Biological control has been the most commonly researched control tactic within fruit fly management programs. For the first time, a review is carried out covering parasitoids and predators of fruit ...flies (Tephritidae) from the Americas and Hawaii, presenting the main biological control programs in this region. In this work, 31 species of fruit flies of economic importance are considered in the genera Anastrepha (11), Rhagoletis (14), Bactrocera (4), Ceratitis (1), and Zeugodacus (1). In this study, a total of 79 parasitoid species of fruit flies of economic importance are listed and, from these, 50 are native and 29 are introduced. A total of 56 species of fruit fly predators occur in the Americas and Hawaii.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host) represent poor ...indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively) could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach) using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A 4-yr study was done to analyze seasonal patterns underlying host plant–fruit fly–parasitoid interactions in a secondary forest in the Argentinean Yunga and its importance for the implementation of ...conservation and augmentative biological control. Larval–pupal hymenopteran parasitoids associated with all host plants and fruit fly species were identified and the seasonal occurrence of fruit, infestation levels, parasitism percentage, and relative parasitoid abundance were determined. Three fruit fly species in two genera were found in association with surveyed plants, two of which (Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann)) are of major economic importance. Infestation levels were strongly influenced by environmental factors and peak fruit availability. Five fruit fly parasitoid species were recovered from fly pupae, four braconid species, and one figitid. Time windows for fruit fly population growth were pinpointed. Based on results, the present analysis proposes an effective fruit fly biological control strategy tailored for the northwestern Argentinean citrus-producing area.
The invasive pest
Drosophila suzukii
(Matsumura) (Diptera: Drosophilidae) was recently recorded in Brazil and constitutes a threat to fruit growing, mainly for small, soft fruits. Recent advances in ...research on ways of controlling
D. suzukii
involve the use of entomopathogenic nematodes (EPNs). In this context, the objective of this study was to evaluate the pathogenicity and virulence of four isolates in different concentrations against
D. suzukii
pupae. The EPN isolates used in trials were
Steinernema brazilense
IBCBn 06,
S. carpocapsae
IBCBn 02,
Heterorhabditis bacteriophora
HB, and
H. amazonensis
IBCBn 24. Both
H. amazonensis
IBCBn 24 and
H. bacteriophora
HB were effective in controlling
D. suzukii
as they caused a mortality rate of 86.25% and 80.0%, and virulence of 549.75 IJs/pupae and 787.75 IJs/pupae in the concentrations of 1800 IJs/ml and 5400 IJs/ml, respectively. The lowest lethal concentrations (LC
50
) of juveniles were found in host pupae with 771.63 IJs/ml of
H. bacteriophora
HB and 1115.49 IJs/ml of
H. amazonensis
IBCBn 24. Results showed that both EPNs,
H. amazonensis
IBCBn 24 and
H. bacteriophora
HB, could be promising eco-friendly biological agents to control
D. suzukii
.
Doses of 40, 80, 120, and 160 Gy were applied to 5-, 6-, 7-, and 8-day-old Anastrepha obliqua larvae, which were exposed to the Neotropical-native braconids Doryctobracon crawfordi and Utetes ...anastrephae and the Asian braconid Diachasmimorpha longicaudata. These tests were performed to know the effect of the increase in host radiation on the emergence of the aforementioned parasitoids and the related consequences of oviposition on the host. The study was based on the fact that higher radiation doses may cause a decrease in the host immune activity. There was a direct relationship between the increase in radiation dose and the parasitoid emergence. Both, the weight and the mortality of the host larvae were not affected by radiation. Although the larval weight of the larvae was lower and the mortality was higher in the younger larvae. Both, the number of scars and immature stages per host puparium originated from the younger larvae were lower than those from older larvae. Only U. anastrephae superparasitized more at lower radiation. Superparasitism by D. longicaudata was more frequent at 160 Gy. Qualitative measurements of melanin in the larvae parasitized showed that the levels were lower with increasing radiation. As radiation doses increased, the antagonistic response of the A. obliqua larva was reduced. Host larvae aged 5- and 6-day-old irradiated at 120–160 Gy significantly improve parasitoid emergence. This evidence is relevant for the mass production of the three tested parasitoid species.
