The First Record of \u3ci\u3eOoencyrtus nezarae\u3c/i\u3e (Hymenoptera: Encyrtidae) on Kudzu Bug (Hemiptera: Plataspidae) in North America

The kudzu bug, Megacopta cribraria (F.) (Heteroptera: Plataspidae), is an invasive insect pest introduced from Asia in 2009 that poses a threat to soybeans (Glycine max [L.] Merr. [Fabales: Fabaceae]) and other legume crops in the United States. Initially discovered in Georgia, M. cribraria rapidly expanded across the southeast until 2014 when a significant decline in its population was observed across many locations. This notable decline in M. cribraria populations is attributed to the emergence of new parasitoids and pathogens in its new invasive range. So far, only a single egg parasitoid, Paratelenomus saccharalis (Dodd) (Hymenoptera: Platygastridae), is known to parasitize the eggs of M. cribraria in the United States. Here, we report a new egg parasitoid of M. cribraria identified as Ooencyrtus nezarae Ishii, 1928 (Hymenoptera: Encyrtidae), recovered from egg masses of M. cribraria collected from soybean in Alabama. O. nezarae is reported to parasitize eggs from a variety of heteropteran families and has been observed parasitizing M. cribraria in China. To the best of our knowledge, this is the first report of O. nezarae in North America. The potentials of O. nezarae for biological control of M. cribraria in the United States and the direction of future studies are discussed

Do age and mating status affect olfactory response of the parasitoid, Microplitis croceipes (Hymenoptera: Braconidae) to host-related plant odors? [version 2; referees: 2 approved]

Background: Parasitic wasps (parasitoids) use volatile organic compounds released by herbivore-infested plants to locate their hosts. Response of parasitoids to plant odors may be plastic and dependent on their physiological state. Using Microplitis croceipes (Hymenoptera: Braconidae), a relatively specialized larval endoparasitoid of Heliothis virescens (Lepidoptera: Noctuidae), we asked whether age and mating status of parasitoids affect their olfactory response to host-related odors. Methods: Four odor stimuli of varying complexity were selected based on previous reports of parasitoid response to cotton volatiles: cis-3-hexenol (a green leaf volatile), α-pinene (a constitutive monoterpene), a 50/50 v/v binary mixture (cis-3-hexenol + α-pinene), and H. virescens-infested cotton odors. Female M. croceipes used in Y-tube olfactometer bioassays were either mated or unmated, and grouped 1–3, 4–6, and 7–9 d-old. Female parasitoids used in electroantennogram (EAG) recording were mated and grouped 1–3, 4–6, 7–9 and 10–12 d-old. Results: In Y-tube olfactometer bioassays, neither age nor mating status played a major role in the attraction of parasitoids to test odor stimuli, with two exceptions: 4–6 d-old mated parasitoids showed attraction to the binary mixture, and 1–3 d-old mated parasitoids showed attraction to H. virescens-infested cotton. Age did not affect EAG response of parasitoids to test stimuli. Conclusions: The present results suggest that age and mating status do not play a major role in modulating olfactory responses of M. croceipes to host-related plant odors. Instead, plasticity of olfactory response may be limited in M. croceipes due to strong innate sensitivity to host-related odor cues

Assessment of frozen larvae of Callosobruchus maculatus as hosts for rearing Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae)

a b s t r a c t The suitability of frozen host larvae for rearing Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae), an ectoparasitoid of Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) and other stored-product insects was investigated. The reproductive potential (number and sex ratio of progeny) of female P. cerealellae was compared on live (fresh) C. maculatus larvae (concealed within cowpea seeds) versus frozen larvae (obtained by freezing infested cowpea seeds at À20°C for 48 h) which were subsequently thawed and held at ambient conditions ($25 ± 1°C, 50 ± 5% RH) for 4, 24, 48, 72, 96, and 120 h before exposure to female parasitoids. No significant differences were recorded in the numbers and sex ratios of the progeny produced by female P. cerealellae on live larvae compared to frozen host larvae that were thawed and held at ambient conditions for up to 96 h, suggesting that live and frozen larvae of C. maculatus are equally suitable for rearing P. cerealellae. However, the data showed that progeny production on frozen hosts gradually declined with thawing duration and was significantly reduced at the thawing duration of 120 h. When live and frozen host larvae were simultaneously presented together to female P. cerealellae at different exposure periods, relatively greater progeny production was recorded on live hosts than on frozen hosts at 12, 24, and 48 h of exposure. This may suggest preference of female P. cerealellae for live versus frozen host larvae. These results are discussed in relation to the life history strategy and host location behavior of P. cerealellae, and may have practical implications in the development of efficient mass rearing systems for the parasitoid

