scholarly journals Host Discrimination by Unmated Individuals of the Gregarious Parasitoid Wasp, Cotesia(=Apanteles)glomerata(Hymenoptera:Braconidae)

1992 ◽  
Vol 27 (2) ◽  
pp. 306-309 ◽  
Author(s):  
Jun TAGAWA
2011 ◽  
Vol 74 (12) ◽  
pp. 1145-1153 ◽  
Author(s):  
MarlÈne Goubault ◽  
Anne Marie Cortesero ◽  
Chrystelle Paty ◽  
Julie Fourrier ◽  
Sonia Dourlot ◽  
...  

1999 ◽  
Vol 47 (1) ◽  
pp. 19 ◽  
Author(s):  
S. A. Field ◽  
M. A. Keller

The ability of host discrimination allows insect parasitoids to avoid superparasitism (oviposition in a previously attacked host). However, superparasitism can sometimes be adaptive, so attempts to identify host discrimination must be made under appropriate ecological conditions. We tested the ability of the parasitoid wasp Trissolcus basalis to discriminate between self- and conspecific-parasitised hosts (conspecific discrimination) under ecologically realistic conditions, in which conspecific discrimination should be adaptive. Data were analysed using a Monte Carlo simulation model that permitted testing of several different ways in which conspecific discrimination could be achieved. We obtained the novel result that females avoided self-superparasitism on a patch consisting of a mixture of self- and conspecific-parasitised hosts, but that this avoidance was not due to true conspecific discrimination. Instead, it was due to short- term discrimination between newly and previously parasitised hosts. Two likely mechanisms for such discrimination are proposed: a short-lived host-derived volatile; and the presence of two or more chemical components in the marking pheromone.


Ethology ◽  
1999 ◽  
Vol 105 (1) ◽  
pp. 57-72 ◽  
Author(s):  
Ian C. W. Hardy ◽  
Jesper B. Pedersen ◽  
Mikael K. Sejr ◽  
Ulla H. Linderoth

2000 ◽  
Vol 78 (8) ◽  
pp. 1494-1499 ◽  
Author(s):  
Thomas S Hoffmeister

Host discrimination by the parasitoid wasp Halticoptera rosae was found to be based upon an external marking pheromone applied to the surface of rose hips in which the host, a fly (Rhagoletis basiola), had deposited its eggs in the fruit pulp. Female wasps marked the sites by repeatedly dabbing the tip of their ovipositor on the fruit surface and discriminated against conspecific marks through antennal contact with marked sites, resulting in cutting off the behavioural sequence leading to oviposition. The same behaviour was observed when wasps were offered fruits on which flies' oviposition sites were artificially marked with methanol extracts of female reproductive tracts, which suggests that the mark is chemical in nature and that the substance is associated with female oviducts and Dufour's or poison glands. Although the host flies respond to fruits that had been previously searched by wasps, no effect on wasp searching behaviour was found on fruits previously searched by conspecifics but without parasitization of the host. The adaptive significance of marking and discrimination decisions made by the parasitoid is discussed.


2007 ◽  
Vol 274 (1625) ◽  
pp. 2571-2577 ◽  
Author(s):  
Marlène Goubault ◽  
Alexandra F.S Mack ◽  
Ian C.W Hardy

Understanding the size of clutches produced by only one parent may require a game-theoretic approach: clutch size may affect offspring fitness in terms of future competitive ability. If larger clutches generate smaller offspring and larger adults are more successful in acquiring and retaining resources, clutch size optima should be reduced when the probability of future competitive encounters is higher. We test this using Goniozus nephantidis , a gregarious parasitoid wasp in which the assumption of size-dependent resource acquisition is met via female–female contests for hosts. As predicted, smaller clutches are produced by mothers experiencing competition, due to fewer eggs being matured and to a reduced proportion of matured eggs being laid. As assumed, smaller clutches generate fewer but larger offspring. We believe this is the first direct evidence for pre-ovipositional and game-theoretic clutch size adjustment in response to an intergenerational fitness effect when clutches are produced by a single individual.


2017 ◽  
Vol 18 ◽  
pp. 17 ◽  
Author(s):  
F. Karamaouna ◽  
M.J.W. Copland

Leptomastix epona (Walker) and Pseudaphycus flavidulus (Brèthes) (Hymenoptera: Encyrtidae) are endoparasitoids of the mealybug Pseudococus viburni (Signoret) (Hemiptera: Pseudococcidae). Leptomastix epona is a solitary parasitoid originating from Europe and P. flavidulus is a gregarious parasitoid from South America. Conspecific and heterospecific host discrimination was examined between unparasitised female adult mealybugs and others already parasitized, at different time intervals between the primary and the following oviposition. Female wasps of L. epona discriminate between unparasitized hosts and hosts parasitized 0-96 hours previously by a conspecific selecting more often the first over the latter for oviposition. Females of P. flavidulus discriminate between unparasitized hosts and hosts parasitized prior to 0-72 hours by a conspecific. Conspecific superparasitism also occurs in both parasitoid species. The secondary sex ratio of L. epona and the clutch size of P. flavidulus are not affected by superparasitism whereas the secondary sex ratio of P. flavidulus in superparasitized hosts is more male biased than in single parasitized hosts. The solitary parasitoid L. epona does not discriminate between unparasitized hosts and hosts parasitized by P. flavidulus 0-3 or 24 hours previously. Nevertheless the gregarious parasitoid P. flavidulus discriminates between unparasitized hosts and hosts parasitized by L. epona 0-3 hours earlier, but it oviposits without discrimination in hosts heterospecifically parasitized 24 hours beforehand. When multiparasitism occurs at 0-3 hours after the first oviposition, L. epona is a superior competitor regardless of which species oviposits first. However, when the time interval between the two ovipositions is 24 hours, the probability of the offspring of P. flavidulus winning the competition with L. epona increases when either species oviposits first. The potential effect of multiparasitism on parasitoid coexistence is discussed in relation to prospects for multiplespecies introductions or augmentative releases for the biological control of the mealybug.


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