The spotted-wing drosophila,
(Matsumura) (Diptera: Drosophilidae), is a pest that reduces the productivity of small fruits. Entomopathogenic nematodes (EPNs) and chemical insecticides can suppress ...this pest, but the compatibility of the two approaches together requires further examination. This laboratory study evaluated the compatibility of
IBCBn 06,
IBCBn 02,
IBCBn 24, and
HB with ten chemical insecticides registered for managing
pupae. In the first study, most insecticides at the recommended rate did not reduce the viability (% of living infective juveniles (IJs)) of
and both
species. The viability of
was lowered by exposure to spinetoram, malathion, abamectin, azadirachtin, deltamethrin, lambda-cyhalothrin, malathion, and spinetoram after 48 h. During infectivity bioassays, phosmet was compatible with all the EPNs, causing minimal changes in infectivity (% pupal mortality) and efficiency relative to EPN-only controls, whereas lambda-cyhalothrin generally reduced infectivity of EPNs on
pupae the most, with a 53, 75, 57, and 13% reduction in infectivity efficiency among
, and
, respectively. The second study compared pupal mortality caused by the two most compatible nematode species and five insecticides in various combinations. Both
species caused 78-79% mortality among
pupae when used alone, and were tested in combination with spinetoram, malathion, azadirachtin, phosmet, or novaluron at a one-quarter rate. Notably,
caused 79% mortality on
pupae when used alone, and 89% mortality when combined with spinetoram, showing an additive effect. Novaluron drastically reduced the number of progeny IJs when combined with
by 270 IJs and
by 218. Any adult flies that emerged from EPN-insecticide-treated pupae had a shorter lifespan than from untreated pupae. The combined use of
and compatible chemical insecticides was promising, except for novaluron.
The figitid Ganaspis pelleranoi and the braconid Doryctobracon areolatus (Hym: Braconidae, Opiinae) are wide-ranging (from Florida, USA to Argentina) fruit fly parasitoids with tropical and ...subtropical distribution with a wet and temperate climate. In Argentina, both parasitoid species are thought to be restricted to the subtropical rainforests of the northwest and northeast, locally known as ‘Yungas’ and ‘Paranaense’ forests, respectively. However, these species recently have been recorded at the Monte and Thistle of the Prepuna eco-region, an arid region of central-western Argentina. Despite the extreme environmental conditions, anthropic artificial irrigation seems to be playing a fundamental role in fostering the presence and persistence of these species. Maximum Entropy (MaxEnt) models were developed to assess the suitability of these areas to harbor both species. The present work is a first approach to identify suitable areas for the distribution of these two fruit fly biological control agents in the American continent; based on 19 bioclimatic variables. Furthermore, the models resulting from including the new records in the ‘Monte’ eco-region suggest that local populations may become adapted to particular micro-environmental conditions generated by artificial irrigation. Models revealed that these artificial oases are suitable for G. pelleranoi but seem to be unsuitable for D. areolatus. This first and new approach to the area suitability of these species invites to produce models that reflect actual distribution including more records of presence in oases with similar conditions, thus decreasing the bias of the model generated by over reliance on areas with higher humidity (forest), which correspond to the distribution known before the inclusion of the new records.