Behavioral Response of Plum Curculio, Conotrachelus nenuphar

Plum curculio, Conotrachelus nenuphar Herbst (Coleoptera: Curculionidae), is a key pest of stone and pome fruits in North America. The behavioral response of adults of different physiological states (sex, age, diet, and mating status) to three commercially available synthetic lures, benzaldehyde (BZ) and plum essence (PE), the male-produced aggregation pheromone, grandisoic acid (GA), or their combinations, was studied in the laboratory. Four choice olfactometer bioassays demonstrated significant attraction of both sexes to PE lure. Both BZ and GA lures were not attractive to plum curculio when tested as commercially formulated. PE had higher release rate (1.51 mg/hr) than BZ (0.36 mg/hr) and GA (ca. 0.04 mg/hr), suggesting that the higher attractiveness of PE may be due to its relatively higher release rates. Tests with combined lures showed a neutral effect of combining GA with PE and an inhibitory effect of combining BZ with PE. The physiological conditions of the weevils had no significant effect on their response to the lures. Olfactometer tests with pure 1,2,4-trichlorobenzene (TCB) confirmed that this compound was inhibitory to plum curculio. These results are discussed in relation to the contrasting field reports which implicated BZ + GA as an effective attractant for plum curculio

New record of Trissolcus solocis (Hymenoptera: Scelionidae) parasitising Halyomorpha halys (Hemiptera: Pentatomidae) in the United States of America

A parasitoid wasp, Trissolcus solocis Johnson, was recorded parasitising eggs of the invasive stink bug Halyomorpha halys (Stål), in the United States. This is the first record of this species parasitising eggs of H. halys. First record of Trissolcus solocis parasitising Halyomorpha halys eggs in the United States and first record of T. solocis in Alabama

Identification of human semiochemicals attractive to the major vectors of onchocerciasis

Background: Entomological indicators are considered key metrics to document the interruption of transmission of Onchocerca volvulus, the etiological agent of human onchocerciasis. Human landing collection is the standard employed for collection of the vectors for this parasite. Recent studies reported the development of traps that have the potential for replacing humans for surveillance of O. volvulus in the vector population. However, the key chemical components of human odor that are attractive to vector black flies have not been identified. Methodology/Principal Findings: Human sweat compounds were analyzed using GC-MS analysis and compounds common to three individuals identified. These common compounds, with others previously identified as attractive to other hematophagous arthropods were evaluated for their ability to stimulate and attract the major onchocerciasis vectors in Africa (Simulium damnosum sensu lato) and Latin America (Simulium ochraceum s. l.) using electroantennography and a Y tube binary choice assay. Medium chain length carboxylic acids and aldehydes were neurostimulatory for S. damnosum s.l. while S. ochraceum s.l. was stimulated by short chain aliphatic alcohols and aldehydes. Both species were attracted to ammonium bicarbonate and acetophenone. The compounds were shown to be attractive to the relevant vector species in field studies, when incorporated into a formulation that permitted a continuous release of the compound over time and used in concert with previously developed trap platforms. Conclusions/Significance: The identification of compounds attractive to the major vectors of O. volvulus will permit the development of optimized traps. Such traps may replace the use of human vector collectors for monitoring the effectiveness of onchocerciasis elimination programs and could find use as a contributing component in an integratedvector control/drug program aimed at eliminating river blindness in Africa

Electroantennogram response of the parasitoid, Microplitis croceipes to host-related odors: The discrepancy between relative abundance and level of antennal responses to volatile compound [version 1; referees: 2 approved, 1 approved with reservations]

