Venom of Pteromalus puparum (Hymenoptera: Pteromalidae) induced endocrine changes in the hemolymph of its host, Pieris rapae (Lepidoptera: Pieridae)

Abstract

Pteromalus puparum is a predominant endoparasitoid wasp of Pieris rapae. Its venom is the only active factor injected into host associated with oviposition. In this report, we explored whether the venom alone from this wasp affects the endocrine system of its host or not. We monitored the changes of hemolymph juvenile hormone (JH; only JH III detected), ecdysteroid, and juvenile hormone esterase activity (JHE) over 72 h in parasitized and venom-microinjected P. rapae pupae. Non-parasitized and PBS-microinjected P. rapae served as controls. Results showed that JH titers were significantly higher in parasitized and venom-microinjected pupae than that in control pupae during 24 to 72 h. After 12 h, JH titers were significantly promoted by parasitization and venom microinjection. JHE activities of non-parasitized and PBS-microinjected pupae were significantly higher than that of parasitized and venom-microinjected pupae, which was with a peak at 12 h (parasitized pupae) or 24 h (venom-microinjected pupae) during 6 to 48 and 12 to 36 h, respectively. The hemolymph titers of ecdysteroid in non-parasitized and PBS-microinjected pupae increased rapidly during 12 to 36 h with a peak at 36 h, and were higher than treatments before 48 h, while presenting a significant difference at 24 to 48 h between the treatments and controls. The results demonstrate that venom alone of this parasitoid wasp can disrupt its host's endocrine system.

Partial venom gland transcriptome of a Drosophila parasitoid wasp, Leptopilina heterotoma, reveals novel and shared bioactive profiles with stinging Hymenoptera

“…JH titer increases in the Lepidoptera Pieris rapae upon parasitism by the endoparasitic wasp Pteromalus puparum (Zhu, 2009). An impressive increase in JH titer of 100 times has been detected in the Lepidoptera Lacanobia oleracea upon parasitism, leading to the arrest of its maturation (Bell, 2010).…”

Conserved microRNA miR-8 blocks activation of the Toll pathway by upregulating Serpin 27 transcripts

“…[21][22][23] Several studies have shown that parasitic wasps have significant effects on host metabolism and development through interruption of host gene transcription, immune pathways, nutrition, and endocrine systems, and even regulate miRNA levels. 18,[24][25][26][27][28][29] Therefore, endoparasitoid wasps provide ideal biological tools to study the basic mechanisms underlying insect immune responses due to their profound impact on the host immune system.…”

A Venom Serpin Splicing Isoform of the Endoparasitoid Wasp Pteromalus puparum Suppresses Host Prophenoloxidase Cascade by Forming Complexes with Host Hemolymph Proteinases

“…Other virulence factors found in some parasitoids, such as PDVs, virus-like particles, or teratocytes, have not been recorded in P. puparum (29). As the major maternal virulence factor in P. puparum, P. puparum venom regulates host development and metabolism (30) and suppresses cellular (27,28,31) and humoral immunity of the host (32)(33)(34). Here we report a serpin gene with 16 predicted splicing isoforms in P. puparum and show that one of these isoforms is a venom protein, which inhibits host PPO activation by forming complexes with host hemolymph proteinases.…”