Expansion of agricultural land is one of the most significant human alterations to the global environment because it entails not only native habitat loss but also introduction of exotic species. ...These alterations affect habitat structure and arthropod dynamics, such as those among host plants, tephritid fruit flies, and their natural enemies. We compared abundance and dynamics of pest and non-pest tephritids and their natural enemies over a mosaic of habitats differing in structure, diversity and disturbance history on the Sierra de San Javier in Tucuman, Argentina. Our prediction was that conserved habitats would be more resistant to the establishment and spread of invasive tephritid species due in part to a greater abundance of natural enemies, a greater diversity of native species in the same family and trophic level, and a greater wealth of biotic interactions. We further predicted that native species with broad host ranges should be more sensitive to habitat loss yet more competitive in less disturbed habitats than generalist native and exotic species. We found that environmental degradation, and introduction and spread of exotic host plants strongly affected distribution patterns, abundance, and phenology of native and exotic tephritids. Monophagous tephritid species and several specialized parasitoids were more sensitive to habitat loss than polyphagous species and parasitoids exhibiting a wide host range. In contrast, native monophagous species and native parasitoids appeared to exclude the invasive Mediterranean fruit fly from conserved patches of native vegetation. Nevertheless, the Mediterranean fruit fly persisted in uncontested exotic host plants and thrived in highly degradeted urban landscapes.
Ceratitis capitata (Wiedemann) and Drosophila suzukii (Matsumura) are two severe invasive pests widespread in all Argentinean fruit-producing regions. Both coexist with the Neotropical pest ...Anastrepha fraterculus (Wiedemann) in northern Argentina. The northwestern region shelters major soft fruit and Citrus producing and exporting industries, which are heavily affected by these dipterans. Eco-friendly strategies are under assessment in Argentina. This study mainly assessed D. suzukii, C. capitata, and A. fraterculus temporal abundance variations and their natural parasitism levels on a 1.5-ha-patch of feral peach trees within a disturbed secondary subtropical rainforest of northwestern Argentina. Fly puparia were mainly collected from the soil under fallen peach. Sampling was performed over three peach fruiting seasons. The most abundant pest species was C. capitata. Drosophila suzukii was only found in the last collecting period, but outnumbered A. fraterculus. Natural parasitism distinctly affected the temporal abundance of these dipterans: it significantly depressed C. capitata abundance in last sampling weeks, it did not substantially affect D. suzukii abundance, but it increased synchronously with the increase in the A. fraterculus abundance. Parasitism on C. capitata was mostly exerted by a combination of both a cosmopolitan pupal and a native larval parasitoid, while A. fraterculus was mainly parasitized by two indigenous larval parasitoids. Only three resident pupal parasitoids were associated with D. suzukii, of which the cosmopolitan Pachycrepoideus vindemiae Rondani (Hymenoptera: Pteromalidae) was the most significant. Data on the resident parasitoid impact are relevant for designing biocontrol strategies in noncrop habitats.
Heterospecific and conspecific host discrimination, and super- and multiparasitism by the neotropical figitid Ganaspis pelleranoi were determined using 6-d-old Ceratitis capitata larvae in choice ...trials, where alternatives such as hosts previously parasitised by the exotic braconid Diachasmimorpha longicaudata, or by conspecific G. pelleranoi, and/or unparasitised hosts were available. Choice assays involved both experienced and naïve figitid females, previously host-exposed and non-host-exposed, respectively. Multiparasitism was mainly avoided if the G. pelleranoi female had a choice between unparasitised and parasitised larvae. Heterospecific host discrimination was highly improved by ovipositional experience. A very limited number of experienced G. pelleranoi females visited, probed, or oviposited host larvae previously parasitised by D. longicaudata. Only 2% of figitid adults were recovered from puparia resulting from larvae previously parasitised by D. longicaudata and exposed to naïve females. No figitid adults were recovered in those treatments involving experienced females. Latency and host examination data, number of visits, probing and oviposition's activities showed that experienced G. pelleranoi female has a higher propensity to forage unparasitised host larvae rather than larvae previously parasitised by conspecific females. Self-superparasitism was greater than conspecific superparasitism when figited females had to choose between unparasitised and conspecific parasitised larvae. The ability of G. pelleranoi females to discriminate previously parasitised medfly larvae suggests low levels of both heterospecific and conspecific competition. Combined releases of D. longicaudata and G. pelleranoi in Argentinean fruit-growing regions could be a more advantageous alternative than individual species releases.
PDF
