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Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae) is an adult parasitoid of lepidopteran pests, and the age of the host has a strong influence on its reproduction. This study aimed to evaluate the biological characteristics of T. howardi reared on different aged pupae of Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae). For that, pupae with 24, 48, 72, 96, 120, 144 or 168 h of age were exposed to parasitism. The experimental design was completely randomized, with seven treatments (pupal age) and ten replications, with each replication consisting of five pupae individualized with one female parasitoid at the respective ages. Tetrastichus howardi parasitized and emerged in pupae of all the evaluated ages. The duration of the cycle (egg-adult) in days, number of parasitoids that emerged per pupa (progeny), progeny per female, sex ratio of the parasitoid and longevity of adults were similar. This is the first record of T. howardi reproducing in C. includens pupae under laboratory conditions. The highest parasitism and development of T. howardi was obtained in 24- to 96-hour-old pupae of C. includens, indicating that this age range is more favorable to rear this parasitoid under laboratory conditions.

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The Genetic Sexing Strain (GSS) of Anastrepha ludens (Loew) Tapachula-7 (Tap-7) produces males emerged from brown pupa [used for the Sterile Insect Technique (SIT)] and females from black pupa (a by-product) that can be sorted by a mechanical process. The early sorting provides young black pupae which were assessed as host of the parasitoid Coptera haywardi (Oglobin). This required an assessment of possible deleterious effects to A. ludens males (that emerged from the brown pupae). Our results demonstrate the host viability of the young Tap-7 black pupae. Nevertheless, A. ludens males obtained from brown pupae showed significantly reduced emergence (77.28%) and flight ability (63.33%). This negatively affected the emission of male signals for mating and, therefore, the competitiveness of A. ludens GSS used for the SIT. Our results suggest that there is no immediate alternative to the use of Tap-7 young black pupae as hosts for the mass rearing of C. haywardi. [ABSTRACT FROM AUTHOR]

Variation in parasitism risk among hosts can arise from between-patch and within-patch factors, but considerably less information is known about the latter. This study investigated how distributions of the oriental fruit fly Bactrocera dorsalis influenced its parasitism by the pupal parasitoid Dirhinus giffardii in the laboratory. Because B. dorsalis larvae pupate underground, pupation depth was considered as an important factor that affects the risk of parasitism. When the density of B. dorsalis larvae was varied (1, 10, and 100 larvae per arena), average pupation depth increased with the density. When the depth of pupae was manipulated, the rate of parasitism differed by depths. Parasitism at 0 cm differed from the random parasitoid model expectation, but parasitism at 1 cm was not different from the model expectation. Few pupae at 2 cm were parasitized. In another experiment, when pupae were simultaneously presented at 0 cm and 1 cm depths, parasitism at 1 cm was weakened by the presence of puape at 0 cm. These results imply that the density of the host influences pupation depth as well as the distribution of parasitism and plays an important role in host-parasitoid dynamics. [ABSTRACT FROM AUTHOR]

This study shows the effectiveness of deliberately selecting for Coptera haywardi individuals to increase a population's capacity to discriminate against parasitised hosts. In the 'selected colony' (F1–F4), females were selected based on their ability to discriminate parasitised fruit fly pupae, determined by their host searching, foraging and oviposition behaviour. Female parasitoids of successive generations of the selected colony (F1–F4) showed an increasing discriminatory ability, including reduced host searching and foraging time. The last selected generation, i.e. F4 showed an increase in fecundity compared to the standard colony. In F4 individuals from the selected colony, antennae length increased but the hind tibia size did not, compared to individuals from the control colony. Flight ability and survival remained unchanged across all generations. This selection process could be an effective method of recuperating the discriminatory capacity of a C. haywardi colony under mass rearing conditions. [ABSTRACT FROM AUTHOR]

