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The leaf miners, Liriomyza trifolii (Burgess) and L. bryoniae (Kaltenbch), (Diptera: Agromyzidae) are of the major pests that attack faba bean (Vicia faba) in Egypt. The incidence of diapause in larval-pupal parasitoids of these pests was studied by large-scale field samplings of their mature larvae and puparia, which were reared under natural outdoor conditions. The population size of L. trifolii was greater than those of L.bryoniae. Four larval-pupal parasitoids; Pseudopzomachus masii Nixon and Opius basalis Fischer (Braconidae), Halticoptera circulus (Walker) and Halticoptera sp. (Eulophidae) were recorded from the puparia of both leaf miner species between 2012 - 2015 seasons. P. masii was the most predominant parasitoid species in the seasons of study. The onset of pupal diapause was found among paper of the 1st sample, during the favorable weather conditions in the host insect until last collected samples 2 weeks before harvest. So, the diapause in Liriomyza spp. seems to be genetically programmed. Two types of diapause were observed during the season: firstly, a facultative winter diapause of 7-8 months, and secondly, a longer winter diapause of 11-21 months. The diapause intensity was highly variable depended upon the time in the season and the Liriomyza species. It appears that the diapaused wasps were able to maintain close developmental synchrony with the proportion of non-parasitized host puparia. This is the first report of diapause in Liriomyza spp. attacking faba bean plants and their larval-pupal parasitoids from the northern region of Egypt. [ABSTRACT FROM AUTHOR]

Egg laying capacity, sex ratio and adult longevity of males and females of the parasitoid species Bracon hebetor (Say) (Hymenoptera: Braconidae) were studied by exposing the wasps to different larval density of the greater wax moth, Galleria mellonella (L.) (Lepidoptera: Pyralidae). Females of B. hebetor could regulate allocation of eggs among host larvae by decreasing the number of eggs laid on a host as host density increases. Also, the wasp females seemed to regulate sex ratio (male /total) based on the number of eggs on the hosts and number of host larvae they encountered. Survival of B. hebetor adults was significantly different among wasps provided with different types of food. Wasp females lived longer period than males when kept only with wax moth larvae. The wasps laid lower number of eggs than those provided with hosts and honey. Combined use of G. mellonella larvae and honey had significant increase on reproductive capacity and longevity of B. hebetor wasps. [ABSTRACT FROM AUTHOR]

The agromyzid leaf miners, Liriomyza trifolii (Burgess) and L. bryoniae (Kaltenbch) (Diptera: Agromyzidae) were found as major pests attacking faba bean (Vicia faba) in Alexandria, Egypt. A survey of their parasitoid species was carried out in 2012/13 and 2013/14 faba bean growing seasons. Parasitoid adults emerged from infested samples with the leaf miners were collected. Seven hymenopterous parasitoid species, belong to the families Braconidae and Eulophidae, were recorded; two braconids; Pseudopzomochus masii Nixon and Opius basalis (Fischer) and five eulophids; Diglyphus isaea (Walker), Chrysocharis pentheus (Kamijo), Halticoptera circulus (Walker), Halticoptera sp. and Zagrammosoma sp. Among the parasitoids surveyed , P. masii was recorded for the first time from Liriomyza spp. in Egypt; its sex ratio was female biased in all collected samples. D. isaea was the most predominant parasitoid species found, accounting 68.3 and 41.4% of the total parasitoids emerged in 2012/13 and 2013/14 seasons, respectively. It was active throughout the growing season and increased in number as the leaf miners' population increased. P. masii came next after D. isaea, particularly in the second season. Natural suppression of Liriomyza spp. by parasitoids seemed to be important for maintaining Liriomyza populations below damaging levels. [ABSTRACT FROM AUTHOR]

Earlier research has shown that the koinobiont parasitoid, Microplitis rufiventris, attacks and can develop on early instars of Spodoptera littoralis larvae with preference to third instars. However, the present study was carried out using the newly moulted sixth instar larvae at two different temperatures (20 ± 1 and 27 ± 1°C) to study the developmental interaction between the parasitoid and the last instar host larvae. Parasitoid eggs laid in singly parasitized host larvae invariably died. As the number of parasitoid eggs/host larvae increased, the proportion of eggs that hatched and number of viable parasitoid larvae successfully reached to their final instar increased. The effect of superparasitization seems to be dose (no. of eggs + parasitoid factors)-temperature-dependent. The results demonstrate a kind of‘Allee effect’ suggesting that superparasitized last instar S. littoralis larvae provide a better host environment than singly parasitized hosts for the parasitoid, M. rufiventris. This may be due to host's hormone and/or low dose of factors injected with parasitoid eggs. The supernumerary individuals of wasp larvae developed normally to the point of emergence but most did not successfully emerge from the host. The improvement of both hatchability and post-embryonic development of parasitoid wasp was significantly (P < 0.01) greater at 20°C than at 27°C. The results of the present study are useful in understanding the evolution of life-history strategies and host range in parasitic hymenoptera. [ABSTRACT FROM AUTHOR]

The effect of mating status and age of the female of Microplitis rufiventris parasitoid on the growth pattern of its teratocytes during the larval development is described as well as the changes in the number of these cells. The growth pattern of teratocytes derived from haploid eggs significantly differed from that of eggs deposited by mated females. Both cell diameter and the number of maturing M. rufiventris teratocytes was fertilization-dependent. Following the parasitization of Spodoptera littoralis larvae with virgin parasitoid females, the host larvae hosted a large number of cells of smaller size at the end of parasitoid development. The opposite effect was seen when the host larvae contained female parasitoid larvae. The age of the female at parasitization had an effect on the maximum cell size attained prior to parasitoid emergence. It seems that there are two factors other than mating which affect the number of teratocytes: degeneration inside the host haemolymph and to some degree accidental ingestion by parasitoid larva. [ABSTRACT FROM AUTHOR]