , RPB1 and RPB2 sequence data supported the inclusion of L.cauligalbarum in the Lecanicillium genus and its recognition as a distinct species.

The western flower thrips, Frankliniella occidentalis Pergande, is an invasive pest that damages agricultural and horticultural crops. The induction of plant defenses and RNA interference (RNAi) technology are potent pest control strategies. This study investigated whether the anti-adaptive ability of F. occidentalis to jasmonic acid (JA)- and methyl jasmonate (MeJA)-induced defenses in kidney bean plants was attenuated after glutathione S-transferase (GST) gene knockdown. The expression of four GSTs in thrips fed JA- and MeJA-induced leaves was analyzed, and FoGSTd1 and FoGSTs1 were upregulated. Exogenous JA- and MeJA-induced defenses led to increases in defensive secondary metabolites (tannins, alkaloids, total phenols, flavonoids, and lignin) in leaves. Metabolome analysis indicated that the JA-induced treatment of leaves led to significant upregulation of defensive metabolites. The activity of GSTs increased in second-instar thrips larvae fed JA- and MeJA-induced leaves. Co-silencing with RNAi simultaneously knocked down FoGSTd1 and FoGSTs1 transcripts and GST activity, and the area damaged by second-instar larvae feeding on JA- and MeJA-induced leaves decreased by 62.22% and 55.24%, respectively. The pupation rate of second-instar larvae also decreased by 39.68% and 39.89%, respectively. Thus, RNAi downregulation of FoGSTd1 and FoGSTs1 reduced the anti-adaptive ability of F. occidentalis to JA- or MeJA-induced defenses in kidney bean plants.

Exogenous calcium (Ca) has been used to induce host plant resistance in response to abiotic and biotic stresses, including from thrips attack. The aim of this study was to determine whether exogenously applied Ca affects the performance of Frankliniella occidentalis. We assessed the development time, total longevity, reproduction, and population parameters of F. occidentalis, and its preference choice on Ca-treated or untreated control kidney bean plants under laboratory conditions. The results showed that F. occidentalis fed on Ca-treated leaves had a longer developmental time but lower longevity (female and male) and fecundity than F. occidentalis fed on control leaves. Population parameters, including the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R₀), were all found higher in control leaves than in Ca-treated leaves, and the mean generation time (T) was shorter. In preference choices, the number of thrips on control plants was higher than the number of thrips on Ca-treated kidney bean plants. Overall, our results indicated that exogenous Ca pretreatment on kidney bean plants affected the life history and preference choice of F. occidentalis, suggesting Ca might be used as a promising elicitor of inducible plant defense against thrips.