The Jewel Wasp Ampulex compressa sample paper PDF

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We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for th...

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The Emerald Jewel Wasp, Ampulex compressa By Henry Chou Introduction Noted for its unique reproductive behavior, Ampulex compressa, known as the jewel wasp or emerald wasp, is a parasitoid wasp with a shiny metallic green-blue body and red thighs/femora on the second and third pairs of legs. First officially catalogued in 1942 on New Caledonia, the jewel wasp has been seen as early as 1742 in scientific literature (Williams, 1942), and has been introduced far beyond its original habitat to many other islands and locations as a form of biological pest control; currently, A. compressa has been introduced primarily in the Neotropical region, from its supposed original Oriental or Ethiopian region (Fox et al, 2006). The wasp hunts cockroaches of the Periplaneta family almost exclusively as its prey, inhabiting areas where the roaches are most prevalent in any given location, such as human habitation in Burma and strangling fig trees in Pusa, India (Williams, 1942). The jewel wasps’ adaptability to different geographical locations and well as its flexibility in finding its preferred prey explains the wide range it is found in and speaks well to its potential as a valued introduction to new places as a form of natural pest control of cockroaches. The jewel wasp differs from other parasitoid wasps in both its approach to prey and the effect its stings has on the unwilling host. In most parasitoid wasps, the female wasp stings her prey, injecting the venom into the hemolymph of the target that spreads via diffusion to the peripheral nervous system and induces muscular paralysis (Haspel and Libersat, 2003); the jewel wasp, when hunting its prey P. americana, stings the cockroach twice directly in its central nervous system. The first sting to the thorax degrades the motor function of the roach’s forward limbs while the second sting to the back of the head induces grooming behavior on the roach

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followed by docile, unresponsive behavior (Fox et al 2009). The resulting passive behavior allows the female A. compressa to snip off P. americana’s antennae for a drink of hemolymph, lead it to a prepared burrow, lay one to two eggs on the roach, and leave the roach alive as a source of fresh food for the wasp’s developing young. The young then proceed to eat the roach alive, cocoon inside the desiccated corpse of their host, and emerge as fully developed emerald wasps to start the cycle again. Morphology, Behavior, and Life Cycle Jewel wasp females average two to three centimeters in length, the males averaging roughly one centimeter smaller, with males from double birth events are even smaller (Fox et el 2009). Like similar wasp species, only A. compressa females hold stingers and actively hunt prey cockroaches, as many are born with mature eggs.

Williams (1942) describes A.

compressa’s attack on a roach that is further expanded by Keasar (et al 2005), who observed ten events during the sequence of attack as a jewel wasp stalks, strikes, and stores the prey roach, though it is noted that the events are not always performed in the same sequence or even preformed at all. The jewel wasp first locates her prey with antennae, then performs a quick leap onto the roach from the side, latching onto the roach’s pronotal plate and then immediately stinging the roach through its first thoracic ganglion (Haspel and Libersat, 2003); this sting introduces venom that acts as a post-synaptic blocker of central nicotinic synapses (Libersat, 2003), immediately resulting in flaccid paralysis of the roach’s forward legs, dropping the prey into a head-down posture as it can no longer support its own body. The roach is not passive during this stage, struggling and thrashing furiously to detach the wasp, even tucking its head down to deny the wasp easy stinger access (Williams, 1942); some roaches in laboratory conditions have shown proactive defensive mechanism before the wasp latches on, such as

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elevating its body, rotating around to try and kick the wasp with its hind legs, or even biting the wasp should A. compressa comes close enough (Fox et al, 2009). The defensive behavior, when successful, detaches the wasp from the roach, with some wasps dying afterwards due to injuries sustained in the struggle (Williams, 1942). In successful stings, the wasp immediately follows up with a second sting to the back of the roach’s head, directly into brain (Gal et al, 2005). Radioactive tagging of the venom by Gal et al (2005) shows that the stinger deposits its load into only the brain, with very little bleed through to other non-neural tissue in the head. The same study also showed that A. compressa actively searches with its stinger to locate the brain in the roach; when comparing sting duration between roaches with brains and roaches without brains, the sting was fifteen times longer when applied to roaches without brains compared to with brains, while the thoracic stings remained the same duration. Further studies on the stinger concluded that the stinger at the very least uses mechanical sensory cues to differentiate between neural and other tissues in the head (Gal et al, 2014) After the initial attack and the successful double stings, the emerald wasp releases the roach and backs off, sometimes probing the roach and pretending to drag it away. The paralysis of the roach wears off after two to three minutes (Haspel et al 2003), and the roach begins to exhibit prolonged grooming behavior continuously for thirty minutes, running its antennae through its mandibles and licking the front legs (Libersat, 2003; Weisel-Eichler et al, 1999). After the thirty minutes, the stung cockroach begins to display hypokinesia, eventually dropping into a state where little to no stimulus would provoke any action from the roach, a state that can last from two to three weeks (Libersat, 2003). While waiting for the roach to drop into a state of inactivity, the jewel wasp may leave in search of a nesting site and return once such site has been located. After the roach has stopped responding to probes from the wasp, A. compressa clips the

