Larval Stage Period Research Articles

Effect of Overlap Some Varieties of Dates and Temperatures on The Biology of Saw-Toothed Grain Beetle Oryzaephilus surinamensis L. (Coleoptera: Silvanidae)

The present research aimed to study of effect of overlap between three varieties of dates including: Brium, Barhi and Khathrawy and three temperatures of 25 , 30 and 35 ± 1 ºC on the biology of saw-toothed grain beetle, Oryzaephilus surinamensis (Coleoptera: Silvanidae) at Relative Humidity of 70 ± 5%.
 The results showed that significant increase happened in the larval stage period at Barhi as compared to Brium and Khathrawy where it were 33.90 , 25.80 and 28.30 days, respectively, at temperature of 25 ± 1 ºC, and it were 24.83 , 19.67 and 21.30 days, respectively, at temperature of 30 ± 1 ºC, and it were 22.83 , 18.25 and 19.67 days, respectively, at temperature of 35 ± 1 ºC. also the results indicated no significant differences in pupal stage period among the varieties at temperatures 30 and 35 ± 1 ºC, while significant increase happened in pupal stage period at Barhi as compared to Brium and Khathrawy where it were 10.4 , 8.2 and 9.7 days, respectively, at temperature of 25 ± 1 ºC, also the results showed that significant reduction happened in adult age and laid eggs number per female at Barhi as compared to Brium and Khathrawy at all temperatures above, and significant increase happened in eggs incubation period at Barhi as compared to Brium and Khathrawy at temperature of 25 ± 1 ºC, whereas eggs incubation period were at Barhi longer than Brium ,and it were at Barhi shorter than Khathrawy at temperature of 35 ± 1 ºC, while there were no significant differences in eggs incubation period among the varieties at temperature of 30 ± 1 ºC.

CERTAIN STORAGE PROTEINS AND THEIR ROLE IN THE RESISTANCE OF SOME LEGUME SEED TYPES AND VARIETIES TO INFESTATION WITH THE COWPEA SEEDS BEETLE, Callosobruchus maculatus (F.)

Seventeen legume seed varieties belonging to ten types were analyzed for each of total proteins, trypsin inhibitors, vicilins and lectins to study the relationship between the presence of the storage seed proteins in legume seeds and resistance to infestation with the cowpea seeds beetle, Callosobruchus maculatus (F.) under no-choice bioassay at constant conditions of 29±1°C and 70 ± 5% RH. The tested types and varieties were cowpea (Fitriat, Forage and Kafr El-Sheikh), fababean (Aquadams, Giza 843 and Sakha 1), pea (Master B and Smooth) common bean (Bronco and Nepraska), lupin (Giza 1 and White lupin), chickpea (Giza 195), soyabean (Giza 111), lentil (Giza 9), guar (Guvar bean) and lablab (Egyptian kidney bean). To clarify the impact of the storage seed proteins in legume seed varieties and types on infestation with C. maculatus, larval period, pupal period, least and mean complete developmental periods, number of emerged adults per female, percentage of adults emergence and sex ratio (as percentage of males) were determined. Moreover, susceptibility index, infested seeds (%), mean number of holes per infested seed, seeds weight loss (%), weight of early emerged adult and number of dead individuals inside seeds per female were assessed as infestation parameters. The obtained results showed that, each of total proteins, trypsin inhibitors, vicilins and lectins of different tested legume seed varieties and types are negatively correlated with all aforesaid resistance parameters with the exception of those respecting larval and pupal durations, least and mean complete developmental periods and number of dead individuals inside seeds per female. As regards total proteins of varieties, larval period, least and mean complete developmental periods, susceptibility index and number of dead individuals inside seeds per female reached high significance degree at 0.01 level of probability, whereas pupal period obviously showed significant correlation coefficient at 0.05 level of probability. But, the other studied resistance parameters did not demonstrate significant correlations. Significancy test of correlation relationships respecting trypsin inhibitors clearly proved to be insignificant for all studied characters, except for those of larval stage period, least and mean developmental periods which cleared highly significant correlations and significant ones with susceptibility index, number of holes per infested seed and number of dead individuals inside seeds per female. All tested seed varieties of guar, lupin and common bean revealed completely linear inverse relationship between trypsin inhibitors and susceptibility to cowpea seeds beetle infestation indicating deterring effects for insect development. Also, vicilins content proved that simple correlation coefficient values regarding the abovementioned resistance parameters reached high significancy degree excepting those concerning larval stage period, percentage of infested seeds, seeds weight loss percentage and weight of emerged adult that showed significant correlation as well as insignificant ones were recorded with sex ratio as percentage of adult males and number of dead individuals inside seeds per female. All tested legume seed varieties of soyabean- Giza111 and lentil- Giza 9 revealed almostly linear inverse relationship between vicilins and susceptibility to cowpea seeds beetle infestation and showed retarding effects for insect development. As concerns lectins of the infested legume seed varieties, the correlation relationships proved to be highly significant with larval stage period, least and mean complete developmental periods, susceptibility index and number of dead individuals inside seeds per female, while in case of number of emerged adults per female, adults emergence percentage, number of holes per infested seed and seeds weight loss percentage the correlation was significant. The correlation of other resistance parameters did not attain significancy degree.