Herbivores emit volatile organic compounds (VOCs) after feeding on plants. Parasitoids exploit these VOCs as odor cues to locate their hosts. In nature, host-related odors are emitted as blends of various compounds occurring in different proportions, and minor blend components can sometimes have profound effects on parasitoid responses. In a previous related study, we identified and quantified VOCs emitted by cotton plant-fed Heliothis virescens (Lepidoptera: Noctuidae) larvae, an herbivore host of the parasitoid Microplitis croceipes (Hymenoptera: Braconidae). In the present study, the olfactory response of female M. croceipes to synthetic versions of 15 previously identified compounds was tested in electroantennogram (EAG) bioassays. Using M. croceipes as a model species, we further asked the question: does the relative abundance of a volatile compound match the level of antennal response in parasitoids? Female M. croceipes showed varying EAG responses to test compounds, indicating different levels of bioactivity in the insect antenna. Eight compounds, including decanal, 1-octen-3-ol, 3-octanone, 2-ethylhexanol, tridecane, tetradecane, α-farnesene and bisabolene, elicited EAG responses above or equal to the 50th percentile rank of all responses. Interestingly, decanal, which represented only 1% of the total amount of odors emitted by cotton-fed hosts, elicited the highest (0.82 mV) EAG response in parasitoids. On the other hand, (E)-β-caryophyllene, the most abundant (29%) blend component, elicited a relatively low (0.17 mV) EAG response. The results suggest that EAG response to host-related volatiles in parasitoids is probably more influenced by the ecological relevance or functional role of the compound in the blend, rather than its relative abundance

Electroantennogram response of the parasitoid, Microplitis croceipes to host-related odors: The discrepancy between relative abundance and level of antennal responses to volatile compound [version 2; referees: 3 approved, 1 approved with reservations]

Herbivores emit volatile organic compounds (VOCs) after feeding on plants. Parasitoids exploit these VOCs as odor cues to locate their hosts. In nature, host-related odors are emitted as blends of various compounds occurring in different proportions, and minor blend components can sometimes have profound effects on parasitoid responses. In a previous related study, we identified and quantified VOCs emitted by cotton plant-fed Heliothis virescens (Lepidoptera: Noctuidae) larvae, an herbivore host of the parasitoid Microplitis croceipes (Hymenoptera: Braconidae). In the present study, the olfactory response of female M. croceipes to synthetic versions of 15 previously identified compounds was tested in electroantennogram (EAG) bioassays. Using M. croceipes as a model species, we further asked the question: does the relative abundance of a volatile compound match the level of antennal response in parasitoids? Female M. croceipes showed varying EAG responses to test compounds, indicating different levels of bioactivity in the insect antenna. Eight compounds, including decanal, 1-octen-3-ol, 3-octanone, 2-ethylhexanol, tridecane, tetradecane, α-farnesene and bisabolene, elicited EAG responses above or equal to the 50th percentile rank of all responses. Interestingly, decanal, which represented only 1% of the total amount of odors emitted by cotton-fed hosts, elicited the highest (0.82 mV) EAG response in parasitoids. On the other hand, (E)-β-caryophyllene, the most abundant (29%) blend component, elicited a relatively low (0.17 mV) EAG response. The results suggest that EAG response to host-related volatiles in parasitoids is probably more influenced by the ecological relevance or functional role of the compound in the blend, rather than its relative abundance

The First Record of \u3ci\u3eOoencyrtus nezarae\u3c/i\u3e (Hymenoptera: Encyrtidae) on Kudzu Bug (Hemiptera: Plataspidae) in North America

The kudzu bug, Megacopta cribraria (F.) (Heteroptera: Plataspidae), is an invasive insect pest introduced from Asia in 2009 that poses a threat to soybeans (Glycine max [L.] Merr. [Fabales: Fabaceae]) and other legume crops in the United States. Initially discovered in Georgia, M. cribraria rapidly expanded across the southeast until 2014 when a significant decline in its population was observed across many locations. This notable decline in M. cribraria populations is attributed to the emergence of new parasitoids and pathogens in its new invasive range. So far, only a single egg parasitoid, Paratelenomus saccharalis (Dodd) (Hymenoptera: Platygastridae), is known to parasitize the eggs of M. cribraria in the United States. Here, we report a new egg parasitoid of M. cribraria identified as Ooencyrtus nezarae Ishii, 1928 (Hymenoptera: Encyrtidae), recovered from egg masses of M. cribraria collected from soybean in Alabama. O. nezarae is reported to parasitize eggs from a variety of heteropteran families and has been observed parasitizing M. cribraria in China. To the best of our knowledge, this is the first report of O. nezarae in North America. The potentials of O. nezarae for biological control of M. cribraria in the United States and the direction of future studies are discussed