Search results for "PARASITOID"

Behavioral responses of the parasitoidMelittobia digitatato volatiles emitted by its natural and laboratory hosts

2010

Responses of macropterous females of the ectoparasitoid Melittobia digitata Dahms (Hymenoptera: Eulophidae) to direct and indirect cues emitted by its natural hosts as well as laboratory hosts were investigated using a Y-tube olfactometer. To locate the nest of mud dauber wasps, Trypoxylon politum Say (Hymenoptera: Crabronidae), and one of their inquilines, Anthrax spec., parasitoids exploit volatiles from the freshly built nest mud and the empty cocoon constructed by the wasps, as well as their meconium. However, the parasitoids did not respond to odors emitted by older nest mud or by the host stages that are attacked (T. politum prepupae and Anthrax spec. larvae). Melittobia digitata was …

Attraction of egg-killing parasitoids toward induced plant volatiles in a multi-herbivore context

2015

In response to insect herbivory, plants emit volatile organic compounds which may act as indirect plant defenses by attracting natural enemies of the attacking herbivore. In nature, plants are often attacked by multiple herbivores, but the majority of studies which have investigated indirect plant defenses to date have focused on the recruitment of different parasitoid species in a single-herbivore context. Here, we report our investigation on the attraction of egg parasitoids of lepidopteran hosts (Trichogramma brassicae and T. evanescens) toward plant volatiles induced by different insect herbivores in olfactometer bioassays. We used a system consisting of a native crucifer, Brassica nigr…

PARASITES AND SEXUAL REPRODUCTION IN PSYCHID MOTHS

2004

Persistence of sexual reproduction among coexisting asexual competitors has been a major paradox in evolutionary biology. The number of empirical studies is still very limited, as few systems with coexisting sexual and strictly asexual lineages have been found. We studied the ecological mechanisms behind the simultaneous coexistence of a sexually and an asexually reproducing closely related species of psychid moth in Central Finland between 1999 and 2001. The two species compete for the same resources and are often infected by the same hymenopteran parasitoids. They are extremely morphologically and behaviorally similar and can be separated only by their reproductive strategy (sexual vs. as…

Bactrocera oleae. Fattori naturali di controllo

2019

Bactrocera oleae. Natural control factors. Natural control factors (parasitoids and climatic factors) influencing the olive fruit fly, Bactrocera oleae, are analysed comparing two different areas of cultivated and wild olives, Sicily and the Western Cape of South Africa. Bactrocera oleae has a similar level of parasitization in both areas, much higher in wild olives than in cultivated ones. Climatic conditions are much more important than climatic factors, influencing the growth of olive fruit fly populations, producing a higher level of infestation in more humid and rainy productive seasons.

Behavioral and Chemical Investigations of Contact Kairomones Released by the Mud Dauber Wasp Trypoxylon politum, a Host of the Parasitoid Melittobia …

2011

Contact kairomones from the host mud dauber wasp Trypoxylon politum Say (Hymenoptera: Crabronidae) that mediate behavioral responses of its ectoparasitoid Melittobia digitata Dahms (Hymenoptera: Eulophidae) were investigated. Chemical residues from host by-products, the cocoon, and the meconium, induced arrestment behavior of macropterous female parasitoids, while those from the host stage attacked, i.e., the prepupa, did not. Melittobia digitata response to polar and apolar extracts of host by-products indicated kairomone(s) solubility mainly in hexane. GC and GC/MS analysis of cocoon and meconium apolar extracts revealed a mixture of linear carboxylic acids from C(6) to C(18), and both ex…

Effect of dual biotic stress on plant volatile synomones used by an egg parasitoid

Plants respond to arthropod herbivory with the induction of volatiles called herbivore-induced plant volatiles (HIPVs). These volatiles appear to be important sources of information that attract parasitoids. Parasitic wasps foraging decisions are often affected by community characteristics such as community diversity and complexity. As part of a complex habitat, the presence of unsuitable hosts (non-host) may affect foraging behavior of parasitoids. In this chapter, we outline the importance of the presence of unsuitable herbivores on the behavioral responses of parasitoids. First we review the foraging behavior of parasitoid in tritrophic interaction. Then we focus on foraging behavior by …

Learning can be detrimental for a parasitic wasp

2021

Animals have evolved the capacity to learn, and the conventional view is that learning allows individuals to improve foraging decisions. The parasitoid Telenomus podisi has been shown to parasitize eggs of the exotic stink bug Halyomorpha halys at the same rate as eggs of its coevolved host, Podisus maculiventris, but the parasitoid cannot complete its development in the exotic species. We hypothesized that T. podisi learns to exploit cues from this non-coevolved species, thereby increasing unsuccessful parasitism rates. We conducted bioassays to compare the responses of naïve vs. experienced parasitoids on chemical footprints left by one of the two host species. Both naïve and experienced …

Biology and behavior of Metaphycus angustifrons Compere (Hymenoptera: Encyrtidae), a newly discovered parasitoid of soft scale insects (Hemiptera: Co…

2011

Abstract Metaphycus angustifrons Compere has recently been found to be the most abundant parasitoid of brown soft scale, Coccus hesperidum L., in southern California. In laboratory experiments we examined several biological parameters of this species. M. angustifrons both oviposits and host feeds in brown soft scale and is a facultatively gregarious endoparasitoid of this soft scale insect. In contrast with other Metaphycus spp., M. angustifrons is a koinobiont parasitoid, allowing its host to grow up to 40% beyond its size at parasitism. Despite its high abundance on brown soft scale in the field, in the laboratory, high rates of parasitoid egg encapsulation are observed; about half of par…

Nectar-Inhabiting Bacteria Affect Olfactory Responses of an Insect Parasitoid by Altering Nectar Odors

2022

AbstractFloral nectar is ubiquitously colonized by a variety of microorganisms among which yeasts and bacteria are the most common. Microorganisms inhabiting floral nectar can alter several nectar traits, including nectar odor by producing microbial volatile organic compounds (mVOCs). Evidence showing that mVOCs can affect the foraging behavior of insect pollinators is increasing in the literature, whereas the role of mVOCs in altering the foraging behavior of third-trophic level organisms such as insect parasitoids is largely overlooked. Parasitoids are frequent visitors of flowers and are well known to feed on nectar. In this study, we isolated bacteria inhabiting floral nectar of buckwhe…

New Records of Sceliotrachelinae (Hymenoptera: Platygastridae) in Iran

2020

The hymenopteran family Platygastridae is a large group of parasitic wasps. A survey was carried out on the subfamily Sceliotrachelinae (Hym.: Platygastridae) in East Azerbaijan and Fars provinces of Iran. The genus Fidobia Ashmead and three species, Allotropa conventus Maneval, Fidiobia hofferi Kozlov and Isolia mongolica (Kozlov) are newly recorded from Iran. Illustrations of the morphological characteristics and their geographical distribution are presented.