The Safflower capsule fly (SCF), Acanthiophilus helianthi Rossi (Diptera: Tephritidae) is the most destructive insect pest attacking the Safflower Carthamus tinctorius L. plant which are cultivated as an oil crop. It is mainly controlled through application of broad-spectrum insecticides, which can adversely affect safflower farms ecosystem and consequently human health. Since a first step in setting up an integrated pest management program is to assess the biological control agents within the ecosystem. Therefore, in this research work the pupal parasitoids of Safflower capsule fly a main insect pest attacking Safflower plants were identified. The impact of these parasitoids against this pest was evaluated on the varying pest generations and within different locations in Kohgiluyeh province during 2008-2009 seasons. Pupal parasitoid adults of SCF were recorded from fieldreared pupae, which had been collected from heavily infested small flower heads of the first generation as well from large flower heads of the second and third generations. Rate of parasitism on A. helianthi pupae was estimated as the number of parasitoids over the total count of parasitoids and flies. Ten hymenopterous species belonging to different families parasitizing insect pupae were screened as follows: Bracon hebetor (Spinola, 1808) and Bracon luteator (Spinola, 1808) (Braconidae); Isocolus tinctorious (Melika and Gharaei, 2006) (Cynipidae); Pronotalia carlinarum (Szelenyi and Erdos, 1951) (Eulophidae); Eurytoma acroptilae (Zerova, 1986) (Eurytomidae); Ormyrus orientalis (Walker, 1871) (Ormyridae); Colotrechnus viridis (Masi, 1921) and Pteromalus sp. (Walker, 1976) (Pteromalidae); and Antistrophoplex conthurnatus (Zerova, 2000) and Microdontomenus annulatus (Masi, 1899) (Torymidae). The average parasitization rate was 23±1 as revealed through the present study. The highest parasitization rate occurred during the first generation in all localities tested, as well as in years. Statistical analysis revealed that there were significant differences between parasitization rates by pupal parasitoids within various host generations and localities.

The Safflower capsule fly (SCF), Acanthiophilus helianthi Rossi (Diptera: Tephritidae) is the most destructive insect pest attacking the Safflower Carthamus tinctorius L. plant which are cultivated as an oil crop. It is mainly controlled through application of broad-spectrum insecticides, which can adversely affect safflower farms ecosystem and consequently human health. Since a first step in setting up an integrated pest management program is to assess the biological control agents within the ecosystem. Therefore, in this research work the pupal parasitoids of Safflower capsule fly a main insect pest attacking Safflower plants were identified. The impact of these parasitoids against this pest was evaluated on the varying pest generations and within different locations in Kohgiluyeh province during 2008-2009 seasons. Pupal parasitoid adults of SCF were recorded from fieldreared pupae, which had been collected from heavily infested small flower heads of the first generation as well from large flower heads of the second and third generations. Rate of parasitism on A. helianthi pupae was estimated as the number of parasitoids over the total count of parasitoids and flies. Ten hymenopterous species belonging to different families parasitizing insect pupae were screened as follows: Bracon hebetor (Spinola, 1808) and Bracon luteator (Spinola, 1808) (Braconidae); Isocolus tinctorious (Melika and Gharaei, 2006) (Cynipidae); Pronotalia carlinarum (Szelenyi and Erdos, 1951) (Eulophidae); Eurytoma acroptilae (Zerova, 1986) (Eurytomidae); Ormyrus orientalis (Walker, 1871) (Ormyridae); Colotrechnus viridis (Masi, 1921) and Pteromalus sp. (Walker, 1976) (Pteromalidae); and Antistrophoplex conthurnatus (Zerova, 2000) and Microdontomenus annulatus (Masi, 1899) (Torymidae). The average parasitization rate was 23±1 as revealed through the present study. The highest parasitization rate occurred during the first generation in all localities tested, as well as in years. Statistical analysis revealed that there were significant differences between parasiti-zation rates by pupal parasitoids within various host generations and localities. [ABSTRACT FROM AUTHOR]

Successful biological control of insect pests often depends on reliable baseline information on natural mortality imposed by natural enemies. Generating such data requires painstaking long-term studies over considerable geographical area. We attempted to produce such data on the extent of natural pupal parasitization of Opisina arenosella (Walker) a defoliating pest of coconut palms. Pupal parasitization in 31 discrete generations across different locations in South Karnataka, India, where coconut is widely cultivated and where Opisina frequently causes serious losses, was quantified between 1999 and 2005. Each parasitoid species makes a characteristic exit hole on the host pupa, which was used to quantify the extent of parasitization. Results show that parasitoids emerged from ~44% and moths from ~41% of the pupae. Consistently, Meteoridea hutsoni (Nixon) was the dominant parasitoid of the region followed by Brachymeria spp. Together, they contributed to ~90% of the pupal parasitization. There was a negative correlation between extent of parasitization by Meteoridea and that of Brachymeria, and between parasitization by Meteoridea and emergence of Opisina moths. Extent of parasitization by Brachymeria does not appear to have significant influence on moth emergence in the study area. Although parasitization by the two parasitoids varied with respect to seasons, the overall parasitization percentage, interestingly, remained unaffected and hovered around 50% all through the year. Finally, we comment on some of the implications of the study on the current recommendations in biological control of Opisina, and emphasize the need for long-term data on natural parasitization before arriving at 'recommendations' in biological control of insect pests. [ABSTRACT FROM AUTHOR]

