We conducted laboratory experiments to examine the effects of single versus double exposures of spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae) female larvae to various concentrations of a Bacillus thuringiensis variety kurstaki (Btk) commercial formulation (Foray 48B). Our main objective was to document the vulnerability to Btk and the sublethal responses of fifth-instar la...

The objective of this study was to determine certain aspects of the biology of Rhipicephalus (Boophilus) decoloratus larvae under laboratory and field conditions. Larvae allowed 48 h to select a vertical questing substrate preferred 90 cm rods in length to those of 60 or 30 cm, while in a separate experiment migration from rods 5 cm or 25 cm in length to rods 45 cm in length continued between 4...

A 10-wk study of the avocado seed-feeding moth Stenoma catenifer Walsingham (Lepidoptera: Elachistidae), was conducted in a commercial 'Hass' avocado (Persea americana Miller [Lauraceae]) orchard in Guatemala. Up to 45% of fruit in the orchard were damaged by larval S. catenifer. Larval-to-adult survivorship for 1,881 S. catenifer larvae in Hass fruit was 37%, and adult sex ratio was 51% female...

The haemolymph of larvae of Tenebrio molitor contains a factor which produces a thermal hysteresis (a difference between the freezing and melting points) of approximately 0-75 °C. When larvae were acclimated to low temperatures or short photoperiod the thermal hysteresis increased more than twofold. Coincident with the increase in thermal hysteresis the supercooling points and lower lethal temp...

of B. sphaericru was based on the instar and age of the larvae, i.e., 2nd instar and early to middle-aged 4th instar larvae that fed on B. sphaeri,cuiwere susceptible, while late 4th instar larvae that ceased to feed and pupated prior to ingestion of B. splnerin r survived the bacillus bui succumbed to the effects of Arosurf MSF. Bioassays also indicated that effective dispersal of B. sphaericu...

Ditylenchus dipsaci larvae survived in soil without a host plant for at least 242 days when held at 15 C and 21 C. Larvae held at 15 C remained infective for 212 days. Moisture levels within both clayey and sandy soils did not appreciably affect recovery of larvae. Active nematodes recovered from soil are not necessarily infective. Temperatures of -12, 0 and 4 C had little adverse effect on lar...

the mill moth, ephestia kuehniella zeller and indian meal moth, plodia interpunctella (hubner) are two injuriously important pests of stored products worldwide. harobracon hebetor (say) has been used as a biological control agent of moth’s larva in peanut storehouses and as well in packaged cereal products. in the present study, the efficacy of h. hebetor in parasitizing larva of the mill moth ...

With an assumption that the larvae of cabbage looper, Trichoplusia ni (Hübner), a secondary pest of cotton, Gossypium hirsutum (L.), could move between cotton plants in the field, we conducted a series of laboratory experiments to determine the larval movement, food choice, consumption, survival, and development on Bt (Bollgard II expressing Cry1Ac and Cry2Ab) and non-Bt cotton. On non-Bt cotto...

We conducted two laboratory experiments to evaluate the dietary effects of phytoplankton and zooplankton on larval survival, duration growth amphidromous atyid shrimp Atyopsis spinipes. In first experiment, commercially preserved or cultured Tetraselmis sp. rotifers were used rear larvae. second feed larvae for 17 days after hatching, which effect supplementing their diet with Artemia nauplii w...