Development of semi-synthetic diet for laboratory rearing of western corn borer (Ostrinia spp.) in Kobe, Japan

A pair wise experiment was conducted, aiming to develop an artificial diet for laboratory rearing of Ostrinia species and for understanding their developmental characteristics in the control environment in insect physiology lab, Kobe University, Japan. Eleven different diets with various recipes were tested to observe the performance of diets and to evaluate the developmental characteristics of three Ostrinia species. In general, the survival was highest with O zaguliaevi adapted nearly all diets we prepared, O furnacalis survived fairy well but none of the diet was found satisfactory for rearing O scapulalis. The period of larval stage was shortest in O zaguliaevi, longest in O furnacalis and intermediate in O scapulalis. Photoperiodism was observed with both O scapulalis and O furnacalis. The type of photoperiodoic response was a typical long day type. Different diet resulted in one hour difference in the critical photoperiod in case of O scapulalis. DOI: http://dx.doi.org/10.3126/ajn.v1i0.7549 Agronomy Journal of Nepal (Agron JN) Vol. 1: 2010 pp.103-106

Sex-Specific Variations in Gypsy Moth Fitness, Immune Function, and Parasite Resistance Mediated by Background Defoliation of the Host Plant

In this study, we investigated the effect of rapid/delayed changes in silver birch foliage quality induced by minor defoliation on gypsy moth fitness, immune function, and resistance of larvae against natural enemies. Insect fitness was estimated as pupal weight, the period of larval stage, and mortality rate. Larval immune status was detected as activity of phenoloxidase in plasma, total hemocyte count (THC) in hemolymph, and encapsulation rate of nylon implant inserted into larvae hemocoel. We revealed that only rapid changes after tree defoliation lead to a strong tendency of suppression in the female's fitness. Delayed changes in foliage chemistry led to a rise of encapsulation response in females. Larval parasitism by hymenoptera was decreased when larvae fed on leaves from previously defoliated trees. We propose that changes in host plant quality drive the sex- specific increase of female encapsulation rate that allows larvae better resistance against the pressure of natural enemies.

Presence of intradermal chigger mite Hannemania hylae (Ewing, 1925) (Acari: Leeuwenhoekiidae) in the troglophile frog Eleutherodactylus longipes (Anura: Brachycephalidae) at Los Riscos Cave, Querétaro, Mexico

ABSTRACT For the first time, we report the presence of Hannemania hylae (Ewing) parasitizing the long-footed robber frog Eleutherodactylus longipes (Baird) in a cave environment in Queretaro State, Mexico. A morphological comparison was performed between H. hylae and its closest species Hannemania bufonis Loomis and Welbourn and Hannemania monticola Welbourn and Loomis. The main characters to separate these species are the size of ocular plate, the length of some scutal setae, and the shape and length of some tarsal setae of the legs I and II. We inspected 47 frogs, the prevalence of infestation was 23.4%, mean abundance was 1.8 mites per host, mean intensity 7.9 mites per infested host, and the range intensity was 1–30 mites. Larvae of H. hylae were only collected during the dry season. A brief discussion is provided about the period of larval stage on the host and seasonality is compared with similar studies.