Factors affecting overwintering mortality in the Mediterranean corn stalk borer, Sesamia nonagrioides Lefebvre (Lepidoptera: Noctuidae), were investigated under field conditions in the southeast Mediterranean region of Turkey. During two consecutive years larvae and pupae were sampled from December to April in maize plots sown on three different dates. Field-collected larvae and pupae were reared and the emerged parasitoids were recorded. An effect of sowing date on total numbers of S. nonagrioides was found with reduced populations in the early sown plots. Larval parasitism did not significantly affect overwintering mortality. Habrobracon hebetor (Say) (Hymenoptera: Braconidae) caused 11% parasitism and was found only in the first year of the study. Pupal parasitoids were predominantly Ichneumon sarcitorius caucasicus Meyer, Barichneumon sp. and Pimpla spuria Gravenhorst (Hymenoptera: Ichneumonidae) and the parasitism level was 11% in both years of the study. [ABSTRACT FROM AUTHOR]

Abstract: Interspecific competition between Xanthopimpla stemmator and Dentichasmias busseolae was studied using pupae of the invasive crambid stemborer Chilo partellus as the host. While X. stemmator is an old association, D. busseolae formed a relatively new association with C. partellus in East Africa. Two different time intervals between parasitism (0 and 48h) and two parasitoid sequences [i.e., X. stemmator before D. busseolae (Xs–Db) and D. busseolae before X. stemmator (Db–Xs)] were chosen. In addition, the parasitoids’ performance on pupae in maize stems and ears was assessed. For both X. stemmator and D. busseolae, there was no difference in foraging time between unparasitized pupae and pupae previously parasitized by the other species, indicating that the two species were not capable of interspecific host discrimination. In the Xs–Db sequence, the time interval between parasitism did not have an influence on the percentage of pupae producing either parasitoid species. By contrast, in the Db–Xs sequence, the percentage of pupae producing X. stemmator was almost 8 times higher in the 0-h than the 48-h interval, while for D. busseolae it was the reverse. In the 0-h interval, X. stemmator outcompeted D. busseolae irrespective of whether it parasitized first or second, while in the 48-h interval, the parasitoid parasitizing first won. While D. busseolae successfully searched for and parasitized pupae in both stems and ears, parasitism of pupae in ears by X. stemmator was negligible. It was concluded that the two species could co-exist because they partly exploit different ecological niches. [Copyright &y& Elsevier]

The outcome of multiparasitism by two pupal parasitoids, the exotic solitary ichneumonid Xanthopimpla stemmator and the indigenous gregarious eulophid Pediobius furvus, was studied using the invasive crambid stem borer Chilo partellus and the indigenous noctuid Busseola fusca as hosts. Two parasitism sequences were observed, where X. stemmator oviposited before P. furvus , and vice versa. In addition, the effect of time between first and second parasitism on parasitoid emergence, development, sex ratio, and number of offspring was assessed. For most treatments, time interval between parasitism had no significant effect on the percentage if pupae producing either P. furvus or X. stemmator . In general, X. stemmator outcompeted P. furvus irrespective of the order of oviposition, time interval between ovipositions and host species. Further studies, especially on host finding capacity of the two parasitoid species are required to determine the competitiveness of the two species under field conditions. [ABSTRACT FROM AUTHOR]

Abstract: The sugarcane borer, Diatraea saccharalis is one of the hosts more used for parasitoid pupal multiplication in Brazil. The parasitoids pupal of Trichospilus diatraeae and Palmistichus elaeisis are generalist natural enemies with potential to suppress populations of diverse families of lepidopteran pests. The success in the utilization of these natural enemies in the field is directly related to the capacity of search of the host, this capacity might be affected by the presence of the pathogens. In this context, the aim of this essay was to detect the presence of intracellular parasites of Phylum Microsporidia. These pathogens may cause morphological and behavioral alterations. The presence of infection was verified by microscopy and was confirmed by amplification of region small subunit (SSU) of ribosomal RNA using universal primers for microsporidia of Nosema sp. The purified PCR products were submitted to sequencing, and the sequences that had been obtained were edited and aligned with the sequences in a Genbank database. In this way, it was possible to verify the presence of intracellular parasites in T. diatraeae, P. elaeisis and D. saccharalis pertaining to Clade Nosema/Vairimorpha. However, this is the first one report about detection of the microsporidia in the parasitoids T. diatraeae and P. elaeisis.