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roach antennae at a specific branch, dictated by the antennae geometry, and takes a sip of roach hemolymph; this tasting of hemolymph may be a way to test the viability of the roach host, as several prey roach has been abandoned at this point by female emerald wasps (Keasar et al 2005, Fox et al 2009) under laboratory conditions. After this tasting, A. compressa will find a nest, assuming it does not have one prepared or searched for it before cutting the roach’s antennae, and leads the insensate roach into. Once the host has been placed in the nest, the female wasp lays one egg along the roach’s mid-coxal plates (Williams, 1942), then seals the nest by scavenging and packing materials into the nest entrance. A pregnant female will oviposit every other day for two months under laboratory conditions (Keasar et al, 2005), constantly hunting down new hosts, new nesting sites and laying eggs. The egg hatches in three days and begins to live on the hemolymph of its living host, using mandibles to cut through the exoskeleton into the body of the host cockroach (Fox et al, 2006). Williams (1942) observed the larva will burrow into the host and eventually totally drain the roach of hemolymph, desiccating it, and then the larva will spin a cocoon and pupate and from which a fully grown A. compressa will emerge from, the whole process lasting from thirtyfour to one-hundred-and-fourth days; subsequent studies by Fox et al (2009) saw an average of fifty-nine days from egg to full adult. Survival of the egg is not guaranteed, as Williams’ (1942) subsequent studies observed; often times, the egg, larval, or pupae form will die for no apparent reason. In cases where two eggs are laid on one host, one or both eggs may die, but should both eggs survive and both reach adulthood, the resulting adults are always male, and smaller than the average (Fox et al 2009). Williams (1942) observed the wasps as very long lived, as males lived an average of two months and the study had one female reaching one-hundred-and-twenty-seven days under laboratory conditions; the subsequent study by Fox et al (2009) observed a lower

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average, but credited the lower life spans due to an increase in ambient temperature, which resulted in a higher level of activity and growth for the wasps. Research Venues Initial interest and research into A. compressa has been in its ability to hunt down and control the local cockroach population; while most studies employ P. americana as the preferred prey for the jewel wasp, it has been established that A. compressa hunts those in the Periplaneta family, not just specifically P. americana (Keasar et al 2005). In addition, Williams (1942) noted that the wasp have a large geographical spread from New Caledonia near Australia to India; Williams’ original presentation was to funded by the Hawaiian Sugar Planters’ Association to seek the possibility of introducing A. compressa as pest control. The hypokinesia induced by emerald wasp venom makes the target roach unable to react to stimuli that would ordinarily have an escape response (Fouad et al, 1995), such as wind stimuli or probing from the jewel wasp; this hypokinesia lasts from two to five weeks after the initial sting (Libersat, 2003) during which the roach is literally unable to escape despite being alive and active. Fox et al (2009) observed that pregnant female emerald wasps attack and sting far more hosts than is necessary for oviposition, rejecting several potential hosts after sampling the hemolymph from the non-reactive roach; the rejected hosts were implanted with eggs days later, but this was speculated due to lack of newly available hosts to attack in a laboratory setting. This research aspect of A. compressa may see additional studies complied in the future, but has already been put into practice well before its mention in 1742. Most parasitoid wasp venom works at the neuromuscular junction, either inhibiting the release of presynaptic excitatory neurotransmitter or blocking the post-synaptic glutamate receptors (Fouad et al, 1995); the resultant inhibitory effect on excitatory neurotransmitters

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displays itself as paralysis of the prey item. Fouad et al (1995) found that A. compressa venom differs in that it does not interact with prey neuromuscular junctions but instead raises the excitatory threshold for certain motor behavior; this is in line with later studies where researchers found that the jewel wasp stings directly into the roach’s central nervous system. Haspel and Libersat (2002) found unequivocally via radiolabeled venom that the first A. compressa sting hits directly into the first thoracic ganglion on prey roaches; the venom acts as an inhibitor on cholinergic synaptic transmissions, completely blocking both evoked and spontaneous activity of motor neurons; this results in the two front legs of the cockroach to become paralyzed and flaccid, dropping the roach into a head-down posture as it loses support from its front pair of legs. Libersat (2003) in a later study found that emerald wasp venom induces temporary flaccid paralysis by post-synaptic block of nicotinic synapse in the central nervous system; injecting a nicotinic antagonist into the thoracic ganglion reproduced near identical transient flaccid paralysis as a A. compressa sting. A later study by Moore et al (2005) analyzed the venom to be a cocktail of GABA, Taurine, and beta-Alanin that act as agonists on ligand-gated chloride channels to produce inhibitory pre and post-synaptic potentials. The first sting paralyzes the host and allows the emerald wasp to perform a longer, more critical sting to the head of the prey cockroach. The prolonged grooming behavior, lasting roughly thirty minutes, is followed by the onset of hypokinesia, during which the roach is unable to exhibit an escape response due to specific stimuli despite all other functions operating normally (Weisel-Eichler et al, 1999), such as grooming, righting behavior, and ability to fly in a wind tunnel (Libersat, 2003). Fouad et al (1995) concluded that the location of the second sting, into the subescophageal ganglion, was in part key to the induced grooming and hypokinesia, as that ganglion is known to be involved in initiation and maintenance of locomotory behavior. A

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later study found that the venom in the second sting contained either dopamine or a dopaminelike substance (Weisel-Eichler et al, 1999), and that application of the second venom to the thoracic ganglion did not induce the same behavior as a normal second sting to the head. The injection site was confirmed by Haspel et al (2003) via radiolabeled venom, showing that the venom appeared in the subesophageal ganglion and central brain sections; these two locations have been linked to motor action expression, sensory stimuli relay, and control of motor action expression. The timing of the resultant grooming is also consistent, lasting only long enough for the hypokinesia to set in and working to keep the stung host stationary (Weisel-Eichler et al, 1999). Gal et al (2005) found that stung roaches acted similar to crickets suffering from depleted dopamine and octopamine stores and that the firing rate of octopaminergic neurons fired five times slower compared to not-stung roaches. Previous studies concluded that while all other motor functions remained normal, escape behaviors from stimuli such as wind and biting are selectively inhibited; at the same time, Gal et al (2005) found that the venom from the sting also lowers the metabolism of the host roach, allowing it to survive longer, lose less water, and consume less oxygen. Further research into this area seem to be focused on either discovering how A. compressa is able to accurately target a specific section of the roach brain via what appears to be mechanical sensors alone, or on how to modify responses via the neural systems.

Literature Cited Fouad, K., W. Rathmayer, and F. Libersat. 1996. Neuromodulation of the escape behavior of the cockroach Periplaneta americana by the venom of the parasitic wasp Ampulex compressa. Journal of Comparative Physiology A 178.1: 91-100.

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Fox, Eduardo Goncalves Paterson, Sandor Christiano Buys, Jace-Nir Reis Dos Santos Mallet and Suzete Bressan Nascimento. 2006. On the morphology of the juvenile stages of Ampulex compressa (Fabricius 1781) (Hymenoptera, Ampulicidae). Zootaxa 1279: 43-51. Fox, Eduardo Goncalves Paterson, Suzete Bressan-Nascimento, and Roberto Eizemberg. 2009. Notes on the Biology and Behavior of Jewel Wasp Ampulex compressa (Frabricius, 1781) (Hymenoptera: Amplulicidae), in the Laboratory, Including First Record of Gregarious Reproduction. Entomological News 120.4: 430-437. Gal, Ram, Lior Ann Rosenber and Frederic Libersat, 2005. Parasitoid Wasp Uses a Venom Cocktail Injected Into the Brain to Manipulate the Behavior and Metabolism of Its Cockroach Prey. Archines of Insect Biochemisty and Physiology 60: 198-208. Gal, Ram, Maayan Kaiser, Gal Haspel, and Frederic Libersat. 2015 Sensory Arsenal on Stinger of the Parasitoid Jewel Wasp and Its Possible Role in Identifying Cockroach Brains. PLoS one 9.2: 1-8. Haspel, Gal, and Frederic Libersat. 2003. Wasp venom blocks central cholinergic synapses to induce transient paralysis in cockroach prey. Developmental Neurobiology 54.4: 628637. Haspel, Gal, Lior Ann Rosenberg, and Frederic Libersat. 2003. Direct injection of venom by a predatory wasp into cockroach brain. Developmental Neurobiology 56.3: 287-292. Keasar, Tamar, Noa Sheffer, Gustavo Glusman, and Frederic Libersat. 2006. Host‐Handling Behavior: An Innate Component of Foraging Behavior in the Parasitoid Wasp Ampulex compressa. Ethology 112.7: 699-706. Libersat, F. 2003. Wasp uses venom cocktail to manipulate the behavior of its cockroach prey. Journal of Comparative Physiology A 189: 479-508.

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Moore, Eugene L., Gal Haspel, Federic Libersat, and Michael E. Adams. 2005. Parasitoid Wasp Sting: A Cocktail of GABA, Taurine and β-Alanine Opens Chloride Channels for Central Synaptic Block and Transient Paralysis of a Cockroach Host. Journal of Neurobiology 66.8: 811-820. Weisel-Eichler, Aviva., Gal Haspel, and Frederic Libersat. 1999. Venom of a parasitoid wasp induces prolonged grooming in the cockroach. Journal of Experimental Biology 202.8: 957-964. Williams, Francis X. 1942. Ampulex Compressa (Fabr.), A Cockroach-Hunting Wasp Introduced from New Caledonia Into Hawaii. Proceedings of the Hawaiian Entomological Society 11.2: 221-233....