Life History of the Emerald Jewel Wasp Ampulex compressa

Ryan Arvidson,Michael E Adams,Victor Landa,Sarah Frankenberg

doi:10.3897/jhr.63.21762

Abstract

The Emerald Jewel Wasp Ampulexcompressa (Fabricius) is an endoparasitoid of the American cockroach Periplanetaamericana (Linnaeus). Its host subjugation strategy is unusual in that envenomation is directed into the host central nervous system, eliciting a long-term behavior modification termed hypokinesia, turning stung cockroaches into a lethargic and compliant, but not paralyzed, living food supply for wasp offspring. A.compressa manipulates hypokinesic cockroaches into a burrow, where it oviposits a single egg onto a mesothoracic leg, hatching three days later. Herein we describe the life history and developmental timing of A.compressa. Using head capsule measurements and observations of mandibular morphology, we found that the larvae develop through three instars, the first two ectoparasitoid, and the third exclusively endoparasitoid. The first two instars have mandibles sufficient for piercing and cutting the cuticle respectively, while the third instar has a larger and blunter mandibular structure. During ecdysis to the third instar, the larva enters the body cavity of the cockroach, consuming internal tissues selectively, including fat body and skeletal muscle, but sparing the gut and Malpighian tubules. The developmental timing to pupation is similar between males and females, but cocoon volume and mass, and pupation duration are sexually dimorphic. Further, we show that the difference in cocoon mass and volume can be used to predict sex before eclosion, which is valuable for studies in venom pharmacology, as only females produce venom.

Highlights

The Emerald Jewel Wasp Ampulex compressa (Hymenoptera, Ampulicidae) employs a unique strategy to subdue and exploit its host, the American cockroach Periplaneta americana (Blattodea, Blattidea)
We report that the third instar larva consumes organs of the host selectively, presumably to preserve its life until development is completed
Over the course of the study, of 1896 cockroaches introduced to female A. compressa, 1656 were parasitized, and 1033 eggs progressed to pupation, of which 962 emerged as adult wasps

Summary

Introduction

The Emerald Jewel Wasp Ampulex compressa (Hymenoptera, Ampulicidae) employs a unique strategy to subdue and exploit its host, the American cockroach Periplaneta americana (Blattodea, Blattidea). The wasp leads the stung cockroach into its burrow by grasping the truncated antennae (Veltman and Wilhelm 1991) and proceeds to lay a single egg on a mesothoracic leg of the host, entombs it by sealing the burrow entrance with miscellaneous debris (Williams 1942). This provides the young wasp larva with a fresh food supply during its development. More recently it has been shown that A. compressa larvae secrete antimicrobial compounds into the cockroach as it is being consumed to sanitize and perhaps preserve the host (Herzner et al 2013; Weiss et al 2014)

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Conclusion