The main objective was to develop an artificial diet for two flat-headed borers, Capnodis tenebrionis L. and C. carbonaria Klug. (Coleoptera: Buprestidae), which are severe pests of stonefruit plantations in the Mediterranean basin. The effect of proteins from various sources, percentage of cortex tissue in the diet and diet structure on larval growth and survival were investigated. The most successful diet contained 2.8% casein and 4.6% dry brewer's yeast as the protein source. For complete larval development and successful pupation it is essential to include cortex tissue from the host plant in the diet. Mean larval development time was shortened by 10-12 days when reared on a diet containing 20% cortex tissue compared with rearing on diet containing 10% cortex tissue. Two different diet structures were required, a viscous matrix for the first and second instar larvae and drier crumbly diet, which allows the larvae to move within the diet, for older larvae. At 28°C on the artificial diet C. tenebrionis and C. carbonaria completed their development in 2-2.5 months compared to the 6-11 months recorded in Israeli orchards. C. tenebrionis successfully completed two generations on the artificial diet.
The larva of the Palaearctic Renocera pallida (Fallén, 1820) is confirmed as a predator of small species of bivalve molluscs of the family Sphaeriidae. To date only the larvae of three Nearctic Renocera species (and larvae of two other species of Sciomyzidae in two genera) are known to have the same food preference. The life cycle, biology, larval feeding and behaviour are described for the first time and compared with that of the Nearctic Renocera. The systematic position and biology of Renocera in general are discussed. Descriptions of the egg, second and third larval instars and the puparium of R. pallida are presented, the main features of the egg and larvae are illustrated by scanning electron micrographs.
We describe here the in vitro rearing of Anagrus breviphragma Soyka, an egg parasitoid of Cicadella viridis (Linnaeus), from the second instar larva to the adult stage. Three media, containing mainly either a commercial tissue culture medium (IPL-41), skimmed milk or veal homogenate, were tested. Larval development occurred on all the diets but few larvae reached the pupal stage on the diets containing skimmed milk or veal homogenate. On the tissue culture medium, pharate adults, albeit malformed, developed. Supplementing the tissue culture medium-based diet with chicken egg yolk alone, or combined with yeast extract, further improved parasitoid development. The addition of both egg yolk and yeast extract resulted in twelve out of twenty larvae reaching the adult stage, of which only four females emerged.
The aim of this study was to evaluate the effects of different diets on the development and reproduction of Lygus rugulipennis Poppius (Heteroptera: Miridae). Using 2 laboratory generations (F1 and F2) obtained from field-collected L. rugulipennis, the following diets were tested: beans, beans plus Tenebrio molitor (L.) (Coleoptera: Tenebrionidae) pupae, and a commercial artificial diet, which was developed for mass rearing of Lygus hesperus Knight. As oviposition substrates, beans and agar/parafilm rolls were used. Our data show that both the artificial diet and the artificial oviposition substrate were ineffective substitutes for beans for both laboratory generations. Stage-dependent and total survival rates clearly indicated that F1 Lygus bugs survive significantly longer when they are reared on vegetable substrates i.e., beans and beans plus pupae. The differential effects of the diets were more pronounced in the F2 generation, in which the embryonic development was longer for eggs from females reared on the artificial diet than on beans, and in which the second instar nymphs did not survive on the artificial diet. Both the total duration of post-embryonic development and the longevity of F1 males were shorter on the artificial diet than on beans. Female fecundity was affected by diet in terms of total duration of the oviposition period and mean number of eggs laid/female, since these parameters were lower on the artificial substrate, compared with those obtained on the bean substrate. However, the diet did not affect the morphological parameters, as there were no significant variations in weight, width of cephalic capsule, and tibia and hemelytra length. Since L. rugulipennis cannot be reared on the commercially available artificial diet, we discuss the necessity to improve both the artificial diet and oviposition substrate so that this Lygus bug and its specific egg parasitod Anaphes fuscipennis Haliday (Hymenoptera: Mymaridae) can be mass reared.
Some previous work on arthropod development is insufficiently detailed or incompletely reported. Much of the published information in this area is of limited use for the general analysis of life cycles. These difficulties arise primarily because many experiments do not control fully for the strain of the material (and even its specific identity) nor for rearing conditions, do not adequately take account of the complexity of life cycles and their stages, or are restricted to only part of the life cycle. For example, 285such factors as variable numbers of instars, sexual differences, abbreviated or hidden stages and dormancies may mean that the "average durations" reported apply to an unknown mixture of developmental types. Nor are experiments always designed or results reported and analysed in a logical and transparent manner. Undefined terms may obscure what actual developmental intervals were measured. Highly derived developmental or demographic measures may obscure core data. Statistical information may be inadequate. Such pitfalls are reviewed here, suggesting ways to ensure that results on the duration of development are both valid for specific studies and more widely useful. General experimental difficulties, recommended background information that should be provided, recommended life-cycle intervals and their terminology, and recommended ways to report numerical and statistical information are briefly summarized in tabular form.
Muga silkworm (Antheraea assamensis Helfer) is endemic to Assam and adjoining areas in North-Eastern India, and naturally produces golden silk. From time immemorial, many ethnic and tribal groups have produced muga silk. Muga silkworms are mostly wild unlike the mulberry silkworm, which is completely domesticated. The muga silkworm is a single species with little genetic variation among populations, survives harsh climatic conditions and is subject to various diseases, pests and predators. Due to the high incidence of disease and natural enemies, and variations in climatic conditions, the production of muga silk has recently declined dramatically. In order to improve the productivity of this silkworm it is important to have a better knowledge of both its host plants and biology. Lack of knowledge of its genetics and host plants is a major bottleneck. This paper reviews various aspects of muga silkworm culture, including the availability of different populations, and methods used to select for improvement in survival, cocoon yield, disease resistance, conservation and egg production., Amelendu Tikader, Kunjupillai Vijayan, Beera Saratchandra., and Obsahuje